bluuebunny/crossref_metadata_2025 huggingface dataset:
Pyrenyl Carbon Nanotubes for Covalent Bilirubin Oxidase Biocathode Design: Should the Nanotubes be Carboxylated?
Authors: Dharmaratne Asantha C. , Moulton James T. , Niroula Jinesh , Walgama Charuksha , Mazumder Suman , Mohanty Smita , Krishnan Sadagopan
Published: December 2019

Understanding the characteristics of nanomaterials in the context of electrode designs for bio‐electrocatalysis is an emerging research direction. Applications for fuel cells, batteries, and biosensors are directly benefited. The objective of this study is to understand the influence of unfunctionalized multiwalled carbon nanotubes (MWNT) in comparison to carboxylated nanotubes (MWNT−COOH) for pi‐pi stacking with 1‐pyrenebutyric acid (Py) and covalent immobilization of bilirubin oxidase (BOD) enzyme toward the resulting oxygen reduction currents. We designed pyrolytic graphite‐edge electrodes modified with MWNT/Py, MWNT−COOH/Py, or only MWNT−COOH for carbodiimide activation and BOD immobilization. The relative increase in surface −COOH groups as we move from MWNT to MWNT/Py to MWNT−COOH/Py modification is voltammetrically estimated. Although the MWNT−COOH/Py displayed the highest relative amount of surface −COOH groups, the oxygen reduction current was the largest for the BOD‐immobilized MWNT/Py electrode than others. Results indicate that unfunctionalized MWNT is the optimal choice for pi‐pi stacking with pyrene linkers and covalent BOD immobilization as biocathode for energy devices. Favorable hydrophobic MWNT surface to interact more closely with the electron‐receiving T1 Cu site of BOD, as opposed to the relatively polar and more defective MWNT−COOH material due to functionalization, is suggested to be one of the underlying factors for the observed electrocatalytic trend.
Experimental validation of using frequency response analysis method in measuring interwinding capacitance of power transformers
Authors: Arumugam Saravanakumar
Published: December 2019

The interwinding capacitance of transformers describes the diagnostic status of winding‐insulation and its geometry. Naturally, there is a constant drive in improvising the existing methods and to attain accurate information while measuring interwinding capacitance of a transformer. In this regard, frequency response analysis method is increasingly used in measuring the interwinding capacitance of transformers. The primary reason for applying this method is to establish a faster evaluation method for diagnosing the status of the winding‐insulation through the interwinding capacitances. However, the pertinent measurement procedures are inadequate as they tend to resolve the interwinding capacitances along with the electromagnetic influence of winding‐core assembly, thus making it difficult to diagnose the status of the winding‐insulation. This intricacy could be overcome by making an optimal choice of terminal configuration, that is, a combination of terminal connection, system function, mode of excitation that would minimize the electromagnetic influence of winding‐core in their respective spectra. In this context, the theoretical aspects of making an optimal choice of terminal configuration have already been investigated, and the suitability of the same on actual in‐service power and distribution transformers needs to be validated. This forms the primary focus of this article. A rigorous and systematic experimental study is adapted to verify the existing findings and validate the same on larger power and distribution transformers. After verification, the proposed method may be identified as sensitive in determining the interwinding capacitance of transformers and further recommended during frequency response measurements.
Solution property preserving reconstruction for finite volume scheme: a boundary variation diminishing+multidimensional optimal order detection framework
Authors: Tann Siengdy , Deng Xi , Shimizu Yuya , Loubère Raphaël , Xiao Feng
Published: December 2019

The purpose of this work is to build a general framework to reconstruct the underlying fields within a finite volume (FV) scheme solving a hyperbolic system of PDEs (Partial Differential Equations). In an FV context, the data are piecewise constants per computational cell and the physical fields are reconstructed taking into account neighbor cell values. These reconstructions are further used to evaluate the physical states usually used to feed a Riemann solver which computes the associated numerical fluxes. The physical field reconstructions must obey some properties linked to the system of PDEs such as the positivity, but also some numerically based ones, like an essentially nonoscillatory behavior. Moreover, the reconstructions should be highly accurate for smooth flows and robust/stable for discontinuous solutions. To ensure a solution property preserving reconstruction, we introduce a methodology to blend high‐/low‐order polynomials and hyperbolic tangent reconstructions. A boundary variation diminishing algorithm is employed to select the best reconstruction in each cell. An a posteriori MOOD detection procedure is employed to ensure the positivity by recomputing the rare problematic cells using a robust first‐order FV scheme. We illustrate the performance of the proposed scheme via the numerical simulations for some benchmark tests which involve vacuum or near vacuum states, strong discontinuities, and also smooth flows. The proposed scheme maintains high accuracy on smooth profile, preserves the positivity and can eliminate the oscillations in the vicinity of discontinuities while maintaining sharper discontinuity with superior solution quality compared to classical highly accurate FV schemes.
Changes in chemical composition and biological activity of essential oil from Thomson navel orange (Citrus sinensis L. Osbeck) peel under freezing, convective, vacuum, and microwave drying methods
Authors: Farahmandfar Reza , Tirgarian Behraad , Dehghan Bahare , Nemati Azeeta
Published: December 2019

