bluuebunny/crossref_metadata_2025 huggingface dataset:
Lanthanide‐Doped Nanoparticles for Near‐Infrared Light Activation of Photopolymerization: Fundamentals, Optimization and Applications
Authors: Li Qin , Yuan Shanshan , Liu Fangfang , Zhu Xiaohui , Liu Jinliang
Published: June 2021

Photopolymerization refers to a type of polymerization process in which light is utilized as excitation source to initiate polymerization of monomers and oligomers. Despite great progress, photopolymerization is typically induced by ultraviolet or visible light, which still greatly restrains its applications. Upconversion nanoparticles (UCNPs) represent a class of optical nanomaterials that are able to convert low‐energy near‐infrared (NIR) light into high‐energy ultraviolet (or visible light) emissions. In this context, UCNP‐assisted photopolymerization has recently attracted extensive attentions due to its unique advantages. In this account, recent advances in the fundamentals, optimization and emerging applications of UCNP‐based photopolymerization are reviewed. Fundamental theories of upconversion luminescence and photopolymerization will be introduced first. Various optimization approaches to improve UCNP‐assisted photopolymerization are then summarized, followed by diverse emerging applications. Challenges and future perspectives in this area will be provided as a conclusion.
Tetrathiomolybdate and Tetraselenotungstate as Sulfur/Selenium Transfer Reagents: Applications in the Synthesis of New Thio/Seleno Sugars
Authors: Kirubakaran Sivapriya , Sureshkumar Devarajulu , Chandrasekaran Srinivasan
Published: June 2021

Sulfur and selenium containing sugars have gained prominence in the last two decades because of their importance in several biological applications. These type of carbohydrate scaffolds are also challenging targets for synthesis. In this personal note, we have summarised the results of our investigation over the last 20 years on the use of two reagents, benzyltriethylammonium tetrathiomolybdate and tetraethylammonium tetraselenotungstate, in efficient transfer of sulfur and selenium respectively to the synthesis of a number of carbohydrate derivatives.
Iodine(III)‐Based Halogen Bond Donors: Properties and Applications
Authors: Robidas Raphaël , Reinhard Dominik L. , Legault Claude Y. , Huber Stefan M.
Published: June 2021

Halogen bonding, the non‐covalent interaction of Lewis bases with an electron‐deficient region of halogen substituents, received increased attention recently. Consequently, the design and evaluation of numerous halogen‐containing species as halogen bond donors have been subject to intense research. More recently, organoiodine compounds at the iodine(III) state have been receiving growing attention in the field. Due to their electronic and structural properties, they provide access to unique binding modes. For this reason, our groups have been involved in the development of such compounds, in the quantification of their halogen bonding strength (through the evaluation of their Lewis acidities), as well as in the evaluation of their activities as catalysts in several model reactions. This account will describe these contributions.
From Cancer to COVID‐19: A Perspective on Targeting Heparan Sulfate‐Protein Interactions
Authors: Chhabra Mohit , Doherty Gareth G. , See Nicholas W. , Gandhi Neha S. , Ferro Vito
Published: June 2021

Heparan sulfate (HS) is a complex, polyanionic polysaccharide ubiquitously expressed on cell surfaces and in the extracellular matrix. HS interacts with numerous proteins to mediate a vast array of biological and pathological processes. Inhibition of HS‐protein interactions is thus an attractive approach for new therapeutic development for cancer and infectious diseases, including COVID‐19; however, synthesis of well‐defined native HS oligosaccharides remains challenging. This has aroused significant interest in the development of HS mimetics which are more synthetically tractable and have fewer side effects, such as undesired anticoagulant activity. This account provides a perspective on the design and synthesis of different classes of HS mimetics with useful properties, and the development of various assays and molecular modelling tools to progress our understanding of their interactions with HS‐binding proteins.
Transition‐Metal Catalyzed Stereoselective Desymmetrization of Prochiral Cyclohexadienones
Authors: Munakala Anandarao , Phanindrudu Mandalaparthi , Chegondi Rambabu
Published: June 2021

The development of transition‐metal catalyzed enantioselective and diastereoselective transformations has contributed many advances in the field of synthetic organic chemistry. Particularly, stereoselective desymmetrization of prochiral cyclohexadienones represents a powerful strategy for accessing highly functionalized and stereochemically enriched scaffolds, which are often found in biologically active compounds and natural products. In recent years, several research groups including our group have made a significant progress on transition‐metal catalyzed stereoselective desymmetrizations of 2,5‐cyclohexadienones. In this account, we will provide an overview of the recent developments in this area employing Pd, Cu, Rh, Au, Ag, Ni, Co, and Mn‐catalysts.
Synthetic Applications of Nickel‐Catalyzed Cross‐Coupling and Cyclisation Reactions
Authors: Durandetti Muriel
Published: June 2021

Since the first studies about fifty years ago, the direct formation of C−C bonds, catalyzed by nickel complexes, has appeared as an important research topic, and has re‐emerged recently as a renewal of nickel chemistry. This account provides a summary of the use of nickel complexes in catalysis, and highlights the evolution of our own research.
Expression and distribution of neuroglobin and hypoxia‐inducible factor‐1α in the adult yak telencephalon
Authors: Du Xiaohua , Mawolo James Blackar , Liu Xia , Mi Xiaoyu , Li Qiao , Wen Yongqiang
Published: June 2021

