bluuebunny/crossref_metadata_2025 huggingface dataset:
Achievements Made in the Building of the National Mineral Deposit Database of China (2020)
Authors: Qi Fanyu , Li Xiaolei , Shang Yuntao , Meng Jie , Gao Xuezheng , Kong Zhaoyu , Li Haixin , Yan Haifei
Published: May 2021

By the end of June 2020, the Database 2020 contained 307,081 pieces of valid mineral deposit data, with an increase of more than 270,000 pieces compared to the 33,794 pieces in the Database 2002.
Significance of the Building of National Mineral Deposit Database of China (2020)
Authors: Qi Fanyu , Li Xiaolei , Shang Yuntao , Meng Jie , Gao Xuezheng , Kong Zhaoyu , Li Haixin , Yan Haifei
Published: May 2021

Data are fundamental strategic resources of a country and are considered as “diamond mines” in the twenty-first century. Xi Jinping, general secretary of the Communist Party of China (CPC) Central Committee, has pointed out that big data is the next stage of informatization development and has significant and profound impacts on the economic development, social progress, and people's lives worldwide.
Dark matter in the type Ib seesaw model
Authors: Chianese M. , Fu B. , King S. F.
Published: May 2021

Abstract

We consider a minimal type Ib seesaw model where the effective neutrino mass operator involves two different Higgs doublets, and the two right-handed neutrinos form a heavy Dirac mass. We propose a minimal dark matter extension of this model, in which the Dirac heavy neutrino is coupled to a dark Dirac fermion and a dark complex scalar field, both charged under a discrete Z2 symmetry, where the lighter of the two is a dark matter candidate. Focussing on the fermionic dark matter case, we explore the parameter space of the seesaw Yukawa couplings, the neutrino portal couplings and dark scalar to dark fermion mass ratio, where correct dark matter relic abundance can be produced by the freeze-in mechanism. By considering the mixing between the standard model neutrinos and the heavy neutrino, we build a connection between the dark matter production and current laboratory experiments ranging from collider to lepton flavour violating experiments. For a GeV mass heavy neutrino, the parameters related to dark matter production are constrained by the experimental results directly and can be further tested by future experiments such as SHiP.
Gravitational waves from dark Yang-Mills sectors
Authors: Halverson James , Long Cody , Maiti Anindita , Nelson Brent , Salinas Gustavo
Published: May 2021

Abstract

Dark Yang-Mills sectors, which are ubiquitous in the string landscape, may be reheated above their critical temperature and subsequently go through a confining first-order phase transition that produces stochastic gravitational waves in the early universe. Taking into account constraints from lattice and from Yang-Mills (center and Weyl) symmetries, we use a phenomenological model to construct an effective potential of the semi quark-gluon plasma phase, from which we compute the gravitational wave signal produced during confinement for numerous gauge groups. The signal is maximized when the dark sector dominates the energy density of the universe at the time of the phase transition. In that case, we find that it is within reach of the next-to-next generation of experiments (BBO, DECIGO) for a range of dark confinement scales near the weak scale.
Exploring the gravity sector of emergent higher-spin gravity: effective action and a solution
Authors: Fredenhagen Stefan , Steinacker Harold C.
Published: May 2021

Abstract

We elaborate the description of the semi-classical gravity sector of Yang-Mills matrix models on a covariant quantum FLRW background. The basic geometric structure is a frame, which arises from the Poisson structure on an underlying S2 bundle over space-time. The equations of motion for the associated Weitzenböck torsion obtained in [1] are rewritten in the form of Yang-Mills-type equations for the frame. An effective action is found which reproduces these equations of motion, which contains an Einstein-Hilbert term coupled to a dilaton, an axion and a Maxwell-type term for the dynamical frame. An explicit rotationally invariant solution is found, which describes a gravitational field coupled to the dilaton.
The near-horizon geometry of supersymmetric rotating AdS4 black holes in M-theory
Authors: Couzens Christopher , Marcus Eric , Stemerdink Koen , van de Heisteeg Damian
Published: May 2021

Abstract

We classify the necessary and sufficient conditions to obtain the near-horizon geometry of extremal supersymmetric rotating black holes embedded in 11d supergravity which are associated to rotating M2-branes. Such rotating black holes admit an AdS2 near-horizon geometry which is fibered by the transverse spacetime directions. In this paper we allow for the most general fibration over AdS2 with a flux configuration permitting rotating M2-branes. Using G-structure techniques we rewrite the conditions for supersymmetry in terms of differential equations on an eight-dimensional balanced space. The 9d compact internal space is a U(1)-fibration over this 8d base. The geometry is constrained by a master equation reminiscent of the one found in the non-rotating case. We give a Lagrangian from which the equations of motion may be derived, and show how the asymptotically AdS4 electrically charged Kerr-Newman black hole in 4d $$ \mathcal{N} $$
N
= 2 supergravity is embedded in the classification. In addition, we present the conditions for the near-horizon geometry of rotating black strings in Type IIB by using dualities with the 11d setup.
Highly boosted Higgs bosons and unitarity in vector-boson fusion at future hadron colliders
Authors: Kilian Wolfgang , Sun Sichun , Yan Qi-Shu , Zhao Xiaoran , Zhao Zhijie
Published: May 2021