Thomson navel orange peel is a by‐product of citrus processing, which contains high levels of bioactive compounds advantageous to human health, nevertheless due to its high moisture content it is exceedingly perishable. Drying is among the most common preservation methods, which could prolong the plants shelf‐life via reducing their moisture value. Taking this into account, depending on their type and conditions, drying techniques could degrade plant heat‐sensitive metabolites and lead to quality decline. Therefore, the goal of this paper was to investigate the influence of seven drying methods named sun, shade, oven, vacuum oven, microwave, and freeze‐drying with different drying conditions on the physical properties, for example, bulk density and color (L*, a*, b*, ΔE, and browning index (BI)) and essential oil characteristics such as extraction yield, chemical composition, antioxidant (total phenolic content (TPC), DPPH, and FRAP essays), and antimicrobial (MIC and MBC) activities of Thomson peel and determine the superior drying procedure. Results showed that freeze‐dried sample had the highest retention of L* (48.54) and b* (49.00) values, lowest BI (216.11) as well as highest EO extraction yield (6.90%), TPC (60.10 GAE/100 g), FRAP (0.52% at 80 mg/ml), and lowest IC50 (5.00 mg/ml), MIC and MBC compared with other drying treatments. Therefore, it could be inferred that freeze‐drying is the most efficient drying approach in respect of preserving both physical and EO attributes of Thomson peel.
The determinants of performance in the Eurozone banking sector: Core versus periphery Eurozone economies
Authors: Agoraki Maria‐Eleni K. , Kouretas Georgios P. , Tsamis Anastassios
Published: December 2019

In the present study we provide a thorough analysis of the effects that a group of bank‐specific as well as industry‐specific determinants along with the regulatory framework developed under the three pillars of Basel II agreement (capital stringency, official disciplinary power and private monitoring) have on the performance of Eurozone banking sector over the period 2007–2016. To this end, we conduct a systematic comparative analysis of the determinants of the performance of the banking sector in periphery Eurozone countries (Greece, Italy, Portugal, Spain) versus banks operating in core Eurozone economies (Germany, France). We provide evidence that is consistent with the argument that banks financed with short‐run capital market funding are more fragile. A further finding of our analysis shows that banks operating in countries which have a more restrictive regulatory framework on banking activities perform better. In addition, it is shown that the better‐performing banks have more equity. Finally, the estimation of the appropriate dynamic models we argue that bank performance is affected by bank‐specific determinants like equity capital and bank size, while the regulatory framework as well as macroeconomic variables play a crucial role.
Response of stream fungi on decomposing leaves to experimental drying
Authors: Niyogi Dev K. , Hu Chia‐Yi , Vessell Brett P.
Published: December 2019

Climate change may lead to increased droughts in the future, which in turn may lead to increased periods of stream drying. We conducted an experiment to test the effects of drying on fungal communities and microbial activity on decaying leaves from a stream. Our experimental setup included immersion of maple leaf cores for 2 weeks in a small stream to allow for the colonization of microbes. Leaves were then subjected for 2 weeks to four treatments: one control, where leaves stayed immersed in the stream, and three drying treatments in different settings (field, lab, and oven). Leaves were then returned to sterile water for 2 weeks of recovery. Microbial respiration declined after all drying treatments compared to the control, with the oven‐dried leaves taking the longest time to recover. All drying treatments had similar respiration to each other and the control after 2 weeks of immersion recovery. Fungal communities on the leaves were assessed by polymerase chain reaction amplification of fungal DNA from leaves followed by denaturing gradient gel electrophoresis (DGGE). Most treatments had very similar communities based on phylotypes from DGGE, with little change during drying and recovery compared to immersion controls. However, the oven‐dried leaves had a very different community developing during recovery. There were no differences in diversity or richness of DGGE phylotypes among treatments after recovery. Overall, the fungal communities, in our experiment, appeared resilient to the effects of short‐term drying, with little change to community structure and relatively fast recovery in activity after rewetting.
The glycolytic shift was involved in CdTe/ZnS quantum dots inducing microglial activation mediated through the mTOR signaling pathway
Authors: Wu Tianshu , He Keyu , Liang Xue , Wei Tingting , Wang Yan , Zou Lingyue , Zhang Ting , Xue Yuying , Tang Meng
Published: December 2019

The excellent optical property and relatively low toxicity of CdTe/ZnS core/shell quantum dots (QDs) make them an advanced fluorescent probe in the application of biomedicines, particularly in neuroscience. Thus, it is important to evaluate the biosafety of CdTe/ZnS QDs on the central nervous system (CNS). Our previous studies have suggested that the high possibility of CdTe/ZnS QDs being transported into the brain across the blood‐brain barrier resulted in microglial activation and a shift of glycometabolism, but their underlying mechanism remains unclear. In this study, when mice were injected intravenously with CdTe/ZnS QDs through tail veins, the microglial activation, polarized into both M1 phenotype and M2 phenotype, and the neuronal impairment were observed in the hippocampus. Meanwhile, the increased pro‐ and anti‐inflammatory cytokines released from BV2 microglial cells treated with CdTe/ZnS QDs also indicated that QD exposure was capable of inducing microglial activation in vitro. We further demonstrated that the glycolytic shift from oxidative phosphorylation switching into aerobic glycolysis was required in the microglial activation into M1 phenotype induced by CdTe/ZnS QD treatment, which was mediated through the mTOR signaling pathway. The findings, taken together, provide a mechanistic insight regarding the CdTe/ZnS QDs inducing microglial activation and the role of the glycolytic shift in it.
COSMO‐RS based ionic liquid screening for the separation of acetonitrile and ethanol azeotropic mixture
Authors: Zhang Zhigang , Lu Ruizhe , Zhang Qinqin , Chen Jinling , Li Wenxiu
Published: December 2019

BACKGROUND

The selection of competent entrainer is very important for separating azeotrope systems by extractive distillation. Ionic liquids (ILs) are outstanding entrainers due to their excellent properties. However, it is time‐consuming to choose suitable ILs from the huge database of anions and cations. Herein, the selectivity and viscosity of ILs were combined as double standards to select suitable ILs for the separation of acetonitrile and ethanol mixture.