The telencephalon is also known as the cerebrum, and it consists of the largest part of the brain. It makes up about 85% of the total weight of the brain. Neuroglobin (Ngb) is a protein found in neurons of both the peripheral and central nervous system that appears to convey some resilience to hypoxia, while the hypoxia‐inducible factor (Hif‐1α) is a dimeric protein complex that plays an integral role in the body's response to low oxygen concentrations, or hypoxia. The study examines the expression of Ngb and Hif‐1α in the telencephalon of adult yak in the telencephalon. The immunohistochemistry (IHC), quantitative real‐time PCR and Western blot (WB) were employed to investigate Ngb and Hif‐1α expression in the telencephalon. Ngb and Hif‐1α are significantly expressed in all tissues of the telencephalon except the hypothalamus. The cerebellar cortex, hippocampus, amygdala, cerebellum and corpus callosum recorded the highest expression but not significant. The overall expression revealed that Ngb expression was higher as compared to Hif‐1α. The IHC results also showed that the expression of Ngb and Hif‐1α were higher in the cerebellar cortex, hippocampus, amygdala, cerebellum and corpus callosum as compared to other regions. The results suggested that Ngb and Hif‐1α expression influence the adaptive mechanism of yak to the high altitude environment. Both Ngb and Hif‐1α participate in oxygen transports throughout the telencephalon and have functions in neuroprotection. Further studies are needed to confirm the mechanism of adaptation.
New aspects of the esophageal histology of the domestic goat (Capra hircus) and European roe deer (Capreolus capreolus)
Authors: Sokołowska Justyna , Urbańska Kaja , Matusiak Joanna , Wiśniewski Jan
Published: June 2021

The present study examines the esophageal wall of animals from two distinct families of the Ruminantia: domestic goats and European roe deer. Five fragments were collected from the entire length of the esophageal wall in five goats and four roe deer and subjected to microscopic and morphometric analyses. All layers of the esophageal wall except the tela submucosa were found to be thicker in the goats. In both species, the esophagus was lined by parakeratinized stratified squamous epithelium, and the tela submucosa was deprived of glands along its entire length. However, the structure of the lamina muscularis mucosae was better developed in goats: it was found to be discontinuous in the proximal part, and then became fused in the cervical part, that is around the most proximal quarter of its length. In contrast, in roe deer, the lamina muscularis mucosae began as sparse, thin muscle bundles at the pharyngeal‐esophageal junction, which thickened and clustered further down the esophagus, but did not fuse. Our findings regarding the microscopic structure of the ruminant esophagus are not fully consistent with the widely‐accepted view and suggest that the histological structure of the esophagus demonstrates interspecies variation within this large suborder. More precisely, species‐specific differences can be seen regarding the presence of esophageal glands and parakeratinized epithelium, and in the organization of the lamina muscularis mucosae.
Effects of 2,6‐Dichlorophenyl Substituents on the Coordination Chemistry of Pyridine Dipyrrolide Iron Complexes
Authors: Hakey Brett M. , Leary Dylan C. , Rodriguez Jose G. , Martinez Jordan C. , Vaughan Nicholas B. , Darmon Jonathan M. , Akhmedov Novruz G. , Petersen Jeffrey L. , Dolinar Brian S. , Milsmann Carsten
Published: June 2021

A series of iron complexes featuring the pyridine dipyrrolide (PDP) pincer ligand [Cl2PhPDPPh]2−, obtained via deprotonation of 2,6‐bis(5‐(2,6‐dichlorophenyl)‐3‐phenyl‐1H‐pyrrol‐2‐yl)pyridine, H2Cl2PhPDPPh, is reported and structurally and spectroscopically characterized. While the bis‐pyridine adduct (Cl2PhPDPPh)Fe(py)2 exhibits nearly identical features as previously reported (MesPDPPh)Fe(py)2 (H2MesPDPPh=2,6‐bis(5‐(2,4,6‐trimethylphenyl)‐3‐phenyl‐1H‐pyrrol‐2‐yl)pyridine), the diethyl ether and tetrahydrofuran adducts (Cl2PhPDPPh)Fe(OEt2) and (Cl2PhPDPPh)Fe(thf) show additional weak Fe−Cl interactions that impact the overall coordination geometries and result in strong deviations from planar coordination environments. The reaction of (Cl2PhPDPPh)Fe(thf) with 1‐adamantyl azide provided the isolable iron imido complex (Cl2PhPDPPh)Fe(N1Ad), highlighting the improved stability of [Cl2PhPDPPh]2− towards intramolecular nitrene group transfer from the high‐valent iron‐imido unit. The electronic structure of (Cl2PhPDPPh)Fe(N1Ad) was investigated by density functional theory (DFT) and complete active space self‐consistent field (CASSCF) calculations. These computational studies suggest energetically close‐lying diamagnetic and paramagnetic states and help to conceptualize the unusual magnetic properties of the complex observed by variable‐temperature 1H NMR spectroscopy.
Testing Fundamental Physics by Using Levitated Mechanical Systems
Authors: Ulbricht Hendrik
Published: June 2021

