bluuebunny/crossref_metadata_2025 huggingface dataset:
Spread‐out Bragg peak proton FLASH irradiation using a clinical synchrocyclotron: Proof of concept and ion chamber characterization
Authors: Darafsheh Arash , Hao Yao , Zhao Xiandong , Zwart Townsend , Wagner Miles , Evans Tucker , Reynoso Francisco , Zhao Tianyu
Published: June 2021

Purpose

The purpose of this work is to (a) demonstrate the feasibility of delivering a spread‐out Bragg peak (SOBP) proton beam in ultra‐high dose rate (FLASH) using a proton therapy synchrocyclotron as a major step toward realizing an experimental platform for preclinical studies, and (b) evaluate the response of four models of ionization chambers in such a radiation field.

Methods

A clinical Mevion HYPERSCAN®synchrocyclotron was adjusted for ultra‐high dose rate proton delivery. Protons with nominal energy of 230 MeV were delivered in pulses with temporal width ranging from 12.5 μs to 24 μs spanning from conventional to FLASH dose rates. A boron carbide absorber and a range modulator block were placed in the beam path for range modulation and creating an SOBP dose profile. The radiation field was defined by a brass aperture with 11 mm diameter. Two Faraday cups were used to determine the number of protons per pulse at various dose rates. The dosimetric response of two cylindrical (IBA CC04 and CC13) and two plane‐parallel (IBA PPC05 and PTW Advanced Markus®) ionization chambers were evaluated. The dose rate was measured using the plane‐parallel ionization chambers. The integral depth dose (IDD) was measured with a PTW Bragg Peak®ionization chamber. The lateral beam profile was measured with EBT‐XD radiochromic film. Monte Carlo simulation was performed in TOPAS as the secondary check for the measurements and as a tool for further optimization of the range modulators’ design.

Results

Faraday cups measurement showed that the maximum protons per pulse is 39.9 pC at 24 μs pulse width. A good agreement between the measured and simulated IDD and lateral beam profiles was observed. The cylindrical ionization chambers showed very high ion recombination and deemed not suitable for absolute dosimetry at ultra‐high dose rates. The average dose rate measured using the PPC05 ionization chamber was 163 Gy/s at the pristine Bragg peak and 126 Gy/s at 1 cm depth for the SOBP beam. The SOBP beam range and modulation were measured 24.4 mm and 19 mm, respectively. The pristine Bragg peak beam had 25.6 mm range. Simulation results showed that the IDD and profile flatness can be improved by the cavity diameter of the range modulator and the number of scanned spots, respectively.

Conclusions

Feasibility of delivering protons in an SOBP pattern with >100 Gy/s average dose rate using a clinical synchrocyclotron was demonstrated. The dose heterogeneity can be improved through optimization of the range modulator and number of delivered spots. Plane‐parallel chambers with smaller gap between electrodes are more suitable for FLASH dosimetry compared to the other ion chambers used in this work.
Biomarkers in Duchenne and Becker muscular dystrophies
Authors: McMillan Hugh J. , Lochmüller Hanns
Published: June 2021

See article on pages 43–49 in this issue.
Zinc deficiency and its association with treatment‐related toxicity in children with cancer
Authors: Chung Jong H. , Phalke Neelam , Hastings Caroline , Killilea David W. , Feusner James H. , Fung Ellen B.
Published: June 2021

Background

Nutritional deficiencies in children with cancer at time of diagnosis and during treatment may negatively affect disease outcome and increase treatment‐related toxicity. Yet zinc, an essential nutrient important for supporting immune function and known for reducing diarrheal episodes, is rarely assessed in these children.

Procedures

Fifty children (1 month to 18 years) with recently diagnosed cancer were enrolled in this study. An age and gender matched control group (n = 50) was also recruited. Plasma and urinary zinc, plasma copper, and C‐reactive protein (CRP) levels were measured at baseline, 3, and 6 months following diagnosis. A retrospective review of the toxicity profile was performed in the cohort of children with cancer for the first 4 years after initial diagnosis.

Results

CRP and plasma copper (both acute‐phase reactants) were elevated in patients with cancer compared to controls at baseline, bothp < .03. Plasma zinc levels were not significantly different from controls at baseline, but decreased by 11% in the cancer group over 6 months of treatment, 83.2 ± 15.6 to 74.3 ± 14.8 μg/dl,p = .01. Plasma zinc dropped to deficient levels in 35% of cases over the initial 6 months. Zinc deficiency at 6 months was related to an increased incidence of severe diarrhea during 4 years of follow‐up,p < .001.

Conclusions

Zinc deficiency is an underrecognized problem among patients undergoing treatment for cancer and is associated with severe diarrhea. Further studies are needed to evaluate causes for zinc deficiency, related effects, and a possible role for zinc supplementation.
The intersectionality of gender and poverty on symptom suffering among adolescents with cancer
Authors: Lyon Maureen E. , Cheng Yao I. , Needle Jennifer , Friebert Sarah , Baker Justin N. , Jiang Jiji , Wang Jichuan
Published: June 2021

Background

To determine if the intersectionality of gender and poverty is associated with health disparities among adolescents with cancer. We hypothesized unobserved latent classes of patients exist with respect to cancer‐related symptoms; and class classification varies by gender–poverty combinations.

