bluuebunny/crossref_metadata_2025 huggingface dataset:
Computational analysis of the proton‐bound acetonitrile dimer, (ACN)2H+
Authors: Haack Alexander , Benter Thorsten , Kersten Hendrik
Published: March 2020

Rationale

In atmospheric pressure ionization mass spectrometry the theoretical thermodynamic treatment of proton‐bound cluster stabilities helps us to understand the prevailing chemical processes. However, such calculations are rather challenging because low‐barrier internal rotations and strong anharmonicity of the hydrogen bonds cause the breakdown of the usually applied harmonic approximation. Even the implemented anharmonic treatment in standard ab initio software failed in the case of (ACN)2H+.

Methods

For a case study of the proton‐bound acetonitrile dimer, (ACN)2H+, we scan the potential energy surface (PES) for the internal rotation and the proton movement in all three spatial directions. We correct the partition functions by treating the internal rotation as a free rotor and by solving the nuclear Schrödinger equation explicitly for the proton movement. An additional PES scan for the dissociation surface further improves the understanding of the cluster behavior.

Results

The internal rotation is essentially barrier free (V0 = 2.6 × 10−6 eV) and the proton's movement between the two nitrogen atoms follows a quartic rather than quadratic potential. As a figure of merit we calculate the free dissociation enthalpy of the dimer. Our description significantly improves the standard results from about 118.3 kJ/mol to 99.6 kJ/mol, compared with the experimentally determined value of 92.2 kJ/mol. The dissociation surface reveals strong crosstalk between modes and is essentially responsible for the observed errors.

Conclusions

The presented corrections to the partition functions significantly improve their accuracy and are rather easy to implement. In addition, this work stresses the importance of alternative theoretical methods for proton‐bound cluster systems besides the standard harmonic approximations.
Synchrotron UV photoactivation of trapped sodiated ions produced from poly(ethylene glycol) by electrospray ionization
Authors: Aloui Inès , Legros Véronique , Giuliani Alexandre , Buchmann William
Published: March 2020

Rationale

By taking advantage of the gas‐phase decompositions of polymer ions, tandem mass spectrometry of polymers allows us to obtain more accurate structural information than from a simple mass measurement. Applied to a model polymer, the goal of this work was to evaluate the performances of an activation technique based on ultraviolet (UV) irradiation, as an alternative to conventional collisional activation.

Methods

Sodiated poly(ethylene glycol) produced by electrospray ionization was isolated in a linear ion trap, then submitted to synchrotron UV irradiation over a range of wavelengths (52 to 248 nm). Fragmentation pathways resulting from UV photoactivation were investigated. The proposed mechanisms take into account: (i) the comparison with collision‐induced dissociation (CID) product ions, (ii) the effect of wavelength‐tunable UV activation, and (iii) deuterium‐labeling and various other complementary experiments. For the highest molecular weight compounds, ion mobility spectrometry was used before UV photoactivation.

Results

Synchrotron UV irradiation can induce dissociation of poly(ethylene glycol) sodiated ions without the requirement of the presence of a specific chromophore, if the photon energy is above 10 eV. UV photoactivation of poly(ethylene glycol) ions can yield fragmentations that differ from those in classical low‐energy CID, especially from higher masses (>4000 g mol−1). A successful coupling of UV photoactivation with ion mobility pre‐filtering was presented.

Conclusions

UV activation combined or not with pre‐filtering ion mobility is a promising alternative approach for the structural characterization of polymers. UV synchrotron radiation with a tunable wavelength was a great opportunity to study the effect of the photon energy, and to probe the mechanisms of ion decomposition from poly(ethylene glycol).
Investigating protein thiol chemistry associated with dehydroascorbate, homocysteine and glutathione using mass spectrometry
Authors: Ahuie Grace Kouakou , Gagnon Hugo , Pace Paul E. , Peskin Alexander V. , Wagner Richard J. , Naylor Stephen , Klarskov Klaus
Published: March 2020

Rationale

Oxidative stress is an imbalance between reactive free radical oxygen species and antioxidant defenses. Its consequences can lead to numerous pathologies. Regulating oxidative stress is the complex interplay between antioxidant recycling and thiol‐containing regulatory proteins. Understanding these regulatory mechanisms is important for preventing onset of oxidative stress. The aim of this study was to investigae S‐thiol protein chemistry associated with oxidized vitamin C (dehydroascorbate, DHA), homocysteine (HcySH) and glutathione (GSH) using mass spectrometry.

Methods

Glutaredoxin‐1 (Grx‐1) was incubated with DHA, with and without GSH and HcySH. Disulfide formation was followed by electrospray ionization mass spectrometry (ESI‐MS) of intact proteins and by LC/ESI‐MS/MS of peptides from protein tryptic digestions. The mechanism of DHA‐mediated S‐thiolation was investigated using two synthetic peptides: AcFHACAAK and AcFHACE. Three proteins, i.e. human hemoglobin (HHb), recombinant peroxiredoxin 2 (Prdx2) and Grx‐1, were S‐homocysteinylated followed by S‐transthiolyation with GSH and investigated by ESI‐MS and ESI‐MS/MS.