We will describe recent progress of experiments towards realising large-mass single particle experiments to test fundamental physics theories such as quantum mechanics and gravity, but also specific candidates of Dark Matter and Dark Energy. We will highlight the connection to the work started by Otto Stern as levitated mechanics experiments are about controlling the centre of mass motion of massive particles and using the same to investigate physical effects. This chapter originated from the foundations of physics session of the Otto Stern Fest at Frankfurt am Main in 2019, so we will also share a view on the Stern Gerlach experiment and how it related to tests of the principle of quantum superposition.
High-Resolution Momentum Imaging—From Stern’s Molecular Beam Method to the COLTRIMS Reaction Microscope
Authors: Jahnke T. , Mergel V. , Jagutzki O. , Czasch A. , Ullmann K. , Ali R. , Frohne V. , Weber T. , Schmidt L. P. , Eckart S. , Schöffler M. , Schößler S. , Voss S. , Landers A. , Fischer D. , Schulz M. , Dorn A. , Spielberger L. , Moshammer R. , Olson R. , Prior M. , Dörner R. , Ullrich J. , Cocke C. L. , Schmidt-Böcking H.
Published: June 2021

Multi-particle momentum imaging experiments are now capable of providing detailed information on the properties and the dynamics of quantum systems in Atomic, Molecular and Photon (AMO) physics. Historically, Otto Stern can be considered the pioneer of high-resolution momentum measurements of particles moving in a vacuum and he was the first to obtain sub-atomic unit (a.u.) momentum resolution (Schmidt-Böcking et al. in The precision limits in a single-event quantum measurement of electron momentum and position, these proceedings [1]). A major contribution to modern experimental atomic and molecular physics was his so-called molecular beam method [2], which Stern developed and employed in his experiments. With this method he discovered several fundamental properties of atoms, molecules and nuclei [2, 3]. As corresponding particle detection techniques were lacking during his time, he was only able to observe the averaged footprints of large particle ensembles. Today it is routinely possible to measure the momenta of single particles, because of the tremendous progress in single particle detection and data acquisition electronics. A “state-of-the-art” COLTRIMS reaction microscope [4–11] can measure, for example, the momenta of several particles ejected in the same quantum process in coincidence with sub-a.u. momentum resolution. Such setups can be used to visualize the dynamics of quantum reactions and image the entangled motion of electrons inside atoms and molecules. This review will briefly summarize Stern’s work and then present in longer detail the historic steps of the development of the COLTRIMS reaction microscope. Furthermore, some benchmark results are shown which initially paved the way for a broad acceptance of the COLTRIMS approach. Finally, a small selection of milestone work is presented which has been performed during the last two decades.
STIRAP: A Historical Perspective and Some News
Authors: Bergmann Klaas
Published: June 2021

A very brief outline of what STIRAP is and does is followed by the presentation of the sequence of experiments, which started some 50 years ago, the visions developed and experimental efforts undertaken, that finally led to the development of STIRAP.
A Greeting from Hamburg to the Otto Stern Symposium
Authors: Toschek Peter E.
Published: June 2021

Dear Chairmen Profs. Herschbach and Toennies, dear organizers Profs. Schmidt-Böcking and Friedrich, dear Colleagues, dear Ladies and Gentlemen. The occasion for our gathering today in this location is a truly historic one: the centenary of the first quantitative experiment with molecular beams, a technique that would enable, in 1922, the first convincing proof of quantum mechanics—the fundamental theory of light and matter—and to give due honor to the pioneer physicist who developed this technique: Otto Stern.
Otto Stern’s Legacy in Quantum Optics: Matter Waves and Deflectometry
Authors: Gerlich Stefan , Fein Yaakov Y. , Shayeghi Armin , Köhler Valentin , Mayor Marcel , Arndt Markus
Published: June 2021

Otto Stern became famous for molecular beam physics, matter-wave research and the discovery of the electron spin, with his work guiding several generations of physicists and chemists. Here we discuss how his legacy has inspired the realization of universal interferometers, which prepare matter waves from atomic, molecular, cluster or eventually nanoparticle beams. Such universal interferometers have proven to be sensitive tools for quantum-assisted force measurements, building on Stern’s pioneering work on electric and magnetic deflectometry. The controlled shift and dephasing of interference fringes by external electric, magnetic or optical fields have been used to determine internal properties of a vast class of particles in a unified experimental framework.
Liquid Micro Jet Studies of the Vacuum Surface of Water and of Chemical Solutions by Molecular Beams and by Soft X-Ray Photoelectron Spectroscopy
Authors: Faubel Manfred
Published: June 2021

Liquid water, with a vapor pressure of 6.1 mbar at freezing point, is rapidly evaporating in high vacuum, rapidly cooling off by the evaporative cooling, and is freezing to ice almost instantly. Nevertheless, liquid water free vacuum surfaces can be prepared for short instances when injecting very small, fast flowing, liquid jets into high vacuum. They provide perfectly suited targets for molecular beams analysis of molecular evaporation of monomers and dimers from liquids. Also, the microjet technology allows ultrahigh vacuum studies of atomic scale liquid surface composition and electronic structures, as will be demonstrated by using highly focused Synchrotron radiation for EUV/XUV-photoelectron spectrocopy on a wide range of chemical solutions.
My Uncle Otto Stern
Authors: Templeton Lieselotte K.
Published: June 2021

It was only since 1946 [1945] when my uncle moved to Berkeley that I got to know him well. Before this time we had never lived in the same town, and I had only seen him rarely. Otto Stern moved into a house he had bought several years earlier in the Berkeley hills not far from my parents’ house. Because he was a bachelor, he hired a housekeeper who came in six days a week for a few hours to cook and keep house. He loved good food and good wine. The housekeeper for the last years did not keep the house as clean as he would have liked, but her cooking met with his approval, so she stayed for many years. On Sundays, he would have dinner with his sister, Berta (my mother) and family, or he would go into town for dinner in a restaurant and then to a movie. He loved movies, and Shirley MacLaine was one of his favorite actresses.
Gauge × gauge = gravity on homogeneous spaces using tensor convolutions
Authors: Borsten L. , Jubb I. , Makwana V. , Nagy S.
Published: June 2021