RESULTS

The selectivity and viscosity of 450 ILs (25 cations and 18 anions) were predicted based on Conductor‐like Screening Model for Real Solvents (COSMO‐RS). 1‐Butyl‐3‐methylimidazolium acetate [BMIM][Ac] was selected as a potential entrainer due to its higher selectivity and lower viscosity and [BMIM][Cl] was chosen as a comparison item as ILs with [Cl]− anion have separation performance next to [Ac]−‐based ILs. The vapor–liquid equilibrium (VLE) data of the acetonitrile + ethanol + ILs systems were determined at 101.3 kPa and correlated with the non‐random two‐liquid (NRTL) model. The result showed that the addition of the two ILs produced a salting‐out effect on acetonitrile and enhanced the relative volatility of acetonitrile to ethanol. Furthermore, [BMIM][Ac] exhibited better separation performance than [BMIM][Cl] and our previous reported ILs, which are consistent with the predicted results. The reduced density gradient (RDG) method indicated that hydrogen bonding dominated the interactions between ethanol and IL.

CONCLUSION

[BMIM][Ac] is a superior entrainer for the separation of acetonitrile–ethanol azeotrope. Compared to the previously studied ILs, there is a stronger hydrogen bond between ethanol and [BMIM][Ac]. This makes ethanol ‘bundled’ and acetonitrile more volatile, resulting in the superior separation performance of [BMIM][Ac]. © 2019 Society of Chemical Industry
Synthesis of novel heterocycles using 1,2,3‐triazole‐4‐carbohydrazides as precursors
Authors: Mohamed Hanan A. , Khidre Rizk E. , Kariuki Benson M. , El‐Hiti Gamal A.
Published: December 2019

Herein, we report the synthesis of various heterocyclic ring systems containing 1,2,3‐triazole from the reactions of acid hydrazides and commercially available reagents, using efficient and simple procedures. Reactions of certain 1,2,3‐triazole‐4‐carbohydrazides and α‐bromoketones in boiling ethanol afforded the corresponding hydrazones rather than the expected triazines. The hydrazones could also be synthesized in 85‐90% yield via an alternative pathway that involved the reaction of 1,2,3‐triazole‐4‐carbohydrazides and 4‐acetyl‐1,2,3‐triazoles in boiling ethanol containing glacial acetic acid. Reaction of one of the 4‐carbohydrazides with carbon disulfide, followed by the reaction with hydrazine hydrate, gave 4H‐1,2,4‐triazole‐3‐thiol in 73% yield, which further reacted with other α‐bromoketones in boiling ethanol to afford 7H‐[1,2,4]triazolo[3,4‐b][1,3,4]thiadiazines in 82‐84% yields. Additionally, reactions of certain carbohydrazides with ethyl 2‐cyano‐3,3‐bis(methylthio)acrylate gave 1‐aryl‐1H‐1,2,3‐triazole‐4‐carbohydrazides rather than the expected 1H‐pyrazole‐4‐carboxylates.
Two‐drug antiretroviral regimens: an assessment of virologic response and durability among treatment‐experienced persons living with HIV in the OPERA® Observational Database
Authors: Pierone Gerald , Henegar Cassidy , Fusco Jennifer , Vannappagari Vani , Aboud Michael , Ragone Leigh , Fusco Gregory
Published: December 2019

Introduction

Two‐drug regimens (2‐DR) have the potential to be a viable solution to the challenges of treatment complexity, cost, adverse effects and contraindications. We sought to describe the real‐world use and effectiveness of 2‐DR among persons living with HIV (PLHIV) in the United States.

Methods

We analysed data for 10,190 treatment‐experienced patients from the OPERA® Observational Database initiating a new 2‐DR or three‐drug regimen (3‐DR) between 1 January 2010 and 30 June 2016. Multivariate Cox Proportional Hazards models were used to estimate the association among 2‐DR or 3‐DR initiation and virologic suppression (viral load (VL) <50 copies/mL), virologic failure (2 VLs > 200 copies/mL or 1 VL > 200 copies/mL + discontinuation) or regimen discontinuation.

Results

Patients initiating a 2‐DR (n = 1337, 13%) were older, and more likely to have a lower CD4 count, a history of AIDS and comorbid conditions than patients initiating a 3‐DR. There was no difference between groups in time to virologic suppression (aHR: 1.00 (95% CI: 0.88, 1.13)) among viraemic patients (baseline VL ≥ 50 copies/mL, n = 4180), or time to virologic failure (aHR: 1.15 (95% CI: 0.90, 1.48)) among virologically stable patients (baseline VL < 50 copies/mL, n = 6010). However, time to discontinuation was shorter following 2‐DR than 3‐DR initiation (aHR: 1.51 (95% CI: 1.41, 1.61)).