Results

ESI‐MS analysis reveals that DHA mediates disulfide formation and S‐thiolation by HcySH as well as GSH of Grx‐1. LC/ESI‐MS/MS analysis allows identification of Grx‐1 S‐thiolated cysteine adducts. The mechanism by which DHA mediates S‐thiolation of heptapeptide AcFHACAAK is shown to be via initial formation of a thiohemiketal adduct. In addition, ESI‐MS of intact proteins shows that GSH can S‐transthiolate S‐homocysteinylated Grx‐1_ HHb and Prdx2. The GS‐S‐protein adducts over time dominate the ESI‐MS spectrum profile.

Conclusions

Mass spectrometry is a unique analytical technique for probing complex reaction mechanisms associated with oxidative stress. Using model proteins, ESI‐MS reveals the mechanism of DHA‐facilitated S‐thiolation, which consists of thiohemiketal formation, disulfide formation or S‐thiolation. Furthermore, protein S‐thiolation by HcySH can be reversed by reversible GSH thiol exchange. The use of mass spectrometry with in vitro models of protein S‐thiolation in oxidative stress may provide significant insight into possible mechanisms of action occurring in vivo.
Finite‐time stability of switched nonlinear time‐delay systems
Authors: Wang Zhichuang , Sun Jian , Chen Jie , Bai Yongqiang
Published: March 2020

This article addresses the problem of finite‐time stability (FTS) and finite‐time contractive stability (FTCS) for switched nonlinear time‐delay systems (SNTDSs). By virtues of the Lyapunov‐Razumikhin method, Lyapunov functionals approach, and the comparison principle technique, we obtain some improved Razumikhin‐type theorems that verify FTS and FTCS property for SNTDSs. Moreover, our results allow the estimate of the upper bound of the derivatives for Lyapunov functions to be mode dependent functions which can be positive and negative. Meanwhile, the proposed results also improve the related existing results on the same topic by removing some restrictive conditions. Finally, two examples are presented to verify the effectiveness of our methods.
Robust time‐varying formation design for multiagent systems with disturbances: Extended‐state‐observer method
Authors: Wang Le , Xi Jianxiang , He Ming , Liu Guangbin
Published: March 2020

Robust time‐varying formation design problems for second‐order multiagent systems subjected to external disturbances are investigated. First, by constructing an extended state observer, the disturbance compensation is estimated, which is a critical term in the proposed robust time‐varying formation control protocol. Then, an explicit expression of the formation center function is determined and impacts of disturbance compensations on the formation center function are presented. With the formation feasibility conditions, robust time‐varying formation design criteria are derived to determine the gain matrix of the formation control protocol by utilizing the algebraic Riccati equation technique. Furthermore, the tracking performance and the robustness property of multiagent systems are analyzed. Finally, the numerical simulation is provided to illustrate the effectiveness of theoretical results.
Graphene Aerogel Modified Carbon Paper as Anode for Lithium‐Ion Batteries
Authors: Angelopoulou Pinelopi , Vrettos Katerina , Georgakilas Vasilios , Avgouropoulos George
Published: March 2020

Carbon paper‐supported graphene aerogels are examined as anode electrodes for lithium‐ion batteries, employing a hydrothermal process and a freeze‐drying step. Triethylenetetramine (TETA) and o‐phenylenediamine (OPD) prove to promote graphene aerogel formation and its chemical bonding onto the surface of carbon paper. The electrochemical results demonstrate that the electrode treated with the former diamine has a remarkable rate capability with higher capacities as compared with the electrode treated with the latter diamine and better stability.
Nitrogen and Phosphorus Doped Activated Carbon Catalyst Prepared from Shrimp Shell and its Application in MFC Air Cathode
Authors: Liu Ting , Jean Pierre Muhoza , Li Huiyu , Wu Wenyu , Tu Maobing , Wang Qunhui , Ma Hongzhi
Published: March 2020

Cathode design and cost is one of the major challenges for microbial fuel cell (MFC) large scale operation due to the adoption of precious Pt/C catalyst. In this work, shrimp shells were chosen to prepare a cheap and sustainable ORR catalyst and applied it in MFC air cathode. Single step pyrolysis and activation at 700 °C with H3PO4 was used to introduce phosphorus atom in the carbon. Three types of catalysts, named shrimp shells activated carbon (SS‐AC), commercial activated carbon (C‐AC) and Pt/C were compared for their performance in MFC system. The results showed that SS‐AC had high porous surface that contained nitrogenous and phosphorous functionalities at a significant percentage with high surface area of about 448.96 m2 g−2. The maximum power density achieved by the MFC that used SS‐AC catalyst was 1207±15 mW m−2 at 3.14 A m−2, 12 % less than Pt/C and 44 % higher than those of the C‐AC. The coulombic efficiency of 67 % was also achieved with this MFC slightly lower than those by Pt/C and higher than those by C‐AC. The good performance of this material was mainly due to the double doped heteroatoms which increases the oxygen reduction sites on the surface of the carbon.
Data‐driven benchmarking in software development effort estimation: The few define the bulk
Authors: Mittas Nikolaos , Angelis Lefteris
Published: March 2020

Context

The rapid evolvement of software development effort estimation models created the need for empirical evaluation of their quality. The empirical evaluation is based either on hypothesis tests with respect to a single criterion or on aggregating methods for multiple criteria. However, a model can be considered as a multidimensional entity performing differently on alternative datasets and its performance can be divergent when expressed by alternative criteria.

Objective

In this study, we explore this multidimensional nature of models by considering them as points in two different spaces (domain and criteria spaces).

Method

Introducing an alternative approach for data‐driven benchmarking, a new framework based on archetypal analysis is proposed for evaluation purposes of multiple models.

