bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of New Peptide‐Based Ligands with 1,2‐HOPO Pendant Chelators and Thermodynamic Evaluation of Their Iron(III) Complexes**
Authors: Al Shaer Danah M. , Albericio Fernando , de la Torre Beatriz G. 
Published: August 2021

AbstractHydroxypyridones (HOPOs) are an important class of chelating compounds. They bind strongly to hard metal ions such as Fe(III). Here we present the solid‐phase synthesis of peptides containing 1,2‐HOPO moieties linked through a carboxylic acid placed at position 4 of the ring. A total of four ligands were studied, two bidentate and two hexadentate. The latter were synthesized by both stepwise and convergent strategies. The ligands and their complexes were characterized from the physico‐chemical perspective. The pKa values for all ligands showed their total deprotonation at pH lower than the physiological pH. The formation constant of the Fe(III) complex (log β) ranged from 23.66, corresponding to ligand A, to 27.63, corresponding to ligand C. The pFe3+ at pH=7.4 revealed that ligands B and C had a strong iron affinity (26.91 and 28.58, respectively), thereby making them suitable for further study in therapeutic applications.
Synthesis and Study of the Thermally Stable Poly(arylene ether ketone) Nanohybrids Containing Cadmium Selenide Nanocrystals
Authors: Zhang Yinan 
Published: August 2021

AbstractIn the present work, the novel nanohybrid material was synthesized with poly(arylene ether ketone) as the matrix. To investigate the effects of the various factors on the photoluminescence properties of the nanomaterial, a series of CdSe/ poly(arylene ether ketone) nanohybrids were obtained with the solvothermal synthesis method under different reaction times, Cd2+/selenourea ratios and polymer content. The formation of the CdSe nanocrystal was confirmed by fourier transform infrared spectroscopy (FTIR), high‐resolution transmission electron microscopy (HRTEM), X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS). According to the HRTEM images, the homogenous dispersion of nanoparticles was found in the nanohybrid material. The optical properties of this new material were investigated by UV‐vis and photoluminescence (PL) spectroscopy. The differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) measurements had showed that the obtained material had excellent thermal properties. In summary, a series of novel CdSe/poly(arylene ether ketone) nanohybrid materials were obtained. Due to its good fluorescence and thermal properties, this material will have a broad potential application in area of optoelectronic devices.
Triethanolamine‐Mediated Magnetically Separable Fe3O4−Pd Nanoparticles Catalyzed Heck Reaction under Ligand‐Free Conditions
Authors: Kumar Pal Chandan , Kumar Jena Ashis , Das Dibya , Sahu Swagatika , Kumar Singh Rajesh 
Published: August 2021

AbstractThe Fe3O4−Pd nanoparticles catalyzed Heck coupling reaction in triethanolamine was performed for the first time in absence of any external ligand. The Fe3O4−Pd/triethanolamine/100 °C catalytic system was found to be highly active in achieving good to excellent yields of the desired (E)‐alkenes. Both acrylates and styrene derivatives were successfully coupled with electron‐rich and electron‐deficient aryl iodides. The scope of the reaction was also expanded to less reactive aryl bromides and aryl chlorides albeit in lower yields. A number of functional groups were well tolerated. More significantly the catalyst showed good recyclability and can be reused up to four consecutive cycles without any decrease in catalytic activity.
2,2,6,6‐Tetramethylpiperidinyloxyl (TEMPO) Radical Mediated Electro‐Oxidation Reactions: A Review
Authors: Prakash Nishitha , Rajeev Rijo , John Anjali , Vijayan Ajesh , George Louis , Varghese Anitha 
Published: August 2021