Conclusions

In this large cohort of treatment‐experienced patients, 2‐DR prescriptions were common and more frequent among patients with significant comorbidity. Virologic response was similar, but duration of use was shorter with a 2‐DR than a 3‐DR, suggesting that 2‐DRs may be a virologically effective treatment strategy for treatment‐experienced PLHIV with existing comorbidities.
Dissecting the human immune system with single cell RNA sequencing technology
Authors: Xu Gang , Liu Yang , Li Hanjie , Liu Lei , Zhang Shuye , Zhang Zheng
Published: December 2019

Single-cell RNA sequencing (scRNA-seq) is a powerful new technology allowing the analysis of transcriptomes from individual cell and is ideally suited to dissect immune cell heterogeneity. ScRNA-seq has already been applied to identify novel immune cell subsets, elaborate cellular differentiation trajectories, and elucidate immunopathogenic mechanisms. Here, we briefly discuss the recent progresses and challenges in the scRNA-seq technology including the workflow, recent applications in immunology, and potential hurdles that need to be overcome. This review will highlight how single cell technology promotes our understanding of human immunology.
Bifurcation analysis for a fractional‐order chemotherapy model with two different delays
Authors: Xu Changjin , Li Peiluan , Liao Maoxin , Yuan Shuai
Published: December 2019

Cancer is one of the most serious diseases in the world. The investigation on cancer treatment has attracted great attention from medical workers, mathematical researchers, and scholars in various fields. To understand the intrinsic characteristics of cancer, numerous scholars have established cancer treatment models and discussed the dynamical properties. However, the main work of many scholars only focuses on the integer‐order cancer treatment models, while the study on fractional‐order ones is quite a few. In the present article, on the basis of previous publications, we will put up a new fractional‐order chemotherapy model with two different delays. By applying the stability theory and the Hopf bifurcation of fractional‐order differential equations, we obtain a series of new stability criteria of the involved model and some sufficient conditions to ensure the existence of Hopf bifurcation of the involved model. Furthermore, the impact of two different delays and the fractional order on the stability and the emergence of Hopf bifurcation of involved model is presented. To illustrate the validity of analytical predictions, we perform computer simulations with Matlab software. The theoretical results in the manuscript are innovative and play an important role in cancer treatment.
Two‐layer flows of generalized immiscible second grade fluids in a rectangular channel
Authors: Luo Liang , Shah Nehad Ali , Alarifi Ibrahim M. , Vieru Dumitru
Published: December 2019

Unsteady one‐dimensional flows of two incompressible and immiscible generalized second grade fluids in a rectangular channel are studied. A constant pressure gradient acts in the flow direction, while the channel walls have oscillating translational motions in their planes. The generalization considered in this paper consists into a mathematical model based on constitutive equations of second grade fluid with Caputo time‐fractional derivative in which the history of the shear stress influences the velocity gradient. The velocity and shear stress fields in the Laplace transform domain are obtained. Numerical solutions for the real velocity and shear stress have been found by employing the Stehfest numerical algorithm for the inverse Laplace transform. The influence of the fractional parameters on the velocity and shear stress has been studied by numerical simulations and graphical illustrations. It is found that the memory effects are significant only for small values of the time t.
Sibship Analysis to Characterize Alligator Gar Reproductive Contributions in Two Texas Systems
Authors: Kreiser Brian R. , Daugherty Daniel J. , Buckmeier David L. , Smith Nathan G. , Newsome Eleanor B.
Published: December 2019

We used sibship analysis to further our understanding of Alligator Gar Atractosteus spatula reproductive biology. Quantifying the relative contributions of spawners and spatial patterns of reproduction is important in making management decisions, especially with regard to long-lived, large-bodied fish like Alligator Gar, for which exploitation of large females may negatively impact recruitment. Using genetic data from age-0 fish, we estimated the effective number of breeders (Nb) and the number of spawning adults (NS) at multiple spatial and temporal scales in two Texas systems over a 2-year period. Analysis of 265 fish collected in 2015 from six sites within an approximately 3,000-ha floodplain wetland system on the Trinity River identified no full siblings or half siblings with a probability greater than 0.90. Estimates of Nb (24–30) and NS (21–33) were comparable among sites, with low levels of relatedness among individuals within sites. Analysis of an additional 136 age-0 Alligator Gar collected during 2015 from six other sites distributed over 275 river kilometers downstream of the wetland system revealed similar patterns. Age-0 fish collected in Choke Canyon Reservoir (N = 131) in 2015 also demonstrated close correspondence between estimates of Nb and NS (54 and 56, respectively). Age-0 Alligator Gar (N = 88) were again collected at three sites in the Trinity River system during 2016; results were comparable to those of the previous year, with no evidence of repeat spawning at each site. The similarities we observed between the estimated Nb and NS indicated little variance in the number of offspring produced among individual spawners. Because individual spawners appear to contribute somewhat equally to the year-classes and spawning appears to occur over a broad geographic extent, there is likely little risk of year-class failure from harvesting a sustainable number of spawning adults.
Occurrence and Co-Occurrence Patterns of Gar in River–Floodplain Habitats: Methods to Leverage Species Coexistence to Benefit Distributional Models
Authors: Schumann David A. , Colvin Michael E. , Miranda Leandro E. , Jones-Farrand D. Todd
Published: December 2019