Results

The benefits of the framework are illustrated through a large‐scale experimental setup on a set of 93 effort estimation models, trained and tested on 10 datasets under 8 criteria providing answers to critical research questions.

Conclusion

The results indicate that a small minority of reference models is enough to define the performance of the bulk of all models. The framework focuses on models that have behavior close to archetypes and especially those that are close to a “best” archetype.
Forming an Ultrathin SnS Layer on Cu2ZnSnS4 Surface to Achieve Highly Efficient Solar Cells with Zn(O,S) Buffer
Authors: Huang Lan , Li Jianmin , Wang Shijin , Zhong Lan , Xiao Xudong
Published: March 2020

Environmental friendliness demands the use of nontoxic elements in all types of solar cells, and Zn(O,S) thin film as an alternative buffer layer to replace CdS layer in chalcopyrite and kesterite solar cells has attracted enormous attention in the past. However, Cu2ZnSnS4 (CZTS) solar cells with a Zn(O,S) buffer are far inferior to those with CdS buffer despite the potentially better band alignment. Herein, by intentionally controlling the precursor composition, the surface of CZTS can be modified to improve the quality of the Zn(O,S)/CZTS junction for the chemical bath‐deposited Zn(O,S) buffer. Such a CZTS solar cell reaches a high conversion efficiency of 7.28%, the highest among all Zn(O,S)‐based kesterite solar cells so far. The CZTS surface that can jointly work well with the Zn(O,S) buffer is further investigated using X‐ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy. The results indicate that an ultrathin SnS layer exists on the CZTS surface and effectively raises the conduction band edge of the absorber surface to form a conduction band offset barrier of ≈0.40 eV, significantly better than that without the assistance of SnS layer. A key route for fabricating highly efficient and low‐cost Cd‐free CZTS thin‐film solar cells is described.
Empirical formulation for estimating the fundamental frequency of historical stone mosques with masonry domes
Authors: Çalik İsmet , Bayraktar Alemdar , Türker Temel , Akköse Mehmet
Published: March 2020

Historical stone mosques with masonry dome are complex structures due to their different structural elements, material properties, boundary conditions, connections, etc. It is very difficult to develop the numerical models representing the real behaviour of these structures. Therefore, their numerical models should be checked with ambient vibration tests for the reliable safety evaluations before the restoration applications. However, it is known that the ambient vibration tests of historical mosques are very difficult and costly and need permissions from the owners and relevant government agencies. The paper aims to develop an empirical formulation for estimating the fundamental frequency of historical stone mosques with masonry dome to check the initial finite element models. Nine stone mosques with masonry dome in different dimensions in the eastern Black Sea Region of Turkey were selected as examples for this purpose. By performing ambient vibration tests of the selected mosques, experimental natural frequencies, mode shapes, and damping ratios have been determined and evaluated together. An empirical formulation for the fundamental frequency and coefficients for the second and third frequencies of stone mosques with masonry dome based on vibration data are obtained by using the statistical regression analysis and verified with the control data. The comparative results confirm that the proposed formulation has a reliable predictive performance.
Regulation of cancer‐immunity cycle and tumor microenvironment by nanobiomaterials to enhance tumor immunotherapy
Authors: Yang Jingxing , Zhang Chunfu
Published: March 2020

In the past decade, we have witnessed the revolution in cancer therapy, especially in the rapid development of cancer immunotherapy. In particular, the introduction of nanomedicine has achieved great improvement in breaking the limitations of and immunological tolerance caused by clinic‐approved immunotherapies (cancer vaccine, CAR‐T, and immune checkpoint blockade) to enhance immunogenicity, antigen presentation and T lymphocyte infiltration for eradicating the primary tumors and distant metastases simultaneously. However, some fundamental but significant issues still need to be thoroughly clarified before the combination of nanomedicine and immunotherapy moves toward clinical translation such as biological safety and synergistic mechanisms of nanomaterials in the systematic immune responses. Therefore, in this review, the role of nanomaterials in cancer immunotherapy is summarized, mainly focusing on the effective activation and long‐term stimulation of both the innate and the adaptive immune responses and regulation of or remodeling the tumor microenvironment, especially the tumor immunosuppressive microenvironment. Also, we elaborate on the targets and challenges of nanomaterials in the cancer‐immunity cycle, summarize several main strategies to convert the cold tumor immune microenvironment to the hot one, and illustrate the progress in regulation of tumor immune microenvironment by targeting specific immunosuppressive cells. Finally, we prospect the nano‐combined immunotherapy strategies in tumor‐targeting, normalization of tumor immune environment and modification of macrophages.

This article is characterized under:

Therapeutic Approaches and Drug Discovery > Emerging Technologies

Diagnostic Tools > In Vivo Nanodiagnostics and Imaging

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology

Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease
One-loop open-string integrals from differential equations: all-order α′-expansions at n points
Authors: Mafra Carlos R. , Schlotterer Oliver
Published: March 2020

