bluuebunny/crossref_metadata_2025 huggingface dataset:
NOx Storage and Reduction Coupled with Selective Catalytic Reduction for NOx Removal in Light‐Duty Vehicles
Authors: González‐Velasco Juan R. , Pereda‐Ayo Beñat , De‐La‐Torre Unai , Urrutxua Maitane , López‐Fonseca Rubén
Published: April 2018

There are two alternative, main technologies for removal of nitrogen oxides (NOx) from vehicle exhaust gases, namely, selective catalytic reduction (SCR) and NOx storage and reduction (NSR). The SCR technology consists of using ammonia (NH3), produced by hydrolysis of urea that is stored into an on‐board tank in the vehicle, to reduce NOx selectively to nitrogen (N2). In the NSR strategy, the conversion of NOx into N2 occurs through a two‐step cyclic operation. During the fuel‐lean stage, the NOx is trapped on the catalyst; then, the engine is switched to a fuel‐rich condition, under which NOx is released and reduced preferentially to N2, although some NH3 can also be produced. The concept of coupling NSR with SCR is based on tuning the operation of the NSR catalyst to produce a controlled amount of NH3, which is stored on the SCR catalyst during the fuel‐rich stage and used to reduce the remaining NOx on the SCR catalyst, placed downstream of the NSR catalyst in a sequential NSR+SCR configuration. Alternatively, the same concept applies to the dual‐layer architecture, which comprises a SCR layer deposited on top of the NSR layer in a single monolith. The internal generation of NH3 in the NSR catalyst avoids the need of external supply from the on‐board tank, but also achieves impressive NOx‐to‐N2 efficiency, apparently allowing zero‐level pollutant emission.
Discrete Element Method Simulation and Experimental Validation of Pattern Development in a Rotating Drum Mixer
Authors: Barczi Tomas , Kohout Martin , Kozakovic Martin , Havlica Jaromir , Ratnayake Chandana
Published: April 2018

The handling and processing of powders and granular materials can be crucial for the quality of a final product. Therefore, a detailed description and analysis of granular flow phenomena from first principles is very valuable. In the present study, simulations of granular mixing and segregation of binary‐sized mixtures using a discrete element method were performed for horizontal rotating drum mixers. Numerical results were compared with experimental measurements and significant agreement between both approaches was found. The development of specific flow patterns was observed. The formation of these complex spatiotemporal patterns is influenced by the size of the mixer, the aspect ratio of length to diameter, the rotational speed of the drum, and the initial distribution of the particles.
Polypyrrole‐Derived Fe−Co−N−C Catalyst for the Oxygen Reduction Reaction: Performance in Alkaline Hydrogen and Ethanol Fuel Cells
Authors: Osmieri Luigi , Zafferoni Claudio , Wang Lianqin , Monteverde Videla Alessandro H. A. , Lavacchi Alessandro , Specchia Stefania
Published: April 2018

Alkaline membrane fuel cells (AMFCs) have started to become more attractive in recent years due to the development of polymeric membranes with good anionic conductivity and durability. However, few studies investigating the performance of H2/O2 fueled AMFCs and alkaline direct ethanol fuel cells (DEFCs) with membrane electrode assemblies (MEAs) fabricated with Pt‐group metal (PGM)‐free catalysts are available in the literature. In this paper, we synthesized and fully characterized a Fe−Co−N−C electrocatalyst for the oxygen reduction reaction (ORR) by a sacrificial method, using pyrrole as a unique and inexpensive precursor for N‐doped carbonaceous materials. Very good ORR activity and stability were obtained in alkaline conditions, most likely due to the presence of Co−Fe@C nanoparticles. We achieved a very high performance in an AMFC, 420 mW cm−2 at 60 °C, among the highest in the literature for PGM‐free catalysts, and a good performance in a passive DEFC, 28 mW cm−2 at room temperature.
Orthogonal Clickable Iron Oxide Nanoparticle Platform for Targeting, Imaging, and On‐Demand Release
Authors: Guldris Noelia , Gallo Juan , García‐Hevia Lorena , Rivas José , Bañobre‐López Manuel , Salonen Laura M.
Published: April 2018

A versatile iron oxide nanoparticle platform is reported that can be orthogonally functionalized to obtain highly derivatized nanomaterials required for a wide variety of applications, such as drug delivery, targeted therapy, or imaging. Facile functionalization of the nanoparticles with two ligands containing isocyanate moieties allows for high coverage of the surface with maleimide and alkyne groups. As a proof‐of‐principle, the nanoparticles were subsequently functionalized with a fluorophore as a drug model and with biotin as a targeting ligand towards tumor cells through Diels–Alder and azide–alkyne cycloaddition reactions, respectively. The thermoreversibility of the Diels–Alder product was exploited to induce the on‐demand release of the loaded molecules by magnetic hyperthermia. Additionally, the nanoparticles were shown to target cancer cells through in vitro experiments, as analyzed by magnetic resonance imaging.
Peripherally Cyanated Subphthalocyanines as Potential n‐Type Organic Semiconductors
Authors: Zango Germán , Sakurai Tsuneaki , Urones Beatriz , Saeki Hidenori , Matsuda Wakana , Martínez‐Díaz M. Victoria , Seki Shu , Torres Tomás
Published: April 2018

