bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Electrospun Composite Fibers in Multiscale Structure and Investigating the Performance on Proliferation and Osteogenic Differentiation of ADSCs
Authors: Xuan Liuyang , Shi Ming , Ma Shuangshuang , Ye Feng , Shi Xuetao , Yan Ling , Li Yan
Published: May 2018

Electrospun composite membranes in multiscale structures are developed for bone tissue engineering. Aligned polycaprolactone (PCL) fibers entrapping CA‐HAp microparticles (containing CaCO3, hydroxyapatite, and casein in a hierarchical organization) are electrospun to find whether synergistic effects of fiber alignment and CA‐HAp microparticles on improving osteogenic differentiation can be obtained. CA‐HAp microparticles are in a spherical morphology of 1.42 ± 0.26 µm. Their presence increases fiber diameter and does not significantly affect fiber alignment. On all membranes, adipose derived stem cells (ADSCs) from humans spread very well. On a random group, cells distribute randomly and the presence of CA‐HAp microparticles facilitates cell proliferation, especially for the one at CA‐HAp/PCL 50 wt%; the one at CA‐HAp/PCL 20 wt% shows significantly much higher alkaline phosphatase (ALP) activity (112.0% higher) than the pure PCL membrane. On aligned samples, cells align along fibers and expression of ALP is enhanced. However, at the same composition (CA‐HAp/PCL 20 wt%), the random sample has much higher ALP activity than the aligned sample. The expressions of osteogenic marker genes are also evaluated. Combining the results and the applicability of membranes together, the random membrane at CA‐HAp/PCL 20 wt% is the best candidate for bone tissue engineering.
The optimal runner on the royal road
Authors: Hamburger Christoph
Published: May 2018

Assuming a simple biophysical model and using the Carathéodory method, we find the optimal strategy to run or swim a race.
Numerical solutions of nonlinear 3‐dimensional Volterra integral‐differential equations with 3D‐block‐pulse functions
Authors: Manafian Jalil , Bolghar Peyman
Published: May 2018

This paper studies nonlinear 3‐dimensional Volterra integral‐differential equations, by implementing 3‐dimensional block‐pulse functions. First, we prove a theorem and corollary about sufficient condition for the minimum of mean square error under the block pulse coefficients and uniqueness of solution of the nonlinear Volterra integral‐differential equations. Then, we convert the main problem to a nonlinear system to the 3‐dimensional block‐pulse functions. In addition, illustrative examples are included to demonstrate the validity and applicability of the presented method.
On S‐asymptotically ω‐periodic and Bloch periodic mild solutions to some fractional differential equations in abstract spaces
Authors: Oueama‐Guengai Enock R. , N'Guérékata Gaston M.
Published: May 2018

We are concerned with the existence and uniqueness of S‐asymptotically ω‐periodic and Bloch periodic mild solutions to the semilinear fractional differential equation of the form
where
is the Riemann‐Liouville derivative, 1 < α < 2 and A is a (generally unbounded) linear operator, which generates a bounded α‐resolvent family Tα(t) on a (complex) Banach space X. We use some classical fixed‐point theorems to reach our results. The results are new even in the context of asymptotically periodic solutions.
Existence of positive weak solutions for a class of Kirrchoff elliptic systems with multiple parameters
Authors: Boulaaras Salah , Guefaifia Rafik
Published: May 2018

In this paper, by using subsuper solutions method, we study the existence of weak positive solution for a class of Kirrchoff elliptic systems in bounded domains with multiple parameters.
An invariant‐region‐preserving limiter for DG schemes to isentropic Euler equations
Authors: Jiang Yi , Liu Hailiang
Published: May 2018

In this article, we introduce an invariant‐region‐preserving (IRP) limiter for the p‐system and the corresponding viscous p‐system, both of which share the same invariant region. Rigorous analysis is presented to show that for smooth solutions the order of approximation accuracy is not destroyed by the IRP limiter, provided the cell average stays away from the boundary of invariant region. Moreover, this limiter is explicit, and easy for computer implementation. A generic algorithm incorporating the IRP limiter is presented for high order finite volume type schemes as long as the evolved cell average of the underlying scheme stays strictly within the invariant region. For high order discontinuous Galerkin (DG) schemes to the p‐system, sufficient conditions are obtained for cell averages to stay in the invariant region. For the viscous p‐system, we design both second and third order IRP DG schemes. Numerical experiments are provided to test the proven properties of the IRP limiter and the performance of IRP DG schemes.
Neurologic impairments from pediatric low‐grade glioma by tumor location and timing of diagnosis
Authors: Sadighi Zsila S. , Curtis Elizabeth , Zabrowksi Jennifer , Billups Catherine , Gajjar Amar , Khan Raja , Qaddoumi Ibrahim
Published: May 2018

Background

The neurologic outcomes of low‐grade gliomas (LGGs) according to tumor location and duration of presenting symptoms remain poorly characterized in children.

Procedure

We retrospectively reviewed neurologic impairments in 246 pediatric patients with LGGs (88 with optic pathway and midline tumors, 56 with posterior fossa tumors, 52 with cerebral hemisphere tumors, 35 with brainstem tumors, and 15 with spinal cord tumors) who were treated at St. Jude Children's Research Hospital between 1995 and 2005. We compared neurologic impairments (defined by Common Terminology Criteria for Adverse Events, version 4.03) by tumor location and prediagnosis symptom interval (PSI) (≥ 3 months or < 3 months) at first and last patient visits.