Abstract

We study generating functions of moduli-space integrals at genus one that are expected to form a basis for massless n-point one-loop amplitudes of open superstrings and open bosonic strings. These integrals are shown to satisfy the same type of linear and homogeneous first-order differential equation w.r.t. the modular parameter τ which is known from the A-elliptic Knizhnik-Zamolodchikov-Bernard associator. The expressions for their τ-derivatives take a universal form for the integration cycles in planar and non-planar one-loop open-string amplitudes. These differential equations manifest the uniformly transcendental appearance of iterated integrals over holomorphic Eisenstein series in the low-energy expansion w.r.t. the inverse string tension α′. In fact, we are led to conjectural matrix representations of certain derivations dual to Eisenstein series. Like this, also the α′-expansion of non-planar integrals is manifestly expressible in terms of iterated Eisenstein integrals without referring to twisted elliptic multiple zeta values. The degeneration of the moduli-space integrals at τ → i∞ is expressed in terms of their genus-zero analogues — (n+2)-point Parke-Taylor integrals over disk boundaries. Our results yield a compact formula for α′-expansions of n-point integrals over boundaries of cylinder- or Möbius-strip worldsheets, where any desired order is accessible from elementary operations.
All-multiplicity one-loop amplitudes in Born-Infeld electrodynamics from generalized unitarity
Authors: Elvang Henriette , Hadjiantonis Marios , Jones Callum R. T. , Paranjape Shruti
Published: March 2020

Abstract

We initiate a study of non-supersymmetric Born-Infeld electrodynamics in 4d at the quantum level. Explicit all-multiplicity expressions are calculated for the purely rational one-loop amplitudes in the self-dual (+ + … +) and next-to-self-dual (− + … +) helicity sectors. Using a supersymmetric decomposition, d-dimensional unitarity cuts of the integrand factorize into tree-amplitudes in a 4d model of Born-Infeld photons coupled to a massive complex scalar. The two-scalar tree-amplitudes needed to construct the Born-Infeld integrand are computed using two complimentary approaches: (1) as a double-copy of Yang-Mills coupled to a massive adjoint scalar with a dimensionally reduced form of Chiral Perturbation Theory, and (2) by imposing consistency with low-energy theorems under a reduction from 4d to 3d and T-duality. The Born-Infeld integrand is integrated in d = 4 − 2ϵ dimensions at order $$ \mathcal{O}\left({\in}^0\right) $$
O

∈
0

using the dimension-shifting formalism. We comment on the implications for electromagnetic duality in quantum Born-Infeld theory.
On scale separation in type II AdS flux vacua
Authors: Font Anamaría , Herráez Alvaro , Ibáñez Luis E.
Published: March 2020

Abstract

We study the separation of AdS and Kaluza-Klein (KK) scales in type II 4d AdS orientifold vacua. We first address this problem in toroidal/orbifold type IIA vacua with metric fluxes, corresponding to compactifications in twisted tori, both from the 4d and 10d points of view. We show how the naive application of the effective 4d theory leads to results which violate the AdS distance conjecture, in a class of$$ \mathcal{N} $$N= 1 supersymmetric models which have a 10d lifting to a compactification onS3× S3. We show how using KK scales properly modified by the compact metric leads to no separationof scales with$$ {M}_{\mathrm{KK}}^2=\mathfrak{c}\left|\Lambda \right|, $$MKK2=cΛ,with c a numerical constant independent of fluxes. This applies with no need to keep non-leading fluxes fixed. We also consider a class of IIB models with non-geometric fluxes in which the effective field theory analysis seems to lead to a naive separation of scales and a violation of the AdS distance conjecture. It has a T-dual which again may be understood as a 10d type IIA theory compactified onS3× S3. In this geometric dual one again observes that the strong AdS distance conjecture is obeyed with$$ {M}_{\mathrm{KK}}^2=\mathfrak{c}^{\prime}\left|\Lambda \right|, $$MKK2=c′Λ,if one takes into account the curvature in the internal space. These findings seem to suggest that all toroidal/orbifold models with fluxes in this class obey$$ {M}_{\mathrm{KK}}^2=\mathfrak{c}\left|\Lambda \right| $$MKK2=cΛwith$$ \mathfrak{c} $$ca flux-independent numerical constant.
A minimally invasive, 3D-fluoroscopy-navigation-guided, 3D-controlled pedicle approach in spine surgery: first reliable results and impact on patient safety
Authors: El Saman André , Meier Simon Lars , Marzi Ingo
Published: March 2020

Purpose

Safe pedicle screw placement is a daily challenge to every spine surgeon. Introduction of minimally invasive approaches in spinal surgery led to an impaired facility of inspection of the surgical field increasing the importance of intraoperative imaging and navigation. During the past years, we established a minimally invasive, navigated approach in our clinical setting.

Methods

We retrospectively reviewed the accuracy of pedicle approaches in patients treated due to traumatic or osteoporotic fractures, spondylitis/discitis, and tumoral lesions. Guide wires for pedicle screws or kyphoplasty cannulas were inserted in a 3D-navigation-guided, minimally invasive technique. Positioning of the guide wires was verified via 3D-scan, and pedicle screws/kyphoplasty cannulas were then visualized via a.p./lateral radiographs. Accuracy data were compared to a standard navigated open approach control group with indications similar to the MIS-group.

Results

23 MIS patients were included in this study (25–84 years, mean 70 years) with a total of 154 placed guide wires. Handling of the navigated Jamshidi needle was easy and secure. The guide wires showed correct placement in 151/154 cases. Three wires (1.9%) needed correction of placement after control scan. There were no vascular or neurologic complications due to wire misplacement. In the open-surgery control group, 7/181 screws (3.9%) needed intraoperative correction presenting no significant difference compared to the correction rate of the MIS-group (p = 0.35).