A series of peripherally dicyano‐, tricyano‐, and tetracyano‐substituted subphthalocyanines (SubPcs) have been prepared through microwave‐assisted, palladium‐mediated cyanation of iodinated precursors. The introduction of π‐accepting cyano groups in the macrocycle clearly influences its electronic and redox properties, which are dependent on the number and relative position of these substituents. Additional functionalization of the periphery of SubPcs with electron‐donating or ‐withdrawing groups allows for a further fine‐tuning of their features, leading to intensely absorbing, strongly electron‐accepting panchromatic dyes with low‐lying LUMO energy levels. Flash‐photolysis time‐resolved microwave conductivity measurements on vapor‐deposited films demonstrate that some of these novel SubPc derivatives display remarkable intrinsic charge‐carrier mobilities that are comparable to or larger than those of other known well‐performing acceptor SubPcs; thus confirming their potential as n‐type organic semiconductors for application in the fabrication of photovoltaic devices.
Circular dichroism studies of low molecular weight hydrogelators: The use of SRCD and addressing practical issues
Authors: Sitsanidis Efstratios D. , Piras Carmen C. , Alexander Bruce D. , Siligardi Giuliano , Jávorfi Tamás , Hall Andrew J. , Edwards Alison A.
Published: April 2018

Circular dichroism (CD) spectroscopy has been used extensively for the investigation of the conformation and configuration of chiral molecules, but its use for evaluating the mode of self‐assembly in soft materials has been limited. Herein, we report a protocol for the study of such materials by electronic CD spectroscopy using commercial/benchtop instruments and synchrotron radiation (SR) using the B23 beamline available at Diamond Light Source. The use of the B23 beamtime for SRCD was advantageous because of the unique enhanced spatial resolution achieved because of its highly collimated and small beamlight cross section (ca. 250 μm) and higher photon flux in the far UV region (175‐250 nm) enhancing the signal‐to‐noise ratio relative to benchtop CD instruments. A set of low molecular weight (LMW) hydrogelators, comprising two Fmoc‐protected enantiomeric monosaccharides and one Fmoc dipeptide (Fmoc‐FF), were studied. The research focused on the optimization of sample preparation and handling, which then enabled the characterization of sample conformational homogeneity and thermal stability. CD spectroscopy, in combination with other spectroscopic techniques and microscopy, will allow a better insight into the self‐assembly of chiral building blocks into higher order structural architectures.
The role of external beam radiotherapy in the treatment of hepatocellular cancer
Authors: Chino Fumiko , Stephens Sarah Jo , Choi Steve S. , Marin Daniele , Kim Charles Y. , Morse Michael A. , Godfrey Devon J. , Czito Brian G. , Willett Christopher G. , Palta Manisha
Published: April 2018

Hepatocellular carcinoma (HCC) is increasing in incidence and mortality. Although the prognosis remains poor, long‐term survival has improved from 3% in 1970 to an 18% 5‐year survival rate today. This is likely because of the introduction of well tolerated, oral antiviral therapies for hepatitis C. Curative options for patients with HCC are often limited by underlying liver dysfunction/cirrhosis and medical comorbidities. Less than one‐third of patients are candidates for surgery, which is the current gold standard for cure. Nonsurgical treatments include embolotherapies, percutaneous ablation, and ablative radiation. Technological advances in radiation delivery in the past several decades now allow for safe and effective ablative doses to the liver. Conformal techniques allow for both dose escalation to target volumes and normal tissue sparing. Multiple retrospective and prospective studies have demonstrated that hypofractionated image‐guided radiation therapy, used as monotherapy or in combination with other liver‐directed therapies, can provide excellent local control that is cost effective. Therefore, as the HCC treatment paradigm continues to evolve, ablative radiation treatment has moved from a palliative treatment to both a “bridge to transplant” and a definitive treatment.
Hematite Photoanode with Complex Nanoarchitecture Providing Tunable Gradient Doping and Low Onset Potential for Photoelectrochemical Water Splitting
Authors: Ahn Hyo‐Jin , Goswami Anandarup , Riboni Francesca , Kment Stepan , Naldoni Alberto , Mohajernia Shiva , Zboril Radek , Schmuki Patrik
Published: April 2018

Over the past years, α‐Fe2O3 (hematite) has re‐emerged as a promising photoanode material in photoelectrochemical (PEC) water splitting. In spite of considerable success in obtaining relatively high solar conversion efficiency, the main drawbacks hindering practical application of hematite are its intrinsically hampered charge transport and sluggish oxygen evolution reaction (OER) kinetics on the photoelectrode surface. In the present work, we report a strategy that synergistically addresses both of these critical limitations. Our approach is based on three key features that are applied simultaneously: i) a careful nanostructuring of the hematite photoanode in the form of nanorods, ii) doping of hematite by Sn4+ ions using a controlled gradient, and iii) surface decoration of hematite by a new class of layered double hydroxide (LDH) OER co‐catalysts based on Zn–Co LDH. All three interconnected forms of functionalization result in an extraordinary cathodic shift of the photocurrent onset potential by more than 300 mV and a PEC performance that reaches a photocurrent density of 2.00 mA cm−2 at 1.50 V vs. the reversible hydrogen electrode.
Facile Enzymatic Synthesis of Phosphatidylthreonine Using an Engineered Phospholipase D
Authors: Damnjanović Jasmina , Matsunaga Nozomi , Adachi Masaatsu , Nakano Hideo , Iwasaki Yugo
Published: April 2018

