bluuebunny/crossref_metadata_2025_split huggingface dataset:
Subcellular distribution of calcium during spermatogenesis of zebrafish, Danio rerio
Authors: Golpour Amin , Pšenička Martin , Niksirat Hamid 
Published: May 2017

AbstractCalcium plays a variety of vital regulatory functions in many physiological and biochemical events in the cell. The aim of this study was to describe the ultrastructural distribution of calcium during different developmental stages of spermatogenesis in a model organism, the zebrafish (Danio rerio), using a combined oxalate–pyroantimonate technique. Samples were treated by potassium oxalate and potassium pyroantimonate during two fixation stages and examined using transmission electron microscopy to detect electron dense intracellular calcium. The subcellular distribution of intracellular calcium was characterized in spermatogonium, spermatocyte, spermatid, and spermatozoon stages. The area which is covered by intracellular calcium in different stages was quantified and compared using software. Isolated calcium deposits were mainly detectable in the cytoplasm and the nucleus of the spermatogonium and spermatocyte. In the spermatid, calcium was partially localized in the cytoplasm as isolated deposits. However, most calcium was transformed from isolated deposits into an unbound pool (free calcium) within the nucleus of the spermatid and the spermatozoon. Interestingly, in the spermatozoon, calcium was mainly localized in a form of an unbound pool which was detectable as an electron‐dense mass within the nucleus. Also, sporadic calcium deposits were scattered in the midpiece and flagellum. The proportional area which was covered by intracellular calcium increased significantly from early to late stages of spermatogenesis. The extent of the area which was covered by intracellular calcium in the spermatozoon was the highest compared to earlier stages. Calcium deposits were also observed in the somatic cells (Sertoli, myoid, Leydig) of zebrafish testis. The notable changes in the distribution of intracellular calcium of germ cells during different developmental stages of zebrafish spermatogenesis suggest its different homeostasis and physiological functions during the process of male gamete development.
A microstructural study of the pleon‐holding mechanism in Carcinus maenas (Decapoda, Brachyura, Portunoidea, Carcinidae) of different sizes
Authors: Köhnk Stephanie , Gorb Stanislav N. , Brandis Dirk 
Published: May 2017

AbstractWithin the Brachyura there are a variety of specialized holding mechanisms, which facilitate the close attachment of the highly reduced pleon underneath the cephalothorax. The most common mechanism in eubrachyurans, known as the press‐button, consists of a sternal protrusion and a corresponding pleonal socket. Reports on the microstructural properties of the surface of these holding structures are scarce and patchy. In this study, the European Green Crab Carcinus maenas, is used as model to describe the microstructure of a typical press‐button mechanism with the use of scanning electron microscopy and light microscopic histology. A highly tuberculate cuticle and an apical ridge on the sternal knob are found in juveniles of both sexes. The microstructures are lost in adult males. In adult females, the holding structures themselves are reduced, but never completely lost. These findings show that C. maenas does not undergo a single “final puberty moult,” after which all juvenile characteristics are lost, as previously assumed. Further comparison of the morphology of juveniles to another species indicates a close resemblance of the holding structures at this stage. Therefore, the use of the microstructure of the pleon‐holding mechanism for phylogenetic analysis is restricted to adult specimens.
Imaging short‐lived reactive oxygen species (ROS) with endogenous contrast MRI
Authors: Tain Rong‐Wen , Scotti Alessandro M. , Li Weiguo , Zhou Xiaohong Joe , Cai Kejia 
Published: May 2017