Habitat segregation and hypothesized biotic interactions among coexisting gar species may confound attempts to describe the distributions of these species by using only macrohabitat availability in the presence of conspecifics. However, the strength of interactions among gar species and the spatial scale at which they occur are largely unknown. We used an existing data set to evaluate the co-occurrence patterns (i.e., random assemblages versus species co-occurring more or less than expected at random) of three gar species in 62 dynamic river–floodplain habitats associated with the lower Mississippi River and its major tributaries. A novel parameterization of a multispecies occupancy model was utilized to examine the spatial relationships among the full array of possible gar assemblages across a gradient of floodplain habitats. Spotted Gar Lepisosteus oculatus were the most abundant and frequently encountered species (~78% of samples). Shortnose Gar L. platostomus (~27% of samples) and Longnose Gar L. osseus (~12% of samples) were relatively uncommon, and no Alligator Gar Atractosteus spatula were captured in over 600 electrofishing transects. Estimated detection probabilities of the encountered species varied (range = 0.27 [Longnose Gar] to 0.80 [Spotted Gar]), and five species-specific environmental and sampling covariates predicted detection. Relatively strong co-occurrence patterns between Shortnose Gar and Longnose Gar were significantly influenced by the proximity of a floodplain lake to a river (i.e., river : lake elevation change and linear distance) and by lake latitude. In contrast, the occurrence patterns of Spotted Gar were largely independent of the other species and had minor influences on the relationship between Longnose Gar and Shortnose Gar. We demonstrate how species co-occurrence patterns can be leveraged to reduce uncertainty associated with species-specific occupancy estimates and how species distribution models can be improved by utilizing abiotic and biotic features of the target ecosystems.
Fabrication of electrospun polyethersulfone/titanium dioxide (PES/TiO2) composite nanofibers membrane and its application for photocatalytic degradation of phenol in aqueous solution
Authors: Ehsani Masoume , Aroujalian Abdolreza
Published: December 2019

The main objective of this research is to use the photocatalytic properties of PES/TiO2 nanofibers membranes to remove the phenol as a toxic pollutant in various effluents. The uniform fibers in terms of minimum bead formation and fibers diameter were fabricated. Therefore, more TiO2 catalysts are on the surface of the fibers which increase the active surface area of nanoparticles and consequently improve the phenol degradation efficiency. The effects of TiO2 concentration on hydrophilicity, mechanical properties, porosity, mean pore size, and water flux of membranes were studied. The PES/TiO2 nanofibers were evaluated for phenol degradation under UVA irradiation through a transparent membrane module. The amount of removable phenol was analyzed with high‐performance liquid chromatography. Central composite design was used as a statistical experimental design. Finally, the effect of TiO2 content in nanofibers and initial phenol concentrations were investigated as well as pH values in synthetic wastewater, on phenol degradation. The results from analysis of variance (ANOVA) analysis indicated that TiO2 content in nanofibers was the most important and effective parameter on phenol degradation. It was also presented that there is no significant interaction between parameters so that the effect of each parameter was investigated separately. Maximum phenol degradation was 43.0 ± 0.3% and found under conditions of TiO2 content, initial phenol concentration, and pH value of 8%, 120 ppm, and 7, respectively.
Altered cerebral perfusion in children with Langerhans cell histiocytosis after chemotherapy
Authors: Han Michelle , Kim Lily H. , Shpanskaya Katie , Kim Christine , Iv Michael , Jeng Michael , Yeom Kristen W.
Published: December 2019

Background and purpose

Children with Langerhans cell histiocytosis (LCH) may develop a wide array of neurological symptoms, but associated cerebral physiologic changes are poorly understood. We examined cerebral hemodynamic properties of pediatric LCH using arterial spin‐labeling (ASL) perfusion magnetic resonance imaging (MRI).

Materials and methods

A retrospective study was performed in 23 children with biopsy‐proven LCH. Analysis was performed on routine brain MRI obtained before or after therapy. Region of interest (ROI) methodology was used to determine ASL cerebral blood flow (CBF) (mL/100 g/min) in the following bilateral regions: angular gyrus, anterior prefrontal cortex, orbitofrontal cortex, dorsal anterior cingulate cortex, and hippocampus. Quantile (median) regression was performed for each ROI location. CBF patterns were compared between pre‐ and posttreatment LCH patients as well as with age‐matched healthy controls.

Results

Significantly reduced CBF was seen in posttreatment children with LCH compared to age‐matched controls in angular gyrus (P = .046), anterior prefrontal cortex (P = .039), and dorsal anterior cingulate cortex (P = .023). Further analysis revealed dominant perfusion abnormalities in the right hemisphere. No significant perfusion differences were observed in the hippocampus or orbitofrontal cortex.

Conclusion

Perfusion in specific cerebral regions may be consistently reduced in children with LCH, and may represent effects of underlying disease physiology and/or sequelae of chemotherapy. Studies that combine a formal cognitive assessment and hemodynamic data may further provide insight into perfusion deficits associated with the disease and the potential neurotoxic effects in children treated by chemotherapy.
Short‐term and long‐term outcomes after preventive surgery in adolescent patients with familial adenomatous polyposis
Authors: Vitellaro Marco , Piozzi Guglielmo , Signoroni Stefano , Ricci Maria Teresa , Ciniselli Chiara Maura , Cardani Anna , Vecchi Irene , Mancini Andrea , Magarotto Andrea , Verderio Paolo , Massimino Maura , Ferrari Andrea , Biasoni Davide
Published: December 2019

Background

APC gene pathogenic variants are characterized by a lifetime risk of nearly 100% to develop a colorectal carcinoma. International guidelines suggest a prophylactic surgery in the second decade.

