bluuebunny/crossref_metadata_2025 huggingface dataset:
Facile synthesis of phenyl‐rich functional siloxanes from simple silanes
Authors: Schneider Alyssa F. , Lu Emily K. , Lu Guanhua , Brook Michael A.
Published: September 2020

Phenyl‐rich silicone polymers are used for their excellent thermal properties and high refractive indices. Traditional syntheses of these polymers utilize cationic or anionic equilibration, which limits the molecular weights that can be achieved due, in part, to the coproduction of cyclic monomers that must be removed. Kinetically controlled processes may reduce the impact of these limitations, but require high temperatures, alkyllithium initiators and an inert atmosphere; precise structures are difficult to access. The Piers‐Rubinsztajn reaction, combined with hydrolysis, allows the synthesis of highly ordered, Si‐H terminated, phenyl‐rich silicone homo‐ and copolymers comprised of phenylmethyl, diphenyl and, dimethylsilicone monomers. The processes are mild and permit a high level of structural control, including alternating copolymers with different levels of phenyl content (Ph/Si = 0.3–1.5) with molecular weights up to ~100 kDa. Yet higher molecular weights could be achieved—Mn up to 300 kDa—when phenyl‐rich siloxanes were incorporated into block copolymers with dimethylsilicones (Ph/Si = 0.4). Unlike kinetic processes in which cyclic byproducts are formed by redistribution or backbiting (particularly at high conversion), in this process cyclics form near the onset of the reaction and only with low molecular weight starting materials (< 4 siloxane units).
The role of Connected Health technologies in supporting families affected by paediatric cancer: A systematic review
Authors: Delemere Emma , Maguire Rebecca
Published: September 2020

Objectives

Families impacted by paediatric cancer are met with logistical, financial and psychological impacts, with severe acute respiratory syndrome coronavirus two creating additional barriers and stressors for these families. Connected Health (CH) may facilitate cancer care. The objective of the present study was to systematically review CH for families/informal caregivers affected by paediatric cancer.

Methods

Using search terms relating to: (1) paediatric cancer, (2) family/caregivers and (3) CH, the databases of PsycINFO, Pubmed, EMBASE and Web of Science were searched. Inclusion criteria included an evaluation of CH technologies for supportive care for families/caregivers affected by paediatric cancer at any stage of treatment or survivorship.

Results

Sixteen studies met inclusion criteria. CH was primarily web‐based (n = 6), however smartphone applications (n = 5), telehealth (n = 2) and online groups (n = 3) were utilised. Intervention areas included psycho‐social (n = 6), health and information provision (n = 8) and palliative care (n = 2).

Conclusions

While limited studies have evaluated the impact of CH on families living with paediatric cancer, emerging evidence suggests potential benefits. More evidenced‐based interventions are required.
Patient values in physiotherapy practice, a qualitative study
Authors: Bastemeijer Carla M. , van Ewijk Johannes P. , Hazelzet Jan A. , Voogt Lennard P.
Published: September 2020

Objectives

Physiotherapy is, like all healthcare professions, relational and value‐laden. Patient‐centred care, evidence‐based practice and value‐based practices are concepts in which patient values lie at the heart of high‐quality healthcare practices. Nevertheless, physiotherapists have limited awareness of what patient values are in the physiotherapy encounter. The purpose of this study is to explore these patient values.

Methods

A qualitative study design using content analysis was used involving 17 adult participants with chronic or recurrent musculoskeletal pain. Data were collected during July 2015–July 2016 in three primary care physiotherapy facilities in Rotterdam, The Netherlands. Two researchers analysed the interviews and derived relevant codes from the data. After an iterative process of comparing, analysing, conceptualizing, and discussing the data, a pre‐existing analytic framework was refined in which distinct values were delineated.

Results

Emerging patient values were encompassed in three themes, each consisting of two to four elements: (1) values about oneself (uniqueness and autonomy), (2) values regarding actions of the professional (technically skilled professional, conscientious professional, compassionate professional, responsive professional) and (3) values regarding interactions between patients and the professionals (partnership and empowerment).

Conclusion

This study emphasizes the need for discussing patient values in the clinical encounter and helps physiotherapists to understand what deems to be important for patients with musculoskeletal pain in physiotherapy practice. The results of this study contribute to the existing body of knowledge of this important aspect of the quality of physiotherapy practice and may inspire clinicians and educators to actively implement patient values in clinical practice and the physiotherapy education.
Wake‐Up Mechanisms in Ferroelectric Lanthanum‐Doped Hf0.5Zr0.5O2 Thin Films
Authors: Mehmood Furqan , Mikolajick Thomas , Schroeder Uwe
Published: September 2020

Since the discovery of ferroelectricity in thin doped hafnium oxide layers, there is a rapidly growing interest in the implementation of this material into nonvolatile memory devices such as ferroelectric capacitors, transistors, or tunnel junctions. In most cases, a field‐cycling‐induced change in the remanent polarization is attributed to wake‐up and fatigue in ferroelectric HfO2 devices. The lanthanum‐doped hafnium/zirconium mixed oxide system is of broad interest due to its high endurance stability and low crystallization temperature which is necessary for low thermal budget, back‐end of line devices. Herein, a detailed temperature‐dependent field‐cycling study is performed in a wide temperature range from liquid nitrogen to room temperature to separate field‐cycling‐induced charge movements from phase change effects. Results are expected to be relevant for similar doped HfO2 ferroelectric layers.
Study of Interfaces in Hf/Fe System Using Magneto‐Optical Kerr Effect and Soft X‐Ray Absorption Spectroscopy
Authors: Vishwakarma Pramod , Gupta Mukul , Reddy Varimalla R. , Phase Deodatta M. , Gupta Ajay
Published: September 2020