Procedure

Cross‐sectional data were collected among adolescents with cancer and families (N = 126 dyads) at four tertiary pediatric hospitals. Adolescents were aged 14–21 years, English speaking, cancer diagnosis, not developmentally delayed, psychotic, homicidal, suicidal, or severely depressed. Latent class analysis and multinomial logit models were used for analysis. Patient‐Reported Outcomes Measurement Information System (PROMIS) pediatric symptom measures, Short forms, evaluated anxiety, depressive symptoms, pain interference, and fatigue. Family‐reported household income used 2016 Federal Poverty Level (FPL) guidelines.

Results

Three distinct groups of patients were identified using PROMIS symptom patterns: High Distress‐25%; High Physical/Low Psychological Distress‐14%; and Low Distress‐62%. Female adolescents living in households with incomes at or below the 2016 FPL had 30 times the odds of being classified in the High Distress class (higher probabilities of experiencing anxiety, depressive symptoms, pain interference, and fatigue) compared to those in the High Physical/Low Psychological Distress class (female and poverty: AOR = 30.27, 95% CI 1.23, 735.10), and this was statistically significant (β = 3.41, 95% CI 0.21, 6.60; p = .04) but not compared to those in Low Distress.

Conclusion

Adolescent females with cancer with households in poverty had significantly greater odds of experiencing high symptom distress, compared to those with high physical but low psychological distress. More comprehensive screening and intervention, as needed, may decrease disparities.
Influence of fiber surface treatment on the tribological properties of Calotropis gigantea plant fiber reinforced polymer composites
Authors: Ramesh Manickam , Deepa Chinnaiyan , Rajeshkumar Lakshminarasimhan , Tamil Selvan Manickam , Balaji Devarajan
Published: June 2021

Recent era witnessed a tremendous growth in utilization of plant fibers to make composite materials, and their industrial applications have multiplied many folds. All these utilizations were kindled by the advantageous features of the plant fibers and their potential to substitute the currently used synthetic fibers in almost all the applications. Current work falls in line with the abovementioned statements, and Calotropis gigantea fibers (CGFs) are reinforced with epoxy matrix to fabricate composite materials. The fiber surfaces were modified with sodium hydroxide (NaOH) and potassium permanganate (KMnO4) solutions. The CGFs reinforced composites with epoxy matrix were fabricated with the aid of compression molding technique and the samples were subjected to wear tests. The effect of fiber surface modification over the tribological characteristics of these composites such as frictional force, coefficient of friction, and rate of wear was evaluated by varying the time of wear from 40 to 1040 s at an interval of 40 s. From the results, it is found that the weight loss varies between 0.0013 and 0.0018g. Scanning electron microscopy studies are also carried out to observe the surfaces of the samples before and after wear tests. Experimental results portrayed that NaOH treated CGF composites rendered better tribological behavior when compared with untreated and KMnO4 treated CGF composites.
Effects of crosslinking density and Lewis acidic sites on conductivity and viscoelasticity of dynamic network electrolytes
Authors: Jing Brian B. , Mata Patricia , Zhao Qiujie , Evans Christopher M.
Published: June 2021

Polymers are promising materials for replacing organic liquids as electrolytes, and network architectures allow for the modulus to be tuned pseudo‐independently of conductivity. When the crosslinks are dynamic bonds, they offer the additional benefits of recyclability and self‐healing in response to damage. Dynamic network electrolytes (DNEs) comprised of precise linker lengths of 2, 3, or 4 repeat units of ethylene oxide and boronic ester junctions were prepared to investigate the roles of dense networks and bond exchange on conductivity and rheological properties. A range of salt concentrations were probed, and longer linker lengths led to consistently higher conductivities even after accounting for difference in the glass transition. In contrast, non‐monotonic trends are observed in the salt dependence of viscosity as a function of linker length. The interaction of anions from the salt with boron leads to a drop in the viscosity, and at a critical salt content the networks no longer form a percolated network. From the bulk viscosity, a Walden Plot shows a transition from superionic to subionic behavior with added salt. These structure–property relationships offer key valuable insights for designing sustainable electrolytes.
Pediatric Pulmonology 2020 year in review: Asthma
Authors: Barber Andrew T. , Loughlin Ceila E.
Published: June 2021

Pediatric asthma is a heterogeneous and common chronic condition with significant morbidity and burden on the healthcare system. Despite advances in the field, the disease has proven to be increasingly complex to diagnose and management strategies are constantly evolving. Studies from 2020 have advanced the field even further, particularly with regard to new methods of diagnosis and monitoring, treatment of severe asthma, modifiable risk factors like exercise and obesity, aerosol delivery, and viral respiratory infections contributing to the development of asthma. Continued studies are needed to improve our care for children with asthma and we look forward to future advances. This article is part of our 2020 “Year in Review” series, in which we summarize publications in major topic areas, in the context of selected literature from other journals relevant to our discipline.
Interobserver agreement in interpretation of chest radiographs for pediatric community acquired pneumonia: Findings of the pedCAPNETZ‐cohort
Authors: Voigt Gesche M. , Thiele Dominik , Wetzke Martin , Weidemann Jürgen , Parpatt Patricia‐Maria , Welte Tobias , Seidenberg Jürgen , Vogelberg Christian , Koster Holger , Rohde Gernot G. U. , Härtel Christoph , Hansen Gesine , Kopp Matthias V.
Published: June 2021