PurposeTo characterize the relaxation properties of reactive oxygen species (ROS) for the development of endogenous ROS contrast magnetic resonance imaging (MRI).Materials and MethodsROS‐producing phantoms and animal models were imaged at 9.4T MRI to obtain T1 and T2 maps. Egg white samples treated with varied concentrations of hydrogen peroxide (H2O2) were used to evaluate the effect of produced ROS in T1 and T2 for up to 4 hours. pH and temperature changes due to H2O2 treatment in egg white were also monitored. The influences from H2O2 itself and oxygen were evaluated in bovine serum albumin (BSA) solution producing no ROS. In addition, dynamic temporal changes of T1 in H2O2‐treated egg white samples were used to estimate ROS concentration over time and hence the detection sensitivity of relaxation‐based endogenous ROS MRI. The relaxivity of ROS was compared with that of Gd‐DTPA as a reference. Finally, the feasibility of in vivo ROS MRI with T1 mapping acquired using an inversion recovery sequence was demonstrated with a well‐established rotenone‐treated mouse model (n = 6).ResultspH and temperature changes in treated egg white samples were insignificant (<0.1 unit and <1°C, respectively). T1 relaxation time in the H2O2‐treated egg white was reduced significantly (P < 0.05), while there was only small reduction in T2 (<10%). In the H2O2‐treated BSA solution that produce no ROS, there was a small change in T1 due to H2O2 itself (±1%), although a significant T2‐shortening effect was observed (>10%, P < 0.05). Also, there was a small reduction in T1 (13 ± 1%) and T2 (1 ± 2%) from molecular oxygen. The detection sensitivity of ROS MRI was estimated around 10 pM. The T1 relaxivity of ROS was found to be much higher than that of Gd‐DTPA (3.4 × 107 vs. 0.9 s−1·mM−1). Finally, significantly reduced T1 was observed in rotenone‐treated mouse brain (5.1 ± 2.5%, P < 0.05).ConclusionWe demonstrated in the study that endogenous ROS MRI based on the paramagnetic effect has sensitivity for in vitro and in vivo applications.Level of Evidence: 2Technical Efficacy Stage: 2J. Magn. Reson. Imaging 2018;47:222–229.
Pioppino mushroom in southern Italy: an undervalued source of nutrients and bioactive compounds
Authors: Landi Nicola , Pacifico Severina , Ragucci Sara , Di Giuseppe Antonella MA , Iannuzzi Federica , Zarrelli Armando , Piccolella Simona , Di Maro Antimo 
Published: May 2017

AbstractBACKGROUNDAgrocybe aegerita (V. Brig.) Singer, commonly known as Pioppino, is a popular edible mushroom, known in the Campania Region (Italy). Despite its habitual consumption, little nutritional and biochemical information is available. Thus, nutritional values, anti‐radical properties and chemical composition of the wild Pioppino were compared to those of the cultivated Agaricus bisporus (J.E. Lange) Imbach (known as Champignon), equally analysed.RESULTSMacronutrient components (proteins, carbohydrates and lipids), free and protein amino acids and fatty acid content of poplar mushroom were achieved. Total phenol content of a defatted Pioppino alcoholic extract (PM) was determined, whereas DPPH and ABTS methods were applied to determine the radical scavenging capabilities of the extract. Ferricyanide and ORAC‐fluorescein methods were also performed. Finally, LC‐HRMS was used to identify and quantify the main metabolites in the extract. PM was mainly constituted of disaccharides, hexitol derivatives and malic acid. Coumaric acid isomers and C6C1 compounds were also detected.CONCLUSIONAll data revealed that wild Pioppino is an excellent functional food, by far exceeding that of the Champignon. Therefore, these data are useful to promote the consumption of this mushroom encouraging thus its biological cultivation, due to wild availability is strongly compromised by the extensive use of fungicides. © 2017 Society of Chemical Industry
Weed interference with peppermint (Mentha x piperita L.) and spearmint (Mentha spicata L.) crops under different herbicide treatments: effects on biomass and essential oil yield
Authors: Karkanis Anestis , Lykas Christos , Liava Vasiliki , Bezou Anna , Petropoulos Spyridon , Tsiropoulos Nikolaos 
Published: May 2017

AbstractBACKGROUND‘Minor crops’ such as spearmint and peppermint are high added value crops, despite the fact that their production area is comparably small worldwide. The main limiting factor in mint commercial cultivation is weed competition. Thus, field experiments were carried out to evaluate the effects of weed interference on growth, biomass and essential oil yield in peppermint and spearmint under different herbicide treatments.RESULTSThe application of pendimethalin and oxyfluorfen provided better control of annual weeds resulting in higher crop yield. Additionally, when treated with herbicides both crops were more competitive against annual weeds in the second year than in the first year. All pre‐emergence herbicides increased biomass yield, since pendimethalin, linuron and oxyfluorfen reduced the density of annual weeds by 71–92%, 63–74% and 86–95%, respectively. Weed interference and herbicide application had no effect on essential oil content; however, a relatively strong impact on essential oil production per cultivated area unit was observed, mainly due to the adverse effect of weed interference on plant growth.CONCLUSIONConsidering that pendimethalin and oxyfluorfen were effective against annual weeds in both spearmint and peppermint crops, these herbicides should be included in integrated weed management systems for better weed management in mint crops. © 2017 Society of Chemical Industry
Body Mass Normalization for Lateral Abdominal Muscle Thickness Measurements in Adolescent Athletes
Authors: Linek Pawel 
Published: May 2017

