bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence, clinical characteristics, and management of irritable bowel syndrome in Vietnam: A scoping review
Authors: Quach Duc Trong , Vu Khoa Tien , Vu Khien Van
Published: July 2021

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders worldwide. Its prevalence varies significantly from country to country, largely due to heterogeneity in the available data. Recent studies show that the prevalence of IBS in Asia is on the rise. However, there are very limited data regarding its prevalence in the Vietnamese population. This review aims to offer an overview of the prevalence and clinical characteristics of IBS in the Vietnamese population; and to discuss the current management of IBS in Vietnam—taking into account the available medical resources and the local spectrum of lower gastrointestinal disorders that may mimic IBS.
Partitioning digraphs with outdegree at least 4
Authors: Liu Guanwu , Yu Xingxing
Published: July 2021

Scott asked the question of determining such that if is a digraph with arcs and minimum outdegree then has a partition such that , where (respectively, ) is the number of arcs from to (respectively, from to ). Lee, Loh, and Sudakov showed that and , and conjectured that for . In this paper, we show and prove some partial results for .
Dengue fever outbreak in Cook Island: A rising concern, efforts, challenges, and future recommendations
Authors: Uwishema Olivier , Nnagha Ekene M. , Chalhoub Elie , Nchasi Goodluck , Mwazighe Rehema M. , Akin Burak T. , Adanur Irem , Onyeaka Helen
Published: July 2021

The Cook Island government has made several efforts to ensure zero confirmed cases and transmission of COVID‐19, especially among visiting travelers. However, the Cook Island ministry of health has to deal with the new strain of dengue fever outbreak, known as dengue fever type 2 (DEN‐2), by adopting several measures to control its spread, especially in the affected parts of the subtropical country. This paper aims to describe the dengue fever response taken in Cook Island and suggest recommendations to control the risk of transmission in endemic parts of the world.
Usefulness of P‐wave duration in patients with sick sinus syndrome as a predictor of atrial fibrillation
Authors: Murase Yosuke , Imai Hajime , Ogawa Yasuhiro , Kano Naoaki , Mamiya Keita , Ikeda Tomoyo , Okabe Kei , Arai Kenji , Yamazoe Shinji , Torii Jun , Kawaguchi Katsuhiro
Published: July 2021

Background

This study aimed to clarify P‐wave duration (PWD) ability before pacemaker implantation to predict worsening atrial fibrillation (AF) burden after the procedure.

Methods

We retrospectively investigated 75 patients who underwent permanent pacemaker implantation due to sick sinus syndrome (SSS) at Komaki City Hospital between January 2006 and May 2019. Worsening AF burden was defined as an increase in the number of AF episodes, each lasting ≥5.5 hours a day.

Results

In the study population, 17 patients (23%) had worsening AF burden during the follow‐up period. These patients had significantly longer PWD in lead Ⅱ (117.9 ± 19.9 ms vs 101.3 ± 20.0 ms, P = .002) than the patients without worsening AF burden. The best discriminative cutoff value for PWD in lead Ⅱ was 108 ms (sensitivity, 77%; specificity, 67%). In multivariate analysis, PWD in lead II ≥108 ms (hazard ratio, 5.395; 95% confidence interval, 1.352‐21.523; P = .017) was an independent predictor of worsening AF burden. Patients with PWD in lead II <108 ms showed a significantly higher event‐free rate against worsening AF burden than those with PWD in lead II ≥108 ms (81% vs 9%, P = .005).

Conclusions

Prolonged PWD before pacemaker implantation was the most important independent predictor of worsening AF burden after the procedure. In patients with SSS, prolonged PWD can be a useful marker for predicting worsening of AF burden after pacemaker implantation.
Association between polypharmacy and depression: a systematic review and meta‐analysis
Authors: Palapinyo Sirinoot , Methaneethorn Janthima , Leelakanok Nattawut
Published: July 2021

Aims

Polypharmacy is associated with multiple adverse health outcomes. The objective of this systematic review and meta‐analysis was to explore the association between polypharmacy and depression.

Methods and results

A systematic literature review was conducted by searching MEDLINE, Scopus, Science Direct, and CINAHL Complete to identify studies assessing the association between polypharmacy and depression published until November 2020. A meta‐analysis was performed using random effect models. Heterogeneity was assessed using theI2‐statistic. Nineteen studies were included in the meta‐analysis. We found that an increase in the number of drugs was associated with an increased risk of depression (OR = 1.55 [95% CI: 1.01, 2.36;I2 = 62%, n = 2]). Further, polypharmacy defined as the concurrent use of five or more medications was associated with an increased risk of depression (OR = 1.73 [95% CI: 1.39, 2.14],I2 = 83%, n = 8).

Conclusion

This meta‐analysis revealed that polypharmacy, both discretely and categorically defined, was associated with an increased risk of depression.
Combining Nd:YAG laser with optical coherence tomography for nonsurgical treatment of basal cell carcinoma
Authors: Markowitz Orit , Bressler Moshe Y.
Published: July 2021

Background

Effective and aesthetically appealing management options are needed for basal cell carcinoma (BCC), the most common skin cancer. The Nd:YAG laser shows promise, but most studies use biopsy to demonstrate tumor clearance. Optical coherence tomography (OCT) could allow good tumor margin control while enabling recurrence monitoring.

Objective

Determine the efficacy of the Nd:YAG laser to treat BCCs while controlling for tumor margin with OCT.

