bluuebunny/crossref_metadata_2025 huggingface dataset:
Utilizing Ternary Strategy to Reduce the Influence of Polymer Batch‐to‐Batch Variation in Organic Solar Cells
Authors: Adil Muhammad Abdullah , Memon Waqar Ali , Zhang Jianqi , Iqbal Muhammad Junaid , Yang Chen , Wang Yuheng , Zou Wenjun , Wei Zhixiang
Published: February 2022

Despite producing the best device performances, several major issues such as the batch‐to‐batch variation and low molecular weight (M
w) optimization greatly hinder the progress for the organic solar cells. Herein, tetraphenylethylene (TPE) as a third component has been added in a series of PM6:Y6 blends with different donor molecular weights (42–129 kDa). Ultimately, ternary devices fabricated by the PM6 with about half the M
w (66 and 74 kDa) of the standard donor (129 kDa) produce an excellent power conversion efficiency (PCE) of 15.09% and 15.15% owing to enhanced morphology and charge mobility, as compared to a standard binary PCE of 15.65%, respectively, indicating the possibility of attaining high‐performance attributes from low M
w polymers. Furthermore, the TPE inclusion in the 129 kDa binary blend leads to a remarkable PCE of 16.48%. This strategy, therefore, illustrates a relatively simple approach to overcome the batch‐to‐batch variation problem associated with polymers for organic solar cells.
Effect of Silver Nanoparticles Prepared from Saraca asoca Leaf Extract on Morphological, Functional, Mechanical, and Antibacterial Properties of Rice Starch Films
Authors: Khurshid Salman , Arif Saqib , Ali Tahira Mohsin , Iqbal Hafiza Mehwish , Shaikh Marium , Khurshid Haris , Akber Qurrat‐ul‐Ain , Yousaf Shahid
Published: February 2022

This study aims to evaluate functional properties of rice starch‐based nanocomposite (NC) films. Silver nanoparticles (SNP) are synthesized using Saraca asoca leaf extract and found to be spherical with diameters ranging between 27 and 45 nm. The SNP solution is added at three different levels: 50, 100, and 150 mL to filmogenic solution (150 mL) and these films are designated as SNP‐50, SNP‐100, and SNP‐150, respectively. In addition to a control film, two more films are made by adding AgNO3 solution (150 mL) and plant extract (150 mL) into filmogenic solutions. Addition of SNP improves tensile strength and decreases elongation at break of rice starch films. NC films show enhanced UV–vis light barrier properties due to increased color intensity and opacity. SNP added films exhibit lower water solubility, water holding capacity, and water vapor permeability. Scanning electron microscopy suggests that control film, SNP‐50, and SNP‐100 have the smoothest surfaces in comparison to all films. SNP incorporation delays biodegradation of films. Silver nanoparticles in the form of colloid, filmogenic solution, and even as discrete films show excellent antibacterial activity against common food pathogens. The SNP concentration significantly correlates (R2 = 0.62–0.96) to the functional properties of films.
The Antioxidant and Antibacterial Activities of the Pyridine‐4‐Aldehyde Schiff Bases Grafted Chloracetyl Chitosan Oligosaccharide Derivatives
Authors: Zhang Jingjing , Zhang Shijin , Wang Linqing , Tan Wenqiang , Li Qing , Guo Zhanyong
Published: February 2022

As a reactive intermediate, chloracetyl chitosan oligosaccharide (CACS) can be nucleophilic substituted by some bioactive groups to give novel derivatives of chitosan oligosaccharide (COS). The Schiff bases of pyridine‐4‐aldehyde are grafted onto CACS to give four COS derivatives in this paper. Specific structural characterization is implemented by fourier‐transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The degree of substitution (DS) of COS derivatives is quantitatively calculated by ratio of hydrogen proton integral. Their antioxidant property is evaluated using free radical scavenging assay towards 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and superoxide anion radicals, and the antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) is also investigated. The results revealed that the pyridine‐4‐aldehyde Schiff bases grafted chloracetyl chitosan oligosaccharide derivatives showed better antioxidant activity as well as antibacterial activity than COS and CACS, which may be related to the positive charge of these derivatives. Among all final products, derivative BPCACS with the highest DS has the best bioactivity with scavenging rate of 91.49% for the DPPH assay and inhibition diameter of 39.25 mm for S. aureus inhibitory assay, respectively. These results indicated that COS derivatives with enhanced biological activities could serve as potential biomaterial for antioxidant and antibacterial applications.
A qualitative study of CLIL employment with a focus on civic engagement in Vietnamese higher education
Authors: Vu Ngoc Tung , Nguyen Thao
Published: February 2022

This qualitative research study explored how content and language integrated learning (CLIL) could be implemented to benefit English‐major teacher candidates in Vietnamese higher education in terms of enhancing their sense of learning value, competence, autonomy, and relatedness. Despite some existing struggles during the implementation, the authors were able to identify and resolve problems of traditional approaches by developing the teacher candidates’ sense of social justice in their teaching and learning. Findings, discussions, and implications are presented at the end of the article.
Impact of an educational intervention on public perception of brachycephalic obstructive airway syndrome in brachycephalic dogs
Authors: Kenny Dan D. , Freemantle Rosie , Jeffery Andrea , Tivers Michael S.
Published: February 2022

Background

The popularity of brachycephalic dogs continues to increase despite inherent breed health problems. Increased education of current and potential brachycephalic dog owners could reduce the desirability of severely affected dogs.