Although chest radiograph (CXR) is commonly used in diagnosing pediatric community acquired pneumonia (pCAP), limited data on interobserver agreement among radiologists exist. PedCAPNETZ is a prospective, observational, and multicenter study on pCAP. N = 233 CXR from patients with clinical diagnosis of pCAP were retrieved and n = 12 CXR without pathological findings were added. All CXR were interpreted by a radiologist at the site of recruitment and by two external, blinded pediatric radiologists. To evaluate interobserver agreement, the reporting of presence or absence of pCAP in CXR was analyzed, and prevalence and bias‐adjusted kappa (PABAK) statistical testing was applied. Overall, n = 190 (82%) of CXR were confirmed as pCAP by two external pediatric radiologists. Compared with patients with pCAP negative CXR, patients with CXR‐confirmed pCAP displayed higher C‐reactive protein levels and a longer duration of symptoms before enrollment (p < .007). Further parameters, that is, age, respiratory rate, and oxygen saturation showed no significant difference. The interobserver agreement between the onsite radiologists and each of the two independent pediatric radiologists for the presence of pCAP was poor to fair (69%; PABAK = 0.39% and 76%; PABAK = 0.53, respectively). The concordance between the external radiologists was fair (81%; PABAK = 0.62). With regard to typical CXR findings for pCAP, chance corrected interrater agreement was highest for pleural effusions, infiltrates, and consolidations and lowest for interstitial patterns and peribronchial thickening. Our data show a poor interobserver agreement in the CXR‐based diagnosis of pCAP and emphasized the need for harmonized interpretation standards.
Rheostat functional outcomes occur when substitutions are introduced at nonconserved positions that diverge with speciation
Authors: Swint‐Kruse Liskin , Martin Tyler A. , Page Braelyn M. , Wu Tiffany , Gerhart Paige M. , Dougherty Larissa L. , Tang Qingling , Parente Daniel J. , Mosier Brian R. , Bantis Leonidas E. , Fenton Aron W.
Published: June 2021

When amino acids vary during evolution, the outcome can be functionally neutral or biologically‐important. We previously found that substituting a subset of nonconserved positions, “rheostat” positions, can have surprising effects on protein function. Since changes at rheostat positions can facilitate functional evolution or cause disease, more examples are needed to understand their unique biophysical characteristics. Here, we explored whether “phylogenetic” patterns of change in multiple sequence alignments (such as positions with subfamily specific conservation) predict the locations of functional rheostat positions. To that end, we experimentally tested eight phylogenetic positions in human liver pyruvate kinase (hLPYK), using 10–15 substitutions per position and biochemical assays that yielded five functional parameters. Five positions were strongly rheostatic and three were non‐neutral. To test the corollary that positions with low phylogenetic scores were not rheostat positions, we combined these phylogenetic positions with previously‐identified hLPYK rheostat, “toggle” (most substitution abolished function), and “neutral” (all substitutions were like wild‐type) positions. Despite representing 428 variants, this set of 33 positions was poorly statistically powered. Thus, we turned to the in vivo phenotypic dataset for E. coli lactose repressor protein (LacI), which comprised 12–13 substitutions at 329 positions and could be used to identify rheostat, toggle, and neutral positions. Combined hLPYK and LacI results show that positions with strong phylogenetic patterns of change are more likely to exhibit rheostat substitution outcomes than neutral or toggle outcomes. Furthermore, phylogenetic patterns were more successful at identifying rheostat positions than were co‐evolutionary or eigenvector centrality measures of evolutionary change.
Mitigation of the convergence issues associated with semi‐replicated bioequivalence data
Authors: Fuglsang Anders
Published: June 2021

Semi‐replicated designs for investigation of bioequivalence constitute a challenge when mixed models are applied. With the commonly available packages and regardless of choice of covariance structure the software may force variance components into the covariance matrix that render it over‐specified. This may give rise to arbitrary estimates of certain variance components, lack of convergence or warnings. Classically the covariance matrix is decomposed as V = ZGZt + R, with G containing the between‐subject variance components, Z being the design matrix for the random effects and R containing the within‐subject variance components. By abandoning the definitions of G and R, and instead working directly in V, it is possible to specify a correct model with only the variance components of interest. Proof‐of‐concept for this idea is delivered with a script in the statistical language R. The script is available as supplementary material (Data S1).
Moving average control charts for the rayleigh and inverse rayleigh distributions under time truncated life test
Authors: Adeoti Olatunde Adebayo , Gadde Srinivasa Rao
Published: June 2021

In this paper, the moving average control chart is developed under time truncated test to monitor the number of failures when the lifetime of an item follows the Rayleigh and inverse Rayleigh distributions. The number of failures is detected when a planned number of items has been placed on a time truncated testing experiment. The average run lengths (ARL) for various parameter settings are used to evaluate the performance of the proposed control chart. Also, the control chart parameters such as test time multiplier () and chart coefficient (k) are obtained by contemplating the in‐control ARL for various sample sizes. The study revealed that the proposed control chart outperform the existing time truncated attribute control chart in the quick detection of shifts in process parameters. The application of the proposed chart methodology is also demonstrated using simulated data.
Objective evaluation of technical dexterity in robotic hepaticojejunostomy: Assessment of hepatopancreatobiliary fellows using cumulative sum analytics
Authors: Robinson Jordan , Watson Michael , Baimas‐George Maria , Iannitti David , Martinie John , Vrochides Dionisios
Published: June 2021

Background

The development of technical dexterity is a critical for surgeons in training. This study describes and assesses the feasibility of an objective method for the evaluation of procedure‐specific technical dexterity in hepatopancreatobiliary (HPB) surgery using cumulative sum (CUSUM) analysis.