Methods

A 1064‐nm Nd:YAG laser was applied to treat 119 BCCs in 102 patients, where tumor margins were approximated using OCT. Lesions were treated every 2 months until no residual tumor remained; patients were monitored for 1 year after treatment completion for clinical and subclinical recurrences. Outcomes were analyzed retrospectively.

Results

Most BCCs cleared after one treatment (85/119, 70.4%). Several factors were significantly associated with a suboptimal response, that is, those with recurrence or requiring ≥2 treatments: lesion size >5 mm (p = 0.03), focal sclerosing subtype (p = 0.018), and immunosuppression (p = 0.039). Midface location, patient compliance, and diagnosis method were codependent variables (r2 = 0.2011, p = 0.0008). All BCCs (119/119) demonstrated complete clinical and subclinical tumor clearance 2 months after final laser treatment. By 1 year, overall clinical recurrence rate (RR) was 1.7% (2/119) and cumulative subclinical RR was 4.2% (5/119). Upon excluding immunosuppressed patients, clinical RR and combined subclinical RR for primary BCC were 1% (1/98) and 2% (2/98), respectively, and 0% (0/17) and 11.8% (2/17), respectively, for recurrent BCC.

Conclusions

The Nd:YAG nonablative laser can offer an effective treatment for BCCs when used with noninvasive diagnostic tools such as OCT.
The iCOLT climate service: Seasonal predictions of irrigation for Emilia‐Romagna, Italy
Authors: Villani Giulia , Tomei Fausto , Pavan Valentina , Pirola Alessandro , Spisni Andrea , Marletto Vittorio
Published: July 2021

Emilia‐Romagna is a region of Northern Italy whose land use is mainly devoted to agriculture, especially over the plain area. Since the region is characterized by summer water shortages and recurrent drought conditions, a summer irrigation water demand forecast system has been developed, operating both at regional and Land Reclamation and Irrigation Board levels. Remote sensing crop detection is used in combination with a soil water balance model as a monitoring tool in support to water management and to optimize the use of available water resources. These instruments are also integrated with operational calibrated probabilistic seasonal forecast products currently based on Copernicus Climate Services, in order to evaluate summer irrigation water needs in advance in support to decision‐making by water managers. Results obtained using this prediction system are characterized by a significant forecast skill. The sources of the predictability of this system are specifically evaluated, showing that the correct representation of crop geographical distribution is crucial for the ability of the system to capture spatial variability in irrigation demand. Furthermore, the system forecast skill is mostly due to the use of an empirical model to assess the hypodermic water table depth initialized by means of the observed meteorological data of the months before the beginning of the summer season. Finally, calibrated probabilistic seasonal predictions also contribute to a minor extent to the good performance of the system as a whole.
Noise2Context: Context‐assisted learning 3D thin‐layer for low‐dose CT
Authors: Zhang Zhicheng , Liang Xiaokun , Zhao Wei , Xing Lei
Published: July 2021

Purpose

Computed tomography (CT) has played a vital role in medical diagnosis, assessment, and therapy planning, etc. In clinical practice, concerns about the increase of x‐ray radiation exposure attract more and more attention. To lower the x‐ray radiation, low‐dose CT (LDCT) has been widely adopted in certain scenarios, while it will induce the degradation of CT image quality. In this paper, we proposed a deep learning‐based method that can train denoising neural networks without any clean data.

Methods

In this work, for 3D thin‐slice LDCT scanning, we first drive an unsupervised loss function which was equivalent to a supervised loss function with paired noisy and clean samples when the noise in the different slices from a single scan was uncorrelated and zero‐mean. Then, we trained the denoising neural network to map one noise LDCT image to its two adjacent LDCT images in a single 3D thin‐layer LDCT scanning, simultaneously. In essence, with some latent assumptions, we proposed an unsupervised loss function to train the denoising neural network in an unsupervised manner, which integrated the similarity between adjacent CT slices in 3D thin‐layer LDCT.

Results

Further experiments on Mayo LDCT dataset and a realistic pig head were carried out. In the experiments using Mayo LDCT dataset, our unsupervised method can obtain performance comparable to that of the supervised baseline. With the realistic pig head, our method can achieve optimal performance at different noise levels as compared to all the other methods that demonstrated the superiority and robustness of the proposed Noise2Context.

Conclusions

In this work, we present a generalizable LDCT image denoising method without any clean data. As a result, our method not only gets rid of the complex artificial image priors but also amounts of paired high‐quality training datasets.
Hybrid equilibrium element with high‐order stress fields for accurate elastic dynamic analysis
Authors: Parrinello Francesco , Borino Guido
Published: July 2021

In the present article the two‐dimensional hybrid equilibrium element formulation is initially developed, with quadratic, cubic, and quartic stress fields, for static analysis of compressible and quasi‐incompressible elastic solids in the variational framework of the minimum complementary energy principle. Thereafter, the high‐order hybrid equilibrium formulation is developed for dynamic analysis of elastic solids in the variational framework of the Toupin principle, which is the complementary form of the Hamilton principle. The Newmark time integration scheme is introduced for discretization of the stress fields in the time domain and dynamic analysis of both the compressible solid and quasi‐incompressible ones. The hybrid equilibrium element formulation provides very accurate solutions with a high‐order stress field and the results of the static and dynamic analyses are compared with the solution of the classic displacement‐based quadratic formulation, showing the convergence of the two formulations to the exact solution and the very satisfying performance of the proposed formulation, especially for analysis of quasi‐incompressible elastic solids.
Asserting Land, Estranging Kin: On Competing Relations of Dependence in Vanuatu
Authors: Bratrud Tom
Published: July 2021