Conclusion

Our study shows the feasibility and reliability of a navigation-guided, minimally invasive pedicle approach in the clinical setting. Therefore, reduced morbidity due to minimized approaches can be combined with higher accuracy of navigated pedicle screw/kyphoplasty cannula placement improving patient safety.
First-order sensitivity of the optimal value in a Markov decision model with respect to deviations in the transition probability function
Authors: Kern Patrick , Simroth Axel , Zähle Henryk
Published: March 2020

Markov decision models (MDM) used in practical applications are most often less complex than the underlying ‘true’ MDM. The reduction of model complexity is performed for several reasons. However, it is obviously of interest to know what kind of model reduction is reasonable (in regard to the optimal value) and what kind is not. In this article we propose a way how to address this question. We introduce a sort of derivative of the optimal value as a function of the transition probabilities, which can be used to measure the (first-order) sensitivity of the optimal value w.r.t. changes in the transition probabilities. ‘Differentiability’ is obtained for a fairly broad class of MDMs, and the ‘derivative’ is specified explicitly. Our theoretical findings are illustrated by means of optimization problems in inventory control and mathematical finance.
Effects of 5-HT2C, 5-HT1A receptor challenges and modafinil on the initiation and persistence of gambling behaviours
Authors: Humby Trevor , Smith Georgia E. , Small Rebecca , Davies William , Carter Jenny , Bentley Chloe A. , Winstanley Catharine A. , Rogers Robert D. , Wilkinson Lawrence S.
Published: March 2020

Rationale

Problematic patterns of gambling are characterised by loss of control and persistent gambling often to recover losses. However, little is known about the mechanisms that mediate initial choices to begin gambling and then continue to gamble in the face of losing outcomes.

Objectives

These experiments first assessed gambling and loss-chasing performance under different win/lose probabilities in C57Bl/6 mice, and then investigated the effects of antagonism of 5-HT2CR with SB242084, 5-HT1AR agonism with 8-OH-DPAT and modafinil, a putative cognitive enhancer.

Results

As seen in humans and other species, mice demonstrated the expected patterns of behaviour as the odds for winning were altered increasing gambling and loss-chasing when winning was more likely. SB242084 decreased the likelihood to initially gamble, but had no effects on subsequent gambling choices in the face of repeated losses. In contrast, 8-OH-DPAT had no effects on choosing to gamble in the first place, but once started 8-OH-DPAT increased gambling choices in a dose-sensitive manner. Modafinil effects were different to the serotonergic drugs in both decreasing the propensity to initiate gambling and chase losses.

Conclusions

We present evidence for dissociable effects of systemic drug administration on different aspects of gambling behaviour. These data extend and reinforce the importance of serotonergic mechanisms in mediating discrete components of gambling behaviour. They further demonstrate the ability of modafinil to reduce gambling behaviour. Our work using a novel mouse paradigm may be of utility in modelling the complex psychological and neurobiological underpinnings of gambling problems, including the analysis of genetic and environmental factors.
AC electrokinetic immobilization of organic dye molecules
Authors: Laux Eva-Maria , Wenger Christian , Bier Frank F. , Hölzel Ralph
Published: March 2020

The application of inhomogeneous AC electric fields for molecular immobilization is a very fast and simple method that does not require any adaptions to the molecule’s functional groups or charges. Here, the method is applied to a completely new category of molecules: small organic fluorescence dyes, whose dimensions amount to only 1 nm or even less. The presented setup and the electric field parameters used allow immobilization of dye molecules on the whole electrode surface as opposed to pure dielectrophoretic applications, where molecules are attracted only to regions of high electric field gradients, i.e., to the electrode tips and edges. In addition to dielectrophoresis and AC electrokinetic flow, molecular scale interactions and electrophoresis at short time scales are discussed as further mechanisms leading to migration and immobilization of the molecules.
Do female rainbow kribs choose males on the basis of their apparent aggression and boldness? A non-correlational mate choice study
Authors: Scherer Ulrike , Godin Jean-Guy J. , Schuett Wiebke
Published: March 2020

Consistent between-individual differences in behaviour, known as personality differences, are heritable and have consequences for individual survival and reproductive success. Therefore, it is likely that personality differences are not just under natural but also under sexual selection. Indeed, the recently developed idea that individuals choose their mate based on its personality finds empirical support. However, most studies on mate choice based on personality traits are correlative pioneering work and there is a paucity of experimental studies that test for causality by disentangling personality measures from other, potentially correlated traits that may be important during mate choice. Here, we tested female preference for the apparent level and consistency of either male aggression (measured as mean distance of approach towards an animated opponent, manipulated by locating males at a fixed distance) or male boldness (measured as activity under a simulated predation threat, manipulated using a gradient in ambient water temperature) in a bi-parental West African cichlid,Pelvicachromis pulcher. Females could observe the apparent behaviour of paired stimulus males and were allowed to choose between the two stimulus males in a subsequent choice test. We found no direct effect of male apparent aggression/boldness on female choice, but an indirect effect such that female preference for the apparently bold male increased with increasing within-male pair contrast in their apparent level of boldness. Our results indicate females consider male boldness per se during mate choice, suggesting male boldness is sexually selected in our study species.