Methods

Dry‐lab HPB procedures were divided into procedural steps with binary outcomes (success or failure). Two HPB fellows completed 20 dry lab hepaticojejunostomy (HJ) procedures. Participant progress was tracked over time with CUSUM analytics to establish a learning curve for procedural proficiency.

Results

The CUSUM charts for 20 consecutive dry‐lab HJ procedures were analysed. A learning curve was created and used to identify areas of weakness to facilitate improvement in technical proficiency.

Conclusions

CUSUM is effective tool for objective evaluation of technical dexterity offering both simplicity and adaptability. We demonstrate its use and feasibility for surgical education and plan to expand its’ application to assess residents performing general surgery procedures.
Optimal allocation in stratified cluster‐based outcome‐dependent sampling designs
Authors: Sauer Sara , Hedt‐Gauthier Bethany , Haneuse Sebastien
Published: June 2021

In public health research, finite resources often require that decisions be made at the study design stage regarding which individuals to sample for detailed data collection. At the same time, when study units are naturally clustered, as patients are in clinics, it may be preferable to sample clusters rather than the study units, especially when the costs associated with travel between clusters are high. In this setting, aggregated data on the outcome and select covariates are sometimes routinely available through, for example, a country's Health Management Information System. If used wisely, this information can be used to guide decisions regarding which clusters to sample, and potentially obtain gains in efficiency over simple random sampling. In this article, we derive a series of formulas for optimal allocation of resources when a single‐stage stratified cluster‐based outcome‐dependent sampling design is to be used and a marginal mean model is specified to answer the question of interest. Specifically, we consider two settings: (i) when a particular parameter in the mean model is of primary interest; and, (ii) when multiple parameters are of interest. We investigate the finite population performance of the optimal allocation framework through a comprehensive simulation study. Our results show that there are trade‐offs that must be considered at the design stage: optimizing for one parameter yields efficiency gains over balanced and simple random sampling, while resulting in losses for the other parameters in the model. Optimizing for all parameters simultaneously yields smaller gains in efficiency, but mitigates the losses for the other parameters in the model.
Bayesian sensitivity analyses for longitudinal data with dropouts that are potentially missing not at random: A high dimensional pattern‐mixture model
Authors: Kaciroti Niko A. , Little Roderick J.A.
Published: June 2021

Randomized clinical trials with outcome measured longitudinally are frequently analyzed using either random effect models or generalized estimating equations. Both approaches assume that the dropout mechanism is missing at random (MAR) or missing completely at random (MCAR). We propose a Bayesian pattern‐mixture model to incorporate missingness mechanisms that might be missing not at random (MNAR), where the distribution of the outcome measure at the follow‐up time , conditional on the prior history, differs across the patterns of missing data. We then perform sensitivity analysis on estimates of the parameters of interest. The sensitivity parameters relate the distribution of the outcome of interest between subjects from a missing‐data pattern at time with that of the observed subjects at time . The large number of the sensitivity parameters is reduced by treating them as random with a prior distribution having some pre‐specified mean and variance, which are varied to explore the sensitivity of inferences. The missing at random (MAR) mechanism is a special case of the proposed model, allowing a sensitivity analysis of deviations from MAR. The proposed approach is applied to data from the Trial of Preventing Hypertension.
Halogenation of the Side Chains in Donor‐Acceptor Based Small Molecules for Photovoltaic Applications: Energetics and Charge‐Transfer Properties from DFT/TDDFT Studies
Authors: Shavez Mohd , Ray Anuj Kumar , Panda Aditya N.
Published: June 2021

Incorporation of halogen atoms in conjugated polymer and small molecule (SM) based donors has been a practical approach to improve the efficiency of devices. In this report, we present a comprehensive study on the effects of halogenation of the side chains of three SM donors on the structural, optoelectronic, and charge‐transfer properties of donors and donor/PC61BM blends. Starting with experimentally prepared three novel SM donors with three different lateral side chains, we have computationally designed three halogenated donor SMs for each of those three SMs. Properties such as HOMO/LUMO energies, open‐circuit voltages, and charge transfer/recombination rates are calculated. Halogenated systems have deeper HOMO values than parent systems, and as a result, larger open‐circuit voltages are obtained for these new systems. In the halogenated systems, rates of charge‐transfer and charge‐recombination are larger and smaller, respectively, than in the parent systems. All these indicate better photovoltaic performances of these halogenated SM‐based devices.
Advanced Nanocarbons for Enhanced Performance and Durability of Platinum Catalysts in Proton Exchange Membrane Fuel Cells
Authors: Qiao Zhi , Wang Chenyu , Zeng Yachao , Spendelow Jacob S. , Wu Gang
Published: June 2021