This paper examines how the new material value of land in postcolonial Vanuatu intensifies people's shaping and re‐shaping of claims to autonomy and dependence. Ahamb, like many other villages in Melanesia, originated as a mission community with people moving in from various original homelands. The mix of people from different places facilitated new kinship bonds and senses of community. However, it has also sparked disputes over land rights and leadership, fuelled by the postcolonial government's incentives for converting customary land into registered titles and leases for wealthy investors. The possibility of leasing out land, and preventing others from leasing out land, creates a dynamic where groups increasingly define themselves in terms of landowner clans that exclude outsiders rather than the wider kin networks that include them. Redefinitions of social boundaries generate secondary disputes over dependence and autonomy where care of kin, Christian commitment and future aspirations sometimes prove to be incompatible and in need of negotiation.
Polypyrrole derivatives for detection of toxic gases: A theoretical study
Authors: Coleone Alex Pifer , Barboza Bruno Hori , Batagin‐Neto Augusto
Published: July 2021

Polypyrrole (PPy) based compounds have been considered interesting materials for several technological applications, mainly due to their unique optoelectronic properties and high versatility of synthesis. In particular, the sensitivity of their electrical properties to external stimuli defines these polymers as promising candidates for chemical sensor applications. However, the demanding processes involved in the synthesis of 3‐4 substituted PPy derivatives hinders the development of optimized systems. In this report, electronic structure calculations were conducted for a set of branched PPy derivatives aiming to identify promising compounds for chemical sensors. The calculations were carried out in the framework of the density functional theory (DFT), by considering oligomeric systems. The influence of the side groups on the local reactivities and adsorption centers of the compounds were evaluated via condensed‐to‐atoms Fukui indexes and molecular electrostatic potentials. DFT‐based adsorption studies and fully atomistic reactive molecular dynamics (FARMD) simulations were conducted for selected systems considering toxic gases as analytes. The results point out PPy, PPy‐CCH and PPy‐CN as promising candidates for chemical sensor applications, presenting high potential for the detection of Cl2 and SO2. FARMD results indicate that the analysis of local reactivities and electrostatic potentials can be used to identify relevant adsorption centers and possible degradation processes.
Respiratory function in children with nephrotic syndrome: Comparative evaluation of impulse oscillometry and spirometry
Authors: Kilci Fatih , Uyan Zeynep S. , Çelakıl Mehtap E. , Doğan Kenan , Bek Kenan
Published: July 2021

Aim

To evaluate the respiratory functions of children with nephrotic syndrome (NS) by impulse oscillometry (IOS) and its correlation with spirometry.

Methods

Fifty‐five NS patients aged 3–18 years were included as the study group and 40 healthy children of the same age formed the control group. Patients were divided into nephrotic phase (first attack and relapse) and remission. Demographic, anthropometric, and laboratory data of the children were recorded. Respiratory functions were evaluated by IOS and spirometry. Children over 6‐years old performed both IOS and spirometry while children under 6 years performed only IOS.

Results

The R (R5%, R10%, R5‐20), AX and Z5% values of IOS in patients with nephrotic phase were higher than remission patients and control group while spirometry indices of PEF% and MEF25‐75% were lower. Z scores of MEF25‐75 were significantly negatively correlated with z scores of R5, R10, Z5, and Fres while they were significantly positively correlated with z scores of X values (5, 10, 15, and 20 Hz). Z scores of forced expiratory volume in 1 /forced vital capacity significantly negatively correlated with z scores of R values (R5, R10), Z5 and AX and positively correlated with z scores of X values (X5, X10, X15 Hz).

Conclusion

Our study demonstrated that respiratory functions measured by IOS and spirometry were affected at the time of nephrotic phase in NS patients. IOS, a novel method easily applicable even in small children, is a potentially valuable tool to detect this condition; given its good correlation with spirometry.
Comparison of pediatric empyema secondary to tuberculosis or non‐tuberculosis community‐acquired pneumonia in those who underwent surgery in high TB burden areas
Authors: Yang Gang , Wen Yang , Chen Ting , Xu Chang , Yuan Miao , Li Yuan
Published: July 2021

Introduction

Tuberculous empyema (TE) in children is common in high‐TB burden and medical resource‐limited areas. However, studies that evaluate the characteristics of TE in children are sparse. This study aimed to analyze the clinical features of pediatric TE receiving surgical intervention.

Methods

We performed a retrospective study of children with empyema secondary to community‐acquired pneumonia who underwent surgery in our institution. The clinical characteristics were compared between TE and empyema secondary non‐tuberculosis infection (non‐tuberculosis empyema, NTE).

Results

One hundred patients were included (27 with TE and 73 with NTE). Stage 3 empyema occupied 81.5% and 45.2% of TE and NTE in this study. The TE children had older age, longer duration of illness, and milder symptoms. Pleural fluid culture was positive for Mycobacterium tuberculosis in 7.4% of patients with TE. Lymph node enlargement, lymph node calcification, and pleural nodules presented in TE with high specificity (93.2%, 98.6%, and 98.5%) but low sensitivity (33.3%, 14.8%, and 29.6%) on CT scan. Thoracoscopy surgery was performed in 14 (51.9%) in TE and 39 (53.4%) in NTE. Postoperative chest‐tube indwelling time was longer (7.85 ± 5.00 vs. 4.89 ± 1.81 days, p < .001), and more patients had incomplete lung expansion after 3 months in TE.