Here is described the newly established method for direct enzymatic synthesis of phosphatidylthreonine (PtdThr). It is the first report on enzymatic synthesis of this rare phospholipid. It utilizes phospholipase D (PLD)‐catalyzed transphosphatidylation, in which the head group of phosphatidylcholine (PtdCho) is exchanged to L‐Threonine (L‐Thr). An attempt to catalyze the reaction between PtdCho and L‐Thr using wild‐type PLD is not successful, possibly because the secondary hydroxyl group of L‐Thr is not accessible to the enzyme. To synthesize Ptd‐L‐Thr, the natural PtdThr isomer, engineered PLD variants active toward secondary hydroxyls of inositol are screened for their ability to accept L‐Thr. Six variants are identified as positive, among which 187F/191Y/385L (FYL) shows highest activity. After optimizing the reaction parameters, Ptd‐L‐Thr content reaches approximately 30 mol%. The product is isolated by column chromatography with the overall yield of 5.2%, and its structure is confirmed by NMR. In addition, the FYL variant can also react on some stereoisomers of threonine, L‐allo‐Thr, and D‐allo‐Thr as well as L‐Thr, but not D‐Thr. Ligand docking simulation explains the enzyme's preference toward these stereoisomers; L‐, L‐allo‐, and D‐allo‐Thr can bind to the enzyme's active site in a productive orientation, whereas D‐Thr binds in a position which makes the reaction impossible to proceed.

Practical Applications: The enzymatic method enables one‐step synthesis of PtdThr from PtdCho and L‐Threonine without any protection/deprotection steps, thereby being much more simple and less hazardous than the currently used chemical methods. The synthesized PtdThr can be isolated in pure form and used as a reagent for elucidation of its biological functions.

A method for one‐step enzymatic synthesis of phosphatidylthreonine (PtdThr) is described. It uses the head group exchange of phosphatidylcholine (PtdCho) with Threonine(Thr) catalyzed by an engineered phospholipase D (PLD). The enzyme can accept some stereoisomers of Thr, that is, L‐Thr, L‐allo‐Thr, and D‐allo‐Thras the substrates to give the corresponding PtdThr, but notD‐Thr. Docking simulation explainsthe enzyme's preference toward thesestereoisomers; L‐, L‐allo‐, and D‐allo‐Thr can bind to the enzyme's active site in a productive orientation, whereas D‐Thrbinds in a non‐productive orientation which makes the reaction impossible to proceed.
A simple, low‐cost and robust capillary zone electrophoresis method with capacitively coupled contactless conductivity detection for the routine determination of four selected penicillins in money‐constrained laboratories
Authors: Paul Prasanta , Sänger‐van de Griend Cari , Adams Erwin , Van Schepdael Ann
Published: April 2018

A simple and robust capillary zone electrophoresis method was developed and validated for the determination of amoxicillin and clavulanate, ampicillin, phenoxymethyl penicillin (Pen V) as well as flucloxacillin. Capacitively coupled contactless conductivity detection was employed as detection mode that makes CE a simple and economic tool for money‐constrained laboratories. The developed method is straightforward and user‐friendly. It offers good sensitivity and sufficient selectivity for the routine assay of the selected penicillins. The repeatabilities were <1.9% RSD for relative peak areas and <1% RSD for migration times for all the analytes. The method showed good linearity (R2 > 0.995) within the 80–120% range of the target concentration (0.5 mg/mL) for each antibiotic. The accuracy of the method, evaluated by standard fortification at three levels, was good for all the analytes. An extended robustness study was performed by varying ±10% of the optimum value of TRIS concentration, l‐histidine concentration and temperature in a full factorial design at two levels. This was to evaluate larger than usual variability of factors on the assay value, in order to better cover potential global variance in lab conditions and equipment. Finally, the method was applied for the determination of percent (%) content of all antibiotics in available formulations.
Agreement of Teachers on Evaluating Assessments of Learning Progressions in English Language Arts and Mathematics
Authors: van Rijn Peter , Graf Edith Aurora , Arieli‐Attali Meirav , Song Yi
Published: April 2018

In this study, we explored the extent to which teachers agree on the ordering and separation of levels of two different learning progressions (LPs) in English language arts (ELA) and mathematics. In a panel meeting akin to a standard‐setting procedure, we asked teachers to link the items and responses of summative educational assessments to LP levels. We evaluated four types of agreement among teachers, with test developers, and with trained raters. Although the results were quite mixed, agreement on the LP levels of mathematics items was generally better than that for ELA tasks. The agreement on the LP levels of ELA sample responses was generally better than that for mathematics. Implications of the results are discussed.
Cardiovascular Safety of the β3‐Adrenoceptor Agonist Mirabegron and the Antimuscarinic Agent Solifenacin in the SYNERGY Trial
Authors: White William B. , Chapple Christopher , Gratzke Christian , Herschorn Sender , Robinson Dudley , Frankel Jeffrey , Ridder Arwin , Stoelzel Matthias , Paireddy Asha , van Maanen Robert , Weber Michael A.
Published: April 2018