Insufficient stability of current carbon supported Pt and Pt alloy catalysts is a significant barrier for proton‐exchange membrane fuel cells (PEMFCs). As a primary degradation cause to trigger Pt nanoparticle migration, dissolution, and aggregation, carbon corrosion remains a significant challenge. Compared with enhancing Pt and PtM alloy particle stability, improving support stability is rather challenging due to carbon's thermodynamic instability under fuel cell operation. In recent years, significant efforts have been made to develop highly durable carbon‐based supports concerning innovative nanostructure design and synthesis along with mechanistic understanding. This review critically discusses recent progress in developing carbon‐based materials for Pt catalysts and provides synthesis–structure–performance correlations to elucidate underlying stability enhancement mechanisms. The mechanisms and impacts of carbon support degradation on Pt catalyst performance are first discussed. The general strategies are summarized to tailor the carbon structures and strengthen the metal–support interactions, followed by discussions on how these designs lead to enhanced support stability. Based on current experimental and theoretical studies, the critical features of carbon supports are analyzed concerning their impacts on the performance and durability of Pt catalysts in fuel cells. Finally, the perspectives are shared on future directions to develop advanced carbon materials with favorable morphologies and nanostructures to increase Pt utilization, strengthen metal‐support interactions, facilitate mass/charge transfer, and enhance corrosion resistance.
Advances in organic thermoelectric materials and devices for smart applications
Authors: Zhao Yue , Liu Liyao , Zhang Fengjiao , Di Chong‐an , Zhu Daoben
Published: June 2021

Organic thermoelectric (OTE) materials have been considered to be promising candidates for large area and low‐cost wearable devices owing to their tailorable molecular structure, intrinsic flexibility, and prominent solution processability. More importantly, OTE materials offer direct energy conversion from the human body, solid‐state cooling at low electric consumption, and diversified functions. Herein, we summarize recent developments of OTE materials and devices for smart applications. We first review the fundamentals of OTE materials from the viewpoint of thermoelectric performance, mechanical properties and bionic functions. Second, we describe OTE devices in flexible generators, photothermoelectric detectors, self‐powered sensors, and ultra‐thin cooling elements. Finally, we present the challenges and perspectives on OTE materials as well as devices in wearable electronics and fascinating applications in the Internet of Things.
Is English consequence compact?
Authors: Paseau A.C. , Griffiths Owen ,   Philosophy Documentation Center
Published: June 2021

By mimicking the standard definition for a formal language, we define what it is for a natural language to be compact. We set out a valid English argument none of whose finite subarguments is valid. We consider one by one objections to the argument's logical validity and then dismiss them. The conclusion is that English—and any other language with the capacity to express the argument—is not compact. This rules out a large class of logics as the correct foundational one, for example any sound and complete logic, and in particular first-order logic. The correct foundational logic is not compact.
The Role of Liquid Biopsies for Monitoring Disease Evolution
Authors: Tinhofer Ingeborg
Published: June 2021

Body fluids of cancer patients have attracted increasing attention in biomedical research within the last 15 years since—as so-called liquid biopsies—they represent a non-invasive source of clinically exploitable biomarkers, including circulating tumor cells (CTCs) and cell-free tumor DNA (ctDNA). Assessment of CTCs in peripheral blood from solid cancer patients has proven useful for detection of subclinical disease which otherwise remains invisible for current staging techniques. Based on results from large cohort studies in breast and colon cancer, diagnostic tests for enumeration of CTCs have been developed which can be used for tumor staging, prognosis, and post-treatment surveillance. Circulating plasma DNA derived from Epstein–Barr or human papilloma viruses has been established as a sensitive and highly specific biomarker for early cancer detection and disease monitoring. More recently, first studies have been initiated for studying the diagnostic value of mutant variants in plasma-derived ctDNA for treatment selection, response assessment and early detection of treatment failure.

Advanced Head and Neck Squamous Cell Carcinoma (HNSCC) represents a malignancy associated with locoregionally advanced stage at presentation, dismal prognosis and little improvement in treatment outcome over the past decade, especially for patients with metastatic disease. HNSCC patients might therefore benefit from incorporation of liquid biopsy-based assays in clinical management. In the following chapters, I will summarize current evidence of the diagnostic value of liquid biopsies in HNSCC and give examples of potential clinical applications.
Novel Approaches in Surgical Management: How to Assess Surgical Margins
Authors: Ferrari Marco , Montalto Nausica , Nicolai Piero
Published: June 2021

The concept of surgical margins was born a long time ago but still lacks a univocal and sound understanding. The current biological rationale behind the recommendations on margins management relies on two pillars: (1) the observation that groups of cancer cells can leave the macroscopic tumor and disseminate throughout adjacent tissues with different degrees of aggressiveness; (2) the belief that removal of all (or most of) cancer cells can cure the patient. However, this background is undermined by some pieces of evidence. For instance, it has been proven that tissues surrounding cancer often bear precancerous traits, which means that cutting through non-cancerous tissues does not equate to cut through healthy tissues. The head and neck exquisitely poses a number of challenges in the achievement of negative margins, with special reference to anatomical complexity, high density in relevant structures, and unique histological heterogeneity of cancers. Currently, intraoperative margins evaluation relies on surgeons’ sight, palpation, ability to map tumor extension on imaging, and knowledge of anatomy, with some optical imaging technologies aiding the delineation of the mucosal margins of excision. Frozen sections are currently used to intraoperatively evaluate margins, yet with debate on whether and how this practice should be performed. Future perspectives on improvement of margins control are threefold: research is oriented towards refinements of understanding of cancers local progression, implementation of technologies to intraoperatively render tumor extension, and employment of optical imaging modalities capable of detecting foci of residual tumor in the surgical bed.
History of the European-Japanese Cerebrovascular Congress
Authors: Tsukahara Tetsuya
Published: June 2021

The European-Japanese Cerebrovascular Congress originally started as a Swiss-Japanese joint conference on cerebral aneurysm. The Congress was held in Zürich, Switzerland, from 5–7 May 2001 with Prof. Y. Yonekawa of Zürich and Prof. Y. Sakurai of Sendai as the presidents.