Interface between layers of Fe and Hf is studied using magneto‐optical Kerr effect (MOKE) and soft X‐ray absorption spectroscopy (SXAS). Measurements as a function of the Fe layer thickness are done in a single sample by making use of a wedge‐shaped geometry for Fe layer sandwiched between two layers of Hf. SXAS measurements at the L‐edge of Fe provide evidence for interfacial alloying between Fe and Hf layers, with the thicknesses of the intermixed layers at Fe‐on‐Hf and Hf‐on‐Fe interfaces being 0.18 ± 0.05 and 0.27 ± 0.05 nm, respectively. Evolution of the MOKE hysteresis loop with Fe layer thickness gives an effective magnetic dead layer of 0.8 ± 0.1 nm at the two Fe/Hf interfaces together. Precise determination of the thickness of the intermixed layer and the magnetic dead layer using two independent techniques allows us to have a better insight into the interfacial magnetism and origin of magnetic dead layer at Fe/Hf interfaces. Present results suggest that the origin of the effective magnetic dead layer is partly due to modified magnetic moments of Fe and Hf in the intermixed regions and partly due to proximity‐induced magnetic moment in the interfacial Hf layers with its magnetic moment aligned antiparallel to the Fe layer.
The Role of Covalent Functionalization in the Thermal Stability and Decomposition of Hybrid Layered Hydroxides
Authors: Oestreicher Víctor , Abellán Gonzalo , Coronado Eugenio
Published: September 2020

The room temperature synthesis of two Co‐based hybrid layered hydroxides containing the same organic ligand (suberate [Sub]), one connected through purely electrostatic interactions (CoAl layered double hydroxide [LDH]), and the other covalently functionalized (α‐CoII simonkolleite phase) has been carried out. The magnetic properties exhibit an acute difference in the magnetization temperatures (from ≈10 K for the CoAl‐LDH to ≈55 K for the α‐CoII). Moreover, the role of the covalent functionalization in the thermal stability and the decomposition has been investigated by a forefront characterization tool consisting of thermogravimetric analysis coupled with gas chromatography and mass spectrometry (TG–GC–MS). The LDH exhibits a higher thermal stability of ≈50 ºC with broad mass loss steps, whereas the water molecules interact stronger with the α‐CoII(Sub) hybrid, suggesting a higher confinement in the interlayer space. Interestingly, at higher temperatures (>400 ºC), the α‐CoII(Sub) gives rise to the selective formation of cycloheptanone, in contrast to the LDH phase leading to different carbonyl containing compounds. These findings offer new fundamental insights into the thermal behavior of hybrid materials based on layered hydroxides, highlighting the important role of covalent functionalization in its properties.
SARS‐CoV‐2: Mechanism of infection and emerging technologies for future prospects
Authors: Li Shiqin , Li Sijia , Disoma Cyrollah , Zheng Rong , Zhou Mei , Razzaq Aroona , Liu Pinjia , Zhou Yuzheng , Dong Zijun , Du Ashuai , Peng Jian , Hu Liqiang , Huang Jufang , Feng Pinghui , Jiang Taijiao , Xia Zanxian
Published: September 2020

The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has spread globally to over 200 countries with more than 23 million confirmed cases and at least 800,000 fatalities as of 23 August 2020. Declared a pandemic on March 11 by World Health Organization, the disease caused by SARS‐CoV‐2 infection, called coronavirus disease 2019 (COVID‐19), has become a global public health crisis that challenged all national healthcare systems. This review summarized the current knowledge about virologic and pathogenic characteristics of SARS‐CoV‐2 with emphasis on potential immunomodulatory mechanism and drug development. With multiple emerging technologies and cross‐disciplinary approaches proving to be crucial in our global response against COVID‐19, the application of PROteolysis TArgeting Chimeras strategy, CRISPR‐Cas9 gene editing technology, and Single‐Nucleotide‐Specific Programmable Riboregulators technology in developing antiviral drugs and detecting infectious diseases are proposed here. We also discussed the available but still limited epidemiology of COVID‐19 as well as the ongoing efforts on vaccine development. In brief, we conducted an in‐depth analysis of the pathogenesis of SARS‐CoV‐2 and reviewed the therapeutic options for COVID‐19. We also proposed key research directions in the future that may help uncover more underlying molecular mechanisms governing the pathology of COVID‐19.
Observer‐based event‐triggered control for systems with slope‐restricted nonlinearities
Authors: Moreira Luciano G. , Gomes da Silva Joao M. , Tarbouriech Sophie , Seuret Alexandre
Published: September 2020

This article presents an observer‐based event‐triggering strategy for systems with slope‐restricted nonlinearities that depend on the state. Both the emulation and codesign problems are addressed. To avoid Zeno behavior, a minimum dwell time is considered. By using a looped‐functional approach and the cone‐bounded properties of the nonlinearity, sufficient conditions based on linear matrix inequalities are derived to ensure global asymptotic stability of the origin of the closed‐loop system under the proposed event‐triggering strategy. These conditions are incorporated into convex optimization problems to optimally determine the event‐triggering function parameters and the observer gain (in the codesign case) aiming at reducing the number of control updates. Numerical examples illustrate the potentialities of the approach.
Flows for floodplain forests: Conversion from an intermittent to continuous flow regime enabled riparian woodland development along a prairie river
Authors: Bigelow Sarah G. , Hillman Evan J. , Hills Brian , Samuelson Glenda M. , Rood Stewart B.
Published: September 2020