There have been concerns that treatment of overactive bladder with β3‐adrenoceptor agonists may potentially have detrimental cardiovascular (CV) side effects. We evaluated the CV safety of mirabegron, a β3‐adrenoceptor agonist, alone and in combination therapy with the antimuscarinic agent solifenacin. The SYNERGY trial was a multinational, multicenter, randomized, double‐blind, parallel‐group, placebo and active‐controlled phase 3 trial. Patients were randomized to receive solifenacin 5 mg + mirabegron 50 mg (combination 5 + 50 mg), solifenacin 5 mg + mirabegron 25 mg (combination 5 + 25 mg), solifenacin 5 mg monotherapy, mirabegron 25 mg monotherapy, mirabegron 50 mg monotherapy, or placebo for a 12‐week double‐blind treatment period. A total of 3398 patients were included in the study. Mean changes from baseline to the end of therapy in ECG parameters were similar across treatment groups, although there was an increase in heart rate of 1 beat/minute in the mirabegron treatment groups. There were no clinically meaningful differences in change from baseline in QTcF between monotherapies and placebo and between monotherapies and combination therapy. There were very few major CV events: 1 of 853 (0.1%) with a nonfatal myocardial infarction in the combination 5 + 25 mg group, 2 of 848 (0.2%) with a nonfatal stroke in the combination 5 + 50 mg group, and no events in the other groups. This CV safety analysis of the combination of mirabegron and solifenacin showed rates of CV events comparable with those for monotherapy treatments based on assessments of vital signs, electrocardiograms, and adjudicated CV events.
Identification of a Siglec-F+ granulocyte-macrophage progenitor
Authors: Bolden Jessica E , Lucas Erin C , Zhou Geyu , O’Sullivan Jeremy A , de Graaf Carolyn A , McKenzie Mark D , Di Rago Ladina , Baldwin Tracey M , Shortt Jake , Alexander Warren S , Bochner Bruce S , Ritchie Matthew E , Hilton Douglas J , Fairfax Kirsten A
Published: April 2018

In recent years multi-parameter flow cytometry has enabled identification of cells at major stages in myeloid development; from pluripotent hematopoietic stem cells, through populations with increasingly limited developmental potential (common myeloid progenitors and granulocyte-macrophage progenitors), to terminally differentiated mature cells. Myeloid progenitors are heterogeneous, and the surface markers that define transition states from progenitors to mature cells are poorly characterized. Siglec-F is a surface glycoprotein frequently used in combination with IL-5 receptor alpha (IL5Rα) for the identification of murine eosinophils. Here, we describe a CD11b+ Siglec-F+ IL5Rα− myeloid population in the bone marrow of C57BL/6 mice. The CD11b+ Siglec-F+ IL5Rα− cells are retained in eosinophil deficient PHIL mice, and are not expanded upon overexpression of IL-5, indicating that they are upstream or independent of the eosinophil lineage. We show these cells to have GMP-like developmental potential in vitro and in vivo, and to be transcriptionally distinct from the classically described GMP population. The CD11b+ Siglec-F+ IL5Rα− population expands in the bone marrow of Myb mutant mice, which is potentially due to negative transcriptional regulation of Siglec-F by Myb. Lastly, we show that the role of Siglec-F may be, at least in part, to regulate GMP viability.

Identification of a population of GMP-like cells that express Siglec-F are multi-potential and prominent in Myb-mutant mice.
Deuterium‐substituted 2‐(2′‐((dimethylamino)methyl)‐4′‐[18F](fluoropropoxy)phenylthio)benzenamine as a serotonin transporter imaging agent
Authors: Liu Futao , Zhu Lin , Choi Seok Rye , Plössl Karl , Zha Zhihao , Kung Hank F.
Published: April 2018

Positron emission tomography imaging of serotonin transporter (SERT) is useful for studying brain diseases with altered serotonergic function. A deuterated imaging agent, ([18F]2‐((2‐((bis(methyl‐d3)amino)methyl)‐4‐(3‐fluoropropoxy‐1,1,2,2,3,3‐d6)phenyl)thio)aniline, [18F]D12FPBM, [18F]1), was prepared as a new chemical entity. The deuterated agent, 1, showed excellent binding affinity to SERT; Ki was 0.086 nM, comparable with the undeuterated FPBM. In vivo biodistribution studies in rats with [18F]1 showed good brain uptake (1.09% dose/g at 2 min post injection) and high specific uptake into the hypothalamus (HY) as compared with cerebellum (CB) (HY/CB = 7.55 at 120 min), suggesting a specific localization to SERT binding sites. Regional brain distribution in rats provided clear indication that [18F]1 concentrated in the hypothalamus, hippocampus, and striatum, areas with a high SERT density. Results indicate that very little D to H substitution effect was found; [18F]FPBM and [18F]1 showed very similar SERT binding. [18F]1 might be an excellent candidate for SERT imaging.
Preparation and evaluation of 188Re sulfide colloidal nanoparticles loaded biodegradable poly (L‐lactic acid) microspheres for radioembolization therapy
Authors: Jamre Mina , Shamsaei Mojtaba , Erfani Mostafa , Sadjadi Sodeh , Ghannadi Maragheh Mohammad
Published: April 2018

Radioembolization with radioactive microspheres has been an effective method for the treatment of liver lesions. The aim of this study was to prepare carrier‐free 188Re loaded poly (L‐lactic acid) (PLLA) microspheres through 188Re sulfide colloidal nanoparticles (188Re‐SC nanoparticles). The formation of 188Re‐SC nanoparticles was confirmed by ultraviolet‐visible spectrophotometry. The labeling yield of 188Re‐SC nanoparticles was verified using the RTLC method. Effects of synthesis parameters on morphology and size of prepared 188Re‐sulfide colloidal‐PLLA microspheres (188Re‐SC‐PLLA microspheres) were studied by scanning electron microscopy. In vitro stability of 188Re‐SC‐PLLA microspheres was investigated in normal saline at room temperature and in human serum at 37°C. In vivo distribution studies and gamma camera imaging were performed in healthy BALB/c mice. The microspheres could be prepared with sizes between 13 and 48 μm (modal value 29 μm) and radiolabeling efficiency >99%. After incubation, the microspheres were found stable in vitro up to 72 hours. The biodistribution after intravenous injection in healthy BALB/c mice showed high accumulation in lung as a first capture pathway organ for microsphere followed by great retention over 48 hours for these microspheres. These data show that 188Re‐SC‐PLLA microspheres are suitable candidate for clinical studies.
Exosomal MicroRNAs in Milk from Mothers Delivering Preterm Infants Survive in Vitro Digestion and Are Taken Up by Human Intestinal Cells
Authors: Kahn Sarah , Liao Yalin , Du Xiaogu , Xu Wei , Li Jie , Lönnerdal Bo
Published: April 2018

Scope

This study investigates the ability of preterm milk exosomes to survive gastric/pancreatic digestion, internalization by intestinal epithelia, and the microRNAs (miRNAs) contents.