Methods

A descriptive analysis was performed evaluating a surgical series of adolescent patients with familial adenomatous polyposis (FAP) enrolled in the prospectively maintained hereditary polyposis registry.

Results

Thirty‐eight adolescent patients (median age 16 years; range, 7‐19) underwent laparoscopic prophylactic surgery. APC gene pathogenic variants were detected in all patients, and six patients were proband. No patients were converted to open surgery. Median postoperative stay was five days (4‐16). Early postoperative complications were one dural puncture and one anastomotic leakage. Regarding late complications, we observed one patient having small bowel obstruction 56 months after surgery. Pathological reports showed one patient with pTis adenocarcinoma in two separate sites; 33 patients with low‐grade dysplasia, four with high‐grade dysplasia. One patient developed a desmoid tumor 37 months after surgery. After a median follow‐up of 40.5 months, no patients died or had a second abdominal surgery because of cancer in rectal stump.

Conclusions

Rectal sparing surgery was the first choice in the major respect of patients’ quality of life. Laparoscopic prophylactic surgery for FAP is well accepted from adolescents. It represents a safe option due to the low incidence of post‐surgical desmoids and quick postoperative recovery.
Permafrost and periglacial processes in mid‐ and low‐latitude mountain regions
Authors: Ruiz‐Fernández Jesús , Oliva Marc , Hughes Philip
Published: December 2019

The Special Issue that justifies this Editorial has been designed to commemorate the 25th anniversary of the first Spanish scientific meeting of the International Permafrost Association organized in 1994 in Madrid. This Special Issue, entitled “Permafrost and periglacial processes in mid‐ and low‐latitude mountains regions,” includes nine papers from various mountain regions around the world, such as the Pyrenees, Sierra Nevada, Galician and Cantabrian Mountains in the Iberian Peninsula, Atacama and Central Andes in South America, Absaroka ranges in North America, and Seckauer Tauern Range in the European Alps. These articles provide new methodologies and approaches focusing on a wide range of periglacial phenomena, such as past cryogenic environments, active periglacial processes, permafrost and ground thermal regime, as well as rock glaciers. As a result of this Special Issue, we have detected several knowledge gaps that should be addressed in the future by the scientific community studying permafrost and periglacial processes in mid‐ and low‐latitude mountains regions, namely: (a) improving the geochronology of past periglacial environments and associated paleoclimatic implications; (b) the study of periglacial features existing in low‐altitude mountain environments and/or in the lowlands; (c) improve our current knowledge of active periglacial processes, permafrost distribution and ground thermal regime in mid‐altitude mountains; (d) the monitoring of periglacial mass wasting processes and mechanisms of sediment transfer; (e) the interaction between glaciers and periglacial processes; and (f) geoecological dynamics in response to climate scenarios anticipating significant changes of temperature and moisture in periglacial regions.
Demonstration of a memory calibration method in water isotope measurement by laser spectroscopy
Authors: Qu Dongmei , Tian Lide , Zhao Huabiao , Yao Ping , Xu Baiqing , Cui Jiangpeng
Published: December 2019

Rationale

Measuring δ18O and δ2H values in water using wavelength‐scanned cavity ring down spectroscopy (WS‐CRDS) requires multiple injections of up to six (and sometimes eight or more) of one sample to remove the memory effect, which decreases the sample throughput and increases the consumables cost. Thus, improved methods for removing the memory effect are required.

Methods

We calculated the memory coefficients by sequential WS‐CRDS measurement of two lab standard waters with isotopic differences, and used them to establish calibration equations. We then used these equations to correct the measured δ18O and δ2H values by removing the memory effect, instead of using multiple injections in the routine daily measurements.

Results

By using this method, the number of injections per sample was reduced to one. The reproducibility (one standard deviation) of the δ18O and δ2H values obtained for quality control sample was less than 0.05‰ and 0.5‰ for an annual average, respectively.

Conclusions

By measuring the memory coefficients and establishing the calibration equations, a highly effective method was developed for determining the δ18O and δ2H values of water, which could significantly improve sample throughput for liquid water dual isotope measurement without sacrificing the precision.
A Novel Supramolecular Silver Coordination Complex Based on a Triazole Carboxylate Ligand: Synthesis and Fluorescence Sensing of Colchicine and a Series of Nitro Explosives
Authors: Xiao Yao , Guan Qing‐Lin , Wang Yu , You Zi‐Xin , Zhang Kai‐Yue , Xing Yong‐Heng , Bai Feng‐Ying , Sun Li–Xian
Published: December 2019