ObjectivesTo determine the value of allometric parameters for ultrasound measurements of the oblique external (OE), oblique internal (OI), and transversus abdominis (TrA) muscles in adolescent athletes. The allometric parameter is the slope of the linear regression line between the log‐transformed body mass and log‐transformed muscle size measurement.MethodsThe study included 114 male adolescent football players between the ages of 10 and 19 years. All individuals with no surgical procedures performed on the trunk area and who had played a sport for at least 2 years were included. A real‐time B‐mode ultrasound scanner with a linear array transducer was used to obtain images of the lateral abdominal muscles from both sides of the body. A stabilometric platform was used to assess the body mass value.ResultsThe correlations between body mass and the OE, OI, and TrA muscle thicknesses were r = 0.73, r = 0.79, and r = 0.64, respectively (in all cases, P < .0001). The allometric parameters were 0.77 for the OE, 0.67 for the OI, and 0.61 for the TrA. Using these parameters, no significant correlations were found between body mass and the allometric‐scaled thickness of the lateral abdominal muscles.ConclusionsSignificant positive correlations exist between body mass and lateral abdominal muscle thickness in adolescent athletes. Therefore, it is reasonable to advise that the values of the allometric parameters for the OE, OI, and TrA muscles obtained in this study should be used, and the allometric‐scaled thicknesses of those muscles should be analyzed in future research on adolescent athletes.
A Prospective Evaluation of Transverse Tracheal Sonography During Emergent Intubation by Emergency Medicine Resident Physicians
Authors: Lahham Shadi , Baydoun Jamie , Bailey James , Sandoval Sandra , Wilson Sean P. , Fox John C. , Slattery David E. 
Published: May 2017

ObjectivesEstablishing a definitive airway is often the first step in emergency department treatment of critically ill patients. Currently, there is no agreed upon consensus as to the most efficacious method of airway confirmation. Our objective was to determine the diagnostic accuracy of real‐time sonography performed by resident physicians to confirm placement of the endotracheal tube during emergent intubation.MethodsWe performed a prospective cohort study of adult patients in the emergency department undergoing emergent endotracheal intubation. Thirty emergency medicine residents, who were blinded to end‐tidal carbon dioxide detection results, performed real‐time transverse tracheal sonography during intubation to evaluate correct endotracheal tube placement.ResultsSeventy‐two patients were enrolled in the study. Sixty‐eight instances (94.4%) were interpreted as correct placement in the trachea; 4 (5.6%) were interpreted as esophageal, of which 1 was a false‐negative finding, therefore conferring sensitivity of 98.5% (95% confidence interval, 92.1%–99.9%) and specificity of 75.0% (95% confidence interval, 19.4%–99.4%) for correct placement. There was no significant difference in accuracy among resident sonographers with different levels of residency training.ConclusionsA simple transverse tracheal sonographic examination performed by emergency medicine resident physicians can be used as an adjunct to help confirm correct endotracheal tube placement during intubation. In our cohort, the level of training did not appear to affect the ability of residents to correctly identify the endotracheal tube position.
Elevated alkaline phosphatase activity in a phosphate‐replete environment: Influence of sinking particles
Authors: Davis Clare E. , Mahaffey Claire 
Published: May 2017