Conclusion

Tuberculosis infection should be screened in management of children with empyema in high‐TB burden areas. Pediatric TE usually presented at older age and with milder respiratory symptoms. Pleural biopsy during surgery is often necessary to confirm the cause of infection. Thoracotomy is still required in some pediatric TE or NTE with delayed treatment in medical resource‐limited area.
Structures of the TetR‐like transcription regulator RcdA alone and in complexes with ligands
Authors: Pietrzyk‐Brzezinska Agnieszka J. , Cociurovscaia Anna
Published: July 2021

RcdA is a helix‐turn‐helix (HTH) transcriptional regulator belonging to the TetR family. The protein regulates the transcription of curlin subunit gene D, the master regulator of biofilm formation. Moreover, it was predicted that it might be involved in the regulation of up to 27 different genes. However, an effector of RcdA and the environmental conditions which trigger RcdA action remain unknown. Herein, we report the first crystal structures of RcdA in complexes with ligands, trimethylamine N‐oxide (TMAO) and tris(hydroxymethyl)aminomethane (Tris), which might serve as RcdA effectors. Based on these structures, the ligand‐binding pocket of RcdA was characterized in detail. The conservation of the amino acid residues forming the ligand‐binding cavity was analyzed and the comprehensive search for RcdA structural homologs was performed. This analysis indicated that RcdA is structurally similar to multidrug‐binding TetR family members, however, its ligand‐binding cavity differs significantly from the pockets of its structural homologs. The interaction of RcdA with TMAO and Tris indicates that the protein might be involved in alkaline stress response.
Spermidine and spermine exert protective effects within the lung
Authors: Wawrzyniak Marcin , Groeger David , Frei Remo , Ferstl Ruth , Wawrzyniak Paulina , Krawczyk Krzysztof , Pugin Benoit , Barcik Weronika , Westermann Patrick , Dreher Anita , Scharl Michael , Jutel Marek , Akdis Cezmi A. , O`Mahony Liam
Published: July 2021

Asthma is a heterologous disease that is influenced by complex interactions between multiple environmental exposures, metabolism, and host immunoregulatory processes. Specific metabolites are increasingly recognized to influence respiratory inflammation. However, the role of protein‐derived metabolites in regulating inflammatory responses in the lung are poorly described. The aims of the present study were to quantify polyamine levels in bronchoalveolar lavages (BALs) from healthy volunteers and asthma patients, and to evaluate the impact of each polyamine on inflammatory responses using in vitro models and in a house dust mite (HDM)‐induced respiratory allergy model. Spermidine levels were decreased, while cadaverine levels were increased in BALs from asthma patients compared to healthy controls, using Ultra Performance Liquid Chromatography (UPLC). Both spermine and spermidine inhibit lipopolysaccharide (LPS)‐induced cytokine secretion from human peripheral blood mononuclear cells (PBMCs) and dendritic cells (DCs) in vitro. In addition, oral gavage with spermine or spermidine modulate HDM‐induced cell infiltration, cytokine secretion, and epithelial cell tight junction expression in murine models. Spermidine also reduces airway hyper‐responsiveness. These results suggest that modulation of polyamine metabolism, in particular spermidine, is associated with respiratory inflammation and these molecules and pathways should be further explored as biomarkers of disease and potential targets for novel therapies.
Exploring the enhanced performance of Sb2S3/doped‐carbon composites as potential anode materials for sodium‐ion batteries: A density functional theory approach
Authors: El Hachimi Abdel Ghafour , Guillén‐López Alfredo , Jaramillo‐Quintero Oscar A. , Rincón Marina E. , Sevilla‐Camacho Perla Yazmín , Muñiz Jesús
Published: July 2021

The improvement of performance in sodium ion batteries is a subject of intense research. In this work, a first principle calculations study at the density functional level on the adsorption process of Na adatoms into Sb2S3/carbon (Sb2S3/CM) and Sb2S3/heteroatom doped‐carbon (Sb2S3/S‐CM, Sb2S3/Sb‐CM) is presented. The sulfur and antimony doped‐carbon substrates enhance the adsorption energies, charge transfer, specific capacities and the diffusion properties of Na adatoms into the Sb2S3/S‐CM and Sb2S3/Sb‐CM composite systems. The Na storage capacity trend and the open circuit voltage profile follows the trend observed in previous experimental results. This work explores perspectives through tailoring 2D carbon anodes with doping heteroatoms in the presence of adsorbed Sb2S3 for an outstanding storage capacity and cycling stability architecture.
Negative binomial graphical model with excess zeros
Authors: Park Beomjin , Choi Hosik , Park Changyi
Published: July 2021

Markov random field or undirected graphical models (GM) are a popular class of GM useful in various fields because they provide an intuitive and interpretable graph expressing the complex relationship between random variables. The zero‐inflated local Poisson graphical model has been proposed as a graphical model for count data with excess zeros. However, as count data are often characterized by over‐dispersion, the local Poisson graphical model may suffer from a poor fit to data. In this paper, we propose a zero‐inflated local negative binomial (NB) graphical model. Due to the dependencies of parameters in our models, a direct optimization of the objective function is difficult. Instead, we devise expectation‐minimization algorithms based on two different parametrizations for the NB distribution. Through a simulation study, we illustrate the effectiveness of our method for learning network structure from over‐dispersed count data with excess zeros. We further apply our method to real data to estimate its network structure.
Connecting Instrumental Variable methods for causal inference to the Estimand Framework
Authors: Bowden Jack , Bornkamp Björn , Glimm Ekkehard , Bretz Frank
Published: July 2021