Methods

Members of the general public were prospectively recruited to assess their understanding and opinions of brachycephalic breed‐related health problems, before and after an educational intervention on brachycephalic obstructive airway syndrome (BOAS).

Results

A total of 587 people participated. Before the intervention most participants considered characteristics of BOAS to be normal for brachycephalic dogs. Following the intervention this was moderately reduced. Responses highlighted that defining ‘normal’ for a breed is difficult. Referring to a trait as ‘normal’, even in a negative context results in normalisation. 99.7% of participants had an improved understanding of BOAS following the intervention. However, only 53.0% of the total participants and 29.3% of brachycephalic dog owning participants had their opinion of brachycephalic dogs changed. 99.5% of participants believed that potential owners should be more aware of BOAS and 57.3% of brachycephalic dog owners would have liked further information about breed health problems before purchasing their dog.

Conclusion

Educational interventions may be beneficial in improving understanding and awareness of BOAS however, normalisation of clinical signs of BOAS remains prevalent.
Isolation, identification and antimicrobial susceptibility profile of Salmonella isolated from poultry farms in Addis Ababa, Ethiopia
Authors: Mohammed Yasin , Dubie Teshager
Published: February 2022

Background

Salmonella has been found to be the major cause of foodborne diseases and a serious public health problem in the world, with an increasing concern for the emergence and spread of antimicrobial‐resistant strains.

Method

A cross‐sectional study was conducted on poultry and poultry farms in Addis Ababa from February 2016 to April 2016 to determine the occurrence and evaluate the antimicrobial susceptibility profile of Salmonella isolates. A total of 200 samples consisting of the cloacal swab (n = 168), pooled litter (n = 12), hand swab (n = 8), pooled feed and water (n = 12) were collected separately from six poultry farms. The samples were examined for the presence of Salmonella through culturing on bacteriological media. Descriptive statistics, Pearson's Chi‐square (X2) and bivariate logistic regression were used in the analysis of the data. Accordingly, out of 200 samples, 23 (11.50%) were Salmonella positive, of which 21(12.50%) were in cloacal swab and 2(16.67%) in the pooled litter. There was no statistical association between the bacteriological status of sample type and Salmonella positivity (X2 = 3.07, P = 0.545). However, there was a statistical association between farms and the rate of Salmonella isolation (X2 = 22.21, P ≤ 0.00). The antimicrobial susceptibility testing for Salmonella isolates was conducted following the Kirby–Bauer disc diffusion method (1961).

Results

Out of 23 samples tested, 95.65% of them were resistant to at least one or more antimicrobials. Multiple drug resistances were observed for 69.56% of Salmonella isolates. The highest resistance (73.9%) was observed in kanamycin followed by tetracycline (65.2%) and streptomycin (56.3%). gentamycin was the most effective antibiotic (95.7%; sensitivity) followed by ciprofloxacin (78.3% sensitivity) and ampicillin (69.6% sensitivity.

Conclusion

This current study finding indicated that further detailed epidemiological and molecular studies are essential on the frequency and sources of acquisition of resistant genes.
In vitro antibacterial and antifungal activities of extracts and fractions of leaves of Ricinus communis Linn against selected pathogens
Authors: Kebede Bedaso , Shibeshi Workineh
Published: February 2022

Introduction

Infectious disease impacts are reduced due to the development of antimicrobial agents. However, the effectiveness of antimicrobial agents is reduced over time because of the emergence of antimicrobial resistance. To overcome these problems, scholars have been searching for alternative medicines. Ricinus communis is used as a traditional treatment for bovine mastitis, wound infection, and other medicinal purposes.

Objective

The objective of the present study was to further evaluate the antimicrobial activities of R. communis leaf extracts and fractions.

Methods

R. communis leaves were macerated in methanol and acetone. The methanol extract showed better antimicrobial activity and subjected to further fractionation via increasing polarity of solvents (n‐hexane, chloroform, ethyl acetate, and aqueous). Test microorganisms included in the study were six laboratory reference bacteria (Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae, Kleibsella pneumoniae, Pseudomonas aeruginosa and Streptococcus pyogenes), two clinical isolate bacteria (E. coli and S. aureus), and Candida albicans. The agar well diffusion method was employed to determine antimicrobial activity. The minimum inhibitory concentrations (MIC) and minimum bactericidal/fungicidal concentrations (MBC/MFC) were determined through broth microdilution.

Results

The results indicated that the best antimicrobial activity for ethyl acetate fraction ranged from 14.67 mm (clinical E. coli) to 20.33 mm (S. aureus) at 400 mg/ml, however, n‐hexane exhibited the lowest antimicrobial activity. Among the tested fractions, ethyl acetate fraction showed the lowest MIC values ranged from 1.5625 mg/ml (S. aureus) to 16.67 mg/ml (Candida albicans). The ethyl acetate fraction showed bactericidal activity against all tested microorganisms.

