bluuebunny/crossref_metadata_2025_split huggingface dataset:
Building crystal structures of conjugated polymers through X‐ray diffraction and molecular modeling
Authors: Yao Ze‐Fan , Li Qi‐Yi , Wu Hao‐Tian , Ding Yi‐Fan , Wang Zi‐Yuan , Lu Yang , Wang Jie‐Yu , Pei Jian 
Published: July 2021

AbstractCrystal structure of conjugated molecules and polymers is fundamentally critical to understand their multilevel microstructures, carrier transport, and diverse functions. However, to determine the crystal structure of conjugated polymers is a significant challenge, mainly due to the poor crystallinity, weak diffraction, and instability under high‐energy radiation. Here, we build the possible crystal structures of eight typical conjugated polymers, covering several widely used molecular segments in organic optoelectronics. We model the packing structures of these seed polymers based on synchrotron X‐ray diffractions and molecular simulations. These crystal structures provide a new platform to predict the packing structures of more related polymer systems, extending the molecular scope. Based on this polymer crystal structure database, the multiscale microstructures and charge transport properties of conjugated polymers can be predicted before experiments. This study sets up a polymer crystal structure database to eliminate the current trial‐and‐error approaches and accelerating the design of high‐performance conjugated polymers.
Addressing the CKM unitarity problem with a vector-like up quark
Authors: Branco G. C. , Penedo J. T. , Pereira Pedro M. F. , Rebelo M. N. , Silva-Marcos J. I. 
Published: July 2021

AbstractWe point out that hints of deviations from unitarity in the first row of the CKM matrix may be explained by the presence of a single vector-like top. We study how the stringent experimental constraints arising from CP Violation in the kaon sector and from meson mixing such as$$ {D}^0\hbox{-} {\overline{D}}^0,{K}^0\hbox{-} {\overline{K}}^0 $$D0‐D¯0,K0‐K¯0and$$ {B}_{d,s}^0\hbox{-} {\overline{B}}_{d,s}^0 $$Bd,s0‐B¯d,s0can be satisfied in the proposed framework. In order for the deviations from unitarity to be of the required size while keeping the theory perturbative, the new top quark should have a massmT≲ 7 TeV which could be probed in upcoming experiments at the energy frontier.
On the transition form factors of the axial-vector resonance f1(1285) and its decay into e+e−
Authors: Zanke Marvin , Hoferichter Martin , Kubis Bastian 
Published: July 2021

Abstract
Estimating the contribution from axial-vector intermediate states to hadronic light-by-light scattering requires input on their transition form factors (TFFs). Due to the Landau–Yang theorem, any experiment sensitive to these TFFs needs to involve at least one virtual photon, which complicates their measurement. Phenomenologically, the situation is best for the f1(1285) resonance, for which information is available from e+e− → e+e−f1, f1 → 4π, f1 → ργ, f1 → ϕγ, and f1 → e+e−. We provide a comprehensive analysis of the f1 TFFs in the framework of vector meson dominance, including short-distance constraints, to determine to which extent the three independent TFFs can be constrained from the available experimental input — a prerequisite for improved calculations of the axial-vector contribution to hadronic light-by-light scattering. In particular, we focus on the process f1 → e+e−, evidence for which has been reported recently by SND for the first time, and discuss the impact that future improved measurements will have on the determination of the f1 TFFs.
Notes on gravity multiplet correlators in AdS3 × S3
Authors: Wen Congkao , Zhang Shun-Qing 
Published: July 2021

Abstract
We present a compact formula in Mellin space for the four-point tree-level holographic correlators of chiral primary operators of arbitrary conformal weights in (2, 0) supergravity on AdS3× S3, with two operators in tensor multiplet and the other two in gravity multiplet. This is achieved by solving the recursion relation arising from a hidden six-dimensional conformal symmetry. We note the compact expression is obtained after carefully analysing the analytic structures of the correlators. Various limits of the correlators are studied, including the maximally R-symmetry violating limit and flat-space limit.
Flat space holography in spin-2 extended dilaton-gravity
Authors: Afshar Hamid , Esmaeili Erfan , Safari H. R. 
Published: July 2021