Abstract

A definition of a convolution of tensor fields on group manifolds is given, which is then generalised to generic homogeneous spaces. This is applied to the product of gauge fields in the context of ‘gravity = gauge × gauge’. In particular, it is shown that the linear Becchi-Rouet-Stora-Tyutin (BRST) gauge transformations of two Yang-Mills gauge fields generate the linear BRST diffeomorphism transformations of the graviton. This facilitates the definition of the ‘gauge × gauge’ convolution product on, for example, the static Einstein universe, and more generally for ultrastatic spacetimes with compact spatial slices.
New physics and the tau polarization vector in b → $$ \mathrm{c}\tau {\overline{\nu}}_{\tau } $$ decays
Authors: Penalva Neus , Hernández Eliecer , Nieves Juan
Published: June 2021

Abstract

For a general Hb → $$ {H}_c\tau {\overline{\nu}}_{\tau } $$

H
c

τ

ν
¯

τ

decay we analyze the role of the τ polarization vector $$ {\mathcal{P}}^{\mu } $$

P
μ

in the context of lepton flavor universality violation studies. We use a general phenomenological approach that includes, in addition to the Standard Model (SM) contribution, vector, axial, scalar, pseudoscalar and tensor new physics (NP) terms which strength is governed by, complex in general, Wilson coefficients. We show that both in the laboratory frame, where the initial hadron is at rest, and in the center of mass of the two final leptons, a $$ \overrightarrow{\mathcal{P}} $$

P
→

component perpendicular to the plane defined by the three-momenta of the final hadron and the τ lepton is only possible for complex Wilson coefficients, being a clear signal for physics beyond the SM as well as time reversal (or CP-symmetry) violation. We make specific evaluations of the different polarization vector components for the Λb → Λc, $$ {\overline{B}}_c $$

B
¯

c

→ ηc, J/ψ and $$ \overline{B} $$

B
¯

→ D(*) semileptonic decays, and describe NP effects in the complete two-dimensional space associated with the independent kinematic variables on which the polarization vector depends. We find that the detailed study of $$ {\mathcal{P}}^{\mu } $$

P
μ

has great potential to discriminate between different NP scenarios for 0− → 0− decays, but also for Λb → Λc transitions. For this latter reaction, we pay special attention to corrections to the SM predictions derived from complex Wilson coefficients contributions.
Dark matter spectra from the electroweak to the Planck scale
Authors: Bauer Christian W. , Rodd Nicholas L. , Webber Bryan R.
Published: June 2021

Abstract

We compute the decay spectrum for dark matter (DM) with masses above the scale of electroweak symmetry breaking, all the way to the Planck scale. For an arbitrary hard process involving a decay to the unbroken standard model, we determine the prompt distribution of stable states including photons, neutrinos, positrons, and antiprotons. These spectra are a crucial ingredient in the search for DM via indirect detection at the highest energies as being probed in current and upcoming experiments including IceCube, HAWC, CTA, and LHAASO. Our approach improves considerably on existing methods, for instance, we include all relevant electroweak interactions.
CDK9 keeps RNA polymerase II on track
Authors: Egloff Sylvain
Published: June 2021

Cyclin-dependent kinase 9 (CDK9), the kinase component of positive transcription elongation factor b (P-TEFb), is essential for transcription of most protein-coding genes by RNA polymerase II (RNAPII). By releasing promoter-proximally paused RNAPII into gene bodies, CDK9 controls the entry of RNAPII into productive elongation and is, therefore, critical for efficient synthesis of full-length messenger (m)RNAs. In recent years, new players involved in P-TEFb-dependent processes have been identified and an important function of CDK9 in coordinating elongation with transcription initiation and termination has been unveiled. As the regulatory functions of CDK9 in gene expression continue to expand, a number of human pathologies, including cancers, have been associated with aberrant CDK9 activity, underscoring the need to properly regulate CDK9. Here, I provide an overview of CDK9 function and regulation, with an emphasis on CDK9 dysregulation in human diseases.
Online Premeans and Their Computation Complexity
Authors: Pasteczka Paweł
Published: June 2021

We extend some approach to the family of symmetric means (i.e. symmetric functions$$\mathscr {M} :\bigcup _{n=1}^\infty I^n \rightarrow I$$M:⋃n=1∞In→Iwith$$\min \le \mathscr {M}\le \max $$min≤M≤max;Iis an interval). Namely, it is known that every symmetric mean can be written in a form$$\mathscr {M}(v_1,\dots ,v_n):=F(f(v_1)+\cdots +f(v_n))$$M(v1,⋯,vn):=F(f(v1)+⋯+f(vn)), where$$f :I \rightarrow G$$f:I→Gand$$F :G \rightarrow I$$F:G→I(G is a commutative semigroup). For$$G=\mathbb {R}^k$$G=Rkor$$G=\mathbb {R}^k \times \mathbb {Z}$$G=Rk×Z($$k \in \mathbb {N}$$k∈N) and continuous functionsfandFwe obtain two series of families (depending onk). It can be treated as a measure of complexity in a family of means (this idea is inspired by theory of regular languages and algorithmics). As a result we characterize the celebrated families of quasi-arithmetic means ($$G=\mathbb {R}\times \mathbb {Z}$$G=R×Z) and Bajraktarević means ($$G=\mathbb {R}^2$$G=R2under some additional assumptions). Moreover, we establish certain estimations of complexity for several other classical families.
Local mortality estimates during the COVID-19 pandemic in Italy
Authors: Cerqua Augusto , Di Stefano Roberta , Letta Marco , Miccoli Sara
Published: June 2021

