bluuebunny/crossref_metadata_2025_split huggingface dataset:
An enquiry into the causes of an explosion accident occurred in a biogas plant
Authors: Boscolo Marco , Bregant Luigi , Miani Stefano , Padoano Elio , Piller Marzio 
Published: May 2019

AbstractBiogas is a versatile carrier of renewable energy produced by means of the digestion of crops, residues, or other wastes, and storage of the gas in dedicated plants. Safety regulations impose operational and technical restrictions to areas interested by the presence of the biogas in order to limit the explosion risk. Conversely, other areas of the plant are not subject to strict safety requirements. Nevertheless, explosions can be triggered in these areas as well, as the present investigation confirms. In the specific case, the production of biogas by anaerobic digestion in a storm‐water tank and its infiltration and accumulation into a technical building through a pipe connection caused the explosion of the building itself. The authors describe the procedures adopted for the enquiry and suggest possible improvements to the safety regulations for biogas plants.
In vivo kinematic analysis of patients with robotic‐assisted total hip arthroplasty during gait at 1‐year follow‐up
Authors: Peng Yun , Arauz Paul , Desai Pooja , Byers Ashlyn , Klemt Christian , Kwon Young‐Min 
Published: May 2019

AbstractBackgroundSuboptimal component positioning has been suggested as an important contributing factor to postoperative gait asymmetry. The aim of this study is to determine whether robotic arm–assisted THA better restores gait symmetry than freehand THA.MethodsComponent orientation and positioning parameters and in vivo gait kinematics were quantified for implanted and native hips in 20 robotic arm–assisted and eight freehand THA patients, using a validated combined three‐dimensional modeling technique.ResultsAlthough neither THA procedure fully restored the native hip geometry, the robotic arm–assisted THA showed a better accuracy than freehand THA, with lower root mean square errors of component orientations. Gait asymmetry was not fully eliminated by either robotic arm–assisted or freehand THA, with increased internal rotation most notably observed in the implanted hip.ConclusionImproved accuracy in restoring native hip geometry achieved by the robotic arm–assisted THA procedure did not fully translate into improved gait symmetry.
Interaction of phages, bacteria, and the human immune system: Evolutionary changes in phage therapy
Authors: Jariah Rizka O.A. , Hakim Mohamad S. 
Published: May 2019

SummaryPhages and bacteria are known to undergo dynamic and co‐evolutionary arms race interactions in order to survive. Recent advances from in vitro and in vivo studies have improved our understanding of the complex interactions between phages, bacteria, and the human immune system. This insight is essential for the development of phage therapy to battle the growing problems of antibiotic resistance. It is also pivotal to prevent the development of phage‐resistance during the implementation of phage therapy in the clinic. In this review, we discuss recent progress of the interactions between phages, bacteria, and the human immune system and its clinical application for phage therapy. Proper phage therapy design will ideally produce large burst sizes, short latent periods, broad host ranges, and a low tendency to select resistance.
Controlled Delivery of Stem Cell-Derived Trophic Factors Accelerates Kidney Repair After Renal Ischemia-Reperfusion Injury in Rats
Authors: Yim Hyung Eun , Kim Doo Sang , Chung Hyun Chul , Shing Brian , Moon Kyung Hyun , George Sunil K. , Kim Michael W. , Atala Zachary , Kim Ji Hyun , Ko In Kap , Yoo James J. 
Published: May 2019

Abstract
Renal disease is a worldwide health issue. Besides transplantation, current therapies revolve around dialysis, which only delays disease progression but cannot replace other renal functions, such as synthesizing erythropoietin. To address these limitations, cell-based approaches have been proposed to restore damaged kidneys as an alternative to current therapies. Recent studies have shown that stem cell-derived secretomes can enhance tissue regeneration. However, many growth factors undergo rapid degradation when they are injected into the body in a soluble form. Efficient delivery and controlled release of secreting factors at the sites of injury would improve the efficacy in tissue regeneration. Herein, we developed a gel-based delivery system for controlled delivery of trophic factors in the conditioned medium (CM) secreted from human placental stem cells (HPSCs) and evaluated the effect of trophic factors on renal regeneration. CM treatment significantly enhanced cell proliferation and survival in vitro. Platelet-rich plasma (PRP) was used as a delivery vehicle for CM. Analysis of the release kinetics demonstrated that CM delivery through the PRP gel resulted in a controlled release of the factors both in vitro and in vivo. In an acute kidney injury model in rats, functional and structural analysis showed that CM delivery using the PRP gel system into the injured kidney minimized renal tissue damage, leading to a more rapid functional recovery when compared with saline, CM, or vehicle only injection groups. These results suggest that controlled delivery of HPSC-derived trophic factors may provide efficient repair of renal tissue injury. Stem Cells Translational Medicine 2019;8:959–970
Functionally Distinctive Ptch Receptors Establish Multimodal Hedgehog Signaling in the Tooth Epithelial Stem Cell Niche
Authors: Binder Martin , Chmielarz Piotr , Mckinnon Peter J. , Biggs Leah C. , Thesleff Irma , Balic Anamaria 
Published: May 2019