Conclusion

Hence, ethyl acetate fraction of crude methanol extract exhibited the best antimicrobial activity.
Isolation and identification of emergent multidrug‐resistant Stenotrophomonas maltophilia from skin ulcers of Sarcoptes‐infested pigs
Authors: Thenissery Anusree , Chandran Rithu , Ravindran Rajasekhar , Ravishankar Chintu , Piriyath Jishnu Haridas
Published: February 2022

Stenotrophomonas maltophilia is an emergent multidrug‐resistant bacterium. Clinical conditions caused by this bacterium range from skin and soft tissue infection to graver septicaemia and cardiac involvement in immunocompromised humans. A recent whole‐genome analysis corroborates the hypothesis of the potential contribution of animals as reservoirs for human infections, strengthening the possibility of zoonoses. This paper reports the isolation of S. maltophilia from skin ulcers of pigs, associated with sarcoptic mange. Swabs from five pigs with skin ulcers were collected and processed. The cultural, biochemical characterisation and antibiotic susceptibility testing of the isolates were performed. The isolated organisms were found to be of similar cultural morphology and biochemical characteristics. Two representative isolates were subjected to molecular characterisation targeting 16s ribosomal RNA (rRNA). The polymerase chain reaction product was subjected to sequencing followed by basic local alignment search tool analysis, confirming the organism as S. maltophilia. Antibiotic susceptibility testing using 11 different antibiotics revealed that the organism is multidrug resistant with susceptibility towards oxytetracycline and cotrimoxazole.
Natural‐clay‐reinforced hydrogel adsorbent: Rapid adsorption of heavy‐metal ions and dyes from textile wastewater
Authors: Wang Zhi‐Ke , Li Ting‐Ting , Peng Hao‐Kai , Ren Hai‐Tao , Lin Jia‐Horng , Lou Ching‐Wen
Published: February 2022

In this study, two natural clay minerals were combined with hydrogels to study the influence of natural adsorbents on the adsorption performance of hydrogels. Here, we separately doped bentonite and vermiculite and discussed their mechanical properties and adsorption properties. It was found that the compressive performance of the hydrogel added with clay increased by 21.6% and the swelling performance decreased or increased to varying degrees. Regarding the adsorption performance of hydrogels, it can be seen from the adsorption Langmuir isotherm model that the adsorption capacity of clay–hydrogels is improved to varying degrees (6.6%–15.8%) compared with non‐clay–hydrogels, and clay–hydrogels have different degrees of improvement (6.6%–15.8%). The hydrogel has a removal efficiency of more than 95% for low concentrations of heavy‐metal ions and dyes. In addition, the clay–hydrogel has low cost and is easy to prepare, and can be recycled many times. Therefore, the material is of great significance for the treatment of pollutants.

Practitioner Points

The effect of natural clay on the adsorption performance of hydrogels was studied.

Clay can enhance the compression and adsorption properties of hydrogels.

The adsorption mechanism and adsorption capacity of clay hydrogels were evaluated.
Synthesis and Electrochemical Behavior of Metal Carbonyl Isocyanoferrocene Compounds [M(CO)6‐n(C≡NFc)n] (M=Cr, Mo, W; n=1, 2, 3)
Authors: Mahrholdt Julia , Kovalski Eduard , Noll Julian , Vrček Valerije , Lang Heinrich
Published: February 2022

The synthesis of [M(CO)6‐n(C≡NFc)n] (n=1: M=Cr, 3 a; M=Mo, 3 b; M=W, 3 c. n=2: M=Mo, 5. n=3: M=Mo, 6. Fc=Fe(η5−C5H4)(η5−C5H5)) by the reaction of [M(CO)5(thf)] (M=Cr, 1 a; M=Mo, 1 b; M=W 1 c) (synthesis of 3 a–c), [Mo(CO)4(nbd)] (4) (synthesis of 5) or [Mo(CO)6] (synthesis of 6) with FcN≡C (2) is discussed. IR studies confirm the formation of cis‐[Mo(CO)4(C≡NFc)2] (5) and mer‐[Mo(CO)3(C≡NFc)3] (6). The electrochemical behavior of 2, 3 a–c, 5 and 6 is reported. Compound 2 shows a reversible Fc redox event at E°1′=355 mV (ΔEp=60 mV). Upon complexation of 2 to M(CO)5 this wave is slightly shifted to E°′=335 (3 a), 345 (3 b) and 340 mV (3 c) showing that in 3 a–c the FcN≡C ligand is more easy to oxidize. The substitution of further CO ligands in 3 b by FcN≡C as characteristic for 5 and 6 influences the respective redox events insignificantly. Reversible oxidation of Cr occurs at 1045 mV (3 a) (ΔEp=60 mV), while for 3 b,c (3 b: 1170 mV, 3 c: 1290 mV) irreversible oxidations were observed. In addition, in situ spectroelectrochemical IR studies were carried out on 3 a–c. The results were further confirmed by DFT calculations.
A perturbative expansion scheme for supermembrane and matrix theory
Authors: Lechtenfeld Olaf , Nicolai Hermann
Published: February 2022

Abstract

We reconsider the supermembrane in a Minkowski background and in the light-cone gauge as a one-dimensional gauge theory of area preserving diffeomorphisms (APDs). Keeping the membrane tensionTas an independent parameter we show thatTis proportional to the gauge couplinggof this gauge theory, such that the small (large) tension limit of the supermembrane corresponds to the weak (strong) coupling limit of the APD gauge theory and its SU(N) matrix model approximation. A perturbative linearization of the supersymmetric theory suitable for a quantum mechanical path-integral treatment can be achieved by formulating a Nicolai map for the matrix model, which we work out explicitly to$$ \mathcal{O}\left({g}^4\right) $$Og4. The corresponding formulæ remain well-defined in the limitN → ∞; this result relies on a cancellation of infinities not present for the bosonic membrane, indicating that theN → ∞limit does not exist for the purely bosonic matrix model. Furthermore we show that the map has improved convergence properties in comparison with the usual perturbative expansions because its Jacobian admits an expansion ingwith a non-zero radius of convergence. Possible implications for unsolved issues with the matrix model of M theory are also mentioned.
Scattering amplitudes of Kaluza-Klein strings and extended massive double-copy
Authors: Li Yao , Hang Yan-Feng , He Hong-Jian , He Song
Published: February 2022