Results

The median age of diagnosis was 7.1 years; median PSI was 2.1 months; and median time to last follow‐up was 11.6 years. LGGs in the cerebral hemispheres resulted in significantly fewer neurologic impairments, compared with that of other locations at baseline (P < 0.001) and at last follow‐up (P < 0.001). In all patients, PSIs greater than 3 months resulted in a significantly higher incidence of ataxia and dysmetria at last follow‐up (42%, P = 0.003). Greater PSI was also significantly associated with worsening lower extremity motor weakness from cerebral hemisphere tumors; dysmetria from optic pathway and midline tumors; eye and visual dysfunction from posterior fossa tumors; and ear and vestibular disturbances from brainstem tumors (P ≤ 0.05).

Conclusion

Neurologic impairment in pediatric LGGs varies by tumor location, and PSIs greater than 3 months affect some functionally important neurologic outcomes.
Perinatal outcomes of single fetal survivor after fetal intervention for complicated monochorionic twins
Authors: Hoffman Mallory , Habli Mounira , Donepudi Roopali , Boring Noemi , Johnson Anthony , Moise Kenneth J. , Papanna Ramesha
Published: May 2018

Objective

To compare perinatal outcomes between acute single fetal demise following fetoscopic laser photocoagulation to planned selective reduction (SR) in complicated monochorionic twin pregnancies.

Methods

This was a secondary analysis of prospectively collected data in complicated monochorionic twin pregnancies from 2 fetal centers from 2011 to 2016. Group 1 included women undergoing fetoscopic laser photocoagulation for twin‐twin transfusion syndrome (TTTS) who experienced a single fetal demise within 24 hours of the procedure. Group 2 consisted of women undergoing planned selective reduction (SR) with TTTS, and Group 3 SR for indications other than TTTS.

Results

Survival of the remaining co‐twin at birth was highest in Group 1 (n = 77 patients; 95%) compared with that in Group 2 (n = 15; 80%) and Group 3 (n = 32; 78%; P = .047). The preterm premature rupture of membrane rate was higher in Group 1 (47%) compared with that in Group 2 (33%) and Group 3 (7%; P < .001). Group 1 had a lower gestational age at delivery and shorter procedure‐to‐delivery interval compared with the other 2 groups (P < .01).

Conclusion

When single fetal demise occurs following fetoscopic laser photocoagulation, the surviving co‐twin is more likely to survive to delivery but has higher PPROM rates and a shorter latency period compared with planned selective reduction for TTTS or other indications.
Factors associated to early intrauterine fetal demise after laser for TTTS by preoperative fetal heart and Doppler ultrasound
Authors: Delabaere Amélie , Leduc France , Reboul Quentin , Fuchs Florent , Wavrant Sandrine , Dubé Johanne , Fouron Jean‐Claude , Audibert François
Published: May 2018

Objective

To determine the prognostic value of fetal Doppler and echocardiographic parameters for intrauterine fetal demise (IUFD) within 24 hours and within 1 week after laser coagulation in monochorionic pregnancies complicated by twin‐twin transfusion syndrome.

Method

This retrospective study correlated the preoperative hemodynamic and echocardiography parameters to the outcome in fetuses with twin‐twin transfusion syndrome undergoing laser therapy.

Results

One hundred and twelve laser coagulations were performed between February 2006 and June 2015. The total (single and double) IUFD rate was 27.7%. Further, 59% of IUFD occurred within 24 hours and 74.4% occurred within 1 week after laser. The following were associated to IUFD within 24 hours: the middle cerebral arterial pulsatility index in the donor, abnormal umbilical artery (UA) end diastolic flow, increased middle cerebral artery peak systolic velocity, and right ventricular myocardial performance index (RV‐MPI) z‐score in the recipient. For IUFD within 1 week were the pulsatility index in the donor UA and the recipient abnormalities in UA, ductus venosus, middle cerebral artery‐peak systolic velocity, and RV‐MPI z‐score.

Conclusion

Following laser was early IUFD that was associated with Doppler findings suggesting donor cerebroplacental redistribution, and recipient overload cardiomyopathy, such as abnormal ductus venosus and UA Dopplers as well as an increase of RV‐MPI.
GOLD assessment of COPD severity in the Clinical Practice Research Datalink (CPRD)
Authors: Rebordosa Cristina , Plana Estel , Aguado Jaume , Thomas Steven , García-Gil Esther , Perez‐Gutthann Susana , Castellsague Jordi
Published: May 2018

Purpose

To evaluate availability of spirometry and symptom data in the Clinical Practice Research Datalink (United Kingdom) to assess COPD severity using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2016 definition and comparing it with an algorithm used in other studies.

Methods

This was a descriptive, noninterventional, secondary database cohort study of patients with COPD aged 40 years or older, who initiated treatment with specific COPD medications. Patients were classified according to COPD severity (1) in GOLD 2016 “ABCD” categories based on symptoms (Medical Research Council dyspnea grade, COPD Assessment Test, breathlessness), percent predicted FEV1, and exacerbation history and (2) as mild, moderate, severe, or very severe based on treatment and exacerbation history.

Results

The study included 63 900 patients with COPD aged 40 years or older that were new users of 1 or more COPD medication of interest. Percent predicted FEV1 was available for 80.9% of patients; symptoms for 75.6% of patients. Classification into GOLD 2016 ABCD categories was possible for 75.6% of the patients. The GOLD 2016 ABCD definition classified more patients under the high‐risk categories (22.1%, A; 18.8%, B; 21.3%, C; 37.9%, D) than did the adapted algorithm (7.9%, mild; 48.6%, moderate; 42.1%, severe; 1.4%, very severe).