Methods and results

At average infant age 1 week and 6 days, milk is collected from mothers who delivered preterm and term infants (n = 10). Milk is exposed to conditions simulating infant gut digestion. Exosomes are isolated and lysed, and the exposed miRNAs are sequenced. Preterm milk exosomes survive in vitro digestion, and can be taken up by intestinal epithelia. Three hundred and thirty miRNAs are identified as preterm milk exosome miRNAs, and in vitro digestion does not have a pronounced effect on their expression. The abundant miRNAs in preterm milk exosomes are similar to those from term milk. Twenty‐one low abundance miRNAs are specifically expressed in preterm milk exosomes compared to early term milk in the current study and what previously is found in mature term milk.

Conclusion

These results for the first time reveal the survivability of preterm milk exosomes following simulated gastric/pancreatic digestion. The authors demonstrate the richness of the miRNAs content in these exosomes. The results improve the knowledge of preterm milk biology and the molecular basis by which exosome miRNAs may uniquely affect preterm infants during early development.
Block‐matching sparsity regularization‐based image reconstruction for low‐dose computed tomography
Authors: Cai Ailong , Li Lei , Zheng Zhizhong , Wang Linyuan , Yan Bin
Published: April 2018

Purpose

Low‐dose computed tomography (CT) imaging has been widely explored because it can reduce the radiation risk to human bodies. This presents challenges in improving the image quality because low radiation dose with reduced tube current and pulse duration introduces severe noise. In this study, we investigate block‐matching sparsity regularization (BMSR) and devise an optimization problem for low‐dose image reconstruction.

Method

The objective function of the program is built by combining the sparse coding of BMSR and analysis error, which is subject to physical data measurement. A practical reconstruction algorithm using hard thresholding and projection‐onto‐convex‐set for fast and stable performance is developed. An efficient scheme for the choices of regularization parameters is analyzed and designed.

Results

In the experiments, the proposed method is compared with a conventional edge preservation method and adaptive dictionary‐based iterative reconstruction. Experiments with clinical images and real CT data indicate that the obtained results show promising capabilities in noise suppression and edge preservation compared with the competing methods.

Conclusions

A block‐matching‐based reconstruction method for low‐dose CT is proposed. Improvements in image quality are verified by quantitative metrics and visual comparisons, thereby indicating the potential of the proposed method for real‐life applications.
Violence targeting children or violent society? Craniofacial injuries among the pre‐Hispanic subadult population of Gran Canaria (Canary Islands)
Authors: Velasco‐Vázquez J. , Delgado‐Darias T. , Alberto‐Barroso V.
Published: April 2018

The approach to Gran Canaria's pre‐Hispanic period has traditionally been dominated by a romantic and propitious view of its indigenous populations advocating a historical evolution on the margin of the conflicts and contradictions common to any society. Yet new data indicate that the ancient Canarians were subject to high rates of internal violence linked to the island's isolation and harsh biogeographical conditions, as well as marked personal differences and a strong hierarchization of the social order. However, the effects of such a degree of violence among the subadult population remain unknown. The study of the assemblage of the victims, particularly the younger members of society, requires a global analysis of the historical conditions to determine whether this violence was exceptional or habitual. The findings of this study point to a prevalence of trauma among subadults (surpassing 20%), thus bolstering the notion of a society with widespread physical violence affecting the whole population or at least that above the age of 5 or 6 years. The data also suggest widespread violence within the framework of interpersonal relationships rather than violence directed specifically against the population's younger sector.
Close but not quite: Two cases of sex chromosome aneuploidies outside the scope of cell free DNA screening
Authors: Sagaser Katelynn G. , Stevens Blair , Davis Jessica , Northrup Hope , Ramdaney Aarti
Published: April 2018

WHAT'S ALREADY KNOWN ABOUT THIS TOPIC?

cfDNA screening reports high sensitivities and specificities for autosomal trisomies, yet challenges still exist in accurate detection of sex chromosome aneuploidies.

WHAT DOES THIS STUDY ADD?

Sex chromosome tetrasomy or pentasomy may be incorrectly reported as a sex chromosome trisomy by cfDNA screening.

Patients with abnormal cfDNA results for sex chromosome trisomies should be counseled on the possibility of sex chromosome tetrasomies or pentasomies and the differences in clinical implications and predicted prognoses with such diagnoses.

All patients with an abnormal cfDNA result for a sex chromosome aneuploidy should be offered prenatal diagnosis and postnatal testing.
Collision‐induced dissociation of [UVIO2(ClO4)]+ revisited: Production of [UVIO2(Cl)]+ and subsequent hydrolysis to create [UVIO2(OH)]+
Authors: Tatosian Irena J. , Iacovino Anna C. , Van Stipdonk Michael J.
Published: April 2018

Rationale

In a previous study [Rapid Commun Mass Spectrom. 2004;18:3028–3034], collision‐induced dissociation (CID) of [UVIO2(ClO4)]+ appeared to be influenced by the high levels of background H2O in a quadrupole ion trap. The CID of the same species was re‐examined here with the goal of determining whether additional, previously obscured dissociation pathways would be revealed under conditions in which the level of background H2O was lower.

