bluuebunny/crossref_metadata_2025 huggingface dataset:
Plant size and neighbourhood characteristics influence survival and growth in a restored ex‐agricultural ecosystem
Authors: Atkinson Joe , Freudenberger David , Dwyer John M. , Standish Rachel J. , Moles Angela T. , Bonser Stephen P.
Published: March 2022

Restoring woody vegetation on degraded agricultural land is a widespread and common ecological restoration practice. However, highly variable plant survival and growth limit outcomes for many projects. Inconsistent reporting and monitoring of projects mean that an assessment of the relative importance of community‐assembly processes is limited, particularly over longer timescales.

We use 7 years of monitoring data of nearly 2000 native trees and shrubs in a restoration project on ex‐agricultural land in south‐western Australia to test the potential effects of facilitation or competition from neighbouring plants, as well as look for patterns in their interaction with the attributes of individuals and species traits.

Overall, plant size was the strongest single predictor of survival and incremental growth. Individual plants in neighbourhoods with higher inter‐generic basal area were more likely to survive, with this effect strongest in smaller individuals. When plants were larger, they were less likely to grow when in neighbourhoods with high intra‐generic basal area. Taller‐growing plants (higher species maximum height) were more likely to survive when individuals were small (basal area of 1–10 cm2), compared with shorter growing plants. Growth was also more likely in taller‐growing plants, and this relationship increased with the size of the individual. Recruitment was very low, with just 148 new recruits recorded across the 42 plots over 7 years.

Maximizing the growth of plants in restorations in the early stages may promote survival and growth in the longer term. We also demonstrate that increased levels of inter‐generic neighbouring plants may improve individual plant survival in the restoration of ex‐agricultural land. As a result, we suggest tailoring direct‐seeding methods to minimize clustering of congeneric individuals. We also highlight the need to find means of promoting recruitment for the long‐term sustainability of restoration efforts.
Uncertainties in linac primary barrier transmission values
Authors: McDermott Patrick N. , Sigler Michael D. , Lake Ian P. , Lack Danielle
Published: March 2022

Primary barrier design for linac shielding depends very sensitively on tenth value layer (TVL) data. Inaccuracies can lead to large discrepancies between measured and calculated values of the barrier transmission. Values of the TVL for concrete quoted in several widely used standard references are substantially different than those calculated more recently. The older standard TVL data predict significantly lower radiation levels outside primary barriers than the more recently calculated values under some circumstances. The difference increases with increasing barrier thickness and energy, and it can be as large as a factor of 4 for 18 MV and concrete thickness of 200 cm. This may be due to significant differences in the beam spectra between the earlier and the more recent calculations. Measured instantaneous air kerma rates sometimes show large variations for the same energy and thickness. This may be due to confounding factors such as extra material on, or inside the barrier, variable field size at the barrier, density of concrete, and distal distance from the barrier surface. In some cases, the older TVL data significantly underestimate measured instantaneous air kerma rates, by up to a factor of 3, even when confounding factors are taken into account. This could lead to the necessity for expensive remediation. The more recent TVL values tend to overestimate the measured instantaneous dose rates. Reference TVL data should be computed in a manner that is mathematically consistent with their use in the calculation of air kerma rate outside barriers directly from the linac “dose” rate in MU/min.
Implementing corrections of isocentric shifts for the stereotactic irradiation of cerebral targets: Clinical validation
Authors: Wegener Sonja , Schindhelm Robert , Sauer Otto A.
Published: March 2022

Purpose: Any Linac will show geometric imprecisions, including non‐ideal alignment of the gantry, collimator and couch axes, and gantry sag or wobble. Their angular dependence can be quantified and resulting changes of the dose distribution predicted (Wack, JACMP 20(5), 2020). We analyzed whether it is feasible to correct geometric shifts during treatment planning. The successful implementation of such a correction procedure was verified by measurements of different stereotactic treatment plans.

Methods: Isocentric shifts were quantified for two Elekta Synergy Agility Linacs using the QualiForMed ISO‐CBCT+ module, yielding the shift between kV and MV isocenters, the gantry flex and wobble as well as the positions of couch and collimator rotation axes. Next, the position of each field's isocenter in the Pinnacle treatment planning system was adjusted accordingly using a script. Fifteen stereotactic treatment plans of cerebral metastases (0.34 to 26.53 cm3) comprising 9–11 beams were investigated; 54 gantry and couch combinations in total. Unmodified plans and corrected plans were measured using the Sun Nuclear SRS‐MapCHECK with the Stereophan phantom and evaluated using gamma analysis.