Three years later, in July of 2004, the second meeting was held at Zürich again with wide-ranging conference topics on cerebral stroke surgery.

The third meeting at Zürich in 2006 was the key congress for future development. The conference was expanded to the European-Japanese Joint Conference for Stroke Surgery.

As the year of 2006 was the 70th Anniversary of the Department of Neurosurgery, University Hospital Zürich, Prof. Krayenbühl, Prof. Yasargil, and Prof. Yonekawa introduced the impressive history of the Department of Neurosurgery at the conference.

At the fourth European-Japanese Joint Conference on Stroke Surgery we moved from Zürich to the Nordic city of Helsinki, with Prof. Juha Hernesniemi as the conference president.

The fifth joint conference was held at Düsseldolf am Rein with Prof. Hans-Jakob Steiger as the Conference president.

The sixth conference, named “The European-Japanese Stroke Surgery Conference” (EJSSC), was held in Utrecht, The Netherlands. Professor Luca Regli and Prof. Gabriel Rinkel were the conference presidents.

The seventh European-Japanese Stroke Surgery Conference (EJSSC) was held in Verona, Italy with the presidents Prof. Alberto Pasqualin and Prof. Giampietro Pinna.

The eighth European-Japanese Cerebrovascular Congress (EJCVC) came back to Zürich in the year 2016 with Prof. Luca Regli as the president.

The ninth European-Japanese Cerebrovascular Congress (EJCVC) was held in the historical room of Grande Ospedale Metropolitano Niguarda Milan, Italy, with Prof. Marco Cenzato as the president.

The tenth European-Japanese Cerebrovascular Congress (EJCVC) will be held in Kyoto. It will be the first meeting of the EJCVC in Japan.

Publication of the proceeding books of the conference as supplements of ACTA Neurochirurgica is one of the main reasons that we have been able to continue this conference for almost 20 years. We sincerely thank Prof. Steiger for his continuous and generous cooperation as the series Editor of ACTA Neurochirurgica.
Complications of Endovascular Treatment of Intracranial Dural Arteriovenous Fistulas
Authors: Kuwayama Naoya , Akioka Naoki
Published: June 2021

Aims: To report the endovascular treatment and complications of intracranial and spinal dural arteriovenous (AV) fistulas. Methods: A retrospective analysis of 863 cases with dural AV fistulas was completed in the nationwide registry study of the Japanese Society of Neuroendovascular Therapy. Results: Treatments included transarterial/transvenous embolization (TAE/TVE), open surgery, stereotactic radiation, and their combinations. Modified Rankin Scale 0 (mRS-0) of the patients before and after treatment were 21% and 68%, and mRS 0-1were 69% and 86%, respectively. Mortality rate after treatment was 0.6%. Major complications of TAE and TVE were cranial nerve palsy and cerebral infarction. Conclusions: Major complications resulted from occlusion of vasa nervosum and material migration via dangerous intracranial and extracranial arterial anastomosis.
Outcomes of Balloon Angioplasty and Stenting for Symptomatic Intracranial Atherosclerotic Stenosis at a High Volume Center
Authors: Ueda Toshihiro , Takada Tatsuro , Usuki Noriko , Takaishi Satoshi , Tokuyama Yoshiaki , Tatsuno Kentaro , Hamada Yuki , Yoshie Tomohide
Published: June 2021

Purpose: This study investigated the periprocedural complication rates, long-term outcome, and restenosis of endovascular treatment for intracranial atherosclerotic stenosis (ICS) at our hospital.

Methods: We retrospectively analyzed the clinical data of 217 patients comprising 256 endovascular treatments for high-grade symptomatic ICS. The lesion was located in the internal carotid artery in 77, the middle cerebral artery in 111, the basilar artery in 29, and the vertebral artery in 39. Patients were divided into two groups, before (early-phase group, 1999–2013) and after approval of Wingspan (late-phase group, 2014–2017).

Results: In the early-phase group (n = 163), 157 lesions were treated by balloon angioplasty and 31 (17%) by coronary stenting. In the late-phase group (n = 54), 33 lesions were treated by balloon angioplasty and 35 (52%) by Wingspan stenting. Overall technical success rates were 96% in the balloon angioplasty and 100% in stenting groups. The 30-day rate of stroke, TIA, and death were 4.8% in the early-phase group and 4.4% in the late-phase group. There was one minor stroke and two TIAs during the follow-up period in the late-phase group.