The Little Bow River (LBR) in western Canada naturally displayed an intermittent flow regime; the channel dried up most summers, excluding the development of riparian woodlands within this semi‐arid ecoregion. Around 1900, the Little Bow Canal was excavated to divert water from the adjacent Highwood River and with flow augmentation the LBR flow became continuous through the growth season. We hypothesized that the continuous regime enabled riparian woodland establishment and assessed conditions with sequential aerial photographs and field observations. Supporting the hypothesis, a few woodland groves established near the Highwood River where balsam poplars (Populus balsamifera) provided an abundant seed source. To investigate the basis for woodland development, we analysed historical hydrology of the LBR and assessed the four larger woodland groves, which included mature poplars, trembling aspen (P. tremuloides) and willow shrubs (Salix bebbiana and S. exigua). Each location had some bank excavation with channelization or gravel mining, and tree ageing through ring counts indicated gradual colonization and pulses of establishment after floods in 1920 and 1942. Thus, the conversion from an intermittent to continuous flow regime enabled woodland development which also benefited from excavations that created barren colonization sites. The study revealed four requirements for riparian woodland colonization in a dry region: (a) seeds, (b) barren sites, (c) bank saturation with higher river flow, and (d) sufficient river flows for tree and shrub survival and growth. While water withdrawal commonly degrades riverine ecosystems, flow augmentation can provide the opposite outcome, enhancing the river and riparian environments.
Residents' perception of flood risk and urban stream restoration using multi‐criteria decision analysis
Authors: Hong Chang‐Yu , Chang Heejun
Published: September 2020

This research examines how individual preferences for the major functions of stream restoration processes are associated with flood prevention and risk mitigation in Johnson Creek of Portland, Oregon, USA. We first reviewed a set of results from an analytical hierarchy process (AHP) model to rank the major stream restoration functions and compared citizens' preferences for “flood prevention” using ordinary least squares regression. Our results show that the perceptions and interests of citizens may be centred on the inconvenience of everyday life arising from the previous flood events. Residents in the highly urbanized downstream regions showed a higher sensitivity to flooding than those living in the upper regions of the watershed. Community participation and annual incomes are positively related to flood risk perception in more developed downstream regions, while ecological or development goals associated with property protection are positively associated with higher flood risk perception in the less developed upper regions. Our findings of citizen perceptions can be adopted to help local government leaders and households mitigate flood risk while also achieving multiple benefits from stream restoration projects.
Bioactivity and DNA/BSA Interactions of Selenium N‐Heterocyclic Carbene Adducts
Authors: Ashraf Rizwan , Iqbal Muhammad Adnan , Bhatti Haq Nawaz , Janjua Muhammad Ramzan Saeed Ashraf , El‐Naggar Mohamed
Published: September 2020

In wake of promising biomedical applications of organo‐selenium compounds, the present work was planned to synthesize selenium adducts (1 s‐‐4 s) and their respective azolium ligands (1 a–4 a), which were subsequently authenticated by various analytical and spectroscopic techniques like microanalysis, UV‐Visible, FT‐IR, 1H & 13C NMR and Electrospray Ionisation‐Mass Spectrometry (ESI‐MS). Moreover, the synthesized compounds were tested for their biological potential like antioxidant, antimicrobial, hemolytic, DNA and Bovin Serum Albumin (BSA) interactions, stability and lipophilicity using in‐vitro models. All the compounds were found stable in solution form for studied period 12–68 hours and showed good lipophilic values in the range of logP 0.66–0.85. In context to biological activities, selenium compounds showed better antimicrobial (ranging 17.4±0.5–25.3±0.8 mm against S. aureus and 18.6±0.7–24.1±0.9 against E.coli at concentration of 0.3 mg/mL for both strains) and antioxidant potential (IC50 ranging 40.0–62.0 μg/mL for DPPH solutions) compared to respective ligands. The interaction study of compounds (1 s–4 s) to DNA and BSA showed prominent binding affinity.
Enhanced Peroxidase Mimetic Activity of Magnetic Porous Carbon (MPC) Utilized in Colorimetric Sensing of Hg (II) Ions in Aqueous Medium
Authors: Christus Augustine Anand Babu , Panneerselvam Perumal
Published: September 2020

A new sensitive colorimetric sensor was designed to investigate the presence of Hg2+ in aqueous solution by using Fe3O4 NP impregnated on carbon nanocomposite(MPC) synthesized from MIL88 A which possess an excellent peroxidase mimicking activity that brings oxidation of 3, 3’, 5, 5’‐ tetramethylbenzidine (TMB) under the influence of hydrogen peroxide (H2O2) to produce blue colour in the solution. The solution was decolorized by the addition of Glutathione (GSH) which restores the TMB radical cations and ceased the oxidation reaction. Addition ofHg2+ ions to the solution bring back a strong blue colour due to the strong affinity of Hg 2+ with the thiol groups of GSH which promote the oxidation of TMB in the solution. Based on these strategies, we have developed a sensitive andselective colorimetric sensor for the determination of Hg (II) in aqueous solution with the detection limit value of 236 pM and a linear relationship of R2=0.994. The proposed mechanism was successfully implemented for the detection of mercury in real water samples for environmental applications.
Light‐Controlled Near‐Field Energy Transfer in Plasmonic Metasurface Coupled MoS2Monolayer
Authors: Deng Miaoyi , Li Ziwei , Rong Xin , Luo Yang , Li Bowen , Zheng Liheng , Wang Xiao , Lin Feng , Meixner Alfred J. , Braun Kai , Zhu Xing , Fang Zheyu
Published: September 2020