Conclusion

Using our adaptation of the GOLD 2016 COPD severity classification, the information in the Clinical Practice Research Datalink allowed us to ascertain COPD severity in approximately 75% of patients with COPD. Algorithms that include medication use tend to misclassify patients with the extreme COPD severity categories.
Selective Enrichment of Polydopamine in Mesoporous Nanocarriers for Nuclear‐Targeted Drug Delivery
Authors: Guan Haidi , Wang Liucan , Zhang Jixi , Xing Yuxin , Cai Kaiyong
Published: May 2018

Small particle size and strong host–guest interactions are prerequisites in the field of nuclear‐targeting nanocarriers for overcoming the multidrug resistance of cancer cells. A novel scheme of synthesizing hybrid organic–inorganic nanocarriers with mesopores is introduced to enhance the delivery efficiency of therapeutic drugs. Specifically, inorganic silica and organic polydopamine (PDA) are integrated inside the pore framework by the assistance of organic silanes terminated by amino/thiol groups. Silica‐etching by hydrothermal treatment leads to the selective enrichment of bioadhesive PDA and size reductions for the hybrids (to ≈30 nm). Interestingly, a high drug loading capacity (523 µg mg−1 for doxorubicin hydrochloride), as well as pH/ glutathione dual‐responsive drug release properties, are realized by the nanocarriers, owing to their high surface area (825 m2 g−1) and the π‐stacking and/or hydrophobic–hydrophobic interactions stemming from PDA. More importantly, the conjugation of TAT peptide facilitates the intranuclear localization of the nanocarriers and the release of the encapsulated drugs directly within the nucleoplasm of the multidrug resistant MCF‐7/ADR cancer cells. Therefore, these results provide a controllable method of engineering high‐surface‐area nanocarriers with bioadhesive polymers on the pore surface for advanced drug delivery applications.
Robust Fabrication of Quantum Dots on Few‐Layer MoS2 by Soft Hydrogen Plasma and Post‐Annealing
Authors: Cai Di , Xiao Shaoqing , Nan Haiyan , Gu Xiaofeng , Ostrikov Kostya (Ken)
Published: May 2018

Apart from unique properties of layered transition‐metal dichalcogenide nanosheets like MoS2, quantum dots (QDs) from these layered materials promise novel science and applications due to their quantum confinement effect. However, the reported fabrication techniques for such QDs all involve the use of liquid organic solvents and the final material extraction from such liquid dispersions. Here a novel and convenient dry method for the synthesis of MoS2 quantum dots interspersed on few‐layer MoS2 using soft hydrogen plasma treatment followed by post‐annealing is demonstrated. The size of MoS2 nanodots can be well controlled by adjusting the working pressure of hydrogen plasma and post‐thermal annealing. This method relies on the cumulative hydrogen ion bombardment effect which can destroy the hexagonal structure of the top MoS2 layer and disintegrate the top layer into MoS2 nanodots and even QDs. Post‐thermal annealing can further reduce the size. Such MoS2 quantum dots interspersed on few‐layer MoS2 exhibit two new photoluminescence peaks at around 575 nm because of the quantum confinement effect. This dry method is versatile, scalable, and compatible with the semiconductor manufacturing processes, and can be extended to other layered materials for applications in hydrogen evolution reaction, catalysis, and energy devices.
Prediction of the in vitro developmental competence of early‐cleavage‐stage human embryos with time‐lapse imaging and oxygen consumption rate measurement
Authors: Goto Kaori , Kumasako Yoko , Koike Megumi , Kanda Akiko , Kido Kyoko , Nagaki Miyuki , Otsu Eiko , Kawabe Fumiko , Kai Yufuko , Utsunomiya Takafumi
Published: May 2018

Purpose

To assess an embryo's ability to develop into a good‐quality blastocyst during the early‐cleavage stage using time‐lapse imaging and the oxygen consumption rate.

Methods

In total, 942 zygotes had their oxygen consumption rates measured. In total, 282 zygotes were assessed by using time‐lapse imaging. In total, 121 zygotes were examined by using both their oxygen consumption rate and time‐lapse imaging.

Results

The embryos with moderate respiration rates of between 0.41 and 0.61 (×1014/mol s−1) on day 3 had a 22.1% chance of becoming good‐quality blastocysts; those outside that range had a 14.3% chance. With the time‐lapse system, when the first division was within 24 hours, 22.3% of the embryos grew to good blastocysts. After 24 hours, the rate dropped to 8.6%. The intervals between two consecutive cleavages were calculated and the duration of the second cell cycle was defined. When the time was between nine hours and 13 hours, there was a higher rate of good blastocysts. Regarding both criteria, when the embryos had progressed in the optimal range, a high percentage of them had become good blastocysts; it was 8.0% outside of that range.