Results: Geometric imprecisions, such as shifts of up to 0.8 mm between kV and MV isocenter, a couch rotation axis 0.9 mm off the kV isocente,r and gantry flex with an amplitude of 1.1 mm, were found. For eight, mostly small PTVs D98 values declined more than 5% by simulating these shifts. The average gamma (2%/2 mm, absolute, global, 20% threshold) was reduced from 0.53 to 0.31 (0.32 to 0.30) for Linac 1 (Linac 2) when including the isocentric corrections. Thus, Linac 1 reached the accuracy level of Linac 2 after correction.

Conclusion: Correcting for Linac geometric deviations during the planning process is feasible and was dosimetrically validated. The dosimetric impact of the geometric imperfections can vary between Linacs and should be assessed and corrected where necessary.
Moving Pictures: Three Installations for Public Life
Authors: Newsom Jennifer
Published: March 2022

Dream The Combine uses film and the scenography of performance to create multiple‐actor events in shared public spaces. Jennifer Newsom, co‐founder (with Tom Carruthers) of the practice, describes how participants perceive each architectural installation differently and how it is their individual perception that pieces parts together to receive alternative forms.
Signature Urbanism: Shaping Subperceptual Forms for the New Multispectral City
Authors: Kripa Ersela , Mueller Stephen
Published: March 2022

Ersela Kripa and Stephen Mueller, codirectors of the Project for Operative Spatial Technologies (POST) research centre at Texas Tech University College of Architecture, describe the city in all its newfound multispectral complexity and how their architectural interventions reveal a world determined by scopic regimes.
Flatness‐based disturbance observer for exoskeleton robots under time‐delayed contact forces
Authors: Rigatos Gerasimos , Abbaszadeh Masoud , Pomares Jorge
Published: March 2022

The article proposes flatness‐based control and a Kalman filter‐based disturbance observer for solving the control problem of a robotic exoskeleton under time‐delayed exogenous disturbances. A two‐link lower‐limb robotic exoskeleton is used as a case study. It is proven that this robotic system is differentially flat. The robot is considered to be subject to unknown contact forces at its free‐end which in turn generate unknown disturbance torques at its joints. It is shown that the dynamic model of the robotic exoskeleton can be transformed into the input–output linearized form and equivalently into the linear canonical Brunovsky form. This linearized description of the exoskeleton's dynamics is both controllable and observable. It allows for designing a stabilizing feedback controller with the use of the pole‐placement (eigenvalues assignment) method. Moreover, it allows for solving the state estimation problem with the use of Kalman Filtering (the use of the Kalman filter on the flatness‐based linearized model of nonlinear dynamical systems is also known as derivative‐free nonlinear Kalman filtering). Furthermore, (i) by extending the state vector of the exoskeleton after considering as additional state variables the additive disturbance torques which affect its joints and (ii) by redesigning the Kalman filter as a disturbance observer, one can achieve the real‐time estimation of the perturbations that affect this robotic system. Finally, by including in the controller of the exoskeleton additional terms that compensate for the estimated disturbance torques, the perturbations' effects can be eliminated and the precise tracking of reference trajectories by the joints of this robot can be ensured.
Constructing Interfacial Nanolayer Stabilizes 4.3 V High‐Voltage All‐Solid‐State Lithium Batteries with PEO‐Based Solid‐State Electrolyte
Authors: Wang Xufeng , Song Yajie , Jiang Xin , Liu Qingsong , Dong Jidong , Wang Jian , Zhou Xin , Li Bing , Yin Geping , Jiang Zaixing , Wang Jiajun
Published: March 2022

The complicated interfacial problems of poly(ethylene oxide) (PEO)‐based solid polymer electrolytes (SPEs) at high voltages severely hinder its practical applications for high‐energy‐density all‐solid‐state lithium batteries (ASSLBs). Herein, the failure mechanisms of ASSLBs with LiNi0.6Co0.2Mn0.2O2 (NCM)‐PEO are studied. It is found that the ASSLBs after charge generates a sharp drop of 0.62 V at the cut‐off voltage of 4.30 V, and induce a high interfacial resistance due to forming an uneven thick cathode electrolyte interface on the NCM surface, as well as cause the destruction of NCM surface structure during storage, leading to serious performance degradation. Constructing the interfacial nanolayer with aromatic polyamide (APA) on the surface of NCM active particles (NCM@APA) can mitigate interfacial side reactions between NCM and SPE. Robust interfacial nanolayers not only effectively protect the crystal structure of NCM but also provide a steady interfacial environment for Li+ diffusion kinetics. Accordingly, NCM@APA||SPE||Li ASSLBs exhibit an acceptable voltage drop of 0.27 V after 10 days storage and a substantially improved electrochemical performance with an average coulombic efficiency of 99.1% and capacity retention of 76.7% at 30 mA g−1 after 80 cycles.
Biomimetic and Biologically Compliant Soft Architectures via 3D and 4D Assembly Methods: A Perspective
Authors: Taylor Jay M. , Luan Haiwen , Lewis Jennifer A. , Rogers John A. , Nuzzo Ralph G. , Braun Paul V.
Published: March 2022