Significance statement

Ever since Darwin introduced the concept of sexual selection, female choice has been studied extensively. However, the hypothesis that consistent between-individual differences in behaviour (known as personality differences) affect mate choice is relatively new. Correlative studies support this idea but provide only suggestive evidence. Here, we used behavioural manipulations in order to disentangle male behaviour from other, potentially correlated male traits, allowing us to test for causality between female choice and personality differences in male aggression and boldness (both in level and consistency of behaviour) in a bi-parental cichlid. We found no overall female preference for male apparent behaviour, but female preference for the bold-appearing male increased with increasing between-male contrast in apparent boldness. Our results indicate a causal link between female choice and male boldness. In future, behavioural manipulations using a temperature gradient could provide further valuable insights.
Patient‐Reported Outcomes and Long‐Term Results of a Randomized Controlled Trial Comparing Single‐Port Versus Conventional Laparoscopic Inguinal Hernia Repair
Authors: Chia Daryl Kai Ann , Lomanto Davide , Wijerathne Sujith
Published: March 2020

Background

Surgical techniques for inguinal hernia repair have evolved rapidly from open methods to conventional laparoscopic totally extra‐peritoneal (CTEP) and recently single‐port TEP (STEP). As there is currently no randomized controlled trial (RCT) reporting long‐term patient‐reported outcomes between CTEP and STEP, we reviewed patients who were randomized to CTEP or STEP 5 years after surgery.

Methods

Telephone interviews were administered to patients with primary unilateral inguinal hernia recruited for the RCT comparing CTEP and STEP in 2011. The modified Body Image Questionnaire was used to measure long‐term patient‐reported outcomes.

Results

Forty‐two out of forty‐nine of the STEP group and forty‐one out of fifty of the CTEP group responded to phone interviews. Median follow‐up time, demographic data and clinical outcomes were comparable between both groups. The Body Image Score (5–20: 5—least dissatisfied, 20—most dissatisfied; BIS score ± SD, STEP vs. CTEP, 5.33 ± 0.90 vs. 7.17 ± 1.87, p < 0.001) and Cosmetic Score (2–20: 2—least satisfied, 20—most satisfied; CS score ± SD, STEP vs. CTEP, 19.05 ± 1.31 vs. 15.87 ± 1.57, p < 0.001) were superior in the STEP group. Similarly, self‐reported scar perception (1—cannot be seen, 2—can barely be seen, 3—visible; scar perception score ± SD, STEP vs. CTEP, 1.29 ± 0.51 vs. 2.55 ± 0.64, p < 0.001) and overall experience score (1—least satisfied, 10—most satisfied; overall satisfaction score ± SD, STEP vs. CTEP, 9.57 ± 0.67 vs. 8.22 ± 0.94, p < 0.001) were superior in the STEP group.

Conclusion

Patients who underwent STEP reported superior cosmetic and satisfaction scores and comparable surgical outcomes 5 years after surgery compared to the CTEP group. STEP should be strongly considered in patients who are concerned about long‐term cosmetic outcomes and should be offered if surgical expertise is available.

Trial registration NCT02302937
Modified Anterior Tibial Artery Perforator‐Pedicled Propeller Flap for Soft‐Tissue Coverage of the Ankle and Heel
Authors: Lin Jian , Zhou Feng , Sun Yi‐Dan , Gao Ya‐Shan , Li Hai‐Zhou , Zheng He‐Ping , Zhang Ying‐Fan , Li Qing‐Feng , Ward Patricia J. , Yang Ya‐Li , Liu Cai‐Yue
Published: March 2020

Background

The ankle and heel are challenging regions to reconstruct functionally. Here, we explored the feasibility and clinical outcomes of a modified anterior tibial artery perforator‐pedicled propeller flap for the repair of soft‐tissue defects of the ankle and heel.

Patients and methods

Between January 2013 and December 2015, 12 patients with soft‐tissue defects of the ankle and/or heel underwent reconstructive surgery that included our flap technique. The flaps measured 20 × 8 cm to 7 × 4 cm. A hand‐held Doppler was used to identify a proper constant perforator in the distal ankle. In each case, the base of the flap was well preserved. The flap was transposed (180° rotation) to reach and cover the defect.

Results

The average follow‐up time was 13 months (10–28 months). We observed good texture matches and contour in all of the flaps. All patients could walk and wear normal footwear. All but one flap survived completely without complications. Partial loss was observed in one patient, and the necrotic region was healed with secondary intention.

Conclusion

Our modified anterior tibial artery free‐style perforator‐pedicled propeller flap provides a novel option for functional ankle and heel reconstruction.

Level of Evidence

Level IV.
Radioimmunotherapy for mantle cell lymphoma: 5-year follow-up of 90 patients from the international RIT registry
Authors: Hohloch Karin , Windemuth-Kieselbach Christine , Zinzani Pier Luigi , Cacchione Roberto , Jurczak Wojciech , Suh C. , Trümper Lorenz , Scholz Christian W.
Published: March 2020

To assess the efficacy of radioimmunotherapy (RIT) with 90yttrium-ibrutinib-tiuxetan (90Y-IT) in mantle cell lymphoma, data from 90 patients registered in the RIT Network with a median follow-up (FU) of 5.5 years after RIT were evaluated. 90Y-IT was given as first-line therapy in 45 (50%) and for relapse in 45 (50%) patients. Most patients received 90Y-IT as consolidation after chemoimmunotherapy in first line (98%) and in relapse (53%). As a first-line treatment, 30 patients (pts.) (67%) achieved CR, 10 pts. (22%) PR%. and 1 pt. (2%) PD, and for 4 pts. (9%), no response data was available. At relapse, CR was achieved in 17 pts. (38%), PR in 6 pts. (13%), SD in 2 pts. (4%), and 6 pts. (13%) had PD, while the response was not documented for 14 pts. (31%). After a median FU of 5.5 years, median PFS for all patients was 2.11 (95% CI, 1.03–2.32) years, and median OS was 4.05 (95% CI, 2.79–7.21) years. Eleven pts. (12.2%) developed second malignancy. In conclusion, this is the largest report of MCL pts. treated with 90Y-IT to date. 90Y-IT was most often used as consolidation after first- and second-line chemotherapy and may improve the results achieved using chemoimmunotherapy alone. However, the results are less encouraging compared to treatment with small molecules such as ibrutinib.
Wall shear stress measurements by white-light oil-film interferometry
Authors: Lunte J. , Schülein E.
Published: March 2020