AbstractOver the last few decades, the interest in green and sustainable chemistry has led to the development of different synthetic methodologies which utilize clean reagents. In that direction, the electro‐oxidation reactions are considered as one of the most interesting and promising methods. This is predominantly due to their environmentally benign nature, as oxidation can be achieved without the need for commonly used oxidizing agents. 2,2,6,6‐Tetramethylpiperidinyloxyl radical commonly known as TEMPO is a stable aminoxyl radical utilized for the oxidation of various classes of alcohols to carbonyl compounds by using cyclic voltammetry. The present review focuses on the various electrochemical reactions utilizing TEMPO as a mediator such as the oxidative conversion of alcohols, carbohydrates, amines, sulphur‐containing compounds, and alkenes in both laboratory as well as industrial scales and covers literature from 1950 till present date. The properties, reactivity, and yield percentages of these reactions would provide a basis for better electrocatalyst design in future studies involving TEMPO and its derivatives as mediators.
Maternal Effects on Embryonic Development and Survival in Walleyes of Lake Nipissing, Ontario
Authors: Johnston T. A. , Harry A. J. , Montgomerie R. D. , Wiegand M. D. , Spiers G. A. , Casselman J. M. , Leggett W. C. 
Published: August 2021

AbstractLife history theory predicts that females may increase reproductive allocation with advancing age as the probability for future reproduction diminishes. In iteroparous fishes, increasing age is usually accompanied by increasing fecundity, but evidence of increasing offspring quality is less consistent. We examined the developmental rate and survival of Walleye Sander vitreus embryos with respect to female age, size, condition, and various ova traits in an exploited stock dominated by young spawners. Embryo batches from individual females were collected in the field on multiple dates and reared to hatch under controlled conditions in both flow‐through and static incubation systems. Survival and thermal inputs to hatch (TU50) were analyzed with respect to spawn date, incubation method, and both maternal and ova traits. Spawning date had a relatively strong effect on embryo survival but only a minor effect on TU50, whereas incubation method had a small effect on survival but a stronger effect on TU50. Embryos reared in static incubators required greater thermal inputs to reach hatch. Using a model selection approach to assess the effects of maternal and ova traits, we found that neither maternal age nor size were strong predictors of survival or TU50. Instead, survival was more strongly related to egg size and fatty acid composition, and TU50 was not strongly related to any maternal or ova trait. Our results suggest that the nature and magnitude of maternal effects on early development and survival may vary among Walleye stocks, modified by physical conditions during incubation.
The CL&Pol polarizable force field for the simulation of ionic liquids and eutectic solvents
Authors: Goloviznina Kateryna , Gong Zheng , Padua Agilio A. H. 
Published: August 2021

AbstractMolecular dynamics (MD) simulation, and theoretical chemistry in general, have been central tools in the study of ionic liquids (ILs) and eutectic solvents, both of which are fluid phases dominated by ionic interactions and strong hydrogen bonds. These systems are still relatively recent, so the amount of experimental information given their enormous diversity is still scarce. Computational studies have produced several important discoveries, besides helping in the interpretation of experimental findings. Here we review the latest developments in the models describing the interactions and conformations of IL phases with atomic detail, in particular polarizable force fields. In these all‐atom models, the response of electron clouds to their electrostatic environment is represented by induced dipoles, therefore moving beyond the pair‐wise additivity of fixed‐charge force fields. Most of the conceptual framework to develop polarizable force fields has been available and implemented in major MD codes, so the main challenge to develop a useful polarizable model for ILs and eutectic solvents is how to handle their diversity in chemical structures and interactions, in order to build a model that can represent solutions, mixtures and interfaces with materials, and that is not too difficult to extend to new systems. As is often the case, force field development is not only science but it is also an art! The ingredients of successful force fields are often the result of pragmatism and heuristics, rather than mathematical complexity and absolutely rigorous physics (although retaining a sound physical basis in the parameters definitely helps). We focus on the CL&Pol polarizable force field for ILs, protic ionic liquids, and eutectic solvents, improving on previous‐generation fixed charge models. The CL&Pol force field is built as a detailed but extendable and transferable model offering more reliable predictions of thermodynamic, structural, and transport properties, which should contribute to the advancement of the field and towards the design of better solvents, electrolytes, lubricants, and so on.This article is categorized under:
Molecular and Statistical Mechanics > Molecular Interactions
Molecular and Statistical Mechanics > Molecular Dynamics and Monte‐Carlo Methods
Connecting Sequent Calculi with Lorenzen-Style Dialogue Games
Authors: Fermüller Christian G. 
Published: August 2021