Abstract

We study the observability of new interactions which modify Higgs-pair production via vector-boson fusion processes at the LHC and at future proton-proton colliders. In an effective-Lagrangian approach, we explore in particular the effect of the operator $$ {h}^2{W}_{\mu \nu}^a{W}^{a,\mu \nu} $$

h
2

W
μν
a

W

a
,
μν

, which describes the interaction of the Higgs boson with transverse vector-boson polarization modes. By tagging highly boosted Higgs bosons in the final state, we determine projected bounds for the coefficient of this operator at the LHC and at a future 27 TeV or 100 TeV collider. Taking into account unitarity constraints, we estimate the new-physics discovery potential of Higgs pair production in this channel.
Free energy and defect C-theorem in free fermion
Authors: Sato Yoshiki
Published: May 2021

Abstract

We describe a p-dimensional conformal defect of a free Dirac fermion on a d-dimensional flat space as boundary conditions on a conformally equivalent space ℍp+1×$$ \mathbbm{S} $$
S
d−p−1. We classify allowed boundary conditions and find that the Dirichlet type of boundary conditions always exists while the Neumann type of boundary condition exists only for a two-codimensional defect. For the two-codimensional defect, a double trace deformation triggers a renormalization group flow from the Neumann boundary condition to the Dirichlet boundary condition, and the free energy at UV fixed point is always larger than that at IR fixed point. This provides us with further support of a conjectured C-theorem in DCFT.
Plastin 3 in health and disease: a matter of balance
Authors: Wolff Lisa , Strathmann Eike A. , Müller Ilka , Mählich Daniela , Veltman Charlotte , Niehoff Anja , Wirth Brunhilde
Published: May 2021

For a long time, PLS3 (plastin 3, also known as T-plastin or fimbrin) has been considered a rather inconspicuous protein, involved in F-actin-binding and -bundling. However, in recent years, a plethora of discoveries have turned PLS3 into a highly interesting protein involved in many cellular processes, signaling pathways, and diseases.PLS3is localized on the X-chromosome, but shows sex-specific, inter-individual and tissue-specific expression variability pointing towards skewed X-inactivation.PLS3is expressed in all solid tissues but usually not in hematopoietic cells. When escaping X-inactivation, PLS3 triggers a plethora of different types of cancers. Elevated PLS3 levels are considered a prognostic biomarker for cancer and refractory response to therapies. When it is knocked out or mutated in humans and mice, it causes osteoporosis with bone fractures; it is the only protein involved in actin dynamics responsible for osteoporosis. Instead, when PLS3 is upregulated, it acts as a highly protective SMN-independent modifier in spinal muscular atrophy (SMA). Here, it seems to counteract reduced F-actin levels by restoring impaired endocytosis and disturbed calcium homeostasis caused by reduced SMN levels. In contrast, an upregulation of PLS3 on wild-type level might cause osteoarthritis. This emphasizes that the amount of PLS3 in our cells must be precisely balanced; both too much and too little can be detrimental. Actin-dynamics, regulated by PLS3 among others, are crucial in a lot of cellular processes including endocytosis, cell migration, axonal growth, neurotransmission, translation, and others. Also, PLS3 levels influence the infection with different bacteria, mycosis, and other pathogens.
Integrin-dependent migratory switches regulate the translocation of Toxoplasma-infected dendritic cells across brain endothelial monolayers
Authors: Ross Emily C. , ten Hoeve Arne L. , Barragan Antonio
Published: May 2021

Multiple cellular processes, such as immune responses and cancer cell metastasis, crucially depend on interconvertible migration modes. However, knowledge is scarce on how infectious agents impact the processes of cell adhesion and migration at restrictive biological barriers. In extracellular matrix, dendritic cells (DCs) infected by the obligate intracellular protozoan Toxoplasma gondii undergo mesenchymal-to-amoeboid transition (MAT) for rapid integrin-independent migration. Here, in a cellular model of the blood–brain barrier, we report that parasitised DCs adhere to polarised endothelium and shift to integrin-dependent motility, accompanied by elevated transendothelial migration (TEM). Upon contact with endothelium, parasitised DCs dramatically reduced velocities and adhered under both static and shear stress conditions, thereby obliterating the infection-induced amoeboid motility displayed in collagen matrix. The motility of adherent parasitised DCs on endothelial monolayers was restored by blockade of β1 and β2 integrins or ICAM-1, which conversely reduced motility on collagen-coated surfaces. Moreover, parasitised DCs exhibited enhanced translocation across highly polarised primary murine brain endothelial cell monolayers. Blockade of β1, β2 integrins, ICAM-1 and PECAM-1 reduced TEM frequencies. Finally, gene silencing of the pan-integrin-cytoskeleton linker talin (Tln1) or of β1 integrin (Itgb1) in primary DCs resulted in increased motility on endothelium and decreased TEM. Adding to the paradigms of leukocyte diapedesis, the findings provide novel insights in how an intracellular pathogen impacts the migratory plasticity of leukocytes in response to the cellular environment, to promote infection-related dissemination.
Correction to: On the Nonstationary Stokes System in a Cone ($$L_p$$ Theory)
Authors: Kozlov V. , Rossmann J.
Published: May 2021

A Correction to this paper has been published: https://doi.org/10.1007/s00021-020-00502-w
Cuticular hydrocarbons on old museum specimens of the spiny mason wasp, Odynerus spinipes (Hymenoptera: Vespidae: Eumeninae), shed light on the distribution and on regional frequencies of distinct chemotypes
Authors: Moris Victoria C. , Christmann Katharina , Wirtgen Aline , Belokobylskij Sergey A. , Berg Alexander , Liebig Wolf-Harald , Soon Villu , Baur Hannes , Schmitt Thomas , Niehuis Oliver
Published: May 2021