A novel supramolecular coordination complex [Ag(HMCTCA)(H2MCTCA)] (1) was firstly synthesized by the reaction of a nitrogen heterocyclic organic ligand H2MCTCA (5‐Methyl‐1‐(4‐carboxylphenyl)‐1H‐1,2,3‐triazole‐4‐carboxylic Acid) with AgNO3. It was characterized in detail by some microanalysis means such as elemental analysis, IR, UV, TG and PXRD. Furthermore, the solid fluorescent behavior was explored at room temperature. The results indicated that coordination complex 1 exhibited excellent fluorescent properties. Based on this phenomenon, we discussed its application in fluorescence sensing. The results illustrated that the coordination complex 1 can be applied to detect colchicine and a series of nitro explosives. It is worth noting that coordination complex 1 showed preeminent sensitivity for detecting p‐nitroaniline (PNA), the detection limit was as low as 0.59 μM.
Numerical modeling of the hydraulic blade pitch actuator in a spar‐type floating wind turbine considering fault conditions and their effects on global dynamic responses
Authors: Cho Seongpil , Bachynski Erin E. , Nejad Amir R. , Gao Zhen , Moan Torgeir
Published: December 2019

This paper deals with numerical modeling of the hydraulic blade pitch actuator and its effect on the dynamic responses of a floating spar‐type wind turbine under valve fault conditions. A spar‐type floating wind turbine concept is modeled and simulated using an aero‐hydro‐servo‐elastic simulation tool (Simo‐Riflex [SR]). Because the blade pitch system has the highest failure rate, a numerical model of the hydraulic blade pitch actuator with/without valve faults is developed and linked to SR to study the effects of faults on global responses of the spar‐type floating wind turbine for different faults, fault magnitudes, and environmental conditions. The consequence of valve faults in the pitch actuator is that the blade cannot be pitched to the desired angle, so there may be a delay in the response due to excessive friction and the wrong voltage, or slit lock may cause runaway blade pitch. A short circuit may cause the blade to get stuck at a particular pitch angle. These faults contribute to rotor imbalance, which result in different effects on the turbine structure and the platform motions. The proposed method for combining global and hydraulic actuator models is demonstrated in case studies with stochastic wind and wave conditions and different types of valve faults.
Cover Image
Authors: Shotwell Carl R. , Cleary John D. , Berglund J. Andrew
Published: December 2019

The cover image is based on the Review Article The Potential of Engineered Eukaryotic RNA‐Binding Proteins as Molecular Tools and Therapeutics, by Carl R. Shotwell, John Cleary, Andy Berglund. https://doi.org/10.1002/wrna.1573

image
Bounds on CP-violating Higgs-gluon interactions: the case of vanishing light-quark Yukawa couplings
Authors: Haisch Ulrich , Hala Amando
Published: December 2019

Abstract

We investigate CP-violating interactions involving the Higgs boson and gluons within an effective field theory approach, focusing on the specific class of new-physics scenarios where the Yukawa couplings of light quarks are zero or strongly suppressed compared to the standard-model expectations. We compute the contributions of the most relevant higher-dimensional operators of Weinberg type to the electric dipole moment of the neutron (nEDM), which are induced by Feynman diagrams that involve an effective CP-violating Higgs-gluon coupling and top-quark loops. The resulting nEDM sensitivities and prospects are discussed and compared to the existing and expected LHC bounds. We find that future nEDM searches can set non-trivial constraints on CP-violating Higgs-gluon interactions even if the Higgs only couples to the third generation of quarks.
Testing the 2HDM explanation of the muon g – 2 anomaly at the LHC
Authors: Iguro Syuhei , Omura Yuji , Takeuchi Michihisa
Published: December 2019

Abstract

The discrepancy between the measured value and the Standard Model pre- diction for the muon anomalous magnetic moment is one of the important issues in the particle physics. In this paper, we consider a two Higgs doublet model (2HDM) where the extra Higgs doublet couples to muon and tau in lepton flavor violating (LFV) way and the one-loop correction involving the scalars largely contributes to the muon anomalous magnetic moment. The couplings should be sizable to explain the discrepancy, so that the extra Higgs bosons would dominantly decay into μτ LFV modes, which makes the model testable at the LHC through multi-lepton signatures even though they are produced via the electroweak interaction. We discuss the current status and the future prospect for the extra Higgs searches at the LHC, and demonstrate the reconstruction of the mass spectrum using the multi-lepton events.
Back(reaction) to the future in the Unruh-de Sitter state
Authors: Aalsma Lars , Parikh Maulik , van der Schaar Jan Pieter
Published: December 2019

Abstract

Motivated by black hole physics, we define the Unruh state for a scalar field in de Sitter space. Like the Bunch-Davies state, the Unruh-de Sitter state appears thermal to a static observer. However, it breaks some of the symmetries of de Sitter space. We calculate the expectation value of the energy-momentum tensor in the Unruh-de Sitter state in two dimensions and find a non-vanishing flux of outgoing negative energy. Extrapolating the result to four dimensions, we argue that this backreacts on the initial de Sitter geometry semi-classically. Notably, we estimate that de Sitter space is destabilized on a timescale set by the gravitational entropy; analogous to black hole evaporation, the endpoint of this instability is a singular geometry outside the regime of effective field theory. Finally, we suggest that the Unruh-de Sitter state may be a natural initial state for patches of de Sitter space, and discuss the implications for slow-roll and eternal inflation, and for de Sitter thermodynamics.
Exotic massive 3D gravities from truncation
Authors: Afshar Hamid Reza , Deger Nihat Sadik
Published: December 2019