AbstractAlkaline phosphatase activity (APA) is traditionally a proxy for phosphate (DIP)‐limitation because it is induced by DIP‐limited microbes to access the labile ester fraction of the organic phosphorus (OP) pool. Here, we present multi‐year summertime depth distributions of APA and enzyme kinetics in the DIP‐replete Celtic Sea. Our findings support the cumulating body of evidence that APA has a potentially widespread role in OP remineralization through the water column. APA and Vmax were positively correlated with depth and DIP, with total APA being threefold higher below (0.93 ± 0.32 nM P h−1) compared to above the thermocline (0.30 ± 0.24 nM P h−1, p < 0.001). Separation of particles by sinking speed demonstrated that APA was eightfold higher on fast sinking (Ffast) particles compared to slow sinking particles (Fslow; p < 0.05). When normalized to particulate organic carbon (POC) and bacterial production (BP), APAPOC and APABP associated with Ffast (0.76 ± 0.10 nmol P μmol C−1 h−1, 21.13 ± 2.2 nmol P nmol C−1, respectively) were fourfold and 25‐fold higher compared to the combined APA associated with dissolved plus suspended (Fsusp) and Fslow fractions (0.19 ± 0.06 nmol P μmol C−1 h−1 and 0.84 ± 0.23 nmol P nmol C−1, respectively). We postulate that this may reflect enhanced ectoenzyme activity associated with bacteria colonizing particle surfaces and/or release by zooplankton via faecal pellet excretion. Knowledge of the disparity between APA and BP associated with particle and dissolved phases is required to accurately define the O2 : P ratio of regenerated P derived from sinking particles as a result of AP‐facilitated remineralization.
Phosgene‐Free Syntheses and Hydrolytic Properties of Water‐Soluble Polyhydroxyurethanes with Ester–Carbonate–Ether Structures in Their Main Chains
Authors: Matsukizono Hiroyuki , Endo Takeshi 
Published: May 2017

Three types of bifunctional 6‐membered cyclic carbonates bearing ester, acyclic carbonate or ether moieties have been derived from nonexpensive trimethylolpropane or di(trimethylolpropane) through phosgene‐free routes and used for the polyaddition reaction with 1,3‐diaminopropane to design polyhydroxyurethanes (PHUs) containing the corresponding linkages in their main chains. Furthermore, these PHUs have been chemically modified via their OH groups to afford water‐soluble PHUs (WSPHUs) and characterized for their hydrolytic properties at different pH conditions. Carbonate and ester bonds in these WSPHUs are easily hydrolyzed under basic conditions and their hydrolytic rates depend on their main chain structures; WSPHUs bearing carbonate structures are degraded faster than WSPHUs with ester linkages, while WSPHUs having ether bonds are slowest hydrolyzed. Moreover, the hydrolytic rates of these WSPHUs can be modulated by the copolymerization of these monomers at different feed ratios.
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Characterizing bacterial communities in paper production—troublemakers revealed
Authors: Zumsteg Anita , Urwyler Simon K. , Glaubitz Joachim 
Published: May 2017

AbstractBiofilm formation is a major cause of reduced paper quality and increased down time during paper manufacturing. This study uses Illumina next‐generation sequencing to identify the microbial populations causing quality issues due to their presence in biofilms and slimes. The paper defects investigated contained traces of the films and/or slime of mainly two genera, Tepidimonas and Chryseobacterium. The Tepidimonas spp. found contributed on average 68% to the total bacterial population. Both genera have been described previously to be associated with biofilms in paper mills. There was indication that Tepidimonas spp. were present as compact biofilm in the head box of one paper machine and was filtered out by the paper web during production. On the other hand Tepidimonas spp. were also present to a large extent in the press and white waters of two nonproblematic paper machines. Therefore, the mere presence of a known biofilm producer alone is not sufficient to cause slimes and therefore paper defects and other critical factors are additionally at play. For instance, we identified Acidovorax sp., which is an early colonizer of paper machines, exhibiting the ability to form extracellular DNA matrices for attachment and biofilm formation.
Fully integrated 3D high‐resolution multicontrast abdominal PET‐MR with high scan efficiency
Authors: Kolbitsch Christoph , Neji Radhouene , Fenchel Matthias , Mallia Andrew , Marsden Paul , Schaeffter Tobias 
Published: May 2017