Abstract
Continuous growth of the mouse incisor teeth is due to the life-long maintenance of epithelial stem cells (SCs) in their niche called cervical loop (CL). Several signaling factors regulate SC maintenance and/or their differentiation to achieve organ homeostasis. Previous studies indicated that Hedgehog signaling is crucial for both the maintenance of the SCs in the niche, as well as for their differentiation. How Hedgehog signaling regulates these two opposing cellular behaviors within the confinement of the CL remains elusive. In this study, we used in vitro organ and cell cultures to pharmacologically attenuate Hedgehog signaling. We analyzed expression of various genes expressed in the SC niche to determine the effect of altered Hedgehog signaling on the cellular hierarchy within the niche. These genes include markers of SCs (Sox2 and Lgr5) and transit-amplifying cells (P-cadherin, Sonic Hedgehog, and Yap). Our results show that Hedgehog signaling is a critical survival factor for SCs in the niche, and that the architecture and the diversity of the SC niche are regulated by multiple Hedgehog ligands. We demonstrated the presence of an additional Hedgehog ligand, nerve-derived Desert Hedgehog, secreted in the proximity of the CL. In addition, we provide evidence that Hedgehog receptors Ptch1 and Ptch2 elicit independent responses, which enable multimodal Hedgehog signaling to simultaneously regulate SC maintenance and differentiation. Our study indicates that the cellular hierarchy in the continuously growing incisor is a result of complex interplay of two Hedgehog ligands with functionally distinct Ptch receptors. Stem Cells 2019;37:1238–1248
IDO1 Maintains Pluripotency of Primed Human Embryonic Stem Cells by Promoting Glycolysis
Authors: Liu Xin , Wang Meiyan , Jiang Tao , He Jingjin , Fu Xuemei , Xu Yang 
Published: May 2019

Abstract
Human embryonic stem cells (hESCs) depend on glycolysis for energy supply and pluripotency and switch to oxidative phosphorylation upon differentiation. The underlying mechanisms remain unclear. Here, we demonstrate that indoleamine 2,3-dioxygenase 1 (IDO1) is expressed in primed hESCs and its expression rapidly downregulated upon hESC differentiation. IDO1 is required to maintain pluripotency by suppressing mitochondria activity and promoting glycolysis through the increase of NAD+/NADH ratio. The upregulation of IDO1 during hESC differentiation suppresses the differentiation of hESCs into certain lineages of cells such as cardiomyocytes, which depend on oxidative phosphorylation to satisfy their high energy demand. Therefore, IDO1 plays important roles in maintaining the pluripotency of hESCs. Stem Cells 2019;37:1158–1165
The flavor dependence of mϱ/fπ
Authors: Nogradi Daniel , Szikszai Lorinc 
Published: May 2019