Methods

Water‐ and methanol‐coordinated [UVIO2(ClO4)]+ precursor ions were generated by electrospray ionization. Multiple‐stage tandem mass spectrometry (MSn) for CID and ion‐molecule reaction (IMR) studies was performed using a linear ion trap mass spectrometer.

Results

Under conditions of low background H2O, CID of [UVIO2(ClO4)]+ generates [UVIO2(Cl)]+, presumably by elimination of two O2 molecules. Using low isolation/reaction times, we found that [UVIO2(Cl)]+ will undergo an IMR with H2O to generate [UVIO2(OH)]+.

Conclusions

With lower levels of background H2O, CID experiments reveal that the intrinsic dissociation pathway for [UVIO2(ClO4)]+ leads to [UVIO2(Cl)]+, apparently by loss of two O2 molecules. We propose that the results reported in the earlier CID study reflected a two‐step process: initial formation of [UVIO2(Cl)]+ by CID, followed by a very rapid hydrolysis reaction to leave [UVIO2(OH)]+.
Dam Removal and Fish Passage Improvement Influence Fish Assemblages in the Penobscot River, Maine
Authors: Watson Jonathan M. , Coghlan Stephen M. , Zydlewski Joseph , Hayes Daniel B. , Kiraly Ian A.
Published: April 2018

Dams and their impoundments disrupt river habitat connectivity to the detriment of migratory fishes. Removal of dams improves riverine connectivity and lotic habitat, which benefits not only these fishes but also resident fluvial specialist species. Restoration efforts on the Penobscot River, Maine, are among the largest recently completed in the United States and include the removal of the two lowermost dams and improvements to fish passage at several remaining barriers. We assessed fish assemblages in the main‐stem river and several major tributaries before (2010–2012) and after (2014–2016) dam removal using boat electrofishing surveys and a stratified random sampling design. In total, we sampled 303 km of shoreline and captured 107,335 individual fish representing 39 species. Similarity indices and rarefaction curves indicated that significant changes in fish assemblage composition occurred in reaches that underwent both habitat and connectivity changes (i.e., directly above removed dams). The newly connected reaches became more similar in fish assemblage composition, as demonstrated by an average increase of 31% in similarity scores. The changes in similarity score in these reaches were driven by increasing access for anadromous fishes and decreasing abundances of slow‐water specialist species. For example, we observed a marked reduction in lacustrine species in former impoundments. These assemblage shifts were further illustrated by nonmetric multidimensional scaling in which sites directly above former dams exhibited the largest ordinal shifts immediately following dam removal. We also found all anadromous species in greatest abundance below the lowermost dam during each respective sampling period, though we did find some anadromous species above the lowermost dam during postremoval sampling. Our results demonstrate the potential for large dam removal projects to restore both fluvial and anadromous fish assemblages.
Landscape heterogeneity following high‐severity fire in California's forests
Authors: Hanson Chad T.
Published: April 2018

Many at‐risk wildlife species depend upon high‐severity fire patches to create “complex early seral forest” (CESF) land cover, characterized by an abundance of snags, downed logs, shrub patches, and regeneration of trees. However, concern has been expressed about whether high‐severity fire might result in persistent type conversion to nonforest, or from pine (Pinus spp.) dominance to forest predominantly consisting of white fir (Abies concolor), Douglas‐fir (Pseudotsuga menziesii), and incense‐cedar (Calocedrus decurrens), as opposed to heterogeneous natural succession and ephemeral occurrence of CESF. If type conversion is common, it could in time harm other at‐risk species that depend on dense, late‐successional forest for some of their habitat needs. I investigated postfire patterns in high‐severity fire patches within yellow pine (Pinus ponderosa and Pinus jeffreyi) and mixed‐conifer forests in California, USA, using field plots evenly spaced along random transects into the interior of patches within fires that occurred from 1999 to 2013. I found natural conifer regeneration in ≥80% of plots, even >300 m into patches. Conifer regeneration was greater closer to low–moderate‐severity areas. Areas with lower conifer regeneration, where CESF would have the greatest longevity—comprised only 4.6% of these fire areas. Pine species dominated regeneration deeper into the interior of large high‐severity patches, and fir–cedar‐dominated at patch edges. Shrubs did not impede conifer regeneration, but greater densities of conifer saplings reduced shrubs, and sapling growth increased with time‐since‐fire. My findings suggest heterogeneous land‐cover patterns are resulting from natural succession in high‐severity fire patches. © 2018 The Wildlife Society.
The First Molybdenum Oxo‐iodide Cluster – [Mo4OI12]2–
Authors: Mikhaylov Maxim A. , Abramov Pavel A. , Novozhilov Igor N. , Sokolov Maxim N.
Published: April 2018

Reaction of Mo(CO)6 with Bu4NI and I2 in diglyme yielded a new butterfly MoIII cluster [Mo4OI12]2–. The structure of tetraphenylphosphonium salt was determined by X‐ray single crystal diffraction. Ph4P+ and Bu4N+ salts were further characterized by elemental analysis, mass spectrometry, energy‐dispersive X‐ray (EDX), IR, Raman, and UV/Vis spectroscopy and CVA studies. The cluster anion has a butterfly array of molybdenum atoms and can be represented as [Mo4(μ4‐O)(μ3‐I)2(μ2‐I4)I6]2–.
Open superstring field theory based on the supermoduli space
Authors: Ohmori Kantaro , Okawa Yuji
Published: April 2018