Recent progress in soft material chemistry and enabling methods of 3D and 4D fabrication—emerging programmable material designs and associated assembly methods for the construction of complex functional structures—is highlighted. The underlying advances in this science allow the creation of soft material architectures with properties and shapes that programmably vary with time. The ability to control composition from the molecular to the macroscale is highlighted—most notably through examples that focus on biomimetic and biologically compliant soft materials. Such advances, when coupled with the ability to program material structure and properties across multiple scales via microfabrication, 3D printing, or other assembly techniques, give rise to responsive (4D) architectures. The challenges and prospects for progress in this emerging field in terms of its capacities for integrating chemistry, form, and function are described in the context of exemplary soft material systems demonstrating important but heretofore difficult‐to‐realize biomimetic and biologically compliant behaviors.
Selective Adsorption and Photocatalytic Clean‐Up of Oil by TiO2 Thin Film Decorated with p‐V3D3 Modified Flowerlike Ag Nanoplates
Authors: Shondo Josiah , Veziroglu Salih , Tjardts Tim , Fiutowski Jacek , Schröder Stefan , Mishra Yogendra Kumar , Strunskus Thomas , Rubahn Horst‐Günther , Faupel Franz , Aktas Oral Cenk
Published: March 2022

Various methods are developed and used to treat oil‐contaminated water, including mechanical separation, chemical treatment, biological treatment, membrane filtration, and sorption. Oil clean‐up via selective sorption of the oil by an engineered surface is the most accepted technique due to its high removal efficiency and low cost. Here, a multifunctional surface providing highly selective oil sorption and clean‐up capability via the photocatalytic decomposition is proposed. This novel surface is named as the “three‐in‐one (3‐in‐1) surface” since it is composed of 1) a highly photocatalytic layer, 2) micro‐ and nanostructures, and 3) a low surface energy layer. First, the TiO2 photocatalytic layer is prepared by magnetron sputtering. Then flowerlike Ag nanoplates are photocatalytically deposited on the sputtered TiO2 layer. Afterward, a low surface energy layer, poly‐1,3,5‐trivinyl‐1,3,5‐trimethylcyclotrisiloxane (p‐V3D3), is over‐coated on Ag/TiO2 surface by initiated chemical vapor deposition (iCVD) while retaining the topographical features of the surface (micro‐ and nanoscale surface structures). The p‐V3D3/Ag/TiO2 surface demonstrates a high selective adsorption to oil whereas simultaneously it shows extreme repellency to water. The p‐V3D3/Ag/TiO2 surface can also be photocatalytically cleaned up and this may find applications in various technology fields including water treatment, microfluidics, self‐cleaning, and water harvesting.
Photo‐Actuated Chiral Smectic Superstructures
Authors: Wu Sai‐Bo , Cao Hui‐Min , Wu Jin‐Bing , Ma Ling‐Ling , Lu Yan‐Qing , Hu Wei
Published: March 2022

Chirality and hierarchy are two representative features of complex configurations inspiring exotic functions. Chiral additives are adopted to break the mirror symmetry of molecular orientation inside smectic layers, and overcome the restriction on in‐layer helical arrangement by virtue of the surface electroclinic effect. The chirality strength of liquid crystals is regulated via the photo‐isomerization of chiral molecular switch, the doping concentration control, and the mixing of different chiral additives. The dynamic evolution of chiral smectic superstructures leads to the reversible rotation of oily streaks (OSs), and even structural transformation between OSs and focal conic domains is demonstrated. This releases new freedom of chiral hierarchical configurations and may inspire fantastic applications in active optics, sensing, and micro‐manufacturing.
In Situ Characterization of Melt–Electrowritten Scaffolds in 3D Using Optical Coherence Tomography
Authors: Collier Evelyn , Maitland Brooke , Sanderson Rowan W. , Shiroud Heidari Behzad , Lamb Christopher , Hepburn Matt S. , Dalton Paul D. , Fang Qi , De-Juan-Pardo Elena M. , Kennedy Brendan F.
Published: March 2022