The mason waspOdynerus spinipesshows an exceptional case of intrasexual cuticular hydrocarbon (CHC) profile dimorphism. Females of this species display one of two CHC profiles (chemotypes) that differ qualitatively and quantitatively from each other. The ratio of the two chemotypes was previously shown to be close to 1:1 at three sites in Southern Germany, which might not be representative given the Palearctic distribution of the species. To infer the frequency of the two chemotypes across the entire distributional range of the species, we analyzed with GC–MS the CHC profile of 1042 dry-mounted specimens stored in private and museum collections. We complemented our sampling by including 324 samples collected and preserved specifically for studying their CHCs. We were capable of reliably identifying the chemotypes in 91% of dry-mounted samples, some of which collected almost 200 years ago. We found both chemotypes to occur in the Far East, the presumed glacial refuge of the species, and their frequency to differ considerably between sites and geographic regions. The geographic structure in the chemotype frequencies could be the result of differential selection regimes and/or different dispersal routes during the colonization of the Western Palearctic. The presented data pave the route for disentangling these factors by providing information where to geographically sampleO. spinipesfor population genetic analyses. They also form the much-needed basis for future studies aiming to understand the evolutionary and geographic origin as well as the genetics of the astounding CHC profile dimorphism thatO. spinipesfemales exhibit.
Changing from a two-tiered to a one-tiered trauma team activation protocol: a before–after observational cohort study investigating the clinical impact of undertriage
Authors: Thorsen Kenneth , Narvestad Jon Kristian , Tjosevik Kjell Egil , Larsen Johannes Wiik , Søreide Kjetil
Published: May 2021

Background

The aim of this study was to compare the effect of the change in TTA protocol from a two-tier to one-tier, with focus on undertriage and mortality.

Material and methods

A before–after observational cohort study based on data extracted from the Stavanger University Hospital Trauma registry in the transition period from two-tier to a one-tier TTA protocol over two consecutive 1-year periods (2017–2018). Comparative analysis was done between the two time-periods for descriptive characteristics and outcomes. The main outcomes of interest were undertriage and mortality.

Results

During the study period 1234 patients were included in the registry, of which 721 (58%) were in the two-tier and 513 (42%) in the one-tier group. About one in five patients (224/1234) were severely injured (ISS > 15).

Median age was 39 in the two-tier period and 43 years in the one-tier period (p = 0.229). Median ISS was 5 for the two-tier period vs 9, in the one-tier period (p = 0.001). The undertriage of severely injured patients in the two-tier period was 18/122 (15%), compared to 31/102 (30%) of patients in the one-tier period (OR = 2.5; 95% CI 1.8–4.52). Overall mortality increased significantly between the two TTA protocols, from 2.5 to 4.7% (p = 0.033), OR 0.51 (0.28–0.96)

Conclusion

A protocol change from two-tiered TTA to one-tiered TTA increased the undertriage in our trauma system. A two-tiered TTA may be beneficial for better patient care.
Glycosylation is a key in SARS-CoV-2 infection
Authors: Reis Celso A. , Tauber Rudolf , Blanchard Véronique
Published: May 2021

SARS-CoV-2 causes the respiratory syndrome COVID-19 and is responsible for the current pandemic. The S protein of SARS-CoV-2-mediating virus binding to target cells and subsequent viral uptake is extensively glycosylated. Here we focus on how glycosylation of both SARS-CoV-2 and target cells crucially impacts SARS-CoV-2 infection at different levels: (1) virus binding and entry to host cells, with glycosaminoglycans of host cells acting as a necessary co-factor for SARS-CoV-2 infection by interacting with the receptor-binding domain of the SARS-CoV-2 spike glycoprotein, (2) innate and adaptive immune response where glycosylation plays both a protective role and contributes to immune evasion by masking of viral polypeptide epitopes and may add to the cytokine cascade via non-fucosylated IgG, and (3) therapy and vaccination where a monoclonal antibody-neutralizing SARS-CoV-2 was shown to interact also with a distinct glycan epitope on the SARS-CoV-2 spike protein. These evidences highlight the importance of ensuring that glycans are considered when tackling this disease, particularly in the development of vaccines, therapeutic strategies and serological testing.
Analysis of machining-induced residual stresses of milled aluminum workpieces, their repeatability, and their resulting distortion
Authors: Weber Daniel , Kirsch Benjamin , Chighizola Christopher R. , D’Elia Christopher R. , Linke Barbara S. , Hill Michael R. , Aurich Jan C.
Published: May 2021

Machining-induced residual stresses (MIRS) are a main driver for distortion of thin-walled monolithic aluminum workpieces. Before one can develop compensation techniques to minimize distortion, the effect of machining on the MIRS has to be fully understood. This means that not only an investigation of the effect of different process parameters on the MIRS is important. In addition, the repeatability of the MIRS resulting from the same machining condition has to be considered. In past research, statistical confidence of MIRS of machined samples was not focused on. In this paper, the repeatability of the MIRS for different machining modes, consisting of a variation in feed per tooth and cutting speed, is investigated. Multiple hole-drilling measurements within one sample and on different samples, machined with the same parameter set, were part of the investigations. Besides, the effect of two different clamping strategies on the MIRS was investigated. The results show that an overall repeatability for MIRS is given for stable machining (between 16 and 34% repeatability standard deviation of maximum normal MIRS), whereas instable machining, detected by vibrations in the force signal, has worse repeatability (54%) independent of the used clamping strategy. Further experiments, where a 1-mm-thick wafer was removed at the milled surface, show the connection between MIRS and their distortion. A numerical stress analysis reveals that the measured stress data is consistent with machining-induced distortion across and within different machining modes. It was found that more and/or deeper MIRS cause more distortion.
Selection of safe artemisinin derivatives using a machine learning-based cardiotoxicity platform and in vitro and in vivo validation
Authors: Kadioglu Onat , Klauck Sabine M. , Fleischer Edmond , Shan Letian , Efferth Thomas
Published: May 2021