Abstract Lorenzen has introduced his dialogical approach to the foundations of logic in the late 1950s to justify intuitionistic logic with respect to first principles about constructive reasoning. In the decades that have passed since, Lorenzen-style dialogue games turned out to be an inspiration for a more pluralistic approach to logical reasoning that covers a wide array of nonclassical logics. In particular, the close connection between (single-sided) sequent calculi and dialogue games is an invitation to look at substructural logics from a dialogical point of view. Focusing on intuitionistic linear logic, we illustrate that intuitions about resource-conscious reasoning are well served by translating sequent calculi into Lorenzen-style dialogue games. We suggest that these dialogue games may be understood as games of information extraction, where a sequent corresponds to the claim that a certain information package can be systematically extracted from a given bundle of such packages of logically structured information. As we will indicate, this opens the field for exploring new logical connectives arising by consideration of further forms of storing and structuring information.
Optimising simulations for diphoton production at hadron colliders using amplitude neural networks
Authors: Aylett-Bullock Joseph , Badger Simon , Moodie Ryan 
Published: August 2021

Abstract
Machine learning technology has the potential to dramatically optimise event generation and simulations. We continue to investigate the use of neural networks to approximate matrix elements for high-multiplicity scattering processes. We focus on the case of loop-induced diphoton production through gluon fusion, and develop a realistic simulation method that can be applied to hadron collider observables. Neural networks are trained using the one-loop amplitudes implemented in the NJet C++ library, and interfaced to the Sherpa Monte Carlo event generator, where we perform a detailed study for 2 → 3 and 2 → 4 scattering problems. We also consider how the trained networks perform when varying the kinematic cuts effecting the phase space and the reliability of the neural network simulations.
Bound states of WIMP dark matter in Higgs-portal models. Part II. Thermal decoupling
Authors: Oncala Ruben , Petraki Kalliopi 
Published: August 2021

Abstract
The Higgs doublet can mediate a long-range interaction between multi-TeV particles coupled to the Weak interactions of the Standard Model, while its emission can lead to very rapid bound-state formation processes and bound-to-bound transitions. Using the rates calculated in a companion paper, here we compute the thermal decoupling of multi-TeV WIMP dark matter coupled to the Higgs, and show that the formation of metastable dark matter bound states via Higgs-doublet emission and their decay decrease the relic density very significantly. This in turn implies that WIMP dark matter may be much heavier than previously anticipated, or conversely that for a given mass, the dark matter couplings to the Higgs may be much lower than previously predicted, thereby altering the dark matter phenomenology. While we focus on a minimal singlet-doublet model in the coannihilation regime, our calculations can be extended to larger multiplets where the effects under consideration are expected to be even more significant.
Resummation of terms enhanced by trilinear squark-Higgs couplings in the MSSM
Authors: Kwasnitza Thomas , Stöckinger Dominik 
Published: August 2021

Abstract
We analyze the appearance of the trilinear squark-Higgs couplings xq in Green functions in the Higgs sector of the MSSM and in threshold corrections to the SM. The results are constraints on maximal powers of xq in QCD-related loop corrections. In practice these often imply all-order resummations of leading or subleading xq contributions in SM-parametrized expressions. We present a variety of all-order resummation relations for ∆λ which include such xq-enhanced terms and different orders in Yukawa and gauge couplings. We contrast which terms cannot be resummed.
Outcomes of patients with ST-segment myocardial infarction admitted during the COVID-19 pandemic
Authors: Rattka M. , Winsauer C. , Stuhler L. , Thiessen K. , Baumhardt M. , Stephan T. , Rottbauer W. , Imhof A. 
Published: August 2021

Abstract
Background
Since the beginning of the SARS-CoV‑2 outbreak, healthcare professionals reported that patients admitted with ST-segment myocardial infarction (STEMI) were in worse condition compared to STEMI patients admitted before the outbreak. However, data on their outcomes are sparse.