The energy transfer from plasmonic nanostructures to semiconductors has been extensively studied to enhance light‐harvesting and tailor light–matter interactions. In this study, the efficient energy transfer from an Au metasurface to monolayered MoS2within a near‐field coupling regime is reported. The metasurface is designed and fabricated to demonstrate strong photoluminescence (PL) and cathodoluminescence (CL) emission spectra. In the coupled heterostructure of MoS2with a metasurface, both the Raman shift and absorption spectral intensities of monolayered MoS2are affected. The spectral profile and PL peak position can be tailored owing to the energy transfer between plasmonic nanostructures and semiconductors. This is confirmed by ultrafast lifetime measurement. A theoretical model of two coupled oscillators is proposed, where the expanded general solutions (EGS) of such a model result in a series of eigenvalues that correspond to the renormalization of energy levels in modulated MoS2. The model can predict the peak shift up to tens of nanometers in hybrid structures and hence provides an alternative method to describe energy transfer between metallic structures and two‐dimensional (2D) semiconductors. A viable approach for studying light–matter interactions in 2D semiconductors via near‐field energy transfer is presented, which may stimulate the applications of functional nanophotonic devices.
Development of a Perovskite Solar Cell Architecture for Opaque Substrates
Authors: Feleki Benjamin T. , Chandrashekar Sanjana , Bouwer Ricardo K. M. , Wienk Martijn M. , Janssen René A. J.
Published: September 2020

To date, substrate‐configuration metal‐halide perovskite solar cells (PSCs) fabricated on opaque substrates such as metal foils provide inferior efficiencies compared with superstrate‐configuration cells on transparent substrates such as glass. Herein, a substrate‐configuration PSC on planarized steel is presented. To quantify the differences between the two configurations, a 15.6%‐efficient n–i–p superstrate‐configuration PSC is transformed step wise into a substrate‐configuration cell. Guided by optical modeling, the opaque Au electrode is replaced by a transparent MoO3/thin Au/polystyrene dielectric–metal–dielectric electrode. The semitransparent device affords efficiencies of 15.4% and 11.4% for bottom and top illumination, respectively. Subsequently, substrate‐configuration PSCs with a metal bottom electrode are fabricated on glass and planarized steel, using a thin MoO3 interlayer between the Au bottom electrode and the SnO2 electron transport layer. The glass‐based substrate‐configuration cell provides 14.0% efficiency with identical open‐circuit voltage and fill factor as the superstrate cell. The cell on planarized steel reaches 11.5% efficiency due to a lower fill factor. For both substrate‐configuration cells, the lower short‐circuit current density limits the efficiency. Optical modeling explains this quantitatively to be due to absorption and reflection by the top electrode and absorption by the organic hole transport layer.
CREW: Cost and Reliability aware Eagle‐Whale optimiser for service placement in Fog
Authors: Paul Martin John , Kandasamy A. , Chandrasekaran K.
Published: September 2020

Integration of Internet of Things (IoT) with industries revamps the traditional ways in which industries work. Fog computing extends Cloud services to the vicinity of end users. Fog reduces delays induced by communication with the distant clouds in IoT environments. The resource constrained nature of Fog computing nodes demands an efficient placement policy for deploying applications, or their services. The distributed and heterogeneous features of Fog environments deem it imperative to consider the reliability performance parameter in placement decisions to provide services without interruptions. Increasing reliability leads to an increase in the cost. In this article, we propose a service placement policy which addresses the conflicting criteria of service reliability and monetary cost. A multiobjective optimisation problem is formulated and a novel placement policy, Cost and Reliability‐aware Eagle‐Whale (CREW), is proposed to provide placement decisions ensuring timely service responses. Considering the exponentially large solution space, CREW adopts Eagle strategy based multi‐Whale optimisation for taking placement decisions. We have considered real time microservice applications for validating our approaches, and CREW has been experimentally shown to outperform the existing popular multiobjective meta‐heuristics such as NSGA‐II and MOWOA based placement strategies.
Enzymatic Modification of Granular Potato Starch Using Isoamylase—Investigation of Morphological, Physicochemical, Molecular, and Techno‐Functional Properties
Authors: Ulbrich Marco , Asiri Saeed A. , Bussert Robert , Flöter Eckhard
Published: September 2020

Granular potato starch is modified using the debranching enzyme isoamylase. The modification is performed in aqueous suspension (40% w/w) at 35 °C by grading the volume (100, 250, and 400 µL/50 g of starch, 200 U · mL−1) of enzyme solution added. The starch products obtained are comprehensively investigated in terms of morphological (scanning electron microscopy), structural (X‐ray diffraction), thermal (differential scanning calorimetry), techno‐functional (solubility, hot paste viscosity, gel strength), and molecular properties (size exclusion chromatography‐multi angle laser light scattering‐differential refractive index detection). The granular integrity is basically preserved after modification and a molecular degradation predominantly of the amylopectin by debranching is proved. However, a slight reduction of the weight average molar mass of the amylose fraction is found too. In addition, the intended partial molecular degradation of the starch polysaccharides, the effect of the preparation procedure including washing with ethanol and grinding impacts several starch characteristics conspicuously.
Generation of hypoimmunogenic human pluripotent stem cells via expression of membrane-bound and secreted β2m-HLA-G fusion proteins
Authors: Shi Lei , Li Wenjing , Liu Yang , Chen Zhenyu , Hui Yi , Hao Pengcheng , Xu Xiangjie , Zhang Shuwei , Feng Hexi , Zhang Bowen , Zhou Shanshan , Li Nan , Xiao Lei , Liu Ling , Ma Lin , Zhang Xiaoqing
Published: September 2020