Recent developments in melt electrowriting (MEW), a high‐resolution additive manufacturing technology, have led to increases in scaffold complexity. However, MEW scaffolds are currently characterized ex situ, which causes time–consuming iterations of characterization and fabrication that limit scaffold throughput and more widespread use of the technology. For the first time, an in situ method to characterize the 3D microstructure of MEW scaffolds using optical coherence tomography (OCT) is described. Calculations of microstructural features are performed on OCT data using a custom algorithm, demonstrating close correspondence with scanning electron microscopy (SEM). For example, OCT calculations of fiber diameter and scaffold thickness are within an average of 0.31 and 1.79 μm, respectively, of corresponding SEM–derived calculations. Additionally, the 3D capabilities of OCT enable the nondestructive characterization of scaffolds with depth–varying microstructures, overcoming some main limitations of SEM. Finally, in situ characterization is achieved by integrating the OCT scanner within an MEW printer, enabling the scaffold microstructure to be evaluated and optimized during manufacture. This new capability represents an important step toward achieving an efficient fabrication–characterization cycle with the guaranteed scaffold quality and reproducibility required to validate the manufacturing process.
Gold‐Catalyzed Reaction of Anthranils with Alkynyl Sulfones for the Regioselective Formation of 3‐Hydroxyquinolines
Authors: Wu Yufeng , Hu Chao , Wang Tao , Eberle Lukas , Hashmi A. Stephen K.
Published: March 2022

The gold‐catalyzed regioselective formation of 3‐hydroxyquinoline is accessed by combining anthranils and alkynyl sulfones. The selective scission of the epoxide intermediate stems from the thermodynamic stability difference of the resultant cation according to quantum chemical calculations. The subsequent semi‐pinacol rearrangement leads to the 1,2‐shift of an aryl or alkyl group originating from the sulfone. A gram‐scale synthesis of 3‐hydroxyquinoline further manifests the viability of the protocol for the preparation of this important scaffold.

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Medical comorbidities and ethnicity impact plasma Alzheimer's disease biomarkers: Important considerations for clinical trials and practice
Authors: O'Bryant Sid E. , Petersen Melissa , Hall James , Johnson Leigh A. ,   for the HABS‐HD Study Team
Published: March 2022

Introduction

Despite the clinical implementation, there remain significant gaps in our knowledge regarding the impact of race/ethnicity or common medical comorbidity on plasma Alzheimer's disease (AD) biomarkers.

Methods

Plasma biomarkers of amyloid beta (Aβ)40, Aβ42, total tau, and neurofilament light chain (NfL) were measured across cognitively normal Mexican Americans (n = 445) and non‐Hispanic Whites (n = 520).

Results

Dyslipidemia was associated with elevated Aβ40 (P = .01) and Aβ42 (P = .001) while hypertension was associated with elevated Aβ40 (P = .003), Aβ42 (P < .001), and total tau (P = .002) levels. Diabetes was associated with higher Aβ40 (P < .001), Aβ42 (P < .001), total tau (P < .001), and NfL (P < .001) levels. Chronic kidney disease (CKD) was associated with elevations in Aβ40 (P < .001), Aβ42 (P < .001), total tau (P < .001), and NfL (P < .001) levels. Mexican Americans had significantly lower Aβ40 (P < .001) and higher total tau (P = .005) levels.

Discussion

Plasma AD biomarkers vary significantly in association with common medical comorbidities as well as ethnicity. These findings are important for those using these biomarkers in clinical practice and clinical trials.
Spectral studies, thermal investigations, and anticancer activity of some divalent metal complexes derived from 2‐(4‐bromophenylamino)acetohydrazide ligand
Authors: Emara Esam M. , El‐Sayed Wael A. , Khalaf‐Allah Abeer S. A. , Alminderej Fahad M. , Abdel‐Monem Yasser K. , Abd‐Rabou Ahmed A.
Published: March 2022