Abstract

We study the scattering amplitudes of massive Kaluza-Klein (KK) states of open and closed bosonic strings under toroidal compactification. We analyze the structure of vertex operators for the KK strings and derive an extended massive KLT-like relation which connects the N-point KK closed-string amplitude to the products of two KK open-string amplitudes at tree level. Taking the low energy field-theory limit of vanishing Regge slope, we derive double-copy construction formula of the N-point massive KK graviton amplitude from the sum of proper products of the corresponding KK gauge boson amplitudes. Then, using the string-based massive double-copy formula, we derive the exact tree-level four-point KK gauge boson amplitudes and KK graviton amplitudes, which fully agree with those given by the KK field-theory calculations. With these, we give an explicit prescription on constructing the exact four-point KK graviton amplitudes from the sum of proper products of the corresponding color-ordered KK gauge boson amplitudes. We further analyze the string-based double-copy construction of five-point and six-point scattering amplitudes of massive KK gauge bosons and KK gravitons.
Geodesically complete black holes in Lorentz-violating gravity
Authors: Carballo-Rubio Raúl , Di Filippo Francesco , Liberati Stefano , Visser Matt
Published: February 2022

Abstract

We present a systematic study of the geometric structure of non-singular spacetimes describing black holes in Lorentz-violating gravity. We start with a review of the definition of trapping horizons, and the associated notions of trapped and marginally trapped surfaces, and then study their significance in frameworks with modified dispersion relations. This leads us to introduce the notion of universally marginally trapped surfaces, as the direct generalization of marginally trapped surfaces for frameworks with infinite signal velocities (Hořava-like frameworks), which then allows us to define universal trapping horizons. We find that trapped surfaces cannot be generalized in the same way, and discuss in detail why this does not prevent using universal trapping horizons to define black holes in Hořava-like frameworks. We then explore the interplay between the kinematical part of Penrose’s singularity theorem, which implies the existence of incomplete null geodesics in the presence of a focusing point, and the existence of multiple different metrics. This allows us to present a complete classification of all possible geometries that neither display incomplete physical trajectories nor curvature singularities. Our main result is that not all classes that exist in frameworks in which all signal velocities are realized in Hořava-like frameworks. However, the taxonomy of geodesically complete black holes in Hořava-like frameworks includes diverse scenarios such as evaporating regular black holes, regular black holes bouncing into regular white holes, and hidden wormholes.
Interacting systems and wormholes
Authors: Betzios P. , Kiritsis E. , Papadoulaki O.
Published: February 2022

Abstract

We consider a class of tripartite systems for which two d-dimensional QFTs are cross-coupled via a third d + 1-dimensional “messenger” QFT. We analyse in detail the example of a pair of one-dimensional matrix quantum mechanics) coupled via a two­dimensional theory of the BF-type and compute its partition function and simple correlators. This construction is extendible in higher dimensions) using a Chern-Simons “messenger” theory. In all such examples, the exact partition function acquires a form, speculated to correspond to systems dual to Euclidean wormholes and the cross correlators are sufficiently soft and consistent with analogous gravitational calculations. Another variant of the tripartite system is studied, where the messenger theory is described by a non-self-interacting (matrix)-field, reaching similar conclusions. While the Euclidean theories we consider are perfectly consistent, the two possible analytic continuations into Lorentzian signature (messenger vs. boundary QFT directions) of the tripartite models, reveal physical features and “pathologies” resembling those of the expected Lorentzian gravitational backgrounds.
Comment on “flavor invariants and renormalization-group equations in the leptonic sector with massive Majorana neutrinos”
Authors: Lu Jianlong
Published: February 2022

Abstract

Recently in JHEP09 (2021) 053, Wang et al. discussed the polynomial ring formed by flavor invariants in the leptonic sector with massive Majorana neutrinos. They have explicitly constructed the finite generating sets of the polynomial rings for both two-generation scenario and three-generation scenario. However, Wang et al.’s claim of the finiteness of the generating sets of the polynomial rings and their calculation by the approach of Hilbert series with generalized Molien-Weyl formula are both based on their assertion that the unitary group U(n, ℂ) is reductive, which is unfortunately incorrect. The property of being reductive is only applicable to linear algebraic groups. And it is well-known that the unitary group U(n, ℂ) is not even a linear algebraic group. In this paper, we point out the above issue and provide a solution to fill in the accompanying logical gaps in JHEP09 (2021) 053. Some important results from the theory of linear algebraic group, the invariant theory of square matrices and group theory are needed in the analysis. We also clarify some somewhat misleading or vague statements in JHEP09 (2021) 053 about the scope of flavor invariants. Note that, although built from incorrect assertion, Wang et al.’s calculation results in JHEP09 (2021) 053 are nonetheless correct, which is ultimately because the ring of invariants of U(n, ℂ) is isomorphic to that of GL(n, ℂ) which is itself reductive.
Patterns of C- and CP-violation in hadronic η and η′ three-body decays
Authors: Akdag Hakan , Isken Tobias , Kubis Bastian
Published: February 2022