Conclusion

Individual embryos with the potential to develop into good‐quality blastocysts could be selected at day 3 of culture using these systems.
Synthesis and analysis of robust control compensators for Space descent & landing
Authors: Simplício P. , Marcos A. , Joffre E. , Zamaro M. , Silva N.
Published: May 2018

In this article, a complete modelling, synthesis, and analysis methodology of control compensators for descent and landing (D&L) on small planetary bodies is presented. These missions are scientifically very rewarding but technically extremely challenging due to the complex and poorly known environment around those bodies, which calls for the ability to manage competing robustness and performance requirements. While this issue is typically addressed via the redefinition of D&L guidance strategies, here, it is tackled through the augmentation with a simple yet robust control compensator. This compensator is designed using linear fractional transformation modelling to capture the interplay with uncertain gravity fields and the recently developed structured
optimisation framework, which has been proved particularly suitable for industry‐oriented applications. The proposed approach is completely generic but uses the scenario of a landing on the Martian moon Phobos as an illustrative example. Different compensators are then verified and compared analytically via the structured singular value μ and through high‐fidelity Monte Carlo simulation.
Synchronization in a network of identical continuous‐ or discrete‐time agents with unknown nonuniform constant input delay
Authors: Zhang Meirong , Saberi Ali , Stoorvogel Anton A.
Published: May 2018

This paper studies the synchronization problem for multiagent systems with identical continuous‐ or discrete‐time agents with unknown nonuniform constant input delays. The agents are connected via full‐ or partial‐state coupling. The agents are assumed to be asymptotically null controllable, ie, all eigenvalues are in the closed left‐half complex plane for continuous‐time agents or in the closed unit disc for discrete‐time agents. We derive an upper bound for the input delay tolerance, which explicitly depends on the agent dynamics. Moreover, for any unknown delay satisfying this upper bound, a low‐gain–based protocol design methodology is proposed without relying on exact knowledge of the network topology such that synchronization is achieved among agents for any network graph in a given set.
Enhancing antireflection property of silicon through direct picosecond laser surface texturing
Authors: Sarath Raghavendra Babu K. E. , Duraiselvam Muthukannan , Manikanta Reddy L.
Published: May 2018

Crystalline silicon was laser surface textured by picosecond pulsed laser to enhance its antireflection property. The influence of laser scan speed and number of passes in fabricating the uniform surface microtexture were evaluated. Surface texture so generated was investigated and a grid of spherical domes and cavities, with nanoripples in the order of incident laser wavelength spread over it was observed. Reflectivity of bare silicon was greater than 40% and was significantly reduced well below 2% upon laser texturing, over a wavelength range of 400 to 700 nm. Antireflecting surface is an essential requirement for more efficient performance of devices for optical and photovoltaic application.
Quantitative Proteomics Study Reveals Changes in the Molecular Landscape of Human Embryonic Stem Cells with Impaired Stem Cell Differentiation upon Exposure to Titanium Dioxide Nanoparticles
Authors: Pan Lei , Lee Yew Mun , Lim Teck Kwang , Lin Qingsong , Xu Xiuqin
Published: May 2018

The increasing number of nanoparticles (NPs) being used in various industries has led to growing concerns of potential hazards that NP exposure can incur on human health. However, its global effects on humans and the underlying mechanisms are not systemically studied. Human embryonic stem cells (hESCs), with the ability to differentiate to any cell types, provide a unique system to assess cellular, developmental, and functional toxicity in vitro within a single system highly relevant to human physiology. Here, the quantitative proteomics approach is adopted to evaluate the molecular consequences of titanium dioxide NPs (TiO2 NPs) exposure in hESCs. The study identifies ≈328 unique proteins significantly affected by TiO2 NPs exposure. Proteomics analysis highlights that TiO2 NPs can induce DNA damage, elevated oxidative stress, apoptotic responses, and cellular differentiation. Furthermore, in vivo analysis demonstrates remarkable reduction in the ability of hESCs in teratoma formation after TiO2 NPs exposure, suggesting impaired pluripotency. Subsequently, it is found that TiO2 NPs can disrupt hESC mesoderm differentiation into cardiomyocytes. The study unveils comprehensive changes in the molecular landscape of hESCs by TiO2 NPs and identifies the impact which TiO2 NPs can have on the pluripotency and differentiation properties of human stem cells.
Synthesis and Characterization of Chemically‐Modified Cassava Starch Grafted with Poly(2‐Ethylhexyl Acrylate) for Blending with Poly(Lactic Acid)
Authors: Bunkerd Ratthaphat , Molloy Robert , Somsunan Runglawan , Punyodom Winita , Topham Paul D. , Tighe Brian J.
Published: May 2018

Native cassava starch (CS) is chemically modified by grafting with 2‐ethylhexyl acrylate (EHA) monomer to make it more hydrophobic for improved blending with poly(lactic acid) (PLA). Grafting is carried out using CS:EHA weight ratios of 2:1, 1:1, 1:2, and 1:3 in a methanol‐water solvent mixture at 45 °C for 48 h. L‐Ascorbic acid and hydrogen peroxide are used as the redox initiating system. Following purification, the poly(2‐ethylhexyl acrylate)‐grafted starch, starch‐g‐PEHA, is obtained either as a finely divided powder or as a slightly tacky solid with % grafting values in the range of 13–26% by weight. The main objective of this chemical modification is to improve the interfacial adhesion between the starch particles and the PLA matrix through the hydrophobic PLA‐PEHA interactions. PLA/starch‐g‐PEHA blends are prepared in the form of solution‐cast films with weight ratios ranging from 100/0 to 60/40. Tensile testing of the films shows a marked increase in extensibility and toughness up to a loading of 10% starch‐g‐PEHA above which the properties deteriorated rapidly due to starch particle aggregation. Thus, for potential use as biodegradable film packaging, the best properties are obtained for the PLA/starch‐g‐PEHA 90/10 blend.
Model‐based systems engineering: Motivation, current status, and research opportunities
Authors: Madni Azad M. , Sievers Michael
Published: May 2018