A series of biologically active metal complexes was yielded from the reactions of 2‐(4‐bromophenylamino)acetohydrazide ligand (HL) with Co(II), Ni(II), Cu(II), Cd(II) chlorides, CuBr2, Cu(CH3COO)2, and Cu(ClO4)2 salts. The structure and stereochemistry of the afforded complexes were elucidated by means of elemental analyses, molar conductance, magnetic susceptibility, thermal analyses (TG/DTG), and spectral techniques (mass, IR, UV‐Vis, and 1H NMR). Elemental analyses along with molar conductance data demonstrated that all metal complexes are nonelectrolyte and were formed with 1L:1M, 1L:2M, and 2L:1M stoichiometry. IR spectral data provided an evidence for the neutral bidentate behavior of the hydrazide ligand toward metal ions via carbonyl oxygen and amino nitrogen atoms (ON donor). Magnetic susceptibility along with electronic absorption spectral results authenticated that all complexes have an octahedral geometry except, CuCl2 complex (3), which possessed a square planar one. The hydrazide ligand and some of its synthesized metal complexes were screened in vitro for their antitumor and apoptotic activity. The results showed that CuBr2 complex (4) has promising anticancer activities against breast MCF7, liver HepG2, and colorectal HCT 116 cancerous cells through induction of proapoptotic gene (Bax) and inhibit the antiapoptotic gene (Bcl‐2), thus increase the Bax/Bcl‐2 ratio. Moreover, these newly synthesized compounds were most potent and can be used as a therapeutic chemoprevention against these cancerous cells compared with doxorubicin (DOX), the currently available anticancer drug against solid tumors.
First trial of wild juvenile collection of tropical sea cucumbers from settling larvae, using coconut fibre from waste husks in Solomon Islands: A new conservation tool
Authors: Tanita Iwao , Masaki Kunihiko , Hirohavi Edward Brown , Diau Billy Anthony , Tsatsia Catherine , Tagua Henry Stanley , Misiga Sebastian , Komatsu Toru , Ramofafia Christain
Published: March 2022

Wild juvenile collection (WJC) from settling larvae has been reported for two temperate holothurians (Apostichopus japonicus and Apostichopus californicus), mainly for the objective of restocking, but its applicability to tropical holothurians is unknown. This study, for the first time, tested the applicability of WJC for tropical sea cucumbers.

First, hatchery‐produced larvae of peanutfish (Stichopus horrens) before settlement were introduced in a tank in which bundles of coconut fibre, rolled mesh bags, and oyster shells were suspended to identify the most suitable settlement material. The results showed that the coconut fibre and mesh bags collected more settling larvae than the oyster shells.

Second, 25 collectors were installed for 3 months in the field in Nggela, Solomon Islands. The newly designed simple collector comprised between two and four net bags filled with coconut fibre, which were tied to a rope vertically moored between a concrete block anchor and polyethylene terephthalate (PET) bottle floats. A total of 14 juvenile holothurians were collected, including Stichopus cf. horrens, stonefish (Actinopyga lecanora), kingfish (Synapta maculata), and five unidentified species. It is characteristic of tropical WJC that diverse species can be collected simultaneously (including rare, non‐culturable species), which is advantageous over hatchery production for restocking purposes. The total yield corresponded to approximately 1% of the total abundance of the ambient holothurian community, demonstrating potential for restocking, considering the ease of the extension and repetition of the trials. Collection in the inner bay areas was successful, whereas rough weather physically damaged the collectors in areas open to the ocean.

These results show that WJC is a viable option for tropical holothurians. Thus, the use of the low‐cost, simple collectors using coconut fibre could be a new conservation measure for endangered holothurian resources, and are manageable by local communities.
Sunscreen pollution and tourism governance: Science and innovation are necessary for biodiversity conservation and sustainable tourism
Authors: Downs Craig A. , Cruz Orion T. , Remengesau Tommy E.
Published: March 2022

Sunscreen pollution can be a symptom of unsustainable tourism and coastal development, impacting marine and aquatic resources. When introduced into marine and freshwater ecosystems, sunscreen pollution can cause a cascade of insults to the ecological structure, from impacting primary production to reducing wildlife reproductive viability and fecundity.

Without intervention, tourism and its associated development in these coastal areas may become self‐destructive, ultimately degrading or destroying the natural resources that are the principal attractions. The environmental sciences that focus on pollution, such as ecotoxicology, environmental contaminant surveys and monitoring, and ecological risk assessments are critical for both describing the pollution phenomenon and identifying pollution sources, as well as providing the basis for mitigation.

As a case study, the Republic of Palau has taken the step of implementing a precautionary governance policy to tourism that conserves and protects its marine and aquatic resources from chemical factors that are known to contribute to sunscreen and cosmetic pollution.

Governance policies can inspire the cosmetic and fashion industries to innovate product formulations that are shown to be ecologically safer – a critical and viable option for pollution mitigation and an essential component for sustained conservation. Safer products and a precautionary approach to governance, when combined with ecologically and culturally cognizant branding and education, may contribute to an authentic experience that effectively promotes environmentally sustainable tourism.
Assessment of Twin Fetal Exposure to Environmental Magnetic and Electromagnetic Fields
Authors: Zhang Chen , Li Congsheng , Yang Lei , Hou Wenjing , Du Mingshan , Wu Tongning , Chen Wei
Published: March 2022