The majority of drug candidates fails the approval phase due to unwanted toxicities and side effects. Establishment of an effective toxicity prediction platform is of utmost importance, to increase the efficiency of the drug discovery process. For this purpose, we developed a toxicity prediction platform with machine-learning strategies. Cardiotoxicity prediction was performed by establishing a model with five parameters (arrhythmia, cardiac failure, heart block, hypertension, myocardial infarction) and additional toxicity predictions such as hepatotoxicity, reproductive toxicity, mutagenicity, and tumorigenicity are performed by using Data Warrior and Pro-Tox-II software. As a case study, we selected artemisinin derivatives to evaluate the platform and to provide a list of safe artemisinin derivatives. Artemisinin from Artemisia annua was described first as an anti-malarial compound and later its anticancer properties were discovered. Here, random forest feature selection algorithm was used for the establishment of cardiotoxicity models. High AUC scores above 0.830 were achieved for all five cardiotoxicity indications. Using a chemical library of 374 artemisinin derivatives as a case study, 7 compounds (deoxydihydro-artemisinin, 3-hydroxy-deoxy-dihydroartemisinin, 3-desoxy-dihydroartemisinin, dihydroartemisinin-furano acetate-d3, deoxyartemisinin, artemisinin G, artemisinin B) passed the toxicity filtering process for hepatotoxicity, mutagenicity, tumorigenicity, and reproductive toxicity in addition to cardiotoxicity. Experimental validation with the cardiomyocyte cell line AC16 supported the findings from the in silico cardiotoxicity model predictions. Transcriptomic profiling of AC16 cells upon artemisinin B treatment revealed a similar gene expression profile as that of the control compound, dexrazoxane. In vivo experiments with a Zebrafish model further substantiated the in silico and in vitro data, as only slight cardiotoxicity in picomolar range was observed. In conclusion, our machine-learning approach combined with in vitro and in vivo experimentation represents a suitable method to predict cardiotoxicity of drug candidates.
Pharmacogenetic association of diabetes-associated genetic risk score with rapid progression of coronary artery calcification following treatment with HMG-CoA-reductase inhibitors —results of the Heinz Nixdorf Recall Study
Authors: Pechlivanis Sonali , Jung Dominik , Moebus Susanne , Lehmann Nils , Mahabadi Amir A. , Hoffmann Per , Erbel Raimund , Nöthen Markus M. , Bachmann Hagen S.
Published: May 2021

HMG-CoA-Reductase inhibitors (HMGRIs) are currently the most widely used group of drugs in patients with coronary artery disease (CAD) and are given preemptively to patients with high levels of cholesterol, including those with diabetes mellitus (DM). However, intake of HMGRIs also increases the progression of coronary artery calcification (CAC) and the risk of developing DM. This study aimed to investigate whether HMGRI intake interacts with the diabetes-associated genetic risk score (GRS) to affect CAC progression using data from the population-based Heinz Nixdorf Recall (HNR) study. CAC was measured in 3157 participants using electron-beam computed tomography twice, at baseline (CACb) and 5 years later (CAC5y). CAC progression was classified as slow, expected, or rapid based on predicted values. Weighted DM GRS was constructed using 100 diabetes mellitus–associated single nucleotide polymorphisms (SNPs). We used log-linear regression to evaluate the interaction of HMGRI intake with diabetes-associated GRS and individual SNPs on CAC progression (rapid vs. expected/slow), adjusting for age, sex, and log(CACb + 1). The prevalence of rapid CAC progression in the HNR study was 19.6%. We did not observe any association of the weighted diabetes mellitus GRS with the rapid progression of CAC (relative risk (RR) [95% confidence interval (95% CI)]: 1.01 [0.94; 1.10]). Furthermore, no indication of an interaction between GRS and HMGRI intake was observed (1.08 [0.83; 1.41]). Our analyses showed no indication that the impact of HMGRIs on CAC progression is significantly more severe in patients with a high genetic risk of developing DM than in those with a low GRS.
Unilateral traumatic brain injury of the left and right hemisphere produces the left hindlimb response in rats
Authors: Bakalkin Georgy , Nosova Olga , Sarkisyan Daniil , Hallberg Mathias , Zhang Mengliang , Schouenborg Jens , Marklund Niklas , Watanabe Hiroyuki
Published: May 2021