We introduce a systematic way of constructing 3D exotic massive gravity theories in the first order formulation. Our method is based on truncating a single degree of freedom in the parity odd gravity models found earlier [1] and supplementing it with appropriate potential terms such that the resulting models have well-defined metric equations but their Bianchi identities are satisfied only on-shell. Hence, they are ‘third way’ consistent. We first re-derive two already known exotic theories using our approach and then construct an extended exotic massive gravity model whose metric field equation is sixth order in derivatives. We also explain how to check Bianchi identities using the first order formulation.
Sum rules for CP-violating operators of Weinberg type
Authors: Haisch Ulrich , Hala Amando
Published: December 2019

Abstract

We estimate the size of the hadronic matrix elements of CP-violating three-gluon and four-gluon Weinberg operators using sum-rule techniques. In the three-gluon case, we are able to reproduce the expressions given in earlier works, while the four-gluon results obtained in this article are new. Our paper therefore represents the first systematic study of contributions to the electric dipole moment of the neutron due to CP-violating dimension-six and dimension-eight operators. We provide many details on both the derivation of the sum rules as well as the analysis of the uncertainties that plague our final predictions.
Entanglement entropy and $$ T\overline{T} $$ deformations beyond antipodal points from holography
Authors: Grieninger Sebastian
Published: December 2019

Abstract

We consider the entanglement entropies in dSd sliced (A)dSd+1 in the presence of a hard radial cutoff for 2 ≤ d ≤ 6. By considering a one parameter family of analytical solutions, parametrized by their turning point in the bulk r*, we are able to compute the entanglement entropy for generic intervals on the cutoff slice. It has been proposed that the field theory dual of this scenario is a strongly coupled CFT, deformed by a certain irrelevant deformation — the so-called $$ T\overline{T} $$
T

T
¯

deformation. Surprisingly, we find that we may write the entanglement entropies formally in the same way as the entanglement entropy for antipodal points on the sphere by introducing an effective radius Reff = R cos(βϵ), where R is the radius of the sphere and βϵ related to the length of the interval. Geometrically, this is equivalent to following the $$ T\overline{T} $$
T

T
¯

trajectory until the generic interval corresponds to antipodal points on the sphere. Finally, we check our results by comparing the asymptotic behavior (no Dirichlet wall present) with the results of Casini, Huerta and Myers. We then switch on counterterms on the cutoff slice which are important with regards to the field theory calculation. We explicitly compute the contributions of the counterterms to the entanglement entropy by considering the Wald entropy. In the second part of this work, we extend the field theory calculation of the entanglement entropy for antipodal points for a d-dimensional field theory in context of DS/dS holography. We find excellent agreement with the results from holography and show, in particular, that the effects of the counterterms in the field theory calculation match the Wald entropy associated with the counterterms on the gravity side.
Learning the Alpha-bits of black holes
Authors: Hayden Patrick , Penington Geoffrey
Published: December 2019

Abstract

When the bulk geometry in AdS/CFT contains a black hole, boundary subregions may be sufficient to reconstruct certain bulk operators if and only if the black hole microstate is known, an example of state dependence. Reconstructions exist for any microstate, but no reconstruction works for all microstates. We refine this dichotomy, demonstrating that the same boundary operator can often be used for large subspaces of black hole microstates, corresponding to a constant fraction α of the black hole entropy. In the Schrödinger picture, the boundary subregion encodes the α-bits (a concept from quantum information) of a bulk region containing the black hole and bounded by extremal surfaces. These results have important consequences for the structure of AdS/CFT and for quantum information. Firstly, they imply that the bulk reconstruction is necessarily only approximate and allow us to place non-perturbative lower bounds on the error when doing so. Second, they provide a simple and tractable limit in which the entanglement wedge is state dependent, but in a highly controlled way. Although the state dependence of operators comes from ordinary quantum error correction, there are clear connections to the Papadodimas-Raju proposal for understanding operators behind black hole horizons. In tensor network toy models of AdS/CFT, we see how state dependence arises from the bulk operator being ‘pushed’ through the black hole itself. Finally, we show that black holes provide the first ‘explicit’ examples of capacity-achieving α-bit codes. Unintuitively, Hawking radiation always reveals the α-bits of a black hole as soon as possible. In an appendix, we apply a result from the quantum information literature to prove that entanglement wedge reconstruction can be made exact to all orders in 1/N.
Quantum corrections for D-brane models with broken supersymmetry
Authors: Buchmuller Wilfried , Dudas Emilian , Tatsuta Yoshiyuki
Published: December 2019

Abstract

Intersecting D-brane models and their T-dual magnetic compactifications yield attractive models of particle physics where magnetic flux plays a twofold role, being the source of fermion chirality as well as supersymmetry breaking. A potential problem of these models is the appearance of tachyons which can only be avoided in certain regions of moduli space and in the presence of Wilson lines. We study the effective four-dimensional field theory for an orientifold compactification of type IIA string theory and the corresponding toroidal compactification of type I string theory. After determining the Kaluza-Klein and Landau-level towers of massive states in different sectors of the model, we evaluate their contributions to the one-loop effective potential, summing over all massive states, and we relate the result to the corresponding string partition functions. We find that the Wilson- line effective potential has only saddle points, and the theory is therefore driven to the tachyonic regime. There tachyon condensation takes place and chiral fermions acquire a mass of the order of the compactification scale. We also find evidence for a tachyonic behaviour of the volume moduli. More work on tachyon condensation is needed to clarify the connection between supersymmetry breaking, a chiral fermion spectrum and vacuum stability.