bluuebunny/crossref_metadata_2025_split 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

AbstractPhotopolymerization 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

AbstractSulfur 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

AbstractHalogen 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

AbstractHeparan 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

AbstractThe 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

AbstractSince 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

AbstractThe 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

AbstractThe 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

AbstractA 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

AbstractWe 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

AbstractMulti-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.
A Greeting from Hamburg to the Otto Stern Symposium
Authors: Toschek Peter E. 
Published: June 2021

AbstractDear 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

AbstractOtto 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

AbstractLiquid 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

AbstractIt 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

AbstractCyclin-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

AbstractWe 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.