Methods
We conducted a prospective, observational, cohort study of STEMI patients admitted during the COVID-19 pandemic from March 21, 2020 to July 31, 2020 (COVID-19 group). Clinical outcomes, 30-day mortality, and reasons potentially related to a delay in patient presentation were assessed and compared with STEMI patients admitted between November 1, 2019 and March 20, 2020 (pre-COVID-19 group).

Results
A total of 124 patients were enrolled, comprising 57 patients in the pre-COVID-19 group and 67 patients in the COVID-19 group. Significantly more patients in the COVID-19 group had a time to first medical contact of greater than 24 h. Additionally, those admitted during the pandemic had a significantly lower left ventricular ejection fraction (LVEF), worse thrombolysis in myocardial infarction (TIMI) flow, received circulatory support significantly more often, and had a significantly higher 30-day mortality. Furthermore, significantly more patients stated that “information by the media” made them hesitate to contact the emergency medical services as soon as possible.

Conclusion
Here, we show that STEMI patients admitted during the COVID-19 pandemic had significantly prolonged times to first medical contact, were in worse condition at admission, and had an increased 30-day mortality. Additionally, we found that “information by the media” made patients during COVID-19 hesitate to contact the emergency medical services. Consequently, public health strategies have to be developed to avoid potential excess mortality of STEMI patients during the pandemic.
Einsatz von Instrumenten bei der klinischen Untersuchung in deutschen HNO-Abteilungen und Privatpraxen heutzutage
Authors: Franzen Achim M. , Sykora Hannes , Hauptmann Michael , Coordes Annekatrin 
Published: August 2021

Zusammenfassung
Hintergrund
Der klassische Stirnreflektor diente dem HNO-Arzt zur Spiegeluntersuchung und ist heute Mediensymbol für den Arzt. Mit welchen Instrumenten heute in Deutschland HNO-Patienten klinisch untersucht werden, ist nicht bekannt. Es ist daher das Ziel der vorgelegten Untersuchung, dies mithilfe einer Befragung zu ermitteln.

Material und Methoden
Es erfolgte die Auswertung von 321 Fragebögen von klinisch tätigen (172) und niedergelassenen (149) HNO-Ärzten.

Ergebnisse
Die HNO-Spiegeluntersuchung wird heute mit einer selbstleuchtenden Kopflampe mit Akku und/oder Lichtleitkabel durchgeführt. Etwa 20 % der Antwortenden verwendet auch einen Stirnspiegel. Das Mikroskop wird von 90 % der teilnehmenden HNO-Ärzte zur Untersuchung der Ohren eingesetzt. Ein starres Endoskop benutzen 53,3 % zur Untersuchung des Kehlkopfs, 41 % für den Epipharynx und 35 % für die Nase/Nasennebenhöhlen (34,6 %). Flexibles Endoskop und Otoskop werden lediglich fakultativ verwendet.

Schlussfolgerung
Die selbstleuchtende, in den neuen Bundesländern häufiger kabellose Kopflampe hat den klassischen Stirnreflektor, mit dem seit ca. 20 Jahren nicht mehr ausgebildet wird, weitgehend verdrängt. Mit großer Regelmäßigkeit werden zumindest einzelne Organe auch mit dem Mikroskop oder starren Endoskop untersucht, während das flexible Endoskop und Otoskop insgesamt viel seltener, vor allem von Jüngeren und im Krankenhaus Tätigen, verwendet werden. Das diagnostische Potenzial der flexiblen Endoskopie wird durch die ambulanten Vergütungsstrukturen in Deutschland möglicherweise kompromittiert.
Die ventrale Abstützung bei dorsalen lumbalen Fusionsoperationen
Authors: Mederake Moritz , Walter Christian 
Published: August 2021