Causal inference methods are gaining increasing prominence in pharmaceutical drug development in light of the recently published addendum on estimands and sensitivity analysis in clinical trials to the E9 guideline of the International Council for Harmonisation. The E9 addendum emphasises the need to account for post‐randomization or ‘intercurrent’ events that can potentially influence the interpretation of a treatment effect estimate at a trial's conclusion. Instrumental Variables (IV) methods have been used extensively in economics, epidemiology, and academic clinical studies for ‘causal inference,’ but less so in the pharmaceutical industry setting until now. In this tutorial article we review the basic tools for causal inference, including graphical diagrams and potential outcomes, as well as several conceptual frameworks that an IV analysis can sit within. We discuss in detail how to map these approaches to the Treatment Policy, Principal Stratum and Hypothetical ‘estimand strategies’ introduced in the E9 addendum, and provide details of their implementation using standard regression models. Specific attention is given to discussing the assumptions each estimation strategy relies on in order to be consistent, the extent to which they can be empirically tested and sensitivity analyses in which specific assumptions can be relaxed. We finish by applying the methods described to simulated data closely matching two recent pharmaceutical trials to further motivate and clarify the ideas.
Synthesis of g‐C3N4, Zn3(PO4)2 and g‐C3N4/Zn3(PO4)2 Composites for Application in Photodegradation of Crystal Violet Dye under Solar Light
Authors: Ben Sachin Kumar , Gupta Sakshi , Raj Krishna Kumar , Chandra Vimlesh
Published: July 2021

The g‐C3N4/Zn3(PO4)2 composites were synthesized in the aqueous medium via chemical precipitation route. The photocatalytic activity of these photocatalysts was evaluated for the degradation of aqueous crystal violet (CV) dye under solar light. The optimum photocatalytic activity of g‐C3N4/Zn3(PO4)2 composite was found for 30 % weight of g‐C3N4. The comparison experiments showed the photocatalytic activity of the g‐C3N4/Zn3(PO4)2 composite increased 2 times compare to bare Zn3(PO4)2 and 1.5 times of g‐C3N4. The enhanced photocatalytic activity originates due to the transfer of photogenerated electrons from the conduction band of g‐C3N4 to the Zn3(PO4)2 which makes well‐separated electron‐hole pairs. The degradation capacity increases with an increase in the pH of the solution up to 8 and then decreases up to 10 and then again starts increasing. The addition of scavengers decreases degradation capacity of g‐C3N4/Zn3(PO4)2 composite in the order of Ethylene diamine tetra‐acetic acid‐Na2 (EDTA)>tert‐butyl alcohol (TBA)>L‐ascorbic acid (AA). The degradation of CV over g‐C3N4/Zn3(PO4)2 composite mainly attributed by the holes. The interfering anions (except Br−) decrease the degradation capacity of Zn3(PO4)2 whereas in the case of composite no change in the degradation capacity was observed. The recycling experiment for the degradation of CV dye was performed on bare Zn3(PO4)2 and g‐C3N4/Zn3(PO4)2 composite and found better stability and recyclability of the composite material.
Universal Fabrication of Highly Efficient Plasmonic Thin‐Films for Label‐Free SERS Detection
Authors: Gullace Sara , Montes‐García Verónica , Martín Victor , Larios David , Girelli Consolaro Valentina , Obelleiro Fernando , Calogero Giuseppe , Casalini Stefano , Samorì Paolo
Published: July 2021

The development of novel, highly efficient, reliable, and robust surface enhanced Raman scattering (SERS) substrates containing a large number of hot spots with programmed size, geometry, and density is extremely interesting since it allows the sensing of numerous (bio‐)chemical species. Herein, an extremely reliable, easy to fabricate, and label‐free SERS sensing platform based on metal nanoparticles (NPs) thin‐film is developed by the layer‐by‐layer growth mediated by polyelectrolytes. A systematic study of the effect of NP composition and size, as well as the number of deposition steps on the substrate's performance, is accomplished by monitoring the SERS enhancement of 1‐naphtalenethiol (532 nm excitation). Distinct evidence of the key role played by the interlayer (poly(diallyldimethylammonium chloride) (PDDA) or PDDA‐functionalized graphene oxide (GO@PDDA)) on the overall SERS efficiency of the plasmonic platforms is provided, revealing in the latter the formation of more uniform hot spots by regulating the interparticle distances to 5 ± 1 nm. The SERS platform efficiency is demonstrated via its high analytical enhancement factor (≈106) and the detection of a prototypical substance(tamoxifen), both in Milli‐Q water and in a real matrix, viz. tap water, opening perspectives towards the use of plasmonic platforms for future high‐performance sensing applications.
Covalent Organic Framework Membranes for Efficient Chemicals Separation
Authors: Wang Rui , Guo Jiaxing , Xue Jian , Wang Haihui
Published: July 2021