Abstract

We construct hadronic amplitudes for the three-body decays η(′) → π+π−π0 and η′ → ηπ+π− in a non-perturbative fashion, allowing for C- and CP-violating asymmetries in the π+π− distributions. These amplitudes are consistent with the constraints of analyticity and unitarity. We find that the currently most accurate Dalitz-plot distributions taken by the KLOE-2 and BESIII collaborations confine the patterns of these asymmetries to a relative per mille and per cent level, respectively. Our dispersive representation allows us to extract the individual coupling strengths of the C- and CP-violating contributions arising from effective isoscalar and isotensor operators in η(′) → π+π−π0 and an effective isovector operator in η′ → ηπ+π−, while the strongly different sensitivities to these operators can be understood from chiral power counting arguments.
The cosmological moduli problem and naturalness
Authors: Bae Kyu Jung , Baer Howard , Barger Vernon , Deal Robert Wiley
Published: February 2022

Abstract

Nowadays, the cosmological moduli problem (CMP) comes in three parts: 1. potential violation of Big-Bang nucleosynthesis (BBN) constraints from late decaying moduli fields, 2. the moduli-induced gravitino problem wherein gravitinos are overproduced and their decays violate BBN or dark matter overproduction bounds and 3. the moduli-induced lightest SUSY particle (LSP) overproduction problem. Also, the CMP may be regarded as either a problem or else a solution to scenarios with dark matter over- or under-production. We examine the cosmological moduli problem and its connection to electroweak naturalness. We calculate the various two-body decay widths of a light modulus field into MSSM particles and gravitinos within general supersymmetric models. We include both phase space and mixing effects. We examine cases without and with helicity suppression of modulus decays to gravitinos (cases 1 & 2) and/or gauginos (cases A & B). For case B1, we evaluate regions of gravitino mass m3/2 vs. modulus mass mϕ parameter space constrained by BBN, by overproduction of gravitinos and by overproduction of neutralino dark matter, along with connections to naturalness. For this case, essentially all of parameter space is excluded unless mϕ ≳ 2.5 × 103 TeV with mϕ< 2m3/2. For a potentially most propitious case B2 with ϕ decay to Higgs and matter turned off, then modulus branching fractions to SUSY and to gravitinos become highly suppressed at large mϕ. But since the modulus number density increases faster than the branching fractions decrease, there is still gross overproduction of neutralino dark matter. We also show that in this scenario the thermally produced gravitino problem is fixed by huge entropy dilution, but non-thermal gravitino production from moduli decay remains a huge problem unless it is kinematically suppressed with mϕ< 2m3/2. In a pedagogical appendix, we present detailed calculations of modulus field two-body decay widths.
QCD factorization for the four-body leptonic B-meson decays
Authors: Wang Chao , Wang Yu-Ming , Wei Yan-Bing
Published: February 2022

Abstract

Employing the QCD factorization formalism we compute $$ {B}_u^{-}\to {\gamma}^{\ast}\mathrm{\ell}{\overline{v}}_{\mathrm{\ell}} $$

B
u
−

→

γ
∗

ℓ

v
¯

ℓ

form factors with an off-shell photon state possessing the virtuality of order mb ΛQCD and $$ {m}_b^2 $$

m
b
2

, respectively, at next-to-leading order in QCD. Perturbative resummation for the enhanced logarithms of mb/ΛQCD in the resulting factorization formulae is subsequently accomplished at next-to-leading logarithmic accuracy with the renormalization-group technique in momentum space. In particular, we derive the soft-collinear factorization formulae for a variety of the subleading power corrections to the exclusive radiative $$ {B}_u^{-}\to {\gamma}^{\ast }{W}^{\ast } $$

B
u
−

→

γ
∗

W
∗

form factors with a hard-collinear photon at $$ \mathcal{O}\left({\alpha}_s^0\right) $$
O

α
s
0

. We further construct a complete set of the angular observables governing the full differential distribution of the four-body leptonic decays $$ {B}_u^{-}\to {\mathrm{\ell}}^{\prime }{\overline{\mathrm{\ell}}}^{\prime}\mathrm{\ell}{\overline{v}}_{\mathrm{\ell}} $$

B
u
−

→

ℓ
′

ℓ
¯

′

ℓ

v
¯

ℓ

with ℓ, ℓ′ ∈ {e, μ} and then perform an exploratory phenomenological analysis for a number of decay observables accessible at the LHCb and Belle II experiments, with an emphasis on the systematic uncertainties arising from the shape parameters of the leading-twist B-meson light-cone distribution amplitude in heavy quark effective theory.
A ν supersymmetric anomaly-free atlas
Authors: Allanach B. C. , Madigan Maeve , Tooby-Smith Joseph
Published: February 2022

Abstract

Extensions of the minimal supersymmetric standard model (MSSM) gauge group abound in the literature. Several of these include an additional U(1)X gauge group. Chiral fermions’ charge assignments under U(1)X are constrained to cancel local anomalies in the extension and they determine the structure and phenomenology of it. We provide all anomaly-free charge assignments up to a maximum absolute charge of Qmax = 10, assuming that the chiral superfield content of the model is that of the MSSM plus up to three Standard Model (SM) singlet superfields. The fermionic components of these SM singlets may play the rôle of right-handed neutrinos, whereas one of the scalar components may play the rôle of the flavon, spontaneously breaking U(1)X. Easily scanned lists of the charge assignments are made publicly available on Zenodo. For the case where no restriction is placed upon Qmax, we also provide an analytic parameterisation of the general solution using simple techniques from algebraic geometry.
Carrollian and Galilean conformal higher-spin algebras in any dimensions
Authors: Campoleoni Andrea , Pekar Simon
Published: February 2022