Abstract

We present a new approach to formulating open superstring field theory based on the covering of the supermoduli space of super-Riemann surfaces and explicitly construct a gauge-invariant action in the Neveu-Schwarz sector up to quartic interactions. The cubic interaction takes a form of an integral over an odd modulus of disks with three punctures and the associated ghost is inserted. The quartic interaction takes a form of an integral over one even modulus and two odd moduli, and it can be interpreted as the integral over the region of the supermoduli space of disks with four punctures which is not covered by Feynman diagrams with two cubic vertices and one propagator. As our approach is based on the covering of the supermoduli space, the resulting theory naturally realizes an A
∞ structure, and the two-string product and the three-string product used in defining the cubic and quartic interactions are constructed to satisfy the A
∞ relations to this order.
$$ \mathcal{N}=2 $$ SYK model in the superspace formalism
Authors: Bulycheva Ksenia
Published: April 2018

Abstract

We use superspace methods to study an SYK-like model with

$$ \mathcal{N}=2 $$

N
=
2

supersymmetry in one dimension, and an analog of this model in two dimensions. We find the four-point function as an expansion in the basis of eigenfunctions of the Casimir of su(1, 1|1). We also find retarded kernels and Lyapunov exponents for both cases.
Conformal structure of massless scalar amplitudes beyond tree level
Authors: Banerjee Nabamita , Banerjee Shamik , Bhatkar Sayali Atul , Jain Sachin
Published: April 2018

Abstract

We show that the one-loop on-shell four-point scattering amplitude of massless ϕ
4 scalar field theory in 4D Minkowski space time, when Mellin transformed to the Celestial sphere at infinity, transforms covariantly under the global conformal group (SL(2, ℂ)) on the sphere. The unitarity of the four-point scalar amplitudes is recast into this Mellin basis. We show that the same conformal structure also appears for the two-loop Mellin amplitude. Finally we comment on some universal structure for all loop four-point Mellin amplitudes specific to this theory.
A subleading power operator basis for the scalar quark current
Authors: Chang Cyuan-Han , Stewart Iain W. , Vita Gherardo
Published: April 2018

Abstract

Factorization theorems play a crucial role in our understanding of the strong interaction. For collider processes they are typically formulated at leading power and much less is known about power corrections in the λ ≪ 1 expansion. Here we present a complete basis of power suppressed operators for a scalar quark current at

$$ \mathcal{O}\left({\lambda}^2\right) $$

O

λ
2

in the amplitude level power expansion in the Soft Collinear Effective Theory, demonstrating that helicity selection rules significantly simplify the construction. This basis applies for the production of any color singlet scalar in

$$ q\overline{q} $$

q

q
¯

annihilation (such as

$$ b\overline{b}\to H $$

b

b
¯

→
H

). We also classify all operators which contribute to the cross section at

$$ \mathcal{O}\left({\lambda}^2\right) $$

O

λ
2

and perform matching calculations to determine their tree level Wilson coefficients. These results can be exploited to study power corrections in both resummed and fixed order perturbation theory, and for analyzing the factorization properties of gauge theory amplitudes and cross sections at subleading power.
Large Higgs-electron Yukawa coupling in 2HDM
Authors: Dery Avital , Frugiuele Claudia , Nir Yosef
Published: April 2018

Abstract

The present upper bound on κ

e
, the ratio between the electron Yukawa coupling and its Standard Model value, is of

$$ \mathcal{O}(600) $$

O

600

. We ask what would be the implications in case that κ

e
is close to this upper bound. The simplest extension that allows for such enhancement is that of two Higgs doublet models (2HDM) without natural flavor conservation. In this framework, we find the following consequences: (i) Under certain conditions, measuring κ

e
and κ

V
would be enough to predict values of Yukawa couplings for other fermions and for the H and A scalars. (ii) In the case that the scalar potential has a softly broken Z
2 symmetry, the second Higgs doublet must be light, but if there is hard breaking of the symmetry, the second Higgs doublet can be much heavier than the electroweak scale and still allow the electron Yukawa coupling to be very different from its SM value. (iii) CP must not be violated at a level higher than

$$ \mathcal{O}\left(0.01/{\kappa}_e\right) $$

O

0.01
/

κ
e

in both the scalar potential and the Yukawa sector. (iv) LHC searches for e
+
e
− resonances constrain this scenario in a significant way. Finally, we study the implications for models where one of the scalar doublets couples only to the first generation, or only to the third generation.
Heavy-flavor parton distributions without heavy-flavor matching prescriptions
Authors: Bertone Valerio , Glazov Alexandre , Mitov Alexander , Papanastasiou Andrew S. , Ubiali Maria
Published: April 2018

Abstract

We show that the well-known obstacle for working with the zero-mass variable flavor number scheme, namely, the omission of

$$ \mathcal{O}(1) $$

O

1

mass power corrections close to the conventional heavy flavor matching point (HFMP) μ

b
= m, can be easily overcome. For this it is sufficient to take advantage of the freedom in choosing the position of the HFMP. We demonstrate that by choosing a sufficiently large HFMP, which could be as large as 10 times the mass of the heavy quark, one can achieve the following improvements: 1) above the HFMP the size of missing power corrections

$$ \mathcal{O}(m) $$

O

m

is restricted by the value of μ

b
and, therefore, the error associated with their omission can be made negligible; 2) additional prescriptions for the definition of cross-sections are not required; 3) the resummation accuracy is maintained and 4) contrary to the common lore we find that the discontinuity of α

s
and pdfs across thresholds leads to improved continuity in predictions for observables. We have considered a large set of proton-proton and electron-proton collider processes, many through NNLO QCD, that demonstrate the broad applicability of our proposal.
Boundaries of amplituhedra and NMHV symbol alphabets at two loops
Authors: Prlina I. , Spradlin M. , Stankowicz J. , Stanojevic S.
Published: April 2018