Covalent organic frameworks (COFs) are an emerging class of organic porous crystalline materials that are composed entirely by organic linkers and connected by strong covalent bonds. The unique characteristics including well‐ordered and tailorable pore channels, high and permanent porosity, excellent thermostability and chemical stability, and ease of functionalization enable COFs to perfectly meet the requirements for the fabrication of advanced separation membranes. Significant progress has been made in the preparation and application of COF membranes over the past few years. Herein, the structure—performance relationship of COF materials on membrane separation is first proposed. The effects of the intrinsic properties of COF materials on membrane separation performance are systematically summarized. The fabrication methods of COF membranes, including both bottom‐up strategy (in situ growth and interface‐assisted synthesis) and top‐down strategy (blending and layer‐by‐layer [LBL] stacking), are then discussed in detail. The application of COF membranes in gas separation (H2 purification, CO2 capture, hydrocarbon separation) and liquid phase separation (water treatment, organic solvent nanofiltration, pervaporation) is highlighted. Finally, the remaining challenges and issues to be resolved in the COF membranes are prospected from the perspective of COF materials.
Finite‐Control‐SetModel Predictive Control for Asymmetrical CascadedH‐BridgeMultilevelGrid‐ConnectedInverter with Flying Capacitor
Authors: Han Jingang , Liu Liang , Yao Gang , Tang Tianhao
Published: July 2021

The multilevel inverter is the most advanced power conversion system, whose main advantage is to improve power quality and efficiency. Cascaded H‐bridge (CHB) multilevel inverter is a kind of inverter that can be selected in the field of motor drive systems, electric vehicles and photovoltaic grid‐connected power generations. However, the CHB multilevel inverters require a great deal of independent direct current (dc) power supplies, which makes the realization of these inverters very complicated in practical applications. In this article, model predictive control for CHB inverter with flying capacitors is proposed to improve the above drawbacks. Simulation and experimental results show that voltage balance of the flying capacitor can be maintained and simultaneously the output voltage of the inverter normally. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.
The Detailed Representation and Computation of the Traction Network and its Application to the Transient Analysis in Electrified Railways
Authors: Zhai Yating , Wu Mingli , Ying Yichen , Li Jing
Published: July 2021

This paper intends to derive a detailed representation and attain a suitable computation method for the traction network. The transient analysis of the lossy multiconductor transmission lines (MTLs) is performed considering the electromagnetic characteristics of the rail track, which accounts for the frequency‐dependent and distributed nature of the line parameters over the entire frequency range for the traction network. Due to the practical difficulty in wideband parameter determination and the complex layout for the traction power supply system, the model implemented has been validated by comparison to several field tests that are carried out on a real high speed railway line for the purpose of identifying possible power quality problem. The good high representation of the frequency‐dependent parameter and the numerical solution will provide a reliable method for the transient analysis of the electrified railway. Afterwards, the transient calculation using vector fitting and modal decomposition is presented to evaluate how the emission is propagating along the MTLs of the electrified railways. Performing detailed and suitable analysis is necessary to determine the overvoltage conditions during the transients. The outcome of the analysis could be beneficial for the transient protection study in the electrified railway system. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.
Hybrid urology conferences: using innovation and new approaches
Authors: Newman Thomas H , Green James SA
Published: July 2021

Medical conferences evolved into virtual meetings in response to the COVID‐19 pandemic. While the virtual format has advantages, many prospective attendees look forward to a time when some face‐to‐face interaction will be possible again. The question is how to make such hybrid events successful.
The effect of resin uptake on the flexural properties of compression molded sandwich composites
Authors: Cao Dongyang , Malakooti Sadeq , Kulkarni Vijay N. , Ren Yao , Liu Yingjian , Nie Xu , Qian Dong , Griffith D. Todd , Lu Hongbing
Published: July 2021

Resin uptake plays a critical role in the stiffness‐to‐weight ratio of wind turbine blades in which sandwich composites are used extensively. This work examines the flexural properties of nominally half‐inch thick sandwich composites made with polyvinyl chloride (PVC) foam cores (H60 and H80; PSC and GPC) at several resin uptakes. We found that the specific flexural strength and modulus for the H80 GPC sandwich composites increase from 82.04 to 90.70 kN · m/kg and 6.03 to 7.13 MN · m/kg, respectively, with 11.0% resin uptake reduction, which stands out among the four core sandwich composites. Considering reaching a high stiffness‐to‐weight ratio while preventing resin starvation, 32% to 38% and 40% to 45% resin uptakes are adequate ranges for the H80 PSC and GPC sandwich composites, respectively. The H60 GPC sandwich composites have lower debonding toughness than H60 PSC due to stress concentration in the smooth side skin‐core interphase region. The ailure mode of the sandwich composites depends on the core stiffness and surface texture. The H60 GPC sandwich composites exhibit core shearing and bottom skin‐core debonding failure, while the H80 GPC and PSC sandwich composites show top skin cracking and core crushing failure. The findings indicate that an appropriate range of resin uptake exists for each type of core sandwich composite, and that within the range, a low‐resin uptake leads to lighter blades and thus lower cyclic gravitational loads, beneficial for long blades.
Parton distributions in the SMEFT from high-energy Drell-Yan tails
Authors: Greljo Admir , Iranipour Shayan , Kassabov Zahari , Madigan Maeve , Moore James , Rojo Juan , Ubiali Maria , Voisey Cameron
Published: July 2021

Abstract

The high-energy tails of charged- and neutral-current Drell-Yan processes provide important constraints on the light quark and anti-quark parton distribution functions (PDFs) in the large-x region. At the same time, short-distance new physics effects such as those encoded by the Standard Model Effective Field Theory (SMEFT) would induce smooth distortions to the same high-energy Drell-Yan tails. In this work, we assess for the first time the interplay between PDFs and EFT effects for high-mass Drell-Yan processes at the LHC and quantify the impact that the consistent joint determination of PDFs and Wilson coefficients has on the bounds derived for the latter. We consider two well-motivated new physics scenarios: 1) electroweak oblique corrections ($$ \hat{W},\hat{Y} $$