Abstract

We present higher-spin algebras containing a Poincaré subalgebra and with the same set of generators as the Lie algebras that are relevant to Vasiliev’s equations in any space-time dimension D ≥ 3. Given these properties, they can be considered either as candidate rigid symmetries for higher-spin gauge theories in Minkowski space or as Carrollian conformal higher-spin symmetries in one less dimension. We build these Lie algebras as quotients of the universal enveloping algebra of $$ \mathfrak{iso}\left(1,D-1\right) $$
iso

1

D
−
1

and we show how to recover them as Inönü-Wigner contractions of the rigid symmetries of higher-spin gauge theories in Anti de Sitter space or, equivalently, of relativistic conformal higher-spin symmetries. We use the same techniques to also define higher-spin algebras with the same set of generators and containing a Galilean conformal subalgebra, to be interpreted as non-relativistic limits of the conformal symmetries of a free scalar field. We begin by showing that the known flat-space higher-spin algebras in three dimensions can be obtained as quotients of the universal enveloping algebra of $$ \mathfrak{iso}\left(1,2\right) $$
iso

1
2

and then we extend the analysis along the same lines to a generic number of space-time dimensions. We also discuss the peculiarities that emerge for D = 5.
Quark and gluon contents of a lepton at high energies
Authors: Han Tao , Ma Yang , Xie Keping
Published: February 2022

Abstract

In high-energy leptonic collisions, such as at a multi-TeV muon collider, the collinear splittings of the electroweak (EW) gauge bosons and leptons are the dominant phenomena, and the scattering processes should thus be formulated in terms of the EW parton distribution functions (EW PDFs). We complete this formalism in the Standard Model to include the QCD sector and evaluate the quark and gluon PDFs inside a lepton at the double-log accuracy. The splittings of the photon and subsequently the quarks and gluons control the quark/gluon PDFs below the EW scale. The massive gauge bosons lead to substantial contributions at high scales. The jet production cross section can reach the order of a few nb (50 pb) in e+e−(μ+μ−) collisions, at the TeV c.m. energies with a moderate acceptance cut, that governs the overall event shape up to about $$ {p}_T^j $$

p
T
j

∼ 60 GeV. To complete the picture, we also provide an estimation of the total cross section for the photon-induced hadronic production at low partonic energies, which can reach the level of one hundred or a few tens of nb in high-energy electron or muon collisions.
Compton black-hole scattering for s ≤ 5/2
Authors: Chiodaroli Marco , Johansson Henrik , Pichini Paolo
Published: February 2022

Abstract

Quantum scattering amplitudes for massive matter have received new attention in connection to classical calculations relevant to gravitational-wave physics. Amplitude methods and insights are now employed for precision computations of observables needed for describing the gravitational dynamics of bound massive objects such as black holes. An important direction is the inclusion of spin effects needed to accurately describe rotating (Kerr) black holes. Higher-spin amplitudes introduced by Arkani-Hamed, Huang and Huang at three points have by now a firm connection to the effective description of Kerr black-hole physics. The corresponding Compton higher-spin amplitudes remain however an elusive open problem. Here we draw from results of the higher-spin literature and show that physical insights can be used to uniquely fix the Compton amplitudes up to spin 5/2, by imposing a constraint on a three-point higher-spin current that is a necessary condition for the existence of an underlying unitary theory. We give the unique effective Lagrangians up to spin 5/2, and show that they reproduce the previously-known amplitudes. For the multi-graviton amplitudes analogous to the Compton amplitude, no further corrections to our Lagrangians are expected, and hence such amplitudes are uniquely predicted. As an essential tool, we introduce a modified version of the massive spinor-helicity formalism which allows us to conveniently obtain higher-spin states, propagators and compact expressions for the amplitudes.
Scalar leptoquark pair production at the LHC: precision predictions in the era of flavour anomalies
Authors: Borschensky Christoph , Fuks Benjamin , Kulesza Anna , Schwartländer Daniel
Published: February 2022

Abstract

We comprehensively examine precision predictions for scalar leptoquark pair production at the LHC. In particular, we investigate the impact of lepton t-channel exchange diagrams that are potentially relevant in the context of leptoquark scenarios providing an explanation for the flavour anomalies. We also evaluate the corresponding total rates at the next-to-leading order in QCD. Moreover, we complement this calculation with the resummation of soft-gluon radiation at the next-to-next-to-leading logarithmic accuracy, hence providing the most precise predictions for leptoquark pair production at the LHC to date. Relying on a variety of benchmark scenarios favoured by the anomalies, our results exhibit an interesting interplay between the t-channel diagram contributions, the flavour texture satisfied by the leptoquark Yukawa couplings, the leptoquark masses and their representations under the Standard Model gauge group, as well as the chosen set of parton densities used for the numerical evaluations. The net effect on a cross section turns out to be very non-generic and ranges up to about 60% with respect to the usual next-to-leading-order predictions in QCD (i.e. without any t-channel contribution) for some scenarios considered. Dedicated calculations are thus required for any individual leptoquark model that could be considered in a collider analysis in order to assess the size of the studied corrections. In order to facilitate such calculations we provide dedicated public numerical packages.
Relativistic-invariant formulation of the NREFT three-particle quantization condition
Authors: Müller Fabian , Pang Jin-Yi , Rusetsky Akaki , Wu Jia-Jun
Published: February 2022

Abstract

A three-particle quantization condition on the lattice is written down in a manifestly relativistic-invariant form by using a generalization of the non-relativistic effective field theory (NREFT) approach. Inclusion of the higher partial waves is explicitly addressed. A partial diagonalization of the quantization condition into the various irreducible representations of the (little groups of the) octahedral group has been carried out both in the center-of-mass frame and in moving frames. Furthermore, producing synthetic data in a toy model, the relativistic invariance is explicitly demonstrated for the three-body bound state spectrum.
One-loop electroweak Sudakov logarithms: a revisitation and automation
Authors: Pagani Davide , Zaro Marco
Published: February 2022