Traumatic brain injury and stroke result in hemiplegia, hemiparesis, and asymmetry in posture. The effects are mostly contralateral; however, ipsilesional deficits may also develop. We here examined whether ablation brain injury and controlled cortical impact (CCI), a rat model of clinical focal traumatic brain injury, both centered over the left or right sensorimotor cortex, induced hindlimb postural asymmetry (HL-PA) with contralesional or ipsilesional limb flexion. The contralesional hindlimb was flexed after left or right side ablation injury. In contrast, both the left and right CCI unexpectedly produced HL-PA with flexion on left side. The flexion persisted after complete spinal cord transection suggesting that CCI triggered neuroplastic processes in lumbar neural circuits enabling asymmetric muscle contraction. Left limb flexion was exhibited under pentobarbital anesthesia. However, under ketamine anesthesia, the body of the left and right CCI rats bent laterally in the coronal plane to the ipsilesional side suggesting that the left and right injury engaged mirror-symmetrical motor pathways. Thus, the effects of the left and right CCI on HL-PA were not mirror-symmetrical in contrast to those of the ablation brain injury, and to the left and right CCI produced body bending. Ipsilateral effects of the left CCI on HL-PA may be mediated by a lateralized motor pathway that is not affected by the left ablation injury. Alternatively, the left-side-specific neurohormonal mechanism that signals from injured brain to spinal cord may be activated by both the left and right CCI but not by ablation injury.
Investigating the Microchannel Architectures Inside the Subchondral Bone in Relation to Estimated Hip Reaction Forces on the Human Femoral Head
Authors: Taheri Shahed , Yoshida Takashi , Böker Kai O. , Foerster Robert H. , Jochim Lina , Flux Anna Lena , Grosskopf Birgit , Lehmann Wolfgang , Schilling Arndt Friedrich
Published: May 2021

The interplay between articular cartilage (AC) and subchondral bone (SB) plays a pivotal role in cartilage homeostasis and functionality. As direct connective pathways between the two are poorly understood, we examined the location-dependent characteristics of the 3D microchannel network within the SB that connects the basal cartilage layer to the bone marrow (i.e. cartilage-bone marrow microchannel connectors; CMMC). 43 measuring points were defined on five human cadaveric femoral heads with no signs of osteoarthritis (OA) (age ≤ 60), and cartilage-bone cylinders with diameters of 2.00 mm were extracted for high-resolution scanning (n = 215). The micro-CT data were categorized into three groups (load-bearing region: LBR, n = 60; non-load-bearing region: NLBR, n = 60; and the peripheral rim: PR, n = 95) based on a gait analysis estimation of the joint reaction force (young, healthy cohort with no signs of OA). At the AC-SB interface, the number of CMMC in the LBR was 1.8 times and 2.2 times higher compared to the NLBR, and the PR, respectively. On the other hand, the median Feret size of the CMMC were smallest in the LBR (55.2 µm) and increased in the NLBR (73.5 µm; p = 0.043) and the PR (89.1 µm; p = 0.043). AC thickness was positively associated with SB thickness (Pearson's r = 0.48; p < 1e-13), CMMC number. (r = 0.46; p < 1e-11), and circularity index (r = 0.61; p < 1e-38). In conclusion, our data suggest that regional differences in the microchannel architecture of SB might reflect regional differences in loading.
Outcomes of Tracheal Resections in Well‐Differentiated Thyroid Cancer—A case series and meta‐analysis
Authors: Warshavsky Anton , Rosen Roni , Nard‐Carmel Narin , Muhanna Nidal , Ungar Omer , Abergel Avraham , Fliss Dan M. , Horowitz Gilad
Published: May 2021

Background

Tracheal invasion in thyroid cancer is a well‐known form of advanced disease. There is an ongoing controversy over outcomes of tracheal shaving in this situation. The aim of this study was to compare the results of tracheal shaving to radical resections in patients with low‐volume tracheal involvement.

Methods

An institutional case series and a meta‐analysis was conducted. All studies that included patients diagnosed with well‐differentiated thyroid cancer (WDTC) and tracheal invasion were analyzed. Patients with low‐volume tracheal invasion (according to the Shin classification) were extracted from the various studies and subsequently included in this study. The outcomes of tracheal shaving and radical resection were consolidated and compared. All recurrences and mortality over 10 years of follow‐up were calculated using the Kaplan–Meier method.

Results

Institutional case series included 22 patients diagnosed with WDTC and tracheal invasion that underwent resection. There was one case of recurrence (4.5%) during the follow‐up period and no mortality. The meta‐analysis yielded a total of 284 patients from six studies who met the inclusion criteria. The 10‐year overall survival was 82.4% for the shave group and 80.8% for the resection group. The combined Kaplan–Meier curves revealed no statistically significant difference between the two techniques (hazard ratio [HR] = 0.86, P = .768). The combined 10‐year local control rate of the shave group was 90.2%.

Conclusions

The outcomes of tracheal shaving in low‐volume invasion are similar to more aggressive forms of tracheal resections. Shave resection is oncologically safe in carefully selected WDTC patients demonstrating minimal tracheal invasion.
Time pressure predicts decisional regret in men with localized prostate cancer: data from a longitudinal multicenter study
Authors: Hilger Caren , Schostak Martin , Otto Isabella , Kendel Friederike
Published: May 2021

Purpose

A substantial proportion of men with localized prostate cancer (lPCa) later regret their treatment decision. We aimed to identify factors contributing to decisional regret.

Methods

We conducted a longitudinal study, in which men with lPCa were surveyed at four measurement points: T0 (baseline) = prior to treatment; T1 = 6; T2 = 12; T3 = 18 months after baseline. χ2-tests and independent t-tests were used to compare men undergoing different treatments [Active Surveillance (AS) vs. local treatment]. Logistic regression models were fitted to investigate the associations between predictors (time pressure, information provided by the urologist, impairment of erectile functioning, satisfaction with sexual life) and the criterion decisional regret.