As systems continue to grow in scale and complexity, the Systems Engineering community has turned to Model‐Based Systems Engineering (MBSE) to manage complexity, maintain consistency, and assure traceability during system development. It is different from “engineering with models,” which has been a common practice in the engineering profession for decades. MBSE is a holistic, systems engineering approach centered on the evolving system model, which serves as the “sole source of truth” about the system. It comprises system specification, design, validation, and configuration management. Even though MBSE is beginning to see a fair amount of use in multiple industries, specific advances are needed on multiple fronts to realize its full benefits. This paper discusses the motivation for MBSE, and its current state of maturity. It presents systems modeling methodologies and the role of ontologies and metamodels in MBSE. It presents model‐based verification and validation (V&V) as an example of MBSE use. An illustrative example of the use of MBSE for design synthesis is presented to demonstrate an important MBSE capability. The paper concludes with a discussion of challenges to widescale adoption and offers promising research directions to fully realize the potential benefits of MBSE.
Electrochemical Proton Reduction Catalyzed by [Fe2(CO)6{μ‐(TeCH2Te)}] Model that Mimics the Structure of the Active Site of [FeFe]‐Hydrogenase
Authors: Abul‐Futouh Hassan , Görls Helmar , Weigand Wolfgang
Published: May 2018

In this report we discuss the synthesis of [Fe2(CO)6{μ‐(TeCH2Te)}] (2) using Fe3(CO)12 and Me2Sn(CH2I)2 in the presence of potassium tellurocyanate, freshly prepared. The resulting complex was characterized by different spectroscopic methods (1H, 13C{1H} and 125Te{1H} NMR) as well as X‐ray diffraction analysis. Moreover, we investigate the redox properties and the catalytic behavior of 2 in the presence of weak and moderate acids, acetic acid (AcOH) and trifluoracetic acid (TFA), respectively, as a source of protons.
Frustrated Lewis Pair based on a peri‐Substituted Biphenylene Scaffold
Authors: Kutter Felix , Lork Enno , Beckmann Jens
Published: May 2018

Starting from 1,8‐dibromo‐biphenylene, [1‐(bromo)biphenylen‐8‐yl]diphenylphosphine (1) and [1‐(diphenylphosphanyl)biphenylen‐8‐yl]dimesitylborane (2) were prepared by sequential metal / halide exchange and salt metathesis reactions. The phosphinoborane 2 comprises a frustrated Lewis pair (FLP) mounted on a peri‐substituted biphenylene scaffold with a P···B distance of 4.100(3) Å. Attempts to capture dihydrogen and carbon dioxide failed, presumably due to the insufficient Lewis acidity of the dimesityl borane group. Compounds 1 and 2 were characterized by heteronuclear NMR spectroscopy and X‐ray crystallography.
Uniqueness of $$ \mathcal{N} $$ = 2 and 3 pure supergravities in 4D
Authors: Boulanger Nicolas , Julia Bernard , Traina Lucas
Published: May 2018

Abstract

After proving the impossibility of consistent non-minimal coupling of a real Rarita-Schwinger gauge field to electromagnetism, we re-derive the necessity of introducing the graviton in order to couple a complex Rarita-Schwinger gauge field to electromagnetism, with or without a cosmological term, thereby obtaining

$$ \mathcal{N} $$

N

= 2 pure supergravity as the only possibility. These results are obtained with the BRST-BV deformation method around the flat and (A)dS backgrounds in 4 dimensions. The same method applied to n

v
vectors,

$$ \mathcal{N} $$

N

real spin-3/2 gauge fields and at most one real spinor field also requires gravity and yields

$$ \mathcal{N} $$

N

= 3 pure supergravity as well as

$$ \mathcal{N} $$

N

= 1 pure supergravity coupled to a vector supermultiplet, with or without cosmological terms. Independently of the matter content, we finally derive strong necessary quadratic constraints on the possible gaugings for an arbitrary number of spin-1 and spin-3/2 gauge fields, that are relevant for larger supergravities.
Diphoton production at the LHC: a QCD study up to NNLO
Authors: Catani Stefano , Cieri Leandro , de Florian Daniel , Ferrera Giancarlo , Grazzini Massimiliano
Published: May 2018

Abstract

We consider the production of prompt-photon pairs at the LHC and we report on a study of QCD radiative corrections up to the next-to-next-to-leading order (NNLO). We present a detailed comparison of next-to-leading order (NLO) results obtained within the standard and smooth cone isolation criteria, by studying the dependence on the isolation parameters. We highlight the role of different partonic subprocesses within the two isolation criteria, and we show that they produce large radiative corrections for both criteria. Smooth cone isolation is a consistent procedure to compute QCD radiative corrections at NLO and beyond. If photon isolation is sufficiently tight, we show that the NLO results for the two isolation procedures are consistent with each other within their perturbative uncertainties. We then extend our study to NNLO by using smooth cone isolation. We discuss the impact of the NNLO corrections and the corresponding perturbative uncertainties for both fiducial cross sections and distributions, and we comment on the comparison with some LHC data. Throughout our study we remark on the main features that are produced by the kinematical selection cuts that are applied to the photons. In particular, we examine soft-gluon singularities that appear in the perturbative computations of the invariant mass distribution of the photon pair, the transverse-momentum spectra of the photons, and the fiducial cross section with asymmetric and symmetric photon transverse-momentum cuts, and we present their behaviour in analytic form.
Exact moments of the Sachdev-Ye-Kitaev model up to order 1/N2
Authors: García-García Antonio M. , Jia Yiyang , Verbaarschot Jacobus J. M.
Published: May 2018