AbstractWe calculate themϱ/fπratio in the chiral and continuum limit for SU(3) gauge theory coupled toNf= 2,3,4,5,6 fermions in the fundamental representation. Keeping all systematic effects under full control we find no statistically significantNf-dependence;mϱ/fπ= 7.95(15). Assuming the KSRF-relations we conclude that 3 other low energy quantities related to the vector meson are alsoNf-independent within errors including theϱππcouplinggϱππ. If the model is thought of as a strong dynamics inspired composite Higgs model our results indicate that the experimentally most easily accessible new composite particle, the vector meson, and its properties may be robust and independent of the fermion content of the model as long as the gauge group is SU(3), providedNf-independence extends all the way to the conformal window.
Belief in a zero-sum game and subjective well-being across 35 countries
Authors: Różycka-Tran Joanna , Piotrowski Jarosław P. , Żemojtel-Piotrowska Magdalena , Jurek Paweł , Osin Evgeny N. , Adams Byron G. , Ardi Rahkman , Bălțătescu Sergiu , Bhomi Arbinda Lal , Bogomaz Sergey A. , Cieciuch Jan , Clinton Amanda , de Clunie Gisela T. , Czarna Anna Z. , Esteves Carla Sofia , Gouveia Valdiney , Halik Murnizam H. J. , Kachatryan Narine , Kamble Shanmukh Vasant , Kawula Anna , Klicperova-Baker Martina , Kospakov Aituar , Letovancova Eva , Lun Vivian Miu-Chi , Cerrato Sara Malo , Muehlbacher Stephan , Nikolic Marija , Pankratova Alina A. , Park Joonha , Paspalanova Elena , Pék Győző , de León Pablo Pérez , Šolcová Iva Poláčková , Shahbaz Wahab , Ha Truong Thi Khanh , Tiliouine Habib , Van Hiel Alain , Vauclair Christin-Melanie , Wills-Herrera Eduardo , Włodarczyk Anna , Yahiiaiev Illia I. , Maltby John 
Published: May 2019

AbstractThis article presents a short research report on the relationship between perceived antagonism in social relations measured using the Belief in a Zero-Sum Game (BZSG) scale, life satisfaction, and positive and negative affect. Given that individuals who believe that life is like a zero-sum game are likely to perceive their daily interactions with others as unfair, we expected that individuals with high BZSG experience more negative affect and fewer positive one, resulting in a lower satisfaction with life. In addition, we examined whether country-level BZSG may play a moderating role in these associations. Data were collected from student samples (N = 7146) in 35 countries. Multilevel modelling revealed that perceived social antagonism in social relations is negatively associated with satisfaction with life and that this relationship is mediated by both positive and negative affect at the individual level. The relation of individual BZSG and negative affect on satisfaction with life were weaker in societies with higher country-level BZSG, suggesting that the effects of BZSG may be less detrimental in these countries. These findings extend previous knowledge about predictors of life satisfaction and suggest that social beliefs might also be an important factor that influences subjective well-being. The contribution of the study is that the separate treatment of life satisfaction and positive and negative affect may be helpful in many research situations, particularly from a cross-cultural perspective.
m6A Regulates Neurogenesis and Neuronal Development by Modulating Histone Methyltransferase Ezh2
Authors: Chen Junchen , Zhang Yi-Chang , Huang Chunmin , Shen Hui , Sun Baofa , Cheng Xuejun , Zhang Yu-Jie , Yang Yun-Gui , Shu Qiang , Yang Ying , Li Xuekun 
Published: May 2019

Abstract
N 6 -methyladenosine (m 6 A), catalyzed by the methyltransferase complex consisting of Mettl3 and Mettl14, is the most abundant RNA modification in mRNAs and participates in diverse biological processes. However, the roles and precise mechanisms of m6A modification in regulating neuronal development and adult neurogenesis remain unclear. Here, we examined the function of Mettl3, the key component of the complex, in neuronal development and adult neurogenesis of mice. We found that the depletion of Mettl3 significantly reduced m6A levels in adult neural stem cells (aNSCs) and inhibited the proliferation of aNSCs. Mettl3 depletion not only inhibited neuronal development and skewed the differentiation of aNSCs more toward glial lineage, but also affected the morphological maturation of newborn neurons in the adult brain. m6A immunoprecipitation combined with deep sequencing (MeRIP-seq) revealed that m6A was predominantly enriched in transcripts related to neurogenesis and neuronal development. Mechanistically, m6A was present on the transcripts of histone methyltransferase Ezh2, and its reduction upon Mettl3 knockdown decreased both Ezh2 protein expression and consequent H3K27me3 levels. The defects of neurogenesis and neuronal development induced by Mettl3 depletion could be rescued by Ezh2 overexpression. Collectively, our results uncover a crosstalk between RNA and histone modifications and indicate that Mettl3-mediated m6A modification plays an important role in regulating neurogenesis and neuronal development through modulating Ezh2.
Characterizing the Current State of Training Courses Available to US Disaster Professionals
Authors: Kirsch Thomas , Keim Mark , Strauss-Riggs Kandra 
Published: May 2019