Allogeneic immune rejection is a major barrier for the application of human pluripotent stem cells (hPSCs) in regenerative medicine. A broad spectrum of immune cells, including T cells, natural killer (NK) cells, and antigen-presenting cells, which either cause direct cell killing or constitute an immunogenic environment, are involved in allograft immune rejection. A strategy to protect donor cells from cytotoxicity while decreasing the secretion of inflammatory cytokines of lymphocytes is still lacking. Here, we engineered hPSCs with no surface expression of classical human leukocyte antigen (HLA) class I proteins via beta-2 microglobulin (B2M) knockout or biallelic knockin of HLA-G1 within the frame of endogenous B2M loci. Elimination of the surface expression of HLA class I proteins protected the engineered hPSCs from cytotoxicity mediated by T cells. However, this lack of surface expression also resulted in missing-self response and NK cell activation, which were largely compromised by expression of β2m-HLA-G1 fusion proteins. We also proved that the engineered β2m-HLA-G5 fusion proteins were soluble, secretable, and capable of safeguarding low immunogenic environments by lowering inflammatory cytokines secretion in allografts. Our current study reveals a novel strategy that may offer unique advantages to construct hypoimmunogenic hPSCs via the expression of membrane-bound and secreted β2m-HLA-G fusion proteins. These engineered hPSCs are expected to serve as an unlimited cell source for generating universally compatible “off-the-shelf” cell grafts in the future.
Stereocomplementary and Parallel Syntheses of Multi‐Substituted (E)‐, (Z)‐Stereodefined α,β‐Unsaturated Esters: Application to Drug Syntheses
Authors: Ashida Yuichiro , Tanabe Yoo
Published: September 2020

Ubiquitous α,β‐unsaturated esters are well recognized as key structural olefin scaffolds in organic chemistry. (E)‐ and (Z)‐steroselectivity is the most critical issue in their synthesis, however, (E)‐ and (Z)‐ stereocomplementary synthetic methods remain quite limited. The present account discloses general (E)‐, (Z)‐stereocomplementary syntheses of a variety of α,β‐unsaturated esters from highly accessible (E)‐, (Z)‐stereodefined enol tosylates derived from β‐ketoesters and α‐formyl esters. Step 1 toward the stereocomplementary preparation of (E)‐, (Z)‐stereodefined enol tosylates is implemented by using inexpensive reagents under mild reaction conditions. Step 2 toward the highly stereoretentive synthesis of (E)‐ and (Z)‐stereodefined α,β‐unsaturated esters involves Suzuki‐Miyaura, Negishi, Sonogashira, Iron‐catalyzed, Mizoroki‐Heck, and Buchwald‐Hartwig cross‐coupling reactions. Notably, this strategy was successfully applied for parallel drug syntheses of (E)‐ and (Z)‐zimelidine, (E)‐ and (Z)‐tamoxifen, and Merck's cyclopropane pharmacophore. Representative successful utilizations by other groups are also introduced.
Poetry in a Time of Pandemic
Authors: Leathers Jacqueline
Published: September 2020

Voices From the Classroom essays share readers’ reflections on teaching experiences, advice for new teachers, and perspectives on current issues.
The shifting shape and functional specializations of the cell cycle during lineage development
Authors: Hwang Yung , Hidalgo Daniel , Socolovsky Merav
Published: September 2020

Essentially all cell cycling in multicellular organisms in vivo takes place in the context of lineage differentiation. This notwithstanding, the regulation of the cell cycle is often assumed to be generic, independent of tissue or developmental stage. Here we review developmental‐stage‐specific cell cycle adaptations that may influence developmental decisions, in mammalian erythropoiesis and in other lineages. The length of the cell cycle influences the balance between self‐renewal and differentiation in multiple tissues, and may determine lineage fate. Shorter cycles contribute to the efficiency of reprogramming somatic cells into induced pluripotency stem cells and help maintain the pluripotent state. While the plasticity of G1 length is well established, the speed of S phase is emerging as a novel regulated parameter that may influence cell fate transitions in the erythroid lineage, in neural tissue and in embryonic stem cells. A slow S phase may stabilize the self‐renewal state, whereas S phase shortening may favor a cell fate change. In the erythroid lineage, functional approaches and single‐cell RNA‐sequencing show that a key transcriptional switch, at the transition from self‐renewal to differentiation, is synchronized with and dependent on S phase. This specific S phase is shorter, as a result of a genome‐wide increase in the speed of replication forks. Furthermore, there is progressive shortening in G1 in the period preceding this switch. Together these studies suggest an integrated regulatory landscape of the cycle and differentiation programs, where cell cycle adaptations are controlled by, and in turn feed back on, the propagation of developmental trajectories.