Abstract

We analytically evaluate the moments of the spectral density of the q-body Sachdev-Ye-Kitaev (SYK) model, and obtain order 1/N
2 corrections for all moments, where N is the total number of Majorana fermions. To order 1/N, moments are given by those of the weight function of the Q-Hermite polynomials. Representing Wick contractions by rooted chord diagrams, we show that the 1/N
2 correction for each chord diagram is proportional to the number of triangular loops of the corresponding intersection graph, with an extra grading factor when q is odd. Therefore the problem of finding 1/N
2 corrections is mapped to a triangle counting problem. Since the total number of triangles is a purely graph-theoretic property, we can compute them for the q = 1 and q = 2 SYK models, where the exact moments can be obtained analytically using other methods, and therefore we have solved the moment problem for any q to 1/N
2 accuracy. The moments are then used to obtain the spectral density of the SYK model to order 1/N
2. We also obtain an exact analytical result for all contraction diagrams contributing to the moments, which can be evaluated up to eighth order. This shows that the Q-Hermite approximation is accurate even for small values of N.
On pp wave limit for η deformed superstrings
Authors: Roychowdhury Dibakar
Published: May 2018

Abstract

In this paper, based on the notion of plane wave string/gauge theory duality, we explore the pp wave limit associated with the bosonic sector of η deformed superstrings propagating in (AdS
5 × S
5)
η
. Our analysis reveals that in the presence of NS-NS and RR fluxes, the pp wave limit associated to full ABF background satisfies type IIB equations in its standard form. However, the beta functions as well as the string Hamiltonian start receiving non trivial curvature corrections as one starts probing beyond pp wave limit which thereby takes solutions away from the standard type IIB form. Furthermore, using uniform gauge, we also explore the BMN dynamics associated with short strings and compute the corresponding Hamiltonian density. Finally, we explore the Penrose limit associated with the HT background and compute the corresponding stringy spectrum for the bosonic sector.
Tinkertoys for the E7 theory
Authors: Chacaltana Oscar , Distler Jacques , Trimm Anderson , Zhu Yinan
Published: May 2018

Abstract

We classify the class S theories of type E
7. These are four-dimensional

$$ \mathcal{N}=2 $$

N
=
2

superconformal field theories arising from the compactification of the E
7 (2, 0) theory on a punctured Riemann surface, C. The classification is given by listing all 3-punctured spheres (“fixtures”), and connecting cylinders, which can arise in a pants-decomposition of C. We find exactly 11,000 fixtures with three regular punctures, and an additional 48 with one “irregular puncture” (in the sense used in our previous works). To organize this large number of theories, we have created a web application at https://golem.ph.utexas.edu/class-S/E7/. Among these theories, we find 10 new ones with a simple exceptional global symmetry group, as well as a new rank-2 SCFT and several new rank-3 SCFTs. As an application, we study the strong-coupling limit of the E
7 gauge theory with 3 hypermultiplets in the 56. Using our results, we also verify recent conjectures that the T
2 compactification of certain 6d (1, 0) theories can alternatively be realized in class S as fixtures in the E
7 or E
8 theories.
Bootstrapping hypercubic and hypertetrahedral theories in three dimensions
Authors: Stergiou Andreas
Published: May 2018

Abstract

There are three generalizations of the Platonic solids that exist in all dimensions, namely the hypertetrahedron, the hypercube, and the hyperoctahedron, with the latter two being dual. Conformal field theories with the associated symmetry groups as global symmetries can be argued to exist in d = 3 spacetime dimensions if the ε = 4 − d expansion is valid when ε → 1. In this paper hypercubic and hypertetrahedral theories are studied with the non-perturbative numerical conformal bootstrap. In the N = 3 cubic case it is found that a bound with a kink is saturated by a solution with properties that cannot be reconciled with the ε expansion of the cubic theory. Possible implications for cubic magnets and structural phase transitions are discussed. For the hypertetrahedral theory evidence is found that the non-conformal window that is seen with the ε expansion exists in d = 3 as well, and a rough estimate of its extent is given.
The Schwarzian theory — origins
Authors: Mertens Thomas G.
Published: May 2018

Abstract

In this paper we further study the 1d Schwarzian theory, the universal low-energy limit of Sachdev-Ye-Kitaev models, using the link with 2d Liouville theory. We provide a path-integral derivation of the structural link between both theories, and study the relation between 3d gravity, 2d Jackiw-Teitelboim gravity, 2d Liouville and the 1d Schwarzian. We then generalize the Schwarzian double-scaling limit to rational models, relevant for SYK-type models with internal symmetries. We identify the holographic gauge theory as a 2d BF theory and compute correlators of the holographically dual 1d particle-on-a-group action, decomposing these into diagrammatic building blocks, in a manner very similar to the Schwarzian theory.
Non-relativistic Maxwell Chern-Simons gravity
Authors: Avilés Luis , Frodden Ernesto , Gomis Joaquim , Hidalgo Diego , Zanelli Jorge
Published: May 2018

Abstract

We consider a non-relativistic (NR) limit of (2 + 1)-dimensional Maxwell Chern-Simons (CS) gravity with gauge algebra [Maxwell] ⊕u(1) ⊕u(1). We obtain a finite NR CS gravity with a degenerate invariant bilinear form. We find two ways out of this difficulty: to consider i) [Maxwell] ⊕u(1), which does not contain Extended Bargmann gravity (EBG); or, ii) the NR limit of [Maxwell] ⊕u(1)⊕u(1)⊕u(1), which is a Maxwellian generalization of the EBG.
F-theory models on K3 surfaces with various Mordell-Weil ranks — constructions that use quadratic base change of rational elliptic surfaces
Authors: Kimura Yusuke
Published: May 2018

Abstract

We constructed several families of elliptic K3 surfaces with Mordell-Weil groups of ranks from 1 to 4. We studied F-theory compactifications on these elliptic K3 surfaces times a K3 surface.