Wall shear stress and wall streamline direction measurements were conducted on a generic delta wing model to demonstrate the potential of the white-light oil-film interferometry in three-dimensional flows. With the proposed algorithm, an automatic oil-film thickness calculation is possible and yields reproducible and plausible wall shear stress distributions on the leeward side of the delta wing for various angles of attack.

Graphic abstract
Influence of wetting conditions on bubble formation from a submerged orifice
Authors: Mirsandi H. , Smit W. J. , Kong G. , Baltussen M. W. , Peters E. A. J. F. , Kuipers J. A. M.
Published: March 2020

The formation of gas bubbles by submerged orifices is a fundamental process encountered in various industrial applications. The dynamics of the contact line and the contact angle may have a significant influence on the detached bubble size depending on the wettability of the system. In this study, the influence of wetting conditions on the dynamics of bubble formation from a submerged orifice is investigated experimentally and numerically. The experiments are performed using a hydrophobic orifice plate and a series of ethanol–water solutions to vary the wettability where the key characteristics of the bubbles are measured using a high-speed, high-resolution camera. An extensive analysis on the influence of wetting conditions on the bubble size, bubble growth mechanism and the behavior of the contact line is given. Bubble growth stages, termed (1) hemispherical spreading, (2) cylindrical spreading, (3) critical growth and (4) necking, are identified based on key geometrical parameters of the bubble and relevant forces acting on the bubble during the growth. The experimental results show that the apparent contact angle varies in a complicated manner as the bubble grows due to the surface roughness and heterogeneity. The experimental findings are finally used to validate the local front reconstruction method with a contact angle model to account for the contact angle hysteresis observed in the experiments.

Graphic abstract
Hernia at the stoma site after loop ileostomy reversal
Authors: Eklöv Karolina , Viktorsson Fred Zika , Frosztega Eric , Bringman Sven , Nygren Jonas , Everhov Åsa H.
Published: March 2020

Purpose

To estimate the incidence of and risk factors for stoma site hernia after closure of a temporary diverting ileostomy.

Method

In a non-comparative cohort study, charts (n = 216) and CT-scans (n = 169) from patients who had undergone loop ileostomy closure following low anterior resection for rectal cancer 2010–2015 (mainly open surgery) at three hospitals were evaluated retrospectively. Patients without hernia diagnosis were evaluated cross-sectionally through a questionnaire (n = 158), and patients with symptoms of bulging or pain were contacted and offered a clinical examination or a CT scan including Valsalva maneuver.

Results

In the chart review, five (2.3%) patients had a diagnosis of incisional hernia at the previous stoma site after 8 months (median). In 12 patients, the CT scan showed a hernia, of which 8 had not been detected previously. The questionnaire was returned by 130 (82%) patients, of which 31% had symptoms of bulging or pain. Less than one in five of patients who reported bulging were diagnosed with hernia, but the absolute majority of the radiologically diagnosed hernias reported symptoms. By combining clinical and radiological diagnosis, the cumulative incidence of hernia was 7.4% during a median follow up time of 30 months. Risk factors for stoma site hernia were male sex and higher BMI.

Conclusion

Hernia at the previous stoma site was underdiagnosed. Less than a third of symptomatic patients had a hernia diagnosis in routine follow up. Randomized studies are needed to evaluate if prophylactic mesh can be used to prevent hernias, especially in patients with risk factors.
Clinical and radiological results of the vascularized medial femoral condyle graft for scaphoid non-union
Authors: Keller Marco , Kastenberger Tobias , Anoar Anizar Faizi , Kaiser Peter , Schmidle Gernot , Gabl Markus , Arora Rohit
Published: March 2020

Introduction

This study evaluated the use of a free vascularized bone graft with and without cartilage from the medial femoral condyle (MFC) in patients with recalcitrant scaphoid non-union, with a special focus on union rates and the osteochondral graft for proximal pole destruction.

Materials and methods

Thirty-eight avascular scaphoid non-unions in 37 patients who were treated with a free osteoperiosteal or osteochondral MFC graft were retrospectively evaluated (mean follow-up 16 months). Bone union, the scapholunate and the radiolunate angles were evaluated on X-ray images. The range of motion, grip strength, VAS, DASH and PRWE scores were evaluated clinically.

Results

The overall union rate was 95%. Bone union was achieved in 27 out of 29 (93%) scaphoids treated with a free osteoperiosteal MFC grafts and in 9 out of 9 (100%) scaphoids treated with a free osteochondral MFC graft. The range of motion remained almost unchanged, while grip strength increased significantly (34 kg vs. 44 kg) and the VAS (22–5), DASH (59–19) and PRWE (62–30) score decreased significantly. The scapholunate (71°–65°) and radiolunate (28°–18°) angle decreased. No major donor site morbidity was observed. Postoperative complications were observed in eight cases (21%).