Estimates of the real death toll of the COVID-19 pandemic have proven to be problematic in many countries, Italy being no exception. Mortality estimates at the local level are even more uncertain as they require stringent conditions, such as granularity and accuracy of the data at hand, which are rarely met. The “official” approach adopted by public institutions to estimate the “excess mortality” during the pandemic draws on a comparison between observed all-cause mortality data for 2020 and averages of mortality figures in the past years for the same period. In this paper, we apply the recently developed machine learning control method to build a more realistic counterfactual scenario of mortality in the absence of COVID-19. We demonstrate that supervised machine learning techniques outperform the official method by substantially improving the prediction accuracy of the local mortality in “ordinary” years, especially in small- and medium-sized municipalities. We then apply the best-performing algorithms to derive estimates of local excess mortality for the period between February and September 2020. Such estimates allow us to provide insights about the demographic evolution of the first wave of the pandemic throughout the country. To help improve diagnostic and monitoring efforts, our dataset is freely available to the research community.
Performing a knee arthroscopy among patients with degenerative knee disease: one-third is potentially low value care
Authors: Rietbergen T. , Marang-van de Mheen P. J. , Diercks R. L. , Janssen R. P. A. , van der Linden-van der Zwaag H. M. J. , Nelissen R. G. H. H. , Steyerberg E. W. , van Bodegom-Vos L. ,   for the SMART study group, Pander P. , Hofstee D. J. , van Geenen R. C. I. , Koenraadt K. L. M. , Onderwater J. P. A. H. , Kleinlugtenbelt Y. V. , Gosens T. , Klos T. V. S. , Rijk P. C. , Dijkstra B. , Zeegers A. V. C. M. , Hoogeslag R. A. G. , Huis in’t Veld M. H. A. , Polak A. A. , Pereira N. R. Paulino , Vervest T. M. J. S. , van der Veen H. C.
Published: June 2021

Purpose

The purpose of this study was to assess in which proportion of patients with degenerative knee disease aged 50+ in whom a knee arthroscopy is performed, no valid surgical indication is reported in medical records, and to explore possible explanatory factors.

Methods

A retrospective study was conducted using administrative data from January to December 2016 in 13 orthopedic centers in the Netherlands. Medical records were selected from a random sample of 538 patients aged 50+ with degenerative knee disease in whom arthroscopy was performed, and reviewed on reported indications for the performed knee arthroscopy. Valid surgical indications were predefined based on clinical national guidelines and expert opinion (e.g., truly locked knee). A knee arthroscopy without a reported valid indication was considered potentially low value care. Multivariate logistic regression analysis was performed to assess whether age, diagnosis (“Arthrosis” versus “Meniscal lesion”), and type of care trajectory (initial or follow-up) were associated with performing a potentially low value knee arthroscopy.

Results

Of 26,991 patients with degenerative knee disease, 2556 (9.5%) underwent an arthroscopy in one of the participating orthopedic centers. Of 538 patients in whom an arthroscopy was performed, 65.1% had a valid indication reported in the medical record and 34.9% without a reported valid indication. From the patients without a valid indication, a joint patient–provider decision or patient request was reported as the main reason. Neither age [OR 1.013 (95% CI 0.984–1.043)], diagnosis [OR 0.998 (95% CI 0.886–1.124)] or type of care trajectory [OR 0.989 (95% CI 0.948–1.032)] were significantly associated with performing a potentially low value knee arthroscopy.

Conclusions

In a random sample of knee arthroscopies performed in 13 orthopedic centers in 2016, 65% had valid indications reported in the medical records but 35% were performed without a reported valid indication and, therefore, potentially low value care. Patient and/or surgeons preference may play a large role in the decision to perform an arthroscopy without a valid indication. Therefore, interventions should be developed to increase adherence to clinical guidelines by surgeons that target invalid indications for a knee arthroscopy to improve care.

Level of evidence

IV.
Measuring appropriate need for unicompartmental knee arthroplasty: results of the MANUKA study
Authors: Klasan Antonio , Luger Matthias , Hochgatterer Rainer , Young Simon W.
Published: June 2021

Purpose

Indications for unicompartmental knee arthroplasty (UKA) are controversial. Studies based solely on radiographic criteria suggest up to 49% of patients with knee osteoarthritis (OA) are suitable for UKA. In contrast, the ‘Appropriate use criteria’ (AUC), developed by the AAOS, apply clinical and radiographic criteria to guide surgical treatment of knee OA. The aim of this study was to analyze patient suitability for TKA, UKA and osteotomy using both radiographic criteria and AUC in a cohort of 300 consecutive knee OA patients.

Methods

Included were consecutive patients with clinical and radiographic signs of knee OA referred to a specialist clinic. Collected were demographic data, radiographic wear patterns and clinical findings that were analyzed using the AUC. A comparison of the radiographic wear patterns with the treatment suggested by the AUC as well as the Surgeon Treatment Decision was performed.

Results

There were 397 knees in 300 patients available for analysis. Median age was 68 [IQR 15], BMI 30 [6] with 55% females. Excellent consistency for both the radiographic criteria and the AUC criteria was found. Based on radiological criteria, 41% of knees were suitable for UKA. However, when using the AUC criteria, UKA was the appropriate treatment in only 13.3% of knees. In 19.1% of knees, no surgical treatment was appropriate at the visit, based on the collected data.