W
̂

,

Y
̂

) and 2) four-fermion interactions potentially related to the LHCb anomalies in R(K(*)). We account for available Drell-Yan data, both from unfolded cross sections and from searches, and carry out dedicated projections for the High-Luminosity LHC. Our main finding is that, while the interplay between PDFs and EFT effects remains moderate for the current dataset, it will become a significant challenge for EFT analyses at the HL-LHC.
TwInflation
Authors: Deshpande Kaustubh , Kumar Soubhik , Sundrum Raman
Published: July 2021

Abstract

The general structure of Hybrid Inflation remains a very well-motivated mechanism for lower-scale cosmic inflation in the face of improving constraints on the tensor-to-scalar ratio. However, as originally modeled, the “waterfall” field in this mechanism gives rise to a hierarchy problem (η−problem) for the inflaton after demanding standard effective field theory (EFT) control. We modify the hybrid mechanism and incorporate a discrete “twin” symmetry, thereby yielding a viable, natural and EFT-controlled model of non-supersymmetric low-scale inflation, “Twinflation”. Analogously to Twin Higgs models, the discrete exchange-symmetry with a “twin” sector reduces quadratic sensitivity in the inflationary potential to ultra-violet physics, at the root of the hierarchy problem. The observed phase of inflation takes place on a hilltop-like potential but without fine-tuning of the initial inflaton position in field-space. We also show that all parameters of the model can take natural values, below any associated EFT-cutoff mass scales and field values, thus ensuring straightforward theoretical control. We discuss the basic phenomenological considerations and constraints, as well as possible future directions.
On local and integrated stress-tensor commutators
Authors: Besken Mert , de Boer Jan , Mathys Grégoire
Published: July 2021

Abstract

We discuss some general aspects of commutators of local operators in Lorentzian CFTs, which can be obtained from a suitable analytic continuation of the Euclidean operator product expansion (OPE). Commutators only make sense as distributions, and care has to be taken to extract the right distribution from the OPE. We provide explicit computations in two and four-dimensional CFTs, focusing mainly on commutators of components of the stress-tensor. We rederive several familiar results, such as the canonical commutation relations of free field theory, the local form of the Poincaré algebra, and the Virasoro algebra of two-dimensional CFT. We then consider commutators of light-ray operators built from the stress-tensor. Using simplifying features of the light sheet limit in four-dimensional CFT we provide a direct computation of the BMS algebra formed by a specific set of light-ray operators in theories with no light scalar conformal primaries. In four-dimensional CFT we define a new infinite set of light-ray operators constructed from the stress-tensor, which all have well-defined matrix elements. These are a direct generalization of the two-dimensional Virasoro light-ray operators that are obtained from a conformal embedding of Minkowski space in the Lorentzian cylinder. They obey Hermiticity conditions similar to their two-dimensional analogues, and also share the property that a semi-infinite subset annihilates the vacuum.
Sawyer-type inequalities for Lorentz spaces
Authors: Pérez Carlos , Roure-Perdices Eduard
Published: July 2021

The Hardy-Littlewood maximal operator M satisfies the classical Sawyer-type estimate $$\begin{aligned} \left\| \frac{Mf}{v}\right\| _{L^{1,\infty }(uv)} \le C_{u,v} \Vert f \Vert _{L^{1}(u)}, \end{aligned}$$

Mf

v

L

1
,
∞

(
u
v
)

≤

C

u
,
v

‖
f
‖

L
1

(
u
)

,

where $$u\in A_1$$

u
∈

A
1

and $$uv\in A_{\infty }$$

u
v
∈

A
∞

. We prove a novel extension of this result to the general restricted weak type case. That is, for $$p>1$$

p
>
1

, $$u\in A_p^{{\mathcal {R}}}$$

u
∈

A
p
R

, and $$uv^p \in A_\infty $$

u

v
p

∈

A
∞

, $$\begin{aligned} \left\| \frac{Mf}{v}\right\| _{L^{p,\infty }(uv^p)} \le C_{u,v} \Vert f \Vert _{L^{p,1}(u)}. \end{aligned}$$

Mf

v

L

p
,
∞

(
u

v
p

)

≤

C

u
,
v

‖
f
‖

L

p
,
1

(
u
)

.

From these estimates, we deduce new weighted restricted weak type bounds and Sawyer-type inequalities for the m-fold product of Hardy-Littlewood maximal operators. We also present an innovative technique that allows us to transfer such estimates to a large class of multi-variable operators, including m-linear Calderón-Zygmund operators, avoiding the $$A_\infty $$

A
∞

extrapolation theorem and producing many estimates that have not appeared in the literature before. In particular, we obtain a new characterization of $$A_p^{{\mathcal {R}}}$$

A
p
R

. Furthermore, we introduce the class of weights that characterizes the restricted weak type bounds for the multi(sub)linear maximal operator $${\mathcal {M}}$$
M
, denoted by $$A_{\mathbf {P}}^{{\mathcal {R}}}$$

A

P

R

, establish analogous bounds for sparse operators and m-linear Calderón-Zygmund operators, and study the corresponding multi-variable Sawyer-type inequalities for such operators and weights. Our results combine mixed restricted weak type norm inequalities, $$A_p^{{\mathcal {R}}}$$