Conclusions

The vascularized medial femoral bone graft leads to a good functional outcome in the treatment of scaphoid non-unions. The graft provides adequate blood supply and structural stability to the scaphoid. A proximal pole destruction can be replaced using an osteochondral graft with promising short-term results preventing carpal osteoarthritis and collapse.
The leading role of pathology in assessing the somatic molecular alterations of cancer: Position Paper of the European Society of Pathology
Authors:   on behalf of the European Society of Pathology (ESP), Matias-Guiu Xavier , Stanta Giorgio , Carneiro Fátima , Ryska Ales , Hoefler Gerald , Moch Holger
Published: March 2020

Molecular pathology is an essential part of pathology complementing conventional morphological tools to obtain a correct integrated diagnosis with appropriate assessment of prognosis and prediction of response to therapy, particularly in cancer. There is a concern about the situation of molecular pathology in some areas of Europe, namely, regarding the central role of pathologists in assessing somatic genomic alterations in cancer. In some countries, there are attempts that other laboratory medicine specialists perform the molecular analysis of somatic alterations in cancer, particularly now when next generation sequencing (NGS) is incorporated into clinical practice. In this scenario, pathologists may play just the role of “tissue providers,” and other specialists may take the lead in molecular analysis. Geneticists and laboratory medicine specialists have all background and skills to perform genetic analysis of germline alterations in hereditary disorders, including familial forms of cancers. However, interpretation of somatic alterations of cancer belongs to the specific scientific domain of pathology. Pathologists are necessary to guarantee the quality of the results, for several reasons: (1) The identified molecular alterations should be interpreted in the appropriate morphologic context, since most of them are context-specific; (2) pre-analytical issues must be taken into consideration; (3) it is crucial to check the proportion of tumor cells in the sample subjected to analysis and presence of inflammatory infiltrate and necrosis should be monitored; and 4) the role of pathologists is crucial to select the most appropriate methods and to control the turnaround time in which the molecular results are delivered in the context of an integrated diagnosis. Obviously, there is the possibility of having core facilities for NGS in a hospital to perform the sequence analysis that are open to other specialties (microbiologists, geneticists), but also in this scenario, pathologists should have the lead in assessing somatic alterations of cancer. In this article, we emphasize the importance of interpreting somatic molecular alterations of the tumors in the context of morphology. In this Position Paper of the European Society of Pathology, we strongly support a central role of pathology departments in the process of analysis and interpretation of somatic molecular alterations in cancer.
Error analysis for quadtree-type mesh coarsening algorithms adapted to pixelized heterogeneous microstructures
Authors: Fischer Andreas , Eidel Bernhard
Published: March 2020

For pixel-based microstructure representations we propose two different variants of adaptive, quadtree-based mesh coarsening algorithms that serve the purpose of a preprocessor for finite element analyses in the context of numerical homogenization. High resolution is preserved at interfaces for accuracy, coarse-graining in the defect-free interior of phases for efficiency. Error analysis is carried out on the micro scale by error estimation which itself is assessed by true error computation. Modified stress recovery schemes for an error indicator are proposed which overcome the deficits of the standard superconvergent recovery scheme for nodal stress computation in cases of interfaces with stiffness jump. By virtue of error analysis the improved efficiency by the reduction of unknowns is put into relation to the increase of the discretization error and thereby sets a rational basis for decisions on favorable meshes having the best trade-off between accuracy and efficiency as underpinned by various examples.
Volterra operators and Hankel forms on Bergman spaces of Dirichlet series
Authors: Bommier-Hato H.
Published: March 2020

For a Dirichlet series g, we study the Volterra operator $$T_g f(s)=-\int ^{+\infty }_{s} f(w)g'(w)dw,$$

T
g

f

(
s
)

=
-

∫
s

+
∞

f

(
w
)

g
′

(
w
)

d
w
,

acting on a class of weighted Hilbert spaces $${{\mathcal {H}}^{2}_{w}}$$

H

w
2

of Dirichlet series. We obtain sufficient / necessary conditions for $$T_g$$

T
g

to be bounded (resp. compact), involving BMO and Bloch type spaces on some half-plane. We also investigate the membership of $$T_g$$

T
g

in Schatten classes. Moreover, we show that if $$T_g$$

T
g

is bounded, then g is in $${{\mathcal {H}}}^p_w$$

H

w
p

, the $$L^p$$

L
p

-version of $${{\mathcal {H}}^{2}_{w}}$$

H

w
2

, for every $$0<p<\infty $$

0
<
p
<
∞

. We also relate the boundedness of $$T_g$$

T
g

to the boundedness of a multiplicative Hankel form of symbol g, and the membership of g in the dual of $${{\mathcal {H}}}^1_w$$

H

w
1

.
The complex geometry of two exceptional flag manifolds
Authors: Kotschick D. , Thung D. K.
Published: March 2020

We discuss the complex geometry of two complex five-dimensional Kähler manifolds which are homogeneous under the exceptional Lie group $$G_2$$

G
2

.
For one of these manifolds, rigidity of the complex structure among all Kählerian complex structures was proved by Brieskorn; for the other one, we prove it here. We relate the Kähler assumption in Brieskorn’s theorem to the question of existence of a complex structure on the six-dimensional sphere, and we compute the Chern numbers of all $$G_2$$

G
2

-invariant almost complex structures on these manifolds.