Conclusion

Application of isolated radiologic criteria in patients with knee OA results in a UKA candidacy is misleadingly high. AUC that are based on both radiological and clinical criteria suggest UKA is appropriate in less than 15% of patients.

Level of evidence

III retrospective study.
Optimal VLBI baseline geometry for UT1-UTC Intensive observations
Authors: Schartner Matthias , Kern Lisa , Nothnagel Axel , Böhm Johannes , Soja Benedikt
Published: June 2021

One of the main tasks of Very Long Baseline Interferometry (VLBI) is the rapid determination of the highly variable Earth’s rotation expressed through the difference between Universal Time UT1 and Coordinated Universal Time UTC (dUT1). For this reason, dedicated one hour, single baseline sessions, called “Intensives”, are observed on a daily basis. Thus far, the optimal geometry of Intensive sessions was understood to include a long east–west extension of the baseline to ensure a dUT1 estimation with highest accuracy. In this publication, we prove that long east–west baselines are the best choice only for certain lengths and orientations. In this respect, optimal orientations may even require significant inclination of the baseline with respect to the equatorial plane. The basis of these findings is a simulation study with subsequent investigations in the partial derivatives of the observed group delays $$\tau $$
τ
with respect to dUT1 $$\partial \tau /\partial dUT1$$

∂
τ
/
∂
d
U
T
1

. Almost 3000 baselines between artificial stations located on a regular $$10 \times 10$$

10
×
10

degree grid are investigated to derive a global and generally valid picture about the best length and orientation of Intensive baselines. Our results reveal that especially equatorial baselines or baselines with a center close to the equatorial plane are not suited for Intensives although they provide a good east–west extension. This is explained by the narrow right ascension band of visible sources and the resulting lack of variety in the partial derivatives. Moreover, it is shown that north–south baselines are also capable of determining dUT1 with reasonable accuracy, given that the baseline orientation is significantly different from the Earth rotation axis. However, great care must be taken to provide accurate polar motion a priori information for these baselines. Finally, we provide a better metric to assess the suitability of Intensive baselines based on the effective spread of $$\partial \tau /\partial dUT1$$

∂
τ
/
∂
d
U
T
1

.
Evaluation of clinical practice guidelines (CPG) on the management of female chronic pelvic pain (CPP) using the AGREE II instrument
Authors: Ghai Vishalli , Subramanian Venkatesh , Jan Haider , Loganathan Jemina , Doumouchtsis Stergios K. ,   CHORUS: An International Collaboration for Harmonising Outcomes, Research and Standards in Urogynaecology and Women’s Health (i-chorus.org)
Published: June 2021

Introduction and hypothesis

Variations in guidelines may result in differences in treatments and potentially poorer health-related outcomes. We aimed to systematically review and evaluate the quality of national and international guidelines and create an inventory of CPG recommendations on CPP.

Methods

We searched EMBASE and MEDLINE databases from inception till August 2020 as well as websites of professional organizations and societies. We selected national and international CPGs reporting on the diagnosis and management of female CPP. We included six CPGs. Five researchers independently assessed the quality of included guidelines using the AGREE II tool and extracted recommendations.

Results

Two hundred thirty-two recommendations were recorded and grouped into six categories: diagnosis, medical treatment, surgical management, behavioural interventions, complementary/alternative therapies and education/research. Thirty-nine (17.11%) recommendations were comparable including: a comprehensive pain history, a multi-disciplinary approach, attributing muscular dysfunction as a cause of CPP and an assessment of quality of life. Two guidelines acknowledged sexual dysfunction associated with CPP and recommended treatment with pelvic floor exercises and behavioural interventions. All guidelines recommended surgical management; however, there was no consensus regarding adhesiolysis, bilateral salpingo-oophorectomy during hysterectomy, neurectomy and laparoscopic uterosacral nerve ablation. Half of recommendations (106, 46.49%) were unreferenced or made in absence of good-quality evidence or supported by expert opinion. Based on the AGREE II assessment, two guidelines were graded as high quality and recommended without modifications (EAU and RCOG). Guidelines performed poorly in the “Applicability”, “Editorial Independence” and “Stakeholder Involvement” domains.

Conclusion

Majority of guidelines were of moderate quality with significant variation in recommendations and quality of guideline development.
A singular eigenvalue problem for the Dirichlet (p, q)-Laplacian
Authors: Bai Yunru , Papageorgiou Nikolaos S. , Zeng Shengda
Published: June 2021

We consider a parametric nonlinear, nonhomogeneous Dirichlet problem driven by the (p, q)-Laplacian with a reaction involving a singular term plus a superlinear reaction which does not satisfy the Ambrosetti–Rabinowitz condition. The main goal of the paper is to look for positive solutions and our approach is based on the use of variational tools combined with suitable truncations and comparison techniques. We prove a bifurcation-type theorem describing in a precise way the dependence of the set of positive solutions on the parameter$$\lambda $$λ. Moreover, we produce minimal positive solutions and determine the monotonicity and continuity properties of the minimal positive solution map.
Texture design of gluten-free bread by mixing under controlled headspace atmosphere
Authors: Paulik Sabina , Paczkowski Christoph , Laukemper Rita , Becker Thomas , Jekle Mario
Published: June 2021