This article is categorized under:

Congenital Diseases > Stem Cells and Development
Upper bound on the solution for a class of 2‐D Chemotaxis model with generalized logistic damping
Authors: Lyu Wenbin , Wang Qiong
Published: September 2020

In this paper, we consider the upper bound of the solution for a class of 2‐D Chemotaxis model with generalized logistic damping in a smooth bounded domain. We show how upper bound of the solution qualitatively depends on the parameters in the equation.
Quantum D = 3 Euclidean and Poincaré symmetries from contraction limits
Authors: Kowalski-Glikman Jerzy , Lukierski Jerzy , Trześniewski Tomasz
Published: September 2020

Abstract

Following the recently obtained complete classification of quantum-deformed $$ \mathfrak{o} $$
o
(4), $$ \mathfrak{o} $$
o
(1, 3) and $$ \mathfrak{o} $$
o
(2) algebras, characterized by classical r-matrices, we study their inhomogeneous D = 3 quantum IW contractions (i.e. the limit of vanishing cosmological constant), with Euclidean or Lorentzian signature. Subsequently, we compare our results with the complete list of D = 3 inhomogeneous Euclidean and D = 3 Poincaré quantum deformations obtained by P. Stachura. It turns out that the IW contractions allow us to recover all Stachura deformations. We further discuss the applicability of our results in the models of 3D quantum gravity in the Chern-Simons formulation (both with and with- out the cosmological constant), where it is known that the relevant quantum deformations should satisfy the Fock-Rosly conditions. The latter deformations in part of the cases are associated with the Drinfeld double structures, which also have been recently investigated in detail.
Fluxes, twisted tori, monodromy and U(1) supermembranes
Authors: del Moral M. P. Garcia , Heras C. Las , Leon P. , Pena J. M. , Restuccia A.
Published: September 2020

Abstract

We show that the D = 11 supermembrane theory (M2-brane) compactified on a M9× T2 target space, with constant fluxes C± naturally incorporates the geometrical structure of a twisted torus. We extend the M2-brane theory to a formulation on a twisted torus bundle. It is consistently fibered over the world volume of the M2-brane. It can also be interpreted as a torus bundle with a nontrivial U(1) connection associated to the fluxes. The structure group G is the area preserving diffeomorphisms. The torus bundle is defined in terms of the monodromy associated to the isotopy classes of symplectomorphisms with π0(G) = SL(2, Z), and classified by the coinvariants of the subgroups of SL(2, Z). The spectrum of the theory is purely discrete since the constant flux induces a central charge on the supersymmetric algebra and a modification on the Hamiltonian which renders the spectrum discrete with finite multiplicity. The theory is invariant under symplectomorphisms connected and non connected to the identity, a result relevant to guarantee the U-dual invariance of the theory. The Hamiltonian of the theory exhibits interesting new U(1) gauge and global symmetries on the worldvolume induced by the symplectomorphim transformations. We construct explicitly the supersymmetric algebra with nontrivial central charges. We show that the zero modes decouple from the nonzero ones. The nonzero mode algebra corresponds to a massive superalgebra that preserves either 1/2 or 1/4 of the original supersymmetry depending on the state considered.
Measuring the quartic Higgs self-coupling at a multi-TeV muon collider
Authors: Chiesa M. , Maltoni F. , Mantani L. , Mele B. , Piccinini F. , Zhao X.
Published: September 2020

Abstract

Measuring the shape of the Higgs boson potential is of paramount importance, and will be a challenging task at current as well as future colliders. While the expectations for the measurement of the trilinear Higgs self-coupling are rather promising, an accurate measurement of the quartic self-coupling interaction is presently considered extremely challenging even at a future 100 TeV proton-proton collider. In this work we explore the sensitivity that a muon collider with a center of mass energy in the multi-TeV range and luminosities of the order of 1035cm−2s−1, as presently under discussion, might provide, thanks to a rather large three Higgs-boson production and to a limited background. By performing a first and simple analysis, we find a clear indication that a muon collider could provide a determination of the quartic Higgs self-coupling that is significantly better than what is currently considered attainable at other future colliders.
Disorder in a two-domain neuronal Ca2+-binding protein regulates domain stability and dynamics using ligand mimicry
Authors: Staby Lasse , Kemplen Katherine R. , Stein Amelie , Ploug Michael , Clarke Jane , Skriver Karen , Heidarsson Pétur O. , Kragelund Birthe B.
Published: September 2020

Understanding the interplay between sequence, structure and function of proteins has been complicated in recent years by the discovery of intrinsically disordered proteins (IDPs), which perform biological functions in the absence of a well-defined three-dimensional fold. Disordered protein sequences account for roughly 30% of the human proteome and in many proteins, disordered and ordered domains coexist. However, few studies have assessed how either feature affects the properties of the other. In this study, we examine the role of a disordered tail in the overall properties of the two-domain, calcium-sensing protein neuronal calcium sensor 1 (NCS-1). We show that loss of just six of the 190 residues at the flexible C-terminus is sufficient to severely affect stability, dynamics, and folding behavior of both ordered domains. We identify specific hydrophobic contacts mediated by the disordered tail that may be responsible for stabilizing the distal N-terminal domain. Moreover, sequence analyses indicate the presence of an LSL-motif in the tail that acts as a mimic of native ligands critical to the observed order–disorder communication. Removing the disordered tail leads to a shorter life-time of the ligand-bound complex likely originating from the observed destabilization. This close relationship between order and disorder may have important implications for how investigations into mixed systems are designed and opens up a novel avenue of drug targeting exploiting this type of behavior.
Standard Diffusion-weighted MRI for the Diagnosis of Central Retinal Artery Occlusion
Authors: Danyel L. A. , Bohner G. , Connolly F. , Siebert E.
Published: September 2020

Purpose

To evaluate diffusion abnormalities of the retina and optic nerve in patients with central retinal artery occlusion (CRAO) using standard stroke diffusion-weighted magnetic resonance imaging (DWI).