Abstract
We present an interacting spin-2 gauge theory coupled to the two-dimensional dilaton-gravity in flat spacetime. The asymptotic symmetry group is enhanced to the central extension of Diff(S1)⋉C∞(S1)⋉Vec(S1) when the central element of the Heisenberg subgroup is zero (vanishing U(1) level). Using the BF-formulation of the model we derive the corresponding boundary coadjoint action which is the spin-2 extension of the warped Schwarzian theory at vanishing U(1) level. We also discuss the thermodynamics of black holes in this model.
A branching process model for dormancy and seed banks in randomly fluctuating environments
Authors: Blath Jochen , Hermann Felix , Slowik Martin 
Published: July 2021

AbstractThe goal of this article is to contribute towards the conceptual and quantitative understanding of the evolutionary benefits for (microbial) populations to maintain a seed bank consisting of dormant individuals when facing fluctuating environmental conditions. To this end, we discuss a class of ‘2-type’ branching processes describing populations of individuals that may switch between ‘active’ and ‘dormant’ states in a random environment oscillating between a ‘healthy’ and a ‘harsh’ state. We incorporate different switching strategies and suggest a method of ‘fair comparison’ to incorporate potentially varying reproductive costs. We then use this concept to compare the fitness of the different strategies in terms of maximal Lyapunov exponents. This gives rise to a ‘fitness map’ depicting the environmental regimes where certain switching strategies are uniquely supercritical.
P2X7R antagonists in chronic stress-based depression models: a review
Authors: von Muecke-Heim Iven-Alex , Ries Clemens , Urbina Lidia , Deussing Jan M. 
Published: July 2021

AbstractDepression affects around 320 million people worldwide. Growing evidence proposes the immune system to be the core interface between psychosocial stress and the neurobiological and behavioural features of depression. Many studies have identified purinergic signalling via the P2X7 receptor (P2X7R) to be of great importance in depression genesis yet only a few have evaluated P2X7R antagonists in chronic stress-based depression models. This review summarizes their findings and analyses their methodology. The four available studies used three to nine weeks of unpredictable, chronic mild stress or unpredictable, chronic stress in male mice or rats. Stress paradigm composition varied moderately, with stimuli being primarily psychophysical rather than psychosocial. Behavioural testing was performed during or after the last week of stress application and resulted in depressive-like behaviours, immune changes (NLRP3 assembly, interleukin-1β level increase, microglia activation) and neuroplasticity impairment. During the second half of each stress paradigm, a P2X7R antagonist (Brilliant Blue G, A-438079, A-804598) was applied. Studies differed with regard to antagonist dosage and application timing. Nonetheless, all treatments attenuated the stress-induced neurobiological changes and depressive-like behaviours. The evidence at hand underpins the importance of P2X7R signalling in chronic stress and depression. However, improvements in study planning and reporting are necessary to minimize experimental bias and increase data purview. To achieve this, we propose adherence to the Research Domain Criteria and the STRANGE framework.
Presynaptic GABAB receptor–mediated network excitation in the medial prefrontal cortex of Tsc2+/- mice
Authors: Bassetti Davide , Luhmann Heiko J. , Kirischuk Sergei 
Published: July 2021

AbstractThe TSC1 and TSC2 tumor suppressor genes control the activity of mechanistic target of rapamycin (mTOR) pathway. Elevated activity of this pathway in Tsc2+/- mouse model leads to reduction of postsynaptic GABAB receptor–mediated inhibition and hyperexcitability in the medial prefrontal cortex (mPFC). In this study, we asked whether presynaptic GABAB receptors (GABABRs) can compensate this shift of hyperexcitability. Experiments were performed in brain slices from adolescent wild-type (WT) and Tsc2+/- mice. Miniature and spontaneous postsynaptic currents (m/sPSCs) were recorded from layer 2/3 pyramidal neurons in mPFC using patch-clamp technique using a Cs+-based intrapipette solution. Presynaptic GABABRs were activated by baclofen (10 µM) or blocked by CGP55845 (1 µM). Independent on genotype, GABABR modulators bidirectionally change miniature excitatory postsynaptic current (mEPSC) frequency by about 10%, indicating presynaptic GABABR-mediated effects on glutamatergic transmission are comparable in both genotypes. In contrast, frequencies of both mIPSCs and sIPCSs were suppressed by baclofen stronger in Tsc2+/- neurons than in WT ones, whereas CGP55845 significantly increased (m/s)IPSC frequencies only in WT cells. Effects of baclofen and CGP55845 on the amplitudes of evoked (e)IPSCs confirmed these observations. These data indicate (1) that GABAergic synapses are inhibited by ambient GABA in WT but not in Tsc2+/- slices, and (2) that baclofen shifts the E/I ratio, determined as the ratio of (m/s)EPSC frequency to (m/s)IPSC frequency, towards excitation only in Tsc2+/- cells. This excitatory presynaptic GABABR-mediated action has to be taken into account for a possible medication of mental disorders using baclofen.
Graphical abstract
Kennwerte und teststatistische Güte des Veterans RAND 12-Item Health Survey (VR-12) bei Patienten mit chronischem Schmerz
Authors: Hüppe M. , Schneider K. , Casser H.-R. , Knille A. , Kohlmann T. , Lindena G. , Nagel B. , Nelles J. , Pfingsten M. , Petzke F. 
Published: July 2021