A
p
R

and $$A_{\mathbf {P}}^{{\mathcal {R}}}$$

A

P

R

weights, and Lorentz spaces.
Development and certification of a reference material for zearalenone in maize germ oil
Authors: Riedel Juliane , Recknagel Sebastian , Sassenroth Diana , Mauch Tatjana , Buttler Sabine , Sommerfeld Thomas , Penk Sibylle , Koch Matthias
Published: July 2021

Zearalenone (ZEN), an estrogenic mycotoxin produced by several species of Fusarium fungi, is a common contaminant of cereal-based food worldwide. Due to frequent occurrences associated with high levels of ZEN, maize oil is a particular source of exposure. Although a European maximum level for ZEN in maize oil exists according to Commission Regulation (EC) No. 1126/2007 along with a newly developed international standard method for analysis, certified reference materials (CRM) are still not available. To overcome this lack, the first CRM for the determination of ZEN in contaminated maize germ oil (ERM®-BC715) was developed in the frame of a European Reference Materials (ERM®) project according to the requirements of ISO Guide 35. The whole process of CRM development including preparation, homogeneity and stability studies, and value assignment is presented. The assignment of the certified mass fraction was based upon an in-house study using high-performance liquid chromatography isotope dilution tandem mass spectrometry. Simultaneously, to support the in-house certification study, an interlaboratory comparison study was conducted with 13 expert laboratories using different analytical methods. The certified mass fraction and expanded uncertainty (k = 2) of ERM®-BC715 (362 ± 22) μg kg−1 ZEN are traceable to the SI. This reference material is intended for analytical quality control and contributes to the improvement of consumer protection and food safety.

Graphical abstract
Molecular Evolution of Tooth-Related Genes Provides New Insights into Dietary Adaptations of Mammals
Authors: Mu Yuan , Tian Ran , Xiao Linlin , Sun Di , Zhang Zepeng , Xu Shixia , Yang Guang
Published: July 2021

Mammals have evolved different tooth phenotypes that are hypothesized to be associated with feeding habits. However, the genetic basis for the linkage has not been well explored. In this study, we investigated 13 tooth-related genes, including seven enamel-related genes (AMELX,AMBN,ENAM,AMTN,ODAM,KLK4andMMP20) and six dentin-related genes (DSPP,COL1A1,DMP1,IBSP,MEPEandSPP1), from 63 mammals to determine their evolutionary history. Our results showed that different evolutionary histories have evolved among divergent feeding habits in mammals. There was stronger positive selection for eight genes (ENAM,AMTN,ODAM,KLK4,DSPP,DMP1,COL1A1,MEPE) in herbivore lineages. In addition,AMELX,AMBN,ENAM,AMTN,MMP20andCOL1A1underwent accelerated evolution in herbivores. While relatively strong positive selection was detected inIBSP,SPP1, andDSPP, accelerated evolution was only detected forMEPEandSPP1genes among the carnivorous lineages. We found positive selection onAMBNandENAMgenes for omnivorous primates in the catarrhini clade. Interestingly, a significantly positive association between the evolutionary rate ofENAM,ODAM,KLK4,MMP20and the average enamel thickness was found in primates. Additionally, we found molecular convergence in some amino acid sites of tooth-related genes among the lineages whose feeding habit are similar. The positive selection of related genes might promote the formation and bio-mineralization of tooth enamel and dentin, which would make the tooth structure stronger. Our results revealed that mammalian tooth-related genes have experienced variable evolutionary histories, which provide some new insights into the molecular basis of dietary adaptation in mammals.
Presentation of dizziness in individuals with chronic otitis media: data from the multinational collaborative COMQ-12 study
Authors: Tailor Bhavesh V. , Phillips John S. , Nunney Ian , Yung Matthew W. , Doruk Can , Kara Hakan , Kong Taehoon , Quaranta Nicola , Peñaranda Augusto , Bernardeschi Daniele , Dai Chunfu , Kania Romain , Denoyelle Françoise , Tono Tetsuya
Published: July 2021

Purpose

In chronic otitis media (COM), disease chronicity and severity of middle ear inflammation may influence the development of inner ear deficits, increasing the risk of vestibular impairment. This secondary analysis of the multinational collaborative Chronic Otitis Media Questionnaire-12 (COMQ-12) dataset sought to determine the prevalence of vestibular symptoms in patients with COM and identify associated disease-related characteristics.

Methods

Adult patients with a diagnosis of COM in outpatient settings at nine otology referral centers across eight countries were included. We investigated the presence of vestibular symptoms (dizziness and/or disequilibrium) using participant responses to item 6 of a native version of the COMQ-12. Audiometric data and otoscopic assessment were also recorded.

Results

This analysis included 477 participants suffering from COM, with 56.2% (n = 268) reporting at least mild inconvenience related to dizziness or disequilibrium. There was a significant association between air conduction thresholds in the worse hearing ear and presence of dizziness [adjusted odds ratio (AOR), 1.01; 95% CI 1.00–1.02;p = 0.0177]. Study participants in European countries (AOR 1.53; 95% CI 1.03–2.28;p = 0.0344) and Colombia (AOR 2.48; 95% CI 1.25–4.92;p = 0.0096) were more likely to report dizziness than participants in Asian countries. However, ear discharge and cholesteatoma showed no association with dizziness in the adjusted analyses.

Conclusion

Vestibular symptoms contribute to burden of disease in patients with COM and associates with hearing disability in the worse hearing ear. Geographical variation in presentation of dizziness may reflect financial barriers to treatment or cultural differences in how patients reflect on their health state.