Results

At baseline, the sample included N = 176 men (AS: n = 100; local treatment: n = 76). At T2 and T3, men after local therapies reported higher regret than men under AS. Decisional regret at T3 was predicted by time pressure at baseline (OR 2.28; CI 1.04–4.99; p < 0.05), erectile dysfunction at T2 and T3 (OR 3.40; CI 1.56–7.42; p < 0.01), and satisfaction with sexual life at T1–T3 (OR 0.44; CI 0.20–0.96; p < 0.05).

Conclusions

Time pressure, erectile dysfunction, and satisfaction with sexual life predict decisional regret in men with lPCa. Mitigating time pressure and realistic expectations concerning treatment side effects may help to prevent decisional regret in PCa survivors.

Trial registration number

DRKS00009510; date of registration: 2015/10/28.
Impact of air–sea coupling on the climate change signal over the Iberian Peninsula
Authors: de la Vara Alba , Cabos William , Sein Dmitry V. , Teichmann Claas , Jacob Daniela
Published: May 2021

In this work we use a regional atmosphere–ocean coupled model (RAOCM) and its stand-alone atmospheric component to gain insight into the impact of atmosphere–ocean coupling on the climate change signal over the Iberian Peninsula (IP). The IP climate is influenced by both the Atlantic Ocean and the Mediterranean sea. Complex interactions with the orography take place there and high-resolution models are required to realistically reproduce its current and future climate. We find that under the RCP8.5 scenario, the generalized 2-m air temperature (T2M) increase by the end of the twenty-first century (2070–2099) in the atmospheric-only simulation is tempered by the coupling. The impact of coupling is specially seen in summer, when the warming is stronger. Precipitation shows regionally-dependent changes in winter, whilst a drier climate is found in summer. The coupling generally reduces the magnitude of the changes. Differences in T2M and precipitation between the coupled and uncoupled simulations are caused by changes in the Atlantic large-scale circulation and in the Mediterranean Sea. Additionally, the differences in projected changes of T2M and precipitation with the RAOCM under the RCP8.5 and RCP4.5 scenarios are tackled. Results show that in winter and summer T2M increases less and precipitation changes are of a smaller magnitude with the RCP4.5. Whilst in summer changes present a similar regional distribution in both runs, in winter there are some differences in the NW of the IP due to differences in the North Atlantic circulation. The differences in the climate change signal from the RAOCM and the driving Global Coupled Model show that regionalization has an effect in terms of higher resolution over the land and ocean.
Disruptions of neurological services, its causes and mitigation strategies during COVID-19: a global review
Authors: García-Azorín David , Seeher Katrin M. , Newton Charles R. , Okubadejo Njideka U. , Pilotto Andrea , Saylor Deanna , Winkler Andrea Sylvia , Charfi Triki Chahnez , Leonardi Matilde
Published: May 2021

Background

The COVID-19 pandemic leads to disruptions of health services worldwide. To evaluate the particular impact on neurological services a rapid review was conducted.

Methods

Studies reporting the provision of neurological services during the pandemic and/or adopted mitigation strategies were included in this review. PubMed and World Health Organization’s (WHO) COVID-19 database were searched. Data extraction followed categories used by WHO COVID-19 pulse surveys and operational guidelines on maintaining essential health services during COVID-19.

Findings

The search yielded 1101 articles, of which 369 fulfilled eligibility criteria, describing data from 210,419 participants, being adults (81%), children (11.4%) or both (7.3%). Included articles reported data from 105 countries and territories covering all WHO regions and World Bank income levels (low income: 1.9%, lower middle: 24.7%, upper middle: 29.5% and high income; 44.8%). Cross-sectoral services for neurological disorders were most frequently disrupted (62.9%), followed by emergency/acute care (47.1%). The degree of disruption was at least moderate for 75% of studies. Travel restrictions due to lockdowns (81.7%) and regulatory closure of services (65.4%) were the most commonly reported causes of disruption. Authors most frequently described telemedicine (82.1%) and novel dispensing approaches for medicines (51.8%) as mitigation strategies. Evidence for the effectiveness of these measures is largely missing.

Interpretation

The COVID-19 pandemic affects all aspects of neurological care. Given the worldwide prevalence of neurological disorders and the potential long-term neurological consequences of COVID-19, service disruptions are devastating. Different strategies such as telemedicine might mitigate the negative effects of the pandemic, but their efficacy and acceptability remain to be seen.
Does the non-absorbable suture closure of the jejunal mesenteric defect reduce the incidence and severity of internal hernias after laparoscopic Roux-en-Y gastric bypass?
Authors: Schneider Romano , Schulenburg Michaela , Kraljević Marko , Klasen Jennifer M. , Peters Thomas , Wölnerhanssen Bettina , Peterli Ralph
Published: May 2021

Purpose

Internal hernias (IH) are frequent complications after laparoscopic Roux-en-Y gastric bypass (LRYGB). Closure of the jejunal mesenteric and the Petersen defect reduces IH incidence in prospective and retrospective trials. This study investigates whether closing the jejunal mesenteric space alone by non-absorbable suture and splitting the omentum can be beneficial to prevent IH after LRYGB.