Methods

In this case-control study, DWI scans of patients with nonarteritic CRAO were retrospectively assessed for acute ischemia of the retina and optic nerve. Two neuroradiologists, blinded for patient diagnosis, randomly evaluated DWI of CRAO patients and controls (a collective of stroke and transient ischemic attack [TIA] patients) for restrictions of the retina and optic nerve. We calculated statistical quality criteria and analyzed inter-rater reliability using unweighted Kappa statistics.

Results

20 CRAO patients (60,6 ± 17 years) and 20 controls (60,7 ± 17 years) were included in the study. Sensitivity, specificity, positive and negative predictive values for retinal DWI restrictions were 75%/80%/79%/76% (reader 1) and 75%/100%/100%/80% (reader 2), respectively. Unweighted Kappa was κ = 0,70 (95% CI 0,48‑0,92), indicating “substantial” interrater reliability. In comparison, sensitivity, specificity, PPV and NPV (positive and negative predictive values) for restrictions of the optic nerve in CRAO were 55%/70%/65%/61% (reader 1) and 25%/100%/100%/57% (reader 2). Inter-rater reliability was “fair” with unweighted Kappa κ = 0,32 (95% CI 0,09‑0,56).

Conclusions

Retinal diffusion restrictions were present in a majority of CRAO patients and detectable with reasonable sensitivity, high specificity and substantial inter-rater reliability. Further studies are necessary to study time dependency of retinal diffusion restrictions, improve image quality and investigate the reliability of retinal DWI to discern CRAO from other causes of acute loss of vision.
Performance of Automated Attenuation Measurements at Identifying Large Vessel Occlusion Stroke on CT Angiography
Authors: Reidler Paul , Stueckelschweiger Lena , Puhr-Westerheide Daniel , Feil Katharina , Kellert Lars , Dimitriadis Konstantinos , Tiedt Steffen , Herzberg Moriz , Rémi Jan , Liebig Thomas , Fabritius Matthias P. , Kunz Wolfgang G.
Published: September 2020

Purpose

Computed tomography angiography (CTA) is routinely used to detect large-vessel occlusion (LVO) in patients with suspected acute ischemic stroke; however, visual analysis is time consuming and prone to error. To evaluate solutions to support imaging triage, we tested performance of automated analysis of CTA source images (CTASI) at identifying patients with LVO.

Methods

Stroke patients with LVO were selected from a prospectively acquired cohort. A control group was selected from consecutive patients with clinically suspected stroke without signs of ischemia on CT perfusion (CTP) or infarct on follow-up. Software-based automated segmentation and Hounsfield unit (HU) measurements were performed on CTASI for all regions of the Alberta Stroke Program Early CT score (ASPECTS). We derived different parameters from raw measurements and analyzed their performance to identify patients with LVO using receiver operating characteristic curve analysis.

Results

The retrospective analysis included 145 patients, 79 patients with LVO stroke and 66 patients without stroke. The parameters hemispheric asymmetry ratio (AR), ratio between highest and lowest regional AR and M2-territory AR produced area under the curve (AUC) values from 0.95–0.97 (all p < 0.001) for detecting presence of LVO in the total population. Resulting sensitivity (sens)/specificity (spec) defined by the Youden index were 0.87/0.97–0.99. Maximum sens/spec defined by the specificity threshold ≥0.70 were 0.91–0.96/0.77–0.83. Performance in a small number of patients with isolated M2 occlusion was lower (AUC: 0.72–0.85).

Conclusion

Automated attenuation measurements on CTASI identify proximal LVO stroke patients with high sensitivity and specificity. This technique can aid in accurate and timely patient selection for thrombectomy, especially in primary stroke centers without CTP capacity.
Wenn ein urologischer Notfall auf eine internistische Krise hinweist
Authors: Abdeen Muhammad , Janssen Martin , Al-Kailani Zaid , Saar Matthias , Siemer Stefan , Stöckle Michael , Aßmann Gunter , Linxweiler Johannes
Published: September 2020

Der Priapismus als klinische Manifestation einer hämatologischen Erkrankung ist selten. In diesem Fall liegt ein sowohl urologischer als auch internistischer Notfall vor, der einer umgehenden Therapie bedarf. Dieser Artikel beschreibt den klinischen Fall eines Priapismus als Erstmanifestation einer bis dahin nicht diagnostizierten chronisch-myeloischen Leukämie (CML) und erläutert die Resultate einer Literaturrecherche zu dieser Thematik.
Treatment type may influence degree of post-dislocation shoulder osteoarthritis: a systematic review and meta-analysis
Authors: Verweij Lukas P. E. , Pruijssen Erik C. , Kerkhoffs Gino M. M. J. , Blankevoort Leendert , Sierevelt Inger N. , van Deurzen Derek F. P. , van den Bekerom Michel P. J.
Published: September 2020

Purpose

Age at primary dislocation, recurrence, and glenoid bone loss are associated with development of osteoarthritis (OA). However, an overview of OA following traumatic anterior shoulder instability is lacking and it is unclear to what degree type of surgery is associated with development of OA in comparison to non-operative treatment. The aim of this study was to determine the degree of OA at long-term follow-up after non-operative and operative treatments for patients with anterior shoulder instability. Surgery is indicated when patients experience recurrence and this is associated with OA; therefore, it was hypothesized that shoulders show a higher proportion or degree of OA following operative treatment compared to non-operative treatment.

Methods

A literature search was performed in the PubMed/Medline, EMBASE, and Cochrane databases. Articles reporting the degree of OA that was assessed with the Samilson–Prieto or Buscayret OA classification method after non-operative and operative treatment for anterior shoulder instability with a minimum of 5 years follow-up were included.