Fetal development is vital in the human lifespan. Therefore, it is essential to characterize exposure by a series of typical environmental magnetic and electromagnetic fields. In particular, there has recently been a sharp increase in the twin birth rate. However, lack of appropriate models has prohibited dosimetric evaluation, restricting characterization of the impact of these environmental factors on twins. The present study developed two whole‐body pregnant models of 31 and 32 weeks of gestation with twin fetuses and explored several typical exposure scenarios, including 50‐Hz uniform magnetic field exposure, local 125‐kHz magnetic field (MF), and 13.56‐MHz electromagnetic field exposure, as well as wideband planewave radiofrequency (RF) exposure from 20 to 6000 MHz. Finally, dosimetric results were derived. Compared to the singleton pregnancy with similar weeks of gestation, twin fetuses were overexposed at 50‐Hz uniform MF, but they were probably underexposed in the RF scenarios with frequencies for wireless communications. Furthermore, the twin fetuses manifested large dosimetric variability compared to the singleton, which was attributed to the incident direction and fetal position. Based on the analysis, the dosimetric results over the entire gestation period were estimated. The results can be helpful to estimate the risk of twin‐fetal exposure to electromagnetic fields and examine the conservativeness of the international guidelines.© 2022 Bioelectromagnetics Society.
Magnetic resonance imaging as a tool for quality control in extrusion‐based bioprinting
Authors: Schmieg Barbara , Gretzinger Sarah , Schuhmann Sebastian , Guthausen Gisela , Hubbuch Jürgen
Published: March 2022

Bioprinting is gaining importance for the manufacturing of tailor‐made hydrogel scaffolds in tissue engineering, pharmaceutical research and cell therapy. However, structure fidelity and geometric deviations of printed objects heavily influence mass transport and process reproducibility. Fast, three‐dimensional and nondestructive quality control methods will be decisive for the approval in larger studies or industry. Magnetic resonance imaging (MRI) meets these requirements for characterizing heterogeneous soft materials with different properties. Complementary to the idea of decentralized 3D printing, magnetic resonance tomography is common in medicine, and image data processing tools can be transferred system‐independently. In this study, a MRI measurement and image analysis protocol was evaluated to jointly assess the reproducibility of three different hydrogels and a reference material. Critical parameters for object quality, namely porosity, hole areas and deviations along the height of the scaffolds are discussed. Geometric deviations could be correlated to specific process parameters, anomalies of the ink or changes of ambient conditions. This strategy allows the systematic investigation of complex 3D objects as well as an implementation as a process control tool. Combined with the monitoring of metadata this approach might pave the way for future industrial applications of 3D printing in the field of biopharmaceutics.
Non‐steady‐state enzyme reaction dynamics
Authors: Kim Kyungwoo , Song Sanggeun , Sung Jaeyoung
Published: March 2022

Michaelis–Menten (MM) enzyme kinetics is and has been widely used since early 20th century. However, the conventional enzyme kinetics is not accurate when the substrate is not in excess or when the steady‐state approximation does not hold. The steady‐state approximation worsens as the enzyme concentration exceeds its substrate concentration, which is the case in many biological processes. Here, to overcome this issue, we present a novel, quasi‐exact solution of the enzyme kinetic equations, which provides the time profiles of the substrate, enzyme‐substrate complex, and product concentrations. Our theory provides more accurate results than the previously reported theories for all parameter spaces investigated and yields a new relationship of the enzyme reaction time or the enzyme reaction rate to the substrate and enzyme concentrations. We demonstrate our results for the catalytic reaction of β‐galactosidase.
Functional MRI evaluation of cognitive effects of carotid stenosis revascularization
Authors: Chinda Betty , Tran Kim H , Doesburg Sam , Siu William , Medvedev George , Liang S Simon , Brooks‐Wilson Angela , Song Xiaowei
Published: March 2022

Introduction

Severe internal carotid stenosis, if left untreated, can pose serious risks for ischemic stroke and cognitive impairments. The effects of revascularization on any aspects of cognition, however, are not well understood, as conflicting results are reported, which have mainly been centered on paper‐based cognitive analyses. Here, we summarized and evaluated the publications to date of functional MRI (fMRI) studies that examined the mechanisms of functional brain activation and connectivity as a way to reflect cognitive effects of revascularization on patients with carotid stenosis.

Methods

A PubMed and Google Scholar (covering the relevant literature until November 1, 2021) search yielded eight original studies of the research line, including seven resting‐state and one task‐based fMRI reports.

Results

Findings demonstrated treatment‐related alterations in fMRI signal intensity and symmetry level, regional fMRI activation pattern, and functional brain network connectivity. The functional brain changes were associated largely with improvement in cognitive function assessed using standard cognitive test scores.