Methods

Observational cohort study of 785 patients undergoing linear LRYGB including omental split at a single institution, with 493 patients without jejunal mesenteric defect closure and 292 patients with closure by non-absorbable suture, and a minimal follow-up of 2 years. Patients were assessed for appearance and severity of IH. Additionally, open mesenteric gaps without herniated bowel as well as early obstructions due to kinking of the entero-enterostomy (EE) were explored.

Results

Through primary mesenteric defect closure, the rate of manifest jejunal mesenteric and Petersen IH could be reduced from 6.5 to 3.8%, but without reaching statistical significance. The most common location for an IH was the jejunal mesenteric space, where defect closure during primary surgery reduced the rate of IH from 5.3 to 2.4%. Higher weight loss seemed to increase the risk of developing an IH.

Conclusion

The closure of the jejunal mesenteric defect by non-absorbable suture may reduce the rate of IH at the jejunal mesenteric space after LRYGB. However, the beneficial effect in our collective is smaller than expected, particularly in patients with good weight loss. The Petersen IH rate remained low by consequent T-shape split of the omentum without suturing of the defect.
Serum IgG levels in children 6 months after SARS-CoV-2 infection and comparison with adults
Authors: Bloise Silvia , Marcellino Alessia , Testa Alessia , Dilillo Anna , Mallardo Saverio , Isoldi Sara , Martucci Vanessa , Sanseviero Maria Teresa , Del Giudice Emanuela , Iorfida Donatella , Ventriglia Flavia , Lubrano Riccardo
Published: May 2021

Since the outbreak of SARS-CoV-2 among the population has occurred quite recently, there is a lack of evidence on the long-term duration of antibody response, especially in children. It is therefore crucial to clarify this aspect, considering its implications in the development of successful surveillance strategies, therapies, and vaccinations. The aim of this study was to assess the antibody response in a children group after SARS-CoV-2 infection, and to compare it with that of their parents affected by SARS-CoV-2 infection. We enrolled 12 children and their parents, both groups being affected by COVID-19 in April 2020. In the children’s group, we collected real-time RT-PCR cycle threshold (Ct) values and gene characterization of first nasal-throat swab at the time of diagnosis (T0); 30 days after the diagnosis (T30), we performed blood tests to detect anti-SARS-CoV-2 IgM and IgG. Finally, 180 days after the diagnosis (T180), we measured anti-SARS-CoV-2 IgG in both children and parents. In children, antibody levels declined significantly at 180 days (T180) after first measurement (T30). There were no significant differences in IgG level related to age, sex, and clinical manifestations. We found a significant correlation between IgG titers at T30 and Ct value of gene N. Children showed a lower level of antibodies against SARS-CoV-2 at T180 compared to their parents.

Conclusion: Antibody responses in children waned 180 days after SARS-CoV-2 infection, and at the same time, their parents showed a different antibody response to the virus. These results highlight that serological tests should be used with caution in surveillance strategies among the general population.

What is known:• Currently is not known how long antibody response will be maintained or if it protects from reinfection.• Recent reports in adults suggest that antibodies to SARS-CoV-2 declined several months after infection, but data are missing in pediatric age.

What is new:• We showed that antibody responses to SARS-CoV-2 wane several months after infection also in children with quantitative differences in antibody levels between children and adults.• In this context, serological tests should be used with caution in surveillance strategies.
Burnout amongst neurosurgical trainees in the UK and Ireland
Authors: Salloum Nadia Liber , Copley Phillip Correia , Mancuso-Marcello Marco , Emelifeonwu John , Kaliaperumal Chandrasekaran
Published: May 2021

Introduction

Burnout is becoming an increasingly recognised phenomenon within the medical profession. This study aims to investigate the presence of burnout amongst neurosurgical trainees in the UK and Ireland as well as investigating potential exacerbating and protective factors.

Method

An online survey was sent to all neurosurgical trainees in the UK and Ireland via the British Neurosurgical Trainees’ Association (BNTA) mailing list. Responding participants anonymously completed the Copenhagen Burnout Inventory (CBI) and answered questions about known risk factors for burnout including workplace environment, workplace bullying, time spent on leisure activities and sleep and reported likelihood of leaving neurosurgery. We also collated data on responders’ demographics. We compared CBI scores for participants with and without risk factors to determine correlation with CBI.

Results

There were 75 respondents (response rate 42%) from a range of ages and all training grades, 72% of whom were male. The median CBI score was 38.85 (IQR 17.76). Participants showed a higher degree of personal and workplace burnout (median CBIs of 47.02, IQR 25.00; and 49.14, IQR 19.64, respectively) compared with patient-related burnout (median CBI 18.67, IQR 25.00). Participants with the following self-reported risk factors were significantly more likely to have higher CBIs: workplace bullying (p = 0.01), getting on less well with colleagues (p < 0.05), working longer hours (p < 0.05) and insufficient sleep, exercise and leisure time (all p < 0.01). Those with higher CBI scores were more likely to consider leaving neurosurgical training (p = 0.01).