ABSTRACTObjective:The objective of this study is to characterize US-based disaster training courses available to disaster response and disaster health professionals. Its purpose is to better inform policies and decision-making regarding workforce and professional development to improve performance.Methods:Courses were identified from 4 inventories of courses: (1) National Library of Medicine Disaster Lit database; (2) TRAIN National Learning Network; (3) Federal Emergency Management Agency (FEMA) National Preparedness Course Catalog; and (4) Preparedness and Emergency Response Learning Centers. An online search used 30 disaster-related key words. Data included the course title, description, target audience, and delivery modality. Levels of learning, target capability, and function were categorized by 3 expert reviewers. Descriptive statistics were used.Results:There were 3662 trainings: 2380 (65%) for professionals (53% for public health); 83% of the courses were distance learning, with 16% via classroom. Half of all trainings focused on 3 of 37 disaster capabilities and 38% of them were related to chemical, biological, radiological, nuclear, and explosives (CBRNE). The educational approach was knowledge-based for all courses and 99.6% imparted only lower levels of learning.Conclusion:Despite thousands of courses available, there remain significant gaps in target audience, subject matter content, educational approaches, and delivery modalities, particularly for health and public health professionals.
The Wave Formation and Sonic Boom due to a Delta Wing
Authors: Oswatitsch K , Sun Y C 
Published: May 2019

SummaryBy employment of the analytical method of characteristics and of a limiting procedure suitable for dealing with the trailing edge expansion, the influence of near-field flow on the far-field wave formation has been investigated for an incident flat delta wing with supersonic leading edges. Though confined in its scope to the front shock in the vertical plane of symmetry of the wing and to a homogeneous atmosphere without density and temperature gradients, the present analysis reveals features of flow which are interesting from the standpoint of the general theory of three-dimensional supersonic flow. It is found that the front shock due to a delta wing will as a rule be cancelled at a finite distance from the wing by the plane-wave expansion emanating from the trailing edge. The over-expansion must then give rise to a rear shock separate from the front one. Thus, at least in the plane of symmetry, a sharp-front wave signature can not, in general, be expected from the wing at a distance beyond the terminating point of the front shock. The boom signature then will be qualitatively different from that of a body of revolution. The general non-equivalence of a wing to a body of revolution in this respect should evoke some rethinking about sonic boom prediction and alleviation.
Dynamical Behaviour of a Materially Damped Flexible Towed Cable
Authors: Cannon T C , Genin J 
Published: May 2019

SummaryThe three-dimensional equations of motion of a flexible towed cable are developed. A closed-form approximation for the equilibrium shape of a cable subjected to arbitrary aerodynamic loading is developed and used in the study of a heavy, vibrating tow cable. Natural frequencies of vibration and cable shapes are computed for typical cables and are shown to be in good agreement with exact, numerically obtained values.
A New Solution of the Turbulent Near-Wake Recompression Problem
Authors: Shamroth S J , McDonald H 
Published: May 2019

SummaryA method is presented for predicting the behaviour of a two-dimensional supersonic turbulent near-wake during the recompression process. In contrast to most previous extensions of Crocco-Lees strong interaction theory, the proposed analysis includes a transverse momentum integral equation. In addition, a modified strip method for conservation of streamwise momentum replaces the usual integral equations. Although a straightforward treatment of the equations results in the appearance of a singularity analogous to the well-known Crocco-Lees critical point, it is shown that solutions can be obtained which do not exhibit a singular behaviour, either by posing the problem as a boundary-value problem rather than an initial-value problem or by making a suitable approximation which suppresses the quasi-elliptic behaviour of the equations. Both procedures lead to an unambiguously defined uniqueness condition for the near-wake recompression solution.
Response of Helicopter Rotor Blades to Random Loads near Hover
Authors: Lakshmikantham C , Rao C V Joga 
Published: May 2019

SummaryThe response of a flexible helicopter rotor blade to random loading is investigated, the random input being the vertical velocity component. The model takes into account blade flexibility in bending as well as torsion, and also general root rigidity. The spectral density and the mean square value of the transverse displacement are computed for both hingeless and hinged rotor blades and the results are evaluated.
A Comparison of Two Prediction Methods with Experiment for Compressible Turbulent Boundary Layers with Air Injection
Authors: Thomas G D , Verma V K , Squire L C 
Published: May 2019