ZusammenfassungDer Veterans RAND 12-Item Health Survey (VR-12) wurde als Selbstbeurteilungsverfahren zur Erfassung gesundheitsbezogener Lebensqualität 2016 in den Deutschen Schmerzfragebogen (DSF) aufgenommen und ersetzt den bis dahin verwendeten lizenzpflichtigen SF-12. Beide Verfahren haben 12 Items und führen zu einer körperlichen und einer psychischen Summenskala. Auswertungen der deutschen Version mit größerer Stichprobe zu Kennwerten und zur teststatistischen Güte des VR-12 bei Patienten mit chronischem Schmerz fehlen bislang.Daten zum VR-12 und weiterer Verfahren des DSF wurden von 11.644 Patienten aus 31 an KEDOQ-Schmerz beteiligten Zentren ausgewertet. Die Patienten hatten den DSF vor Beginn einer angestrebten schmerztherapeutischen Behandlung ausgefüllt. Die Bestimmung der Änderungssensitivität erfolgte für 565 Patienten, für die der VR-12 aus einem Verlaufsfragebogen des DSF mehrere Monate nach der Ersterhebung vorlag.Die Reliabilität (Cronbachs Alpha) der körperlichen Summenskala war rtt = 0,78 und für die psychische Summenskala rtt = 0,84. Die psychische Summenskala wies deutliche Beziehungen zu den Depression-Angst-Stress-Skalen (DASS) auf (r = −0,51 bis r = −0,72), die körperliche Summenskala korrelierte höher mit Bereichen schmerzbedingter Beeinträchtigungen (r = −0,48 bis r = −0,52). Patienten mit höherer Schmerzchronifizierung, solche mit höherem Schmerz-Schweregrad und solche mit Hinweis auf hohe psychische Belastung beschrieben in beiden Summenskalen signifikant geringere gesundheitsbezogene Lebensqualität. Die Effektstärke (ES) der Veränderung im Sinne einer Verbesserung der gesundheitsbezogenen Lebensqualität war in der psychischen Summenskala ES = 0,33 und in der körperlichen Summenskala ES = 0,51.Die Ergebnisse sind in Übereinstimmung zu Befunden zum SF-36 bzw. SF-12 bei anderen Patientenkollektiven mit chronischem Schmerz. Sie zeigen zusammengefasst, dass mit dem VR-12 ein angemessener Ersatz zum SF-12 im Deutschen Schmerzfragebogen integriert wurde.
Translation and modulation invariant Hilbert spaces
Authors: Toft Joachim , Gumber Anupam , Manna Ramesh , Ratnakumar P. K. 
Published: July 2021

AbstractLet$$\mathcal H$$Hbe a Hilbert space of distributions on$$\mathbf{R}^{d}$$Rdwhich contains at least one non-zero element of the Feichtinger algebra$$S_0$$S0and is continuously embedded in$$\mathscr {D}'$$D′. If$$\mathcal H$$His translation and modulation invariant, also in the sense of its norm, then we prove that$$\mathcal H= L^2$$H=L2, with the same norm apart from a multiplicative constant.
Oxygenation Status of Malignant Tumors vs. Normal Tissues: Critical Evaluation and Updated Data Source Based on Direct Measurements with pO2 Microsensors
Authors: Vaupel Peter , Flood Ann Barry , Swartz Harold M. 
Published: July 2021