Conclusion

We identified a high burnout incidence in a cohort representative of UK neurosurgical trainees, although our results may have been skewed somewhat by selection bias. We determined potential risk factors for burnout related to specific workplace stressors and time for non-work activities. In the future, changes to training curricula should address these issues, aiming to improve training, enhance patient care and reduce attrition rates.
Electronic structure and reactivity of tirapazamine as a radiosensitizer
Authors: Romero José , Maihom Thana , Limão-Vieira Paulo , Probst Michael
Published: May 2021

Tirapazamine (TP) has been shown to enhance the cytotoxic effects of ionizing radiation in hypoxic cells, thus making it a candidate for a radiosensitizer. This selective behavior is often directly linked to the abundance of O2. In this paper, we study the electronic properties of TP in vacuum, micro-hydrated from one up to three molecules of water and embedded in a continuum of water. We discuss electron affinities, charge distribution, and bond dissociation energies of TP, and find that these properties do not change significantly upon hydration. In agreement with its large electron affinity, and bond breaking triggered by electron attachment requires energies higher than 2.5 eV, ruling out the direct formation of bioactive TP radicals. Our results suggest, therefore, that the selective behavior of TP cannot be explained by a one-electron reduction from a neighboring O2 molecule. Alternatively, we propose that TP’s hypoxic selectivity could be a consequence of O2 scavenging hydrogen radicals.
Discrete element modelling of rockfill railway embankments
Authors: de Frias Lopez Ricardo , Larsson Stefan , Silfwerbrand Johan
Published: May 2021

There is a need of reducing the uncertainty in traffic loading-induced settlements within railway embankments. A previously developed model for unbound stone-based materials has been implemented for modelling rockfill embankments. Particles were represented by simple breakable tetrahedral clumps of spheres with four asperities each. Both corner breakage and particle splitting were allowed. Embankments with heights between 2 and 10 m were generated by successive dumping and compaction of layers of clumps on top of each other, mimicking the construction of real embankments. Cyclic loading of the embankments representing railway traffic, for both breakable and unbreakable assemblies, was carried out. Results show that the mechanical response is marked by a substantial degree of uncertainty exacerbated by particle degradation, especially for intermediate to high embankments. An analysis of particle rotation showed that particle rearrangement mostly accumulates in the top layers, resulting in a lack of influence of embankment height on settlements. Breakage, even being of (very) limited magnitude, had a statistically significant effect. Good agreement with common geostatic theories predicting horizontal pressures was also observed. Regarding resilient response, linear stiffening with embankment height is observed with a minor influence of breakage. All in all, it is shown that the specific scale, boundary and stress conditions of embankments results in a behaviour deviating from that observed under triaxial conditions. Therefore, the key contribution is showing that it is possible to realistically model high rockfill embankments under a large number of loading cycles and furthermore including degradation, something not attempted to date.

Graphic abstract
Clinical evaluation of rapid point-of-care antigen tests for diagnosis of SARS-CoV-2 infection
Authors: Koeleman Johannes G. M. , Brand Henk , de Man Stijn J. , Ong David S. Y.
Published: May 2021

The RT-qPCR in respiratory specimens is the gold standard for diagnosing acute COVID-19 infections. However, this test takes considerable time before test results become available, thereby delaying patients from being diagnosed, treated, and isolated immediately. Rapid antigen tests could overcome this problem. In the first study, clinical performances of five rapid antigen tests were compared to RT-qPCR in upper respiratory specimens from 40 patients with positive and 40 with negative RTq-PCR results. In the second study, the rapid antigen test with one of the best test characteristics (Romed) was evaluated in a large prospective collection of upper respiratory specimens from 900 different COVID-19-suspected patients (300 emergency room patients, 300 nursing home patients, and 300 health care workers). Test specificities ranged from 87.5 to 100.0%, and test sensitivities from 55.0 to 80.0%. The clinical specificity of the Romed test was 99.8% (95% CI 98.9–100). Overall clinical sensitivity in the study population was 73.3% (95% CI 67.9–78.2), whereas sensitivity in the different patient groups varied from 65.3 to 86.7%. Sensitivity was 83.0 to 86.7% in patients with short duration of symptoms. In a population with a COVID-19 prevalence of 1%, the negative predictive value in all patients was 99.7%. There is a large variability in diagnostic performance between rapid antigen tests. The Romed rapid antigen test showed a good clinical performance in patients with high viral loads (RT-qPCR cycle threshold ≤30), which makes this antigen test suitable for rapid identification of COVID-19-infected health care workers and patients.
Usability evaluation of a virtual reality smartphone app for a living museum
Authors: Othman Mohd Kamal , Nogoibaeva Altynai , Leong Lai San , Barawi Mohamad Hardyman
Published: May 2021

This paper elaborates the empirical evidence of a usability evaluation of a VR and non-VR virtual tour application for a living museum. The System Usability Scale (SUS) was used in between participants experiments (Group 1: non-VR version and Group 2: VR version) with 40 participants. The results show that the mean scores of all components for the VR version are higher compared to the non-VR version, overall SUS score (72.10 vs 68.10), usability score (75.50 vs 71.70), and learnability (58.40 vs 57.00). Further analysis using a two-tailed independent t test showed no difference between the non-VR and VR versions. Additionally, no significant difference was observed between the groups in the context of gender, nationality, and prior experience (other VR tour applications) for overall SUS score, usability score, and learnability score. Α two-tailed independent t test indicated no significant difference in the usability score between participants with VR experience and no VR experience. However, a significant difference was found between participants with VR experience and no VR experience for both SUS score (t(38) = 2.17, p = 0.037) and learnability score (t(38) = 2.40, p = 0.021). The independent t test results indicated a significant difference between participant with and without previous visits to SCV for the usability score (t(38) = −2.31, p = 0.027), while there was no significant differences observed in other components. It can be concluded that both versions passed based on the SUS score. However, the sub-scale usability and learnability scores indicated some usability issue.