Abstract

In this work we revisit the algorithm of Denner and Pozzorini for the calculation of one-loop electroweak Sudakov logarithms and we automate it in the MadGraph5_aMC-@NLO framework. We adapt the formulas for modern calculations, keeping light-quarks and photons strictly massless and dealing with infrared divergences via dimensional regularisation. We improve the approximation by taking into account additional logarithms that are angular dependent. We prove that an imaginary term has been previously omitted and we show that it cannot be in general neglected for 2 → n processes with n > 2. We extend the algorithm to NLO EW corrections to squared matrix-elements that involve also QCD corrections on top of subleading LO terms. Furthermore, we discuss the usage of this algorithm for approximating physical observables and cross sections. We propose a new approach in which the QED component is consistently removed and we show how it can be superior to the commonly used approaches. The relevance of all the novelties introduced in this work is corroborated by numerical results obtained for several processes in a completely automated way. We thoroughly compare exact NLO EW corrections and their Sudakov approximations both at the amplitude level and for physical observables in high-energy hadronic collisions.
Twist1 regulates macrophage plasticity to promote renal fibrosis through galectin-3
Authors: Wu Qingfeng , Sun Shiren , Wei Lei , Liu Minna , Liu Hao , Liu Ting , Zhou Ying , Jia Qing , Wang Di , Yang Zhen , Duan Menglu , Yang Xiaoxia , Gao Peisong , Ning Xiaoxuan
Published: February 2022

Renal interstitial fibrosis is the pathological basis of end-stage renal disease, in which the heterogeneity of macrophages in renal microenvironment plays an important role. However, the molecular mechanisms of macrophage plasticity during renal fibrosis progression remain unclear. In this study, we found for the first time that increased expression of Twist1 in macrophages was significantly associated with the severity of renal fibrosis in IgA nephropathy patients and mice with unilateral ureteral obstruction (UUO). Ablation of Twist1 in macrophages markedly alleviated renal tubular injury and renal fibrosis in UUO mice, accompanied by a lower extent of macrophage infiltration and M2 polarization in the kidney. The knockdown of Twist1 inhibited the chemotaxis and migration of macrophages, at least partially, through the CCL2/CCR2 axis. Twist1 downregulation inhibited M2 macrophage polarization and reduced the secretion of the profibrotic factors Arg-1, MR (CD206), IL-10, and TGF-β. Galectin-3 was decreased in the macrophages of the conditional Twist1-deficient mice, and Twist1 was shown to directly activate galectin-3 transcription. Up-regulation of galectin-3 recovered Twist1-mediated M2 macrophage polarization. In conclusion, Twist1/galectin-3 signaling regulates macrophage plasticity (M2 phenotype) and promotes renal fibrosis. This study could suggest new strategies for delaying kidney fibrosis in patients with chronic kidney disease.
Multi-task Learning-Based Spoofing-Robust Automatic Speaker Verification System
Authors: Zhao Yuanjun , Togneri Roberto , Sreeram Victor
Published: February 2022

Spoofing attacks posed by generating artificial speech can severely degrade the performance of a speaker verification system. Recently, many anti-spoofing countermeasures have been proposed for detecting varying types of attacks from synthetic speech to replay presentations. While there are numerous effective defenses reported on standalone anti-spoofing solutions, the integration for speaker verification and spoofing detection systems has obvious benefits. In this paper, we propose a spoofing-robust automatic speaker verification system for diverse attacks based on a multi-task learning architecture. This deep learning-based model is jointly trained with time-frequency representations from utterances to provide recognition decisions for both tasks simultaneously. Compared with other state-of-the-art systems on the ASVspoof 2017 and 2019 corpora, a substantial improvement of the combined system under different spoofing conditions can be obtained.
Total hip arthroplasty compared to bipolar and unipolar hemiarthroplasty for displaced hip fractures in the elderly: a Bayesian network meta-analysis
Authors: Migliorini Filippo , Maffulli Nicola , Trivellas Mira , Eschweiler Jörg , Hildebrand Frank , Betsch Marcel
Published: February 2022

Purpose

Displaced femoral neck fractures (FNF) usually require surgical treatment with either a total hip arthroplasty (THA), unipolar hemiarthroplasty (U-HHA), or bipolar hemiarthroplasty (B-HHA). However, there is still controversy regarding the optimal implant. This network meta-analysis compared the outcomes and complication rates of THA versus B-HHA and versus U-HHA in elderly patients with FNF.

Material and methods

This study was conducted according to the PRISMA extension statement for reporting of systematic reviews, and incorporated network meta-analyses of health care interventions. The literature search was performed in September 2020. All randomized clinical trials comparing two or more of the index surgical interventions for displaced FNF in the elderly were eligible for inclusion. For the Bayesian network meta-analysis, the standardized mean difference (SMD) and Log Odd Ratio (LOR) were used.

Results

Data from 24 RCTs (2808 procedures) were analysed. The mean follow-up was 33.8 months. The THA group had the longest surgical time (SMD 85.74) and the greatest Harris Hip Score (SMD − 17.31). THA scored similarly in terms of mortality (LOR 3.89), but had lower rates of revision surgeries (LOR 2.24), higher rates of dislocations (LOR 2.60), and lower rates of acetabular erosion (LOR − 0.02). Cementless implants required a shorter surgical duration (− 18.05 min; P = 0.03). Mortality was positively associated with acetabular erosion (P = 0.006), female gender (P = 0.007), revision (P < 0.0001).