Conclusions

These findings support the contribution of fMRI to the understanding of brain functional activation and connectivity changes revealing cognitive effects of revascularization in the management of severe carotid stenosis. The review also highlighted the importance of reproducibility through enhancing experimental designs and cognitive task applications with future research for potential clinical translation.
The role of consumer mindsets to reduce health‐related stress
Authors: Hong JungHwa (Jenny) , Ahn Sun Young , Camp Kerri M. , James Kevin
Published: March 2022

Medical professionals often struggle to persuade patients to adopt a healthy lifestyle. Despite consumers' increased interest in adopting a healthy lifestyle, the pursuit of wellness could make consumers feel stressed, which can cause or lead to many diseases. To reduce their stress, consumers can use either a problem‐focused or emotion‐focused coping strategy. A problem‐focused coping strategy focuses on potential actions one can take in response to stress. In contrast, an emotion‐focused coping strategy focuses on the emotional consequences of the situation and regulating the resulting emotions. Based on implicit self‐theories, this research suggests that consumers' different mindsets, either a growth or fixed mindset, influence their preferences for coping strategies to mitigate stress. The results of this study indicated that consumers with a growth mindset (vs. a fixed mindset) prefer to use a problem‐focused coping strategy (vs. emotion‐focused coping strategy) to reduce health‐related stress. Process evidence suggests that the findings are driven by differences in consumers' mindsets and how much they attribute their stress to controllable factors. Practical implications are discussed and include approaches medical professionals can use to implement a tailored messaging strategy based on the patient's mindset.
Do parasocial relationships and the quality of communication with AI shopping chatbots determine middle‐aged women consumers' continuance usage intentions?
Authors: Lee Minsun , Park Jee‐Sun
Published: March 2022

Artificial intelligence (AI) assistants, or chatbots, have become widely used on several retailers' websites. Effective interaction and communication with AI chatbots can deliver a better consumer experience by assisting with decision‐making, ultimately supporting purchase intentions. Based on parasocial theory, this study focuses on how interactions with AI shopping chatbots impact consumers' perceptions of communication quality, satisfaction, and continuance usage intentions. Partial least squares structural equation modeling (PLS‐SEM) was employed to assess the proposed research model using data from 184 Korean middle‐aged women who shop online. Participants completed the shopping process with the assistance of an AI shopping chatbot and responded to survey items about their experiences. In particular, the findings reveal the structural process whereby a consumer's parasocial relationship with an AI shopping chatbot ultimately increases continuance usage intentions through perceived communication quality and satisfaction. The results indicate that a parasocial relationship positively influences communication quality with the chatbot, which in turn increases satisfaction and continuance usage intentions. These findings provide marketers with theoretical and practical guidance for enhancing consumer experiences in the online shopping environment.
Development, validation, and reproducibility of the pullback pressure gradient (PPG) derived from manual fractional flow reserve pullbacks
Authors: Sonck Jeroen , Mizukami Takuya , Johnson Nils P. , Nagumo Sakura , Gallinoro Emanuele , Candreva Alessandro , Mileva Niya , Munhoz Daniel , Shinke Toshiro , Svanerud Johan , Barbato Emanuele , De Bruyne Bernard , Collet Carlos
Published: March 2022

Fractional flow reserve (FFR) pullbacks assess the location and magnitude of pressure drops along the coronary artery. The pullback pressure gradient (PPG) quantifies the FFR pullback curve and provides a numeric expression of focal versus diffuse coronary artery disease. This study aims (1) to validate the PPG using manual FFR pullbacks compared with motorized FFR pullbacks as a reference; and (2) to determine the intra‐ and interoperator reproducibility of the PPG derived from manual FFR pullbacks. Patients with stable coronary artery disease and an FFR ≤ 0.80 were included. All patients underwent FFR pullback evaluation either with a motorized device or manually, depending on the study cohort. The agreement of the PPG between repeated pullbacks was assessed using the Bland–Altman method. Overall, 116 FFR pullback maneuvers (96 manual and 20 motorized) were analyzed. There was excellent agreement between the PPG derived from manual and motorized pullbacks (mean difference −0.01 ± 0.07, 95% limits of agreement [LOA] −0.14 to 0.12). The intra‐ and interoperator reproducibility of PPG derived from manual pullbacks were excellent (mean difference <0.01, 95% LOA −0.11 to 0.12, and mean difference <0.01, 95% LOA −0.12 to 0.11, respectively). The duration of the pullback maneuver did not impact the reproducibility of the PPG (r = 0.12, 95% CI: −0.29 to 0.49, p = 0.567). Manual pullbacks allow for an accurate PPG calculation. The inter‐ and intraoperator reproducibility of PPG derived from manual pullbacks were excellent.
Coronary complete revascularization strategy: A puzzle still hard to complete
Authors: Tarantini Giuseppe , Cardaioli Francesco
Published: March 2022

Key Points

Most SIHD patients present with MVD. The role and impact of CR in this setting is still a matter of debate.