Conclusions: Endovascular treatment for symptomatic ICS in this study appeared to be safe and effective if patients are properly selected. However, future well-designed randomized trials with different techniques and modified patients selection criteria are certainly warranted.
Fire Following Earthquake—The Potential in Istanbul
Authors: Scawthorn C.
Published: June 2021

Fire following earthquake is a little recognized risk in seismic regions with significant wood building inventories. Methods exist for quantifying this risk, and examples are provided in this chapter for San Francisco, Istanbul and Montreal. There are many opportunities for reducing this risk, and examples are provided regarding reducing fire station vulnerability and improving emergency firefighting water supply. Once accomplished however, vigilance is required to maintain these mitigation measures.
Risk Oriented Earthquake Hazard Assessment: Influence of Spatial Discretisation and Non-ergodic Ground-Motion Models
Authors: Stafford Peter J.
Published: June 2021

Three important aspects of ground-motion modelling for regional or portfolio risk analyses are discussed. The first issue is the treatment of discretisation of continuous ground-motion fields for generating spatially correlated discrete fields. Shortcomings of the present approach in which correlation models based upon point estimates of ground motions are used to represent correlations within and between spatial regions are highlighted. It is shown that risk results will be dependent upon the chosen spatial resolution if the effects of discretisation are not adequately treated. Two aspects of non-ergodic groundmotion modelling are then discussed. Correlation models generally used within risk modelling are traditionally based upon very simple partitioning of ground-motion residuals. As regional risk analyses move to non-ergodic applications where systematic site effects are considered, these correlation models (both inter-period and spatial models) need to be revised. The nature of these revisions are shown herein. Finally, evidence for significantly reduced between-event variability within earthquake sequences is presented. The ability to progressively constrain location and sequence-dependent systematic offsets from ergodic models as earthquake sequences develop can have significant implications for aftershock risk assessments.
Unpacking the New Complexities of EU–Turkey Relations: Merging Theories, Institutions, and Policies
Authors: Turhan Ebru , Reiners Wulf
Published: June 2021

This chapter presents the rationale, objectives, and structure of this volume and introduces the reader to the new complexities that epitomize EU–Turkey relations. To this end, it provides a set of guiding questions for the volume, offers a systematic overview of the major milestones in the EU–Turkey relationship, and classifies the key determinants of these developments under three categories: multilateral frameworks and external crises, internal EU and Turkish domestic developments, and EU–Turkey bilateral processes. The chapter then introduces the three-dimensional approach of the volume that brings together the analytical lenses of (1) theories and concepts, (2) institutions, and (3) policies based on a comprehensive survey of both key primary sources and academic literature dealing with the relationship. In a final step, the chapter presents the ensuing fifteen contributions to the volume.
Turkey as a Special and (Almost) Dead Case of EU Enlargement Policy
Authors: Lippert Barbara
Published: June 2021

This chapter analyzes the relationship between the EU and Turkey from the perspective of the EU’s enlargement policy. It sets out to explain the extent to which Turkey represents a special and difficult case for EU enlargement policy and addresses the following aspects of the relationship. First, the overall concepts, motives, and criteria of EU enlargement are introduced. The second section deals with critical questions that Turkey poses for the EU in this respect. The third section outlines how specific features of the EU–Turkey relationship have played out from the onset and during accession negotiations. While no full or detailed account of the history of relations is given, the focus is on those issues that make Turkey a special and (almost) dead case of EU enlargement policy. Finally, a brief outlook on the future of bilateral relations is presented which shows the persistent ambivalences that characterize Brussels’ relationship with Ankara.
Constructivist Approaches to EU–Turkey Relations
Authors: Aydın-Düzgit Senem , Rumelili Bahar
Published: June 2021

This chapter provides a critical survey of constructivist approaches to EU–Turkey relations, which place significance on the role of norms, identities, discourse, ideas, and values in the relationship. It outlines the main contours of the constructivist school of thought in International Relations (IR) with a discussion of how the different variants of constructivism can be applied to the study of the case of EU–Turkey relations. It is followed by an illustrative survey of the academic contributions in the field of EU–Turkey relations that base their accounts on constructivist theoretical premises in three periods: 1997–1999, 2000–2010, and 2011–2020. The chapter concludes with a discussion of potential areas for further constructivist research on EU–Turkey relations.
Europeanization and EU–Turkey Relations: Three Domains, Four Periods
Authors: Alpan Başak
Published: June 2021

Europeanization is deservedly one of the most popular yet most volatile buzzwords for Turkish politics and EU–Turkey relations. This chapter takes stock of the Europeanization literature and examines the EU–Turkey relationship by referring to particular mechanisms and variants of Europeanization. The main argument is that Europeanization is a versatile and complex process covering vast areas of policy, politics, and polity, intertwined with larger domestic, regional, and global processes, which is not limited to Turkey’s EU accession. The analysis refers to particular mechanisms and variants of Europeanization in four different phases between 1963 and early 2020: In the first period, ‘Europeanization as rapprochement’, Turkey’s age-old Westernization project was consolidated through Europeanization. In the second period, ‘Europeanization as democratic conditionality’, there has been strong interest in the impact of Europeanization on particular aspects of domestic issues through conditionality and the EU’s role as a ‘democratization anchor’. In the third period, ‘Europeanization as retrenchment’, and the fourth period, ‘Europeanization as denial’, ‘Europe’ was no longer the lingua franca in the Turkish political landscape, a trend that is also associated with a ‘de-Europeanization’ turn in the literature. This does not mean that ‘Europe’ completely disappeared from domestic policy orientations, political debates, and identity negotiations. Rather, Ankara used ‘Europe’ strategically to justify actions that were criticized by the EU.
Rhetorical Entrapment in EU–Turkey Relations
Authors: Schimmelfennig Frank
Published: June 2021