AbstractImmature and chaotic vascular networks with critically increased intervascular distances are characteristic features of malignant tumors. Spatial and temporal heterogeneities of blood flow and associated availabilities of O2, together with limited diffusive O2 transport, and -in some patients- anemia, obligatorily lead to tumor hypoxia (= critically reduced O2 levels) on macro- and microscopic scales. This detrimental condition, recently classified as a key hallmark of malignant growth, acts (a) as a barrier in most antitumor treatments, and (b) leads to malignant progression based on hypoxia-induced changes of the genome, transcriptome, and proteome, and finally to poor patient survival. This knowledge is, to a great extent, based on the systematic detection of tumor hypoxia in the clinical setting since the late 1980s. Precise assessment of the tumor oxygenation status was made possible using minimally invasive polarographic pO2 microsensors in a series of research projects. To assess tumor hypoxia in the clinical setting, it is highly desirable to use technologies with (a) high spatial and temporal resolutions, (b) the capability to judge the severity of tumor hypoxia, (c) to allow mapping of pO2 of the whole tumor mass, and (d) to enable serial investigations in order to verify treatment-related changes in tumor hypoxia. Selection and treatment of cancer patients according to their individual tumor oxygenation/hypoxia status for intensified and/or personalized hypoxia-targeted treatment strategies should be the ultimate goal.
Multiscale Coupling of One-dimensional Vascular Models and Elastic Tissues
Authors: Heltai Luca , Caiazzo Alfonso , Müller Lucas O. 
Published: July 2021

AbstractWe present a computational multiscale model for the efficient simulation of vascularized tissues, composed of an elastic three-dimensional matrix and a vascular network. The effect of blood vessel pressure on the elastic tissue is surrogated via hyper-singular forcing terms in the elasticity equations, which depend on the fluid pressure. In turn, the blood flow in vessels is treated as a one-dimensional network. Intravascular pressure and velocity are simulated using a high-order finite volume scheme, while the elasticity equations for the tissue are solved using a finite element method. This work addresses the feasibility and the potential of the proposed coupled multiscale model. In particular, we assess whether the multiscale model is able to reproduce the tissue response at the effective scale (of the order of millimeters) while modeling the vasculature at the microscale. We validate the multiscale method against a full scale (three-dimensional) model, where the fluid/tissue interface is fully discretized and treated as a Neumann boundary for the elasticity equation. Next, we present simulation results obtained with the proposed approach in a realistic scenario, demonstrating that the method can robustly and efficiently handle the one-way coupling between complex fluid microstructures and the elastic matrix.
Three-Dimensional (3D) Textiles in Architecture and Fashion Design: a Brief Overview of the Opportunities and Limits in Current Practice
Authors: Giglio Andrea , Paoletti Ingrid , Conti Giovanni Maria 
Published: July 2021

AbstractThree-dimensional (3D) textiles prove characteristics in structures and performance which can be as attractive as to be the main object of a high number of research and applications in specialist markets (from small medical devices to large engineering structure) where the performance demands are severe ([1] in J Eng Fibers Fabr.). Nevertheless, much of the research has come from academia and there are few relatively small companies that, even if have expertise, lack the resources to develop R&D programmes. This prevents to broaden their application and to consolidate their use in new markets ([2] in Advances in 3D Textiles, pp 1-18). The paper aims at exploring the potentialities and future implementations of 3D textiles in architecture and fashion design. Both are fields where the demand to balance requirements of environmental sustainability, low time-consuming production and high performance is emerging, in their own respective scale. A set of more than 10 real case studies are collected and analysed with the aim at underlining the potentialities and the limits of 3D textiles in practice. The overview suggests that a more integrated workflow among modelling and simulation tools and bigger effort from industry to enhance manufacturing options and increase the interest on new material systems, bring about new application such as indoor environmental quality (IEQ) or human body protection.
Urban Boundary Layers Over Dense and Tall Canopies
Authors: Makedonas Alexandros , Carpentieri Matteo , Placidi Marco 
Published: July 2021

AbstractWind-tunnel experiments were carried out on four urban morphologies: two tall canopies with uniform height and two super-tall canopies with a large variation in element heights (where the maximum element height is more than double the average canopy height, $$h_{max}=2.5h_{avg}$$

h

max

=
2.5

h

avg

). The average canopy height and packing density are fixed across the surfaces to $$h_{avg} = 80~\hbox {mm}$$

h

avg

=
80

mm

, and $$\lambda _{p} = 0.44$$

λ
p

=
0.44

, respectively. A combination of laser Doppler anemometry and direct-drag measurements are used to calculate and scale the mean velocity profiles with the boundary-layer depth $$\delta $$
δ
. In the uniform-height experiment, the high packing density results in a ‘skimming flow’ regime with very little flow penetration into the canopy. This leads to a surprisingly shallow roughness sublayer (depth $$\approx 1.15h_{avg}$$