ZusammenfassungDie ventrale Abstützung im Rahmen dorsaler Fusionsoperationen ist insbesondere bei instabilen Pathologien, wie Spondylolisthesen oder Spondylodiszitiden, entscheidend für das Operationsergebnis. Der komplikative Verlauf einer Patientin mit simultan bestehender Spondylolisthese und Spondylodiszitis wird dargestellt und anhand der Literatur und des eigenen Behandlungsalgorithmus reevaluiert. Bei alleiniger Spondylodiszitis ist ein Beckenkamminterponat als Abstützung ausreichend. Bei zusätzlichen Störungen des sagittalen Profils ist eine Cage-Implantation zu bevorzugen.
$$\ell _2$$-penalized approximate likelihood inference in logit mixed models for regional prevalence estimation under covariate rank-deficiency
Authors: Krause Joscha , Burgard Jan Pablo , Morales Domingo 
Published: August 2021

AbstractRegional prevalence estimation requires the use of suitable statistical methods on epidemiologic data with substantial local detail. Small area estimation with medical treatment records as covariates marks a promising combination for this purpose. However, medical routine data often has strong internal correlation due to diagnosis-related grouping in the records. Depending on the strength of the correlation, the space spanned by the covariates can become rank-deficient. In this case, prevalence estimates suffer from unacceptable uncertainty as the individual contributions of the covariates to the model cannot be identified properly. We propose an area-level logit mixed model for regional prevalence estimation with a new fitting algorithm to solve this problem. We extend the Laplace approximation to the log-likelihood by an$$\ell _2$$ℓ2-penalty in order to stabilize the estimation process in the presence of covariate rank-deficiency. Empirical best predictors under the model and a parametric bootstrap for mean squared error estimation are presented. A Monte Carlo simulation study is conducted to evaluate the properties of our methodology in a controlled environment. We further provide an empirical application where the district-level prevalence of multiple sclerosis in Germany is estimated using health insurance records.
Automorphisms and periods of cubic fourfolds
Authors: Laza Radu , Zheng Zhiwei 
Published: August 2021

AbstractWe classify the symplectic automorphism groups for cubic fourfolds. The main inputs are the global Torelli theorem for cubic fourfolds and the classification of the fixed-point sublattices of the Leech lattice. Among the highlights of our results, we note that there are 34 possible groups of symplectic automorphisms, with 6 maximal cases. The six maximal cases correspond to 8 non-isomorphic, and isolated in moduli, cubic fourfolds; six of them previously identified by other authors. Finally, the Fermat cubic fourfold has the largest possible order (174, 960) for the automorphism group (non-necessarily symplectic) among all smooth cubic fourfolds.
Assessing prevalence and correlates of blue-colored flesh in lingcod (Ophiodon elongatus) across their geographic range
Authors: Galloway Aaron W. E. , Beaudreau Anne H. , Thomas Michael D. , Basnett Bonnie L. , Lam Laurel S. , Hamilton Scott L. , Andrews Kelly S. , Schram Julie B. , Watson Jessica , Samhouri Jameal F. 
Published: August 2021

AbstractIntraspecific variation in external and internal pigmentation is common among fishes and explained by a variety of biological and ecological factors. Blue-colored flesh in fishes is relatively rare but has been documented in some species of the sculpin, greenling, and perch families. Diet, starvation, photoprotection, and camouflage have all been suggested as proximate mechanisms driving blue flesh, but causal factors are poorly understood. We evaluated the relative importance of biological and spatial factors that could explain variation in blue coloration in 2021 lingcod (Ophiodon elongatus) captured across their range in the northeastern Pacific, from southeast Alaska to southern California. The probability of having blue flesh was highest for fish that were female, caught in shallower water, and smaller in body size. The incidence of blueness varied by region (4–25% of all fish) but was also confounded by differences in sex ratios of fish caught among regions. We analyzed the multivariate fatty acid composition of a subset of 175 fish from across the sampling range to test for differences in trophic biomarkers in blue lingcod. Lingcod fatty acid composition differed between regions and flesh colors but not between sexes. Blue-fleshed fish had lower concentrations of total fatty acids, 18:1ω-9, 16:1ω-7, 18:1ω-7, and ω-6 fatty acids, suggesting differences in energetics and energy storage in blue fish. While our data indicate potential links between diet and blue flesh in lingcod, important questions remain about the physiological mechanisms governing blueness and its biological consequences.