Gluing pairs of identical rational elliptic surfaces with nonzero Mordell-Weil ranks yields elliptic K3 surfaces, the Mordell-Weil groups of which have nonzero ranks. The sum of the ranks of the singularity type and the Mordell-Weil group of any rational elliptic surface with a global section is 8. By utilizing this property, families of rational elliptic surfaces with various nonzero Mordell-Weil ranks can be obtained by choosing appropriate singularity types. Gluing pairs of these rational elliptic surfaces yields families of elliptic K3 surfaces with various nonzero Mordell-Weil ranks.

We also determined the global structures of the gauge groups that arise in F-theory compactifications on the resulting K3 surfaces times a K3 surface. U(1) gauge fields arise in these compactifications.
Seeking fixed points in multiple coupling scalar theories in the ε expansion
Authors: Osborn Hugh , Stergiou Andreas
Published: May 2018

Abstract

Fixed points for scalar theories in 4 − ε, 6 − ε and 3 − ε dimensions are discussed. It is shown how a large range of known fixed points for the four dimensional case can be obtained by using a general framework with two couplings. The original maximal symmetry, O(N), is broken to various subgroups, both discrete and continuous. A similar discussion is applied to the six dimensional case. Perturbative applications of the a-theorem are used to help classify potential fixed points. At lowest order in the ε-expansion it is shown that at fixed points there is a lower bound for a which is saturated at bifurcation points.
Non-planar one-loop Parke-Taylor factors in the CHY approach for quadratic propagators
Authors: Ahmadiniaz Naser , Gomez Humberto , Lopez-Arcos Cristhiam
Published: May 2018

Abstract

In this work we have studied the Kleiss-Kuijf relations for the recently introduced Parke-Taylor factors at one-loop in the CHY approach, that reproduce quadratic Feynman propagators. By doing this, we were able to identify the non-planar one-loop Parke-Taylor factors. In order to check that, in fact, these new factors can describe non-planar amplitudes, we applied them to the bi-adjoint Φ3 theory. As a byproduct, we found a new type of graphs that we called the non-planar CHY-graphs. These graphs encode all the information for the subleading order at one-loop, and there is not an equivalent of these in the Feynman formalism.
Applications of RNA Indexes for Precision Oncology in Breast Cancer
Authors: Ma Liming , Liang Zirui , Zhou Hui , Qu Lianghu
Published: May 2018

Precision oncology aims to offer the most appropriate treatments to cancer patients mainly based on their individual genetic information. Genomics has provided numerous valuable data on driver mutations and risk loci; however, it remains a formidable challenge to transform these data into therapeutic agents. Transcriptomics describes the multifarious expression patterns of both mRNAs and non-coding RNAs (ncRNAs), which facilitates the deciphering of genomic codes. In this review, we take breast cancer as an example to demonstrate the applications of these rich RNA resources in precision medicine exploration. These include the use of mRNA profiles in triple-negative breast cancer (TNBC) subtyping to inform corresponding candidate targeted therapies; current advancements and achievements of high-throughput RNA interference (RNAi) screening technologies in breast cancer; and microRNAs as functional signatures for defining cell identities and regulating the biological activities of breast cancer cells. We summarize the benefits of transcriptomic analyses in breast cancer management and propose that unscrambling the core signaling networks of cancer may be an important task of multiple-omic data integration for precision oncology.
Cognitive Outcomes After Anterior Communicating Artery Aneurysm Repair
Authors: Nassiri Farshad , Workewych Adriana M. , Badhiwala Jetan H. , Cusimano Michael D.
Published: May 2018

Background The long-term cognitive and quality-of-life (QoL) outcomes after treatment of ruptured anterior communicating artery (ACoA) aneurysms are unknown. Methods Potential participants were all consecutive patients with ruptured ACoA aneurysms who were treated at one institution from July 1992 to December 2008. All potential participants were asked to complete the Cognitive Failures Questionnaire (CFQ), Center for Epidemiology Studies-Depression (CES-D) questionnaire, Short Form 36 (SF-36) questionnaire, and Telephone Interview for Cognitive Status-Modified (TICS-M). Patient charts were retrospectively reviewed for baseline demographics and clinical status, intra-operative details, and post-operative course. Reporting of cognitive and QoL assessment results was stratified by treatment method (endovascular coil embolization and surgical clipping by pterional craniotomy or orbitocranial craniotomy). Results In total, 82 patients (18 treated with coiling, 27 by orbitocranial craniotomy, and 37 by pterional craniotomy) were included in this study. In total, 32 patients (9 treated by coiling, 11 by orbitocranial craniotomy, and 16 by pterional craniotomy) completed follow-up cognitive and QoL questionnaires. The mean follow-up for patients who completed the questionnaires was 8.64±3.81 years. The three groups did not differ in questionnaires assessing cognitive status (TICS-M p=0.114, CFQ p=0.111). Moreover, there were no observed differences in QoL or depression scores between the three groups. Conclusions At long-term follow-up, QoL, cognitive, and depression test scores of patients with ruptured ACoA aneurysms are similar across open surgery and coiling modalities. Our results emphasize the importance of considering long-term outcomes with validated daily measures of functioning when reporting on outcomes after treatment for ruptured intracranial aneurysms. Larger prospective studies are required to further explore the results.
Continuing clozapine treatment after a diagnosis of cardiomyopathy
Authors: Williams F. , Lenihan F. , Rowe A.
Published: May 2018