≈
1.15

h

avg

), and a well-defined inertial sublayer above it. In the heterogeneous-height canopies, despite the same packing density and average height, the flow features are significantly different. The height heterogeneity enhances mixing, thus encouraging deep flow penetration into the canopy. A deeper roughness sublayer is found to exist extending up to just above the tallest element height (corresponding to $$z/h_{avg} = 2.85$$

z
/

h

avg

=
2.85

), which is found to be the dominant length scale controlling the flow behaviour. Results point toward the existence of a constant-stress layer for all surfaces considered herein despite the severity of the surface roughness ($$\delta /h_{avg} = 3 - 6.25$$

δ
/

h

avg

=
3
-
6.25

). This contrasts with the previous literature.
Concomitant Trajectories of Internalising, Externalising, and Peer Problems Across Childhood: a Person-centered Approach
Authors: Girard Lisa-Christine 
Published: July 2021

AbstractThis study investigated trajectories of concomitant internalising, externalising, and peer problems, and associated risk factors for group-membership, using a person-centered approach to better understand heterogeneity in subgroups identified. A cohort of 7,507 children in Ireland was followed from infancy to late childhood (50.3%, males; 84.9% Irish). The parent-version of the Strengths and Difficulties Questionnaire was used when children were 3, 5, 7 and 9 years of age. Information on antecedent risk factors was collected when children were 9 months. Group-based multi-trajectory modelling and multinomial logistic regression were used. Six subgroups of children with distinct profiles were identified, evidencing both homotypic and heterotypic comorbidity. No support of a ‘pure’ internalising, externalising or peer problems group was found in any identified trajectory group. Difficulties in one problem domain indicated the presence of difficulty in another problem domain for all children in elevated groups. Risk factors associated with group-membership were complex, with only three common factors across elevated groups: prenatal exposure to smoking, maternal education, and maternal stress. Specific risk factors for group-membership included low birth weight, sex, maternal age, maternal depression, family composition, social class, medical card status and quality of attachment. Despite some overlap in predictors, the combination of predictors specific to each group would suggest tailored programming. For children with the most acute problems, programming targets should include families with boys, born with low birth weight, exposed to smoking prenatally, with mothers who have lower levels of education, postnatal depression, increased stress and fewer financial resources.
Sequential learning to accelerate discovery of alkali-activated binders
Authors: Völker Christoph , Firdous Rafia , Stephan Dietmar , Kruschwitz Sabine 
Published: July 2021

AbstractAlkali-activated binders (AAB) can provide a clean alternative to conventional cement in terms of CO2emissions. However, as yet there are no sufficiently accurate material models to effectively predict the AAB properties, thus making optimal mix design highly costly and reducing the attractiveness of such binders. This work adopts sequential learning (SL) in high-dimensional material spaces (consisting of composition and processing data) to find AABs that exhibit desired properties. The SL approach combines machine learning models and feedback from real experiments. For this purpose, 131 data points were collected from different publications. The data sources are described in detail, and the differences between the binders are discussed. The sought-after target property is the compressive strength of the binders after 28 days. The success is benchmarked in terms of the number of experiments required to find materials with the desired strength. The influence of some constraints was systematically analyzed, e.g., the possibility to parallelize the experiments, the influence of the chosen algorithm and the size of the training data set. The results show the advantage of SL, i.e., the amount of data required can potentially be reduced by at least one order of magnitude compared to traditional machine learning models, while at the same time exploiting highly complex information. This brings applications in laboratory practice within reach.
Structurally nanoengineered antimicrobial peptide polymers: design, synthesis and biomedical applications
Authors: Ramamurthy Ronisha , Mehta Chetan H. , Nayak Usha Y. 
Published: July 2021

Abstract
Antimicrobial resistance not only increases the contagiousness of infectious diseases but also a threat for the future as it is one of the health care concern around the globe. Conventional antibiotics are unsuccessful in combating chronic infections caused by multidrug-resistant (MDR) bacteria, therefore it is important to design and develop novel strategies to tackle this problems. Among various novel strategies, Structurally Nanoengineered Antimicrobial Peptide Polymers (SNAPPs) have been introduced in recent years to overcome this global health care issue and they are found to be more efficient in their performance. Many facile methods are adapted to synthesize complex SNAPPs with required dimensions and unique functionalities. Their unique characteristics and remarkable properties have been exploited for their immense applications in various fields including biomedicine, targeting therapies, gene delivery, bioimaging, and many more. This review article deals with its background, design, synthesis, mechanism of action, and wider applications in various fields of SNAPPs.

Graphic abstract