Gluten-free breads often show a reduced specific bread volume, in comparison to gluten-containing products, caused by non-adapted processing technologies of gluten-free dough. In this investigation, different mixing speeds and durations (600–3000 rpm for 3 min, 5 min or 8 min, respectively) as well as variations in the pressure (prel – 50 toprel + 130 kPa) in the headspace atmosphere during mixing (Stephan mixer) and pressure ratios of overpressure/negative pressure of 8 min mixing (20/80, 50/50, 80/20) were studied to determine their impact on the gas volume fraction of dough and specific volume of breads. A pressure rise ofprel 50 kPa,prel100 kPa orprel130 kPa increased the gas volume fraction in dough of 60%, 100% or 120%, respectively, and led to a significant higher specific bread volume (7%) and the reduction of crumb hardness (35%) atprel130 kPa. A linear correlation (R2 = 0.843) between the pressure and specific volume of breads was found. An extended first mixing phase at overpressure resulted in the formation of a very fine pore structure, whereby a short overpressure phase caused the formation of big pores. Thus, the control of the headspace atmosphere during mixing is a suitable parameter to adjust the density of dough and consequently, the pore size distribution for a specific texture design.
Reachability Problems on Reliable and Lossy Queue Automata
Authors: Köcher Chris
Published: June 2021

We study the reachability problem for queue automata and lossy queue automata. Concretely, we consider the set of queue contents which are forwards resp. backwards reachable from a given set of queue contents. Here, we prove the preservation of regularity if the queue automaton loops through some special sets of transformation sequences. This is a generalization of the results by Boigelot et al. and Abdulla et al. regarding queue automata looping through a single sequence of transformations. We also prove that our construction is possible in polynomial time.
A Parameterized Complexity View on Collapsing k-Cores
Authors: Luo Junjie , Molter Hendrik , Suchý Ondřej
Published: June 2021

We study the -hard graph problemCollapsed k-Corewhere, given an undirected graphGand integersb,x, andk, we are asked to removebvertices such that thek-core of remaining graph, that is, the (uniquely determined) largest induced subgraph with minimum degreek, has size at mostx.Collapsed k-Corewas introduced by Zhang et al. (2017) and it is motivated by the study of engagement behavior of users in a social network and measuring the resilience of a network against user drop outs.Collapsed k-Coreis a generalization ofr-Degenerate Vertex Deletion(which is known to be -hard for allr≥ 0) where, given an undirected graphGand integersbandr, we are asked to removebvertices such that the remaining graph isr-degenerate, that is, every its subgraph has minimum degree at mostr. We investigate the parameterized complexity ofCollapsed k-Corewith respect to the parametersb,x, andk, and several structural parameters of the input graph. We reveal a dichotomy in the computational complexity ofCollapsed k-Corefork≤ 2 andk≥ 3. For the latter case it is known that for allx≥ 0Collapsed k-Coreis -hard when parameterized byb. Fork≤ 2 we show thatCollapsed k-Coreis -hard when parameterized byband in when parameterized by (b+x). Furthermore, we outline thatCollapsed k-Coreis in when parameterized by the treewidth of the input graph and presumably does not admit a polynomial kernel when parameterized by the vertex cover number of the input graph.
Improving the usability of piezoresistive bond lines in wood by using impedance measurements
Authors: Schäfer Jesco , Jager Christopher , Schwarz Ulrich , Winkler Christoph
Published: June 2021

Various studies on wood adhesives filled with conductive fillers for future application to structural monitoring showed a piezoresistive (resistance change with strain) response of the adhesive bond lines that is measurable under direct current. The results also showed a relatively high signal noise with low sensitivity. Using impedance spectroscopy as a measurement technique, the improvements in frequency-dependent piezoresistivity over DC (Direct Current) resistography of multifunctional bonded wood were studied. Beech specimens were bonded by one-component polyurethane prepolymer (1C-PUR) filled with carbon black and tested under shear load. The quality of the piezoresistive properties was described by calculating the signal-to-noise ratio (SNR) of the measured signal. A setup-specific frequency band with optimized SNR between 100 kHz and 1 MHz could be derived from the measurements. Several frequencies showed a signal with higher quality resulting in a higher SNR. Regardless of the variations in impedance spectra for all specimens, this frequency band provided several frequencies with improved signal quality. These frequencies give a more reliable signal with lower noise compared to the signal from DC resistography.
A randomized prospective study: assessment of transient ureteral stenting by mono-J insertion after primary URS and stone extraction (FaST 3)
Authors: Reicherz Alina , Westhues Hannah , Häuser Lorine , Wenzel Patricia , Noldus Joachim , Bach Peter
Published: June 2021

To compare the outcome of a short-term insertion of a mono-J catheter for 6 h following ureteroscopic stone removal to a conventional double-J catheter. This single-center academic study (Fast Track Stent study 3) evaluated stenting in 108 patients with urinary calculi after ureterorenoscopy. Patients were prospectively randomized into two study arms before primary ureterorenoscopy: (1) mono-J insertion for 6 h after ureterorenoscopy and (2) double-J insertion for 3–5 days after ureterorenoscopy. Study endpoints were stent-related symptoms assessed by an ureteral stent symptom questionnaire (USSQ) and reintervention rates. Stone sizes and location, age, operation duration, BMI, and gender were recorded. Of 67 patients undergoing ureterorenoscopy, 36 patients were analyzed in the double-J arm and 31 patients in the mono-J arm. Mean operation time was 27.5 ± 1.3 min versus 24.0 ± 1.3 min, and stone size was 5.2 mm versus 4.5 mm for mono-J versus double-J, respectively (p = 0.06 and p = 0.15). FaST 3 was terminated early due to a high reintervention rate of 35.5% for the mono-J group and 16.7% for the double-J group (p = 0.27). One day after ureterorenoscopy, USSQ scores were similar between the study arms (Urinary Index: p = 0.09; Pain Index: p = 0.67). However, after 3–5 weeks, the Pain Index was significantly lower in those patients who had a double-J inserted after ureterorenoscopy (p = 0.04). Short-term insertion of mono-J post-ureterorenoscopy results in similar micturition symptoms and pain one day after ureterorenoscopy compared to double-J insertion. The reintervention rate was non-significant between the treatment groups most likely due to the early termination of the study (p = 0.27). Ethics approval/Trail Registration: No. 18-6435, 2018
High Familial Recurrence of Congenital Heart Defects in Laterality Defects Patients: An Evaluation of 184 Families
Authors: Hu Huifang , Chen Weicheng , Sheng Wei , Huang Guoying
Published: June 2021