A patient in a medium secure psychiatric unit with a 19-year history of treatment-resistant schizophrenia and violence whose mental illness only responded to clozapine, was noted to have a sustained tachycardia. Echocardiography revealed mild biventricular cardiomyopathy. The patient was not significantly affected by this. Initial recommendation from Cardiology was to consider discontinuation of clozapine. It was decided, however, that the risk of worsening psychosis and resultant violence outweighed the risk of the patient’s relatively mild cardiomyopathy. The patient was commenced on ramipril, and later bisoprolol. The patient no longer requires treatment in a medium secure unit and has remained on clozapine with follow-up from cardiology.
Models of internal jumps and the fronts of gravity currents: unifying two-layer theories and deriving new results
Authors: Ungarish Marius , Hogg Andrew J.
Published: May 2018

The steady speeds of the front of a gravity current and of an internal jump on a two-layer stratification are often sought in terms of the heights of the relatively dense fluid both up- and downstream from the front or jump, the height of the channel within which they flow, the densities of the two fluids and gravitational acceleration. In this study a unifying framework is presented for calculating the speeds by balancing mass and momentum fluxes across a control volume spanning the front or jump and by ensuring the assumed pressure field is single-valued, which is shown to be equivalent to forming a vorticity balance over the control volume. Previous models have assumed the velocity field is piecewise constant in each layer with a vortex sheet at their interface and invoked explicit or implicit closure assumptions about the dissipative effects to derive the speed. The new formulation yields all of the previously presented expressions and demonstrates that analysing the vorticity balance within the control volume is a useful means of constraining possible closure assumptions, which is arguably more effective than consideration of the flow energetics. However the new approach also reveals that a novel class of models may be developed in which there is shear in the velocity field in the wake downstream of the front or the jump, thus spreading the vorticity over a layer of non-vanishing thickness, rather than concentrating it into a vortex sheet. Mass, momentum and vorticity balances applied over the control volume allow the thickness of the wake and the speed of the front/jump to be evaluated. Results from this vortex-wake model are consistent with published numerical simulations and with data from laboratory experiments, and improve upon predictions from previous formulae. The results may be applied readily to Boussinesq and non-Boussinesq systems and because they arise as simple algebraic expressions, can be straightforwardly incorporated as jump conditions into spatially and temporally varying descriptions of the motion.
On the deflection of a liquid jet by an air-cushioning layer
Authors: Moore Madeleine Rose , Whiteley J. P. , Oliver J. M.
Published: May 2018

A hierarchy of models is formulated for the deflection of a thin two-dimensional liquid jet as it passes over a thin air-cushioning layer above a rigid flat impermeable substrate. We perform a systematic derivation of the leading-order equations of motion for the jet in the distinguished limit in which the air pressure jump, surface tension and gravity affect the displacement of the centreline of the jet, but not its thickness or velocity. We identify thereby the axial length scales for centreline deflection in regimes in which the air layer is dominated by viscous or inertial effects. The derived length scales and reduced equations aim to expand the suite of tools available for future analyses of the evolution of lamellae and ejecta in impact problems. Assuming that the jet is sufficiently long that tip and entry effects can be neglected, we demonstrate that the centreline of a constant-thickness jet moving with constant axial speed is destabilised by the air layer for sufficiently small surface tension. Expressions for the fastest-growing modes are obtained in both the viscous-dominated air and inertia-dominated air regimes. For a finite-length jet emanating from a nozzle, we show that, in one particular asymptotic limit, the evolution of the jet centreline is akin to the flapping of an unfurling flag above a thin air layer. We discuss the distinguished limit in which tip retraction can be neglected and perform numerical investigations into the resulting model. We show that the cushioning layer causes the jet centreline to bend, leading to rupture of the air layer. We discuss how our toolbox of models can be adapted and utilised in the context of recent experimental and numerical studies of splash dynamics.
The European Paromomyidae (Primates, Mammalia): taxonomy, phylogeny, and biogeographic implications
Authors: López-Torres Sergi , Silcox Mary T.
Published: May 2018

Plesiadapiforms represent the first radiation of Primates, appearing near the Cretaceous-Paleogene boundary. Eleven families of plesiadapiforms are recognized, including the Paromomyidae. Four species of paromomyids from the early Eocene have been reported from Europe:Arcius fuscusRussell et al., 1967,Arcius lapparentiRussell et al., 1967, andArcius rougieriGodinot, 1984 from France andArcius zbyszewskiiEstravís, 2000 from Portugal. OtherArciusspecimens from the early Eocene are known from Masia de l’Hereuet (Spain), Abbey Wood (England), and Sotteville-sur-Mer (Normandy, France). A cladistic analysis of the European paromomyids has never previously been published. A total of 53 dental characters were analyzed for the fourArciusspecies and the specimens from Spain, England, and Normandy. The results of a parsimony analysis using TNT agree with previous conceptions ofA. zbyszewskiias the most primitive member of the genus. Consistent with existing hypotheses,Arcius rougieriis positioned as the sister taxon ofA. fuscusandA. lapparenti, and the results suggest that the fossil from Normandy isA. zbyszewskii. However, the English fossil pertains to a primitive lineage, rather than grouping withA. lapparentias had been suggested; as such it is recognized here as a distinct species (Arcius hookerinew species). The Spanish fossils cluster together with the French species but do not show the previously proposed special relationship withA. lapparentiand are sufficiently distinct to be placed in a new species (Arcius ilerdensis).Arciusis recovered as monophyletic, which is consistent with a single migration event from North America to Europe around the earliest Eocene through the Greenland land bridge.

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