Conclusion

THA led to the highest Harris Hip scores and lowest rate of revision surgery compared to B-HHA and U-HHA. However, B-HHA had the lowest dislocation rate when compared with U-HHA and THA. No significant differences in functional outcomes and complication rates were found between cemented and uncemented implants; however, a tendency for lower mortality, revision and dislocation rates in cemented implants was evidenced.

Level of evidence

I, Bayesian network meta-analysis of RCTs.
Digitalisierung im Gesundheitswesen und ihre Effekte auf die Qualität der Gesundheitsversorgung
Authors: Brönneke Jan Benedikt , Debatin Jörg Felix
Published: February 2022

Die Sicherung der Qualität von Gesundheitsleistungen ist ein Kernanliegen des Systems der gesetzlichen Krankenversicherung. Es ist daher nicht überraschend, dass die jüngeren Initiativen zur (weiteren) Digitalisierung des Gesundheitssystems ohne Ausnahme mit der Sicherung oder gar Steigerung der Qualität der Leistungserbringung begründet werden. Dies betrifft beispielsweise die Einführung der elektronischen Patientenakte und anderer Anwendungen der Telematikinfrastruktur mit dem Patientendaten-Schutz-Gesetz (PDSG), aber auch die Einführung der digitalen Gesundheitsanwendungen mit dem Digitale-Versorgung-Gesetz (DVG) sowie die Stärkung der Krankenhaus-IT mit dem Krankenhauszukunftsgesetz (KHZG).

Der Artikel beleuchtet die Frage, in welchem Verhältnis der Einsatz verschiedener digitaler Lösungen zu den klassischen Zielen der Qualitätssicherung in der Gesundheitsversorgung steht, insbesondere ob digitale Lösungen geeignet sind, Qualitätssicherung zu befördern.

Es zeigt sich, dass digitale Lösungen grundsätzlich geeignet sind, Qualität zu sichern. Dies ist auf 2 Charakteristika digitaler Lösungen zurückzuführen: die Möglichkeit zur umfassenden Erhebung von Daten und die Möglichkeit der zeit- und ortsunabhängigen Bereitstellung von Daten. Es zeigt sich aber auch, dass der Nutzen digitaler Lösungen vom konkreten Anwendungsfall abhängig ist.
6 Monate Zulassung von Kaftrio® in Deutschland – erste Erfahrungen aus dem „wahren Leben“ von Menschen mit CF
Authors: Thomassen J. C. , Meyer M. , Hagmeyer L. , Striegel A. K. , Metz F. , Körner R. , Rietschel E. , van Koningsbruggen-Rietschel S.
Published: February 2022

Hintergrund

Mit der Weiterentwicklung der „Cystic-fibrosis-transmembrane-conductance-regulator“(CFTR)-Modulatoren und der Zulassung von Kaftrio® (Elexacaftor, Tezacaftor, Ivacaftor) für einen Großteil der Menschen mit CF steht neben der etablierten symptomatischen Therapie nun eine weitere vielversprechende Therapieoption zur kausalen Behandlung der CF zur Verfügung.

Fragestellung

Ziel der hier vorliegenden Arbeit ist es, erste Effekte der Kaftrio®-Therapie auf den klinischen Phänotyp von Menschen mit CF 6 Monate nach der Zulassung zu untersuchen sowie die Ergebnisse in den Kontext neuer daraus resultierender Fragestellungen für die zukünftige Behandlung von CF-Patient*innen zu stellen.

Material und Methoden

Im Rahmen dieser Arbeit wurden anonymisiert klinische Daten (FEV1, Body-Mass-Index, HbA1c, Schweiß-Chlorid-Konzentration, Leberwerte) von 56 an der Uniklinik Köln betreuten Patient*innen retrospektiv ausgewertet, die die Voraussetzungen für eine Behandlung mit Kaftrio® erfüllt haben (Alter >12 Jahre, F508del homozygot oder heterozygot) und die mindestens >4 Wochen Kaftrio® eingenommen haben. Unterschiede zwischen den Gruppen wurden mithilfe des „Paired-t“-Tests berechnet. Ein p-Wert <0,05 wurde als statistisch signifikant gewertet.

Ergebnisse

In der untersuchten Kohorte konnte unter Kaftrio®-Therapie ein durchschnittlicher Anstieg der Einsekundenkapazität (FEV1-Werte in % des Sollwertes) um 11,3 % nachgewiesen werden. Ferner kam es unter Kaftrio® zu einem signifikanten Anstieg des Body-Mass Index (BMI) (+0,89 kg/m2), einer deutlichen Reduktion der Schweiß-Chlorid-Konzentration um durchschnittlich 58,8 mmol/l sowie zu einem Anstieg der Leberwerte.

Diskussion

Unsere retrospektive Datenerhebung bestätigt die aus den Zulassungsstudien beschriebenen positiven Effekte der Kaftrio®-Therapie auf den klinischen Phänotyp der Menschen mit CF. Mit der Besserung der Lungenfunktion, des Ernährungsstatus und der daraus resultierenden gesteigerten Lebenserwartung wird neben der Reevaluation bisheriger Behandlungsstandards der Fokus zukünftig auch auf dem Erhalt der Lebensqualität durch frühzeitige Diagnostik und effiziente Therapie möglicher Begleiterkrankungen liegen müssen.