Abstract

In this sequel to [3] we classify the boundaries of amplituhedra relevant for determining the branch points of general two-loop amplitudes in planar

$$ \mathcal{N}=4 $$

N
=
4

super-Yang-Mills theory. We explain the connection to on-shell diagrams, which serves as a useful cross-check. We determine the branch points of all two-loop NMHV amplitudes by solving the Landau equations for the relevant configurations and are led thereby to a conjecture for the symbol alphabets of all such amplitudes.
From spinning conformal blocks to matrix Calogero-Sutherland models
Authors: Schomerus Volker , Sobko Evgeny
Published: April 2018

Abstract

In this paper we develop further the relation between conformal four-point blocks involving external spinning fields and Calogero-Sutherland quantum mechanics with matrix-valued potentials. To this end, the analysis of [1] is extended to arbitrary dimensions and to the case of boundary two-point functions. In particular, we construct the potential for any set of external tensor fields. Some of the resulting Schrödinger equations are mapped explicitly to the known Casimir equations for 4-dimensional seed conformal blocks. Our approach furnishes solutions of Casimir equations for external fields of arbitrary spin and dimension in terms of functions on the conformal group. This allows us to reinterpret standard operations on conformal blocks in terms of group-theoretic objects. In particular, we shall discuss the relation between the construction of spinning blocks in any dimension through differential operators acting on seed blocks and the action of left/right invariant vector fields on the conformal group.
Incoherent transport for phases that spontaneously break translations
Authors: Donos Aristomenis , Gauntlett Jerome P. , Griffin Tom , Ziogas Vaios
Published: April 2018

Abstract

We consider phases of matter at finite charge density which spontaneously break spatial translations. Without taking a hydrodynamic limit we identify a boost invariant incoherent current operator. We also derive expressions for the small frequency behaviour of the thermoelectric conductivities generalising those that have been derived in a translationally invariant context. Within holographic constructions we show that the DC conductivity for the incoherent current can be obtained from a solution to a Stokes flow for an auxiliary fluid on the black hole horizon combined with specific thermodynamic quantities associated with the equilibrium black hole solutions.
Non Abelian T-duality in Gauged Linear Sigma Models
Authors: Bizet Nana Cabo , Martínez-Merino Aldo , Zayas Leopoldo A. Pando , Santos-Silva Roberto
Published: April 2018

Abstract

Abelian T-duality in Gauged Linear Sigma Models (GLSM) forms the basis of the physical understanding of Mirror Symmetry as presented by Hori and Vafa. We consider an alternative formulation of Abelian T-duality on GLSM’s as a gauging of a global U(1) symmetry with the addition of appropriate Lagrange multipliers. For GLSMs with Abelian gauge groups and without superpotential we reproduce the dual models introduced by Hori and Vafa. We extend the construction to formulate non-Abelian T-duality on GLSMs with global non-Abelian symmetries. The equations of motion that lead to the dual model are obtained for a general group, they depend in general on semi-chiral superfields; for cases such as SU(2) they depend on twisted chiral superfields. We solve the equations of motion for an SU(2) gauged group with a choice of a particular Lie algebra direction of the vector superfield. This direction covers a non-Abelian sector that can be described by a family of Abelian dualities. The dual model Lagrangian depends on twisted chiral superfields and a twisted superpotential is generated. We explore some non-perturbative aspects by making an Ansatz for the instanton corrections in the dual theories. We verify that the effective potential for the U(1) field strength in a fixed configuration on the original theory matches the one of the dual theory. Imposing restrictions on the vector superfield, more general non-Abelian dual models are obtained. We analyze the dual models via the geometry of their susy vacua.
Percutaneous left ventricular assist device vs. intra‐aortic balloon pump in patients with severe left ventricular dysfunction undergoing cardiovascular intervention: A meta‐analysis
Authors: Hu Fang‐Bin , Cui Lian‐Qun
Published: April 2018

Objective

Although controversial, the intra‐aortic balloon pump (IABP) and percutaneous left ventricular assist device (PLVAD) are widely used for initial hemodynamic stabilization. We performed a meta‐analysis to compare the clinical outcomes of these two devices in patients with severe left ventricular (LV) dysfunction undergoing percutaneous coronary intervention (PCI) or ventricular tachycardia (VT) ablation.

Methods

MEDLINE, EMBASE, the Cochrane Registry of Controlled Trials, and reference lists of relevant articles were searched. We included randomized controlled trials (RCTs) and prospective observational studies. Meta‐analysis was conducted using a random effects model.

Results

The quantitative analysis included 4 RCTs and 2 observational studies. A total of 348 patients received PLVAD and 340 received IABP. Meta‐analysis revealed that early mortality rates (in‐hospital or 30‐day) did not differ between the PLVAD and IABP groups (relative risk (RR) = 1.03, 95% confidence interval (CI) = 0.70–1.51, P = 0.89). Significant differences were observed between the two groups in the composite, in‐hospital, non‐major adverse cardiac and cerebrovascular events (MACCE) rate (RR = 1.30, 95% CI = 1.01–1.68, P = 0.04).

Conclusions

Compared with IABP, PLVAD with active circulatory support did not improve early survival in those with severe left ventricular dysfunction undergoing either PCI or VT ablation, but increased the in‐hospital non‐MACCE rate.