Results

Thirty-six articles met the eligibility criteria of which 1 reported the degree of OA for non-operative treatment and 35 reported the degree of OA for 9 different operative procedures. A total of 1832 patients (1854 shoulders) were included. OA proportions of non-operative and operative treatments are similar at any point of follow-up. The Latarjet procedure showed a lower degree of OA compared to non-operative treatment and the other operative procedures, except for the Bristow procedure and Rockwood capsular shift. The meta-analyses showed comparable development of OA over time among the treatment options. An increase in OA proportion was observed when comparing the injured to the contralateral shoulder. However, a difference between the operative subgroups was observed in neither analysis.

Conclusion

Non-operative and operative treatments show similar OA proportions at any point of follow-up. The hypothesis that shoulders showed a higher proportion or degree of OA following operative treatment compared to non-operative treatment is not supported by the data. Operative treatment according to the Latarjet procedure results in a lower degree of OA compared to other treatments, including non-operative treatment.

Level of evidence

IV.
Urethral closure occurs by recoiling, pressure transmission, and a guarding reflex
Authors: Bergström Bo S.
Published: September 2020

Enhörning’s abdominal pressure transmission theory (ET) is built on Pascal’s law of fluid pressures. A theory that rejects ET also rejects this basic physical law and cannot be considered scientifically sound. The integral theory (IT) of female stress urinary incontinence rejects ET. This issue is discussed from the viewpoint of the urethral hanging theory of female stress urinary incontinence (UHT).
Burkholder–Davis–Gundy Inequalities in UMD Banach Spaces
Authors: Yaroslavtsev Ivan
Published: September 2020

In this paper we prove Burkholder–Davis–Gundy inequalities for a general martingaleMwith values in a UMD Banach spaceX. Assuming that$$M_0=0$$M0=0, we show that the following two-sided inequality holds for all$$1\le p<\infty $$1≤p<∞: Here$$ \gamma ([\![M]\!]_t) $$γ([[M]]t)is the$$L^2$$L2-norm of the unique Gaussian measure onXhaving$$[\![M]\!]_t(x^*,y^*):= [\langle M,x^*\rangle , \langle M,y^*\rangle ]_t$$[[M]]t(x∗,y∗):=[⟨M,x∗⟩,⟨M,y∗⟩]tas its covariance bilinear form. This extends to general UMD spaces a recent result by Veraar and the author, where a pointwise version of ($$\star $$⋆) was proved for UMD Banach functions spacesX. We show that for continuous martingales, ($$\star $$⋆) holds for all$$0<p<\infty $$0<p<∞, and that for purely discontinuous martingales the right-hand side of ($$\star $$⋆) can be expressed more explicitly in terms of the jumps ofM. For martingales with independent increments, ($$\star $$⋆) is shown to hold more generally in reflexive Banach spacesXwith finite cotype. In the converse direction, we show that the validity of ($$\star $$⋆) for arbitrary martingales implies the UMD property forX. As an application we prove various Itô isomorphisms for vector-valued stochastic integrals with respect to general martingales, which extends earlier results by van Neerven, Veraar, and Weis for vector-valued stochastic integrals with respect to a Brownian motion. We also provide Itô isomorphisms for vector-valued stochastic integrals with respect to compensated Poisson and general random measures.
Der Einsatz von Immuncheckpoint-Inhibitoren im onkologischen Alltag
Authors: Schardt Julian
Published: September 2020

Hintergrund

Die Einführung von Immuncheckpoint-Inhibitoren (ICI) hat die Behandlungskonzepte der Onkologie für eine Vielzahl von unterschiedlichen Krebsarten maßgeblich verändert. Dabei werden in der klinischen Routine v. a. humanisierte Antikörper gegen Immuncheckpoints wie „cytotoxic T‑lymphocyte associated protein 4“ (CTLA-4) oder „programmed cell death 1/programmed cell death ligand 1“ (PD1/PD-L1) eingesetzt.

Fragestellung

Übersicht zur Therapielandschaft mit Immuncheckpoint-Inhibitoren bei mehrheitlich soliden Tumoren in der Onkologie.

Material und Methoden

Darstellung und Diskussion aktueller Studienresultate, Einbezug aktueller Behandlungsempfehlungen und Zulassungsindikationen.

Ergebnisse

Sieben verschiedene Immuncheckpoint-Inhibitoren werden in der Onkologie therapeutisch eingesetzt: ein Anti-CTLA-4-Antikörper, 3 Anti-PD1-Antikörper und 3 Anti-PD-L1-Antiköper. FDA-Zulassung auf dem US-Markt für 17 verschiedene Tumorentitäten und einer agnostischen Indikation (Tumoren mit defizienter Mismatch-repair-Maschinerie/hohe Mikrosatelliteninstabilität). Langzeitremissionen sind in ca. zwei Drittel der Patienten mit Tumoransprechen möglich.

Schlussfolgerungen

Nutzen der Immuncheckpoint-Inhibitoren nur für einen Teil der behandelten Patienten. Primäre und sekundäre Resistenzmechanismen erst in Anfängen verstanden. Kombinationstherapien der Immuncheckpoint-Inhibitoren mit z. B. Chemotherapie, neuen Immuncheckpoint-Inhibitoren (z. B. Anti-LAG3-Antikörper) oder gezielten Therapien (z. B. CDK4/6, PARP-Inhibitoren) zur Verbesserung der Wirksamkeit werden in klinischen Studien untersucht. Verlässliche, prädiktive Marker sind dringend erforderlich.