This chapter describes and applies the rhetorical action approach to EU–Turkey relations. Generally, rhetorical entrapment denotes the mechanism by which actors are compelled to act in conformance with their prior argumentative commitments. In the context of EU enlargement, member states have committed themselves to enlargement norms and promises in line with the fundamental purpose and values of the EU (such as pan-European community building, liberal democracy and supranationalism). Rhetorical entrapment played an important role in bringing about Eastern enlargement when the Eastern European countries faced significant resistance among the old member states. Finally, the chapter analyzes the rhetorical entrapment mechanism in the accession process of Turkey, which had an even more unfavorable starting position. As long as Turkey progressed on meeting the official political criteria for EU membership, however, the opponents of Turkish membership were bound by their normative commitment and felt compelled to decide in favor of accession negotiations. The rhetorical entrapment mechanism also elucidates why accession negotiations began to stall soon after their start. The opponents of Turkish membership were released from the rhetorical trap when Turkey failed to heed its own promises and honor its own obligations as a candidate state.
SU(3) analysis of four-quark operators: K → ππ and vacuum matrix elements
Authors: Pich A. , Rodríguez-Sánchez A.
Published: June 2021

Abstract

Hadronic matrix elements of local four-quark operators play a central role in non-leptonic kaon decays, while vacuum matrix elements involving the same kind of operators appear in inclusive dispersion relations, such as those relevant inτ-decay analyses. Using an SU(3)L⊗ SU(3)Rdecomposition of the operators, we derive generic relations between these matrix elements, extending well-known results that link observables in the two different sectors. Two relevant phenomenological applications are presented. First, we determine the electroweak-penguin contribution to the kaon CP-violating ratioε′/ε, using the measured hadronic spectral functions inτdecay. Second, we fit our SU(3) dynamical parameters to the most recent lattice data onK→ππmatrix elements. The comparison of this numerical fit with results from previous analytical approaches provides an interesting anatomy of the ∆I=$$ \frac{1}{2} $$12enhancement, confirming old suggestions about its underlying dynamical origin.
Cascade of phase transitions in a planar Dirac material
Authors: Kanazawa Takuya , Kieburg Mario , Verbaarschot Jacobus J.M.
Published: June 2021

Abstract

We investigate a model of interacting Dirac fermions in 2 + 1 dimensions with M flavors and N colors having the U(M)×SU(N ) symmetry. In the large-N limit, we find that the U(M) symmetry is spontaneously broken in a variety of ways. In the vacuum, when the parity-breaking flavor-singlet mass is varied, the ground state undergoes a sequence of M first-order phase transitions, experiencing M + 1 phases characterized by symmetry breaking U(M)→U(M − k)×U(k) with k ∈ {0, 1, 2, · · · , M}, bearing a close resemblance to the vacuum structure of three-dimensional QCD. At finite temperature and chemical potential, a rich phase diagram with first and second-order phase transitions and tricritical points is observed. Also exotic phases with spontaneous symmetry breaking of the form as U(3)→U(1)3, U(4)→U(2)×U(1)2, and U(5)→U(2)2×U(1) exist. For a large flavor-singlet mass, the increase of the chemical potential μ brings about M consecutive first-order transitions that separate the low-μ phase diagram with vanishing fermion density from the high-μ region with a high fermion density.
Renormalization of the C2HDM with FeynMaster 2
Authors: Fontes Duarte , Romão Jorge C.
Published: June 2021

Abstract

We present the one-loop electroweak renormalization of the CP-violating 2-Higgs-Doublet Model with softly broken ℤ2 symmetry (C2HDM). The existence of CP violation in the scalar sector of the model leads to a quite unique process of renormalization, since it requires the introduction of several non-physical parameters. The C2HDM will thus have more independent counterterms than independent renormalized parameters. As a consequence, different combinations of counterterms can be taken as independent for the same set of independent renormalized parameters. We compare the behaviour of selected combinations in specific NLO processes, which are assured to be gauge independent via a simple prescription. FeynMaster 2 is used to derive the Feynman rules, counterterms and one-loop processes in a simultaneously automatic and flexible way. This illustrates its use as an ideal tool to renormalize models such as the C2HDM and investigate them at NLO.
Correction to: Development of certified reference materials for the determination of cadmium and acrylamide in cocoa
Authors: Recknagel Sebastian , Koch Matthias , Köppen Robert , Buttler Sabine , Penk Sibylle , Mauch Tatjana , Sommerfeld Thomas , Witt Angelika
Published: June 2021

A Correction to this paper has been published: 10.1007/s00216-021-03428-y
Counting the Number of τ-Exceptional Sequences over Nakayama Algebras
Authors: Msapato Dixy
Published: June 2021

The notion of a τ-exceptional sequence was introduced by Buan and Marsh in (2018) as a generalisation of an exceptional sequence for finite dimensional algebras. We calculate the number of complete τ-exceptional sequences over certain classes of Nakayama algebras. In some cases, we obtain closed formulas which also count other well known combinatorial objects, and exceptional sequences of path algebras of Dynkin quivers.