SummaryTwo prediction methods for compressible turbulent boundary layers with air injection have been developed. The results from the two methods are compared with experiment for constant pressure flows at Mach numbers from 1.8 to 3.6. In general the results from the two methods and from experiment are in close agreement. However, there are some differences at the higher Mach numbers and it is suggested that both methods need further development for use at Mach numbers above 3.
Effects of Contraction Geometry on Non-Isotropic Free-Stream Turbulence
Authors: Klein A , Ramjee V 
Published: May 2019

SummaryThe effects of contraction geometry on non-isotropic free-stream turbulence were investigated experimentally. Eight nozzles of circular cross-section, having different contour shapes and various non-dimensional lengths, were tested. The contraction ratio was 10:1. The results are compared with test data for isotropic turbulence and with a well-known linear theory. It is found that the variation of the lateral component of turbulent energy along the nozzles is similar to that with isotropic free-stream turbulence, whereas the behaviour of the longitudinal component is entirely different. The change of turbulence depends on local contraction ratio only.
The Mixing Length Derived from Kármán’s Similarity Hypothesis
Authors: Nishioka Michio , Iida Shūsuke 
Published: May 2019

SummaryFrom Kármán’s similarity hypothesis, we derive the equation which describes the mixing length in terms of the turbulent shear stress. For a boundary layer with linear stress distribution, the equation is in reasonable agreement with Bradshaw’s measurements. For a boundary layer with injection, it is shown that injection has an appreciable effect upon the mixing length when (vw/2) /(τ/ρ)1/2becomes comparable to the Kármán constant. Close similarity is also pointed out between the hypotheses due to Kármán and Townsend. Moreover, the diffusion constant in Townsend’s hypothesis is determined to be 0.25, which is in good agreement with the value 0.2 obtained by Townsend from one experiment.
Use of Surface Fences to Measure Wall Shear Stress in Three-dimensional Boundary Layers
Authors: Vagt J D , Fernholz H 
Published: May 2019

SummaryIf surface fences are to be applied for measuring skin friction in three-dimensional boundary layers they must be calibrated for both magnitude and direction of the shear stress. Results of the calibration for fences of different height are given. Furthermore, a manufacturing process and a mounting procedure are described to obtain surface fences with identical calibration curves.
Separated Flow Past a Slender Delta Wing at Incidence
Authors: Barsby J E 
Published: May 2019

SummarySolutions to the problem of separated flow past slender delta wings for moderate values of a suitably defined incidence parameter have been calculated by Smith, using a vortex sheet model. By increasing the accuracy of the finite-difference technique, and by replacing Smith’s original nested iteration procedure, to solve the non-linear simultaneous equations that arise, by a Newton’s method, it is possible to extend the range of the incidence parameter over which solutions can be obtained. Furthermore for sufficiently small values of the incidence parameter, new and unexpected results in the form of vortex systems that originate inboard from the leading edge have been discovered. These new solutions are the only solutions, to the author’s knowledge, of a vortex sheet leaving a smooth surface.Interest has centred upon the shape of the finite vortex sheet, the position of the isolated vortex, and the lift, and variations of these quantities are shown as functions of the incidence parameter. Although no experimental evidence is available, comparisons are made with the simpler Brown and Michael model in which all the vorticity is assumed to be concentrated onto an isolated line vortex. Agreement between these two models becomes very close as the value of the incidence parameter is reduced.
The Transonic Aerofoil Problem with Embedded Shocks
Authors: Nørstrud Helge 
Published: May 2019

SummaryThe integral equation approach to the mixed flow problem of infinite wings at high subsonic speeds is adopted for non-circulatory and circulatory (lifting) flows. The solutions are determined from a system of non-linear algebraic equations and, to ensure always unique solutions, the method of differentiation with respect to a parameter has been applied. The resulting Cauchy problem is then solved with the linearised flow solution as the initial value vector. For the case of embedded shocks in the flow field, the method of steepest descent has been added to the calculation scheme. Results for subcritical and supercritical flows past aerofoils are given and compared with solutions obtained by finite-difference techniques.