This study shows that SIDH patients, especially those older and affected by multiple comorbidities, may benefit from a CR strategy during index procedure.

While waiting for further evidence, CR may be a reasonable approach for SIHD MVD patients. However, careful patient selection is mandatory to achieve satisfactory results without undue patient risk.
Leak closure following left atrial appendage exclusion procedures: A multicenter registry
Authors: Killu Ammar M. , Gbolabo Adeola Oluwaseun , Della Rocca Domenico G. , Ellis Christopher , Sugrue Alan M. , Simard Trevor , Friedman Paul A. , Kawsara Akram , Horton Rodney P. , Natale Andrea , Alkhouli Mohamad , Holmes David R.
Published: March 2022

Background

Though infrequent, incomplete left atrial appendage closure (LAAC) may result from residual leaks. Percutaneous closure has been described though data is limited.

Methods

We compiled a registry from four centers of patients undergoing percutaneous closure of residual leaks following LAAC via surgical means or with the Watchman device. Leak severity was classified as none (no leak), mild (1–2 mm), moderate (3–4 mm), or severe (≥5 mm). Procedural and clinical success was defined as the elimination of leak or mild residual leak at the conclusion of the procedure or follow‐up, respectively.

Results

Of 72 (age 72.2 ± 9.2 years; 67% male) patients, 53 had undergone prior LAAC using the Watchman device and 19 patients surgical LAAC. Mean CHADS2‐VA2Sc score was 4.0 ± 1.8. The median leak size was 5 mm, range: 2–13). A total of 13 received Amplatzer Vascular Plug‐II, 18 received Amplatzer Duct Occluder‐II and 40 patients received coils. One underwent closure using a 21 mm‐Watchman. Procedural success was 94%. Zero surgical and nine Watchman patients (13%) had a residual leak at procedural‐end (five mild, three moderate, and one severe)—only one patient had no reduction in leak size. Overall leak size reduction was 94%. Two (3%) had intraoperative pericardial effusion. There were no device embolizations, device‐related thrombi, or procedural deaths. Clinical success was maintained at 94%. Two had cerebrovascular accidents—at 2 days (transient ischemic attack) and 10 months postprocedure. Two had major bleeding outside the 30‐day periprocedural window.

Conclusion

Percutaneous closure of residual leaks following left atrial appendage closure is feasible and associated with good outcomes. The procedural risk appears to be satisfactory.
Unilateral digital clubbing in hemiplegia due to a putaminal hemorrhage
Authors: Kinjo Takeshi , Arakaki Wakako , Fujita Jiro
Published: March 2022

Digital clubbing usually occurs bilaterally; however, unilateral clubbing can be seen in hemiplegia and local vascular lesions. We highlight a case of unilateral digital clubbing due to putaminal hemorrhage. Further accumulation of cases will enable exploration of the mechanisms of clubbing.
Digital video electrochemistry (DVEC) applied to the study of Prussian Blue films
Authors: García‐Jareño José J. , Agrisuelas Jerónimo , Roig Antoni F. , Vicente Francisco
Published: March 2022

Prussian Blue films were electrogenerated on a Pt disc electrode and color changes were studied by digital video electrochemistry together with cyclic voltammetry. Three systems of peaks were detected. Peaks corresponding to the reduction to the Everitt's Salt form and to the oxidation to Prussian Yellow are well related to color changes expressed as color intensities derivatives. Color changes showed that these peaks involved complexes mechanisms and intermediate species were detected. These also showed the existence of different sites of iron atoms in the crystal structure with different reactivity. A non‐zero baseline and a third electrochemical process at the more negative potentials proved not related to color changes.
Electron‐Rich Diruthenium Complexes with π‐Extended Alkenyl Ligands and Their F4TCNQ Charge‐Transfer Salts**
Authors: Das Rajorshi , Linseis Michael , Schupp Stefan M. , Schmidt‐Mende Lukas , Winter Rainer F.
Published: March 2022

The synthesis of dinuclear ruthenium alkenyl complexes with {Ru(CO)(PiPr3)2(L)} entities (L=Cl−in complexesRu2‐3andRu2‐7; L=acetylacetonate (acac−) in complexesRu2‐4andRu2‐8) and with π‐conjugated 2,7‐divinylphenanthrenediyl (Ru2‐3,