As a rare disease with genetic pathogenesis, observational study about familial CHD recurrence risk on CHD patients with laterality defects is lacking. This study aimed to investigate familial recurrence among families of patients with CHD and laterality defects, and compare them with CHD patients without laterality defects. A total of 184 patients with CHD and laterality defects treated in Cardiovascular Center, Children’s Hospital of Fudan University were observed from 2008 to 2019. A detailed family history was documented by trained staff using questionnaires, and information about the subtypes of CHD and laterality defects was also collected. In addition, positive family history information, including all three degrees relatives and all affected family members, was reconfirmed by trained medical staff through face-to-face interviews, telephone interviews, and letter return visits. Of the 184 included patients, 30 had at least one family member (from among three linear generations and distant relatives) with CHD. The familial recurrence rate of CHD in our cohort was 16.3% (30/184), which was higher than the 3.3% (67/2024) of patients with CHD without laterality defects. This result shows that the recurrence rate among the first-, second-, and third-degree relatives was 11.7% (11/94), 1.5% (3/204), and 3.1% (6/91) and that the recurrence rate among siblings (21.4%, 9/42) was higher than that among parents (3.8%, 2/52). The familial recurrence risk of CHD among patients with CHD and laterality defects is high, which is consistent with the previous study that reported a high familial recurrence of heterotaxy of 10%. First-degree relatives have a higher recurrence rate than second- and third-degree relatives, especially siblings. These findings have important significance for prenatal screening, intervention, and genetic counseling in the Chinese population, but may not be generalizable to other populations that may have different rates of familial and sporadic cases.
Elevated Atmospheric CO2 Modifies Mostly the Metabolic Active Rhizosphere Soil Microbiome in the Giessen FACE Experiment
Authors: Rosado-Porto David , Ratering Stefan , Cardinale Massimiliano , Maisinger Corinna , Moser Gerald , Deppe Marianna , Müller Christoph , Schnell Sylvia
Published: June 2021

Elevated levels of atmospheric CO2 lead to the increase of plant photosynthetic rates, carbon inputs into soil and root exudation. In this work, the effects of rising atmospheric CO2 levels on the metabolic active soil microbiome have been investigated at the Giessen free-air CO2 enrichment (Gi-FACE) experiment on a permanent grassland site near Giessen, Germany. The aim was to assess the effects of increased C supply into the soil, due to elevated CO2, on the active soil microbiome composition. RNA extraction and 16S rRNA (cDNA) metabarcoding sequencing were performed from bulk and rhizosphere soils, and the obtained data were processed for a compositional data analysis calculating diversity indices and differential abundance analyses. The structure of the metabolic active microbiome in the rhizospheric soil showed a clear separation between elevated and ambient CO2 (p = 0.002); increased atmospheric CO2 concentration exerted a significant influence on the microbiomes differentiation (p = 0.01). In contrast, elevated CO2 had no major influence on the structure of the bulk soil microbiome (p = 0.097). Differential abundance results demonstrated that 42 bacterial genera were stimulated under elevated CO2. The RNA-based metabarcoding approach used in this research showed that the ongoing atmospheric CO2 increase of climate change will significantly shift the microbiome structure in the rhizosphere.
Differential Response of the Microbiome of Pocillopora acuta to Reciprocal Transplantation Within Singapore
Authors: Deignan Lindsey K. , McDougald Diane
Published: June 2021

As corals continue to decline globally, particularly due to climate change, it is vital to understand the extent to which their microbiome may confer an adaptive resilience against environmental stress. Corals that survive on the urban reefs of Singapore are ideal candidates to study the association of scleractinians with their microbiome, which in turn can inform reef conservation and management. In this study, we monitored differences in the microbiome of Pocillopora acuta colonies reciprocally transplanted between two reefs, Raffles and Kusu, within the Port of Singapore, where corals face intense anthropogenic impacts. Pocillopora acuta had previously been shown to host distinct microbial communities between these two reefs. Amplicon sequencing (16S rRNA) was used to assess the coral microbiomes at 1, 2, 4, and 10 days post-transplantation. Coral microbiomes responded rapidly to transplantation, becoming similar to those of the local corals at the destination reef within one day at Raffles and within two days at Kusu. Elevated nitrate concentrations were detected at Raffles for the duration of the study, potentially influencing the microbiome’s response to transplantation. The persistence of corals within the port of Singapore highlights the ability of corals to adapt to stressful environments. Further, coral resilience appears to coincide with a dynamic microbiome which can undergo shifts in composition without succumbing to dysbiosis.