PurposeTo provide 3D multicontrast anatomical MR with high isotropic resolution and metabolic positron emission tomography (PET) images using a respiratory motion‐compensated simultaneous PET‐MR examination with high scan efficiency.Theory and MethodsStandard abdominal PET‐MR examinations combine MR data obtained during multiple breath‐holds with free‐breathing PET acquisitions, limiting the achievable image resolution and potentially causing misalignment errors between breath‐hold and free‐breathing data. Here, a 3D free‐breathing PET‐MR acquisition is presented, yielding T1 and T2‐weighted MR images with an isotropic resolution of 1.5 mm3. In addition, nonrigid respiratory motion information and respiratory‐resolved attenuation‐correction maps are obtained without an increase in scan time. Motion information is used in motion‐compensated image reconstructions to improve MR and PET image quality while shortening scan times.ResultsThe proposed approach was evaluated in 11 oncology patients and provided respiratory motion information with an accuracy of 1.3 ± 0.1 mm. Sharpness of anatomical features was increased by 19 ± 13% compared with the uncorrected MR images in a 54 ± 26% shorter scan time than a gated MR acquisition. The MR‐based motion information improved uptake values (75 ± 94%) and resolution (16 ± 27%) of simultaneously acquired PET images.ConclusionsThe proposed method provides motion‐compensated 3D high‐quality MR and PET images in a comprehensive and highly efficient examination. Magn Reson Med 79:900–911, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Phase‐field material point method for brittle fracture
Authors: Kakouris E. G. , Triantafyllou S. P. 
Published: May 2017

SummaryThe material point method for the analysis of deformable bodies is revisited and originally upgraded to simulate crack propagation in brittle media. In this setting, phase‐field modelling is introduced to resolve the crack path geometry. Following a particle in cell approach, the coupled continuum/phase‐field governing equations are defined at a set of material points and interpolated at the nodal points of an Eulerian, ie, non‐evolving, mesh. The accuracy of the simulated crack path is thus decoupled from the quality of the underlying finite element mesh and relieved from corresponding mesh‐distortion errors. A staggered incremental procedure is implemented for the solution of the discrete coupled governing equations of the phase‐field brittle fracture problem. The proposed method is verified through a series of benchmark tests while comparisons are made between the proposed scheme, the corresponding finite element implementation, and experimental results.
Level set shape and topology optimization of finite strain bilateral contact problems
Authors: Lawry Matthew , Maute Kurt 
Published: May 2017

SummaryThis paper presents a method for the optimization of multicomponent structures comprised of 2 and 3 materials considering large motion sliding contact and separation along interfaces. The structural geometry is defined by an explicit level set method, which allows for both shape and topology changes. The mechanical model assumes finite strains, a nonlinear elastic material behavior, and a quasi‐static response. Identification of overlapping surface position is handled by a coupled parametric representation of contact surfaces. A stabilized Lagrange method and an active set strategy are used to model frictionless contact and separation. The mechanical model is discretized by the extended FEM, which maintains a clear definition of geometry. Face‐oriented ghost penalization and dynamic relaxation are implemented to improve the stability of the physical response prediction. A nonlinear programming scheme is used to solve the optimization problem, which is regularized by introducing a perimeter penalty into the objective function. Design sensitivities are determined by the adjoint method. The main characteristics of the proposed method are studied by numerical examples in 2 dimensions. The numerical results demonstrate improved design performance when compared to models optimized with a small strain assumption. Additionally, examples with load path dependent objectives display nonintuitive designs.
Indonesian healthy living intentions: Segmentation study insights
Authors: Arli Denni , Dietrich Timo , Tkaczynski Aaron , Rundle‐Thiele Sharyn 
Published: May 2017

Obesity is a global epidemic. The very rapid growth rates of obesity prevalence observed in developing countries is alarming. Segmentation is under applied in social marketing and, when it is applied, it is based primarily on demographic data in samples drawn from developed nations. The current study adopts psychographic segmentation to understand lifestyle attitudes and intentions towards exercise and weight loss among an Indonesian sample. TwoStep cluster analysis (n = 499) identified 4 distinct segments (At risk, Conscious healthy, Overweight, and Tryers). The results of this study demonstrate that different groups exist in the larger population and that consideration of these groups may assist social marketers in creating service/intervention offerings that meet the needs of a broader range of people in the market, thus extending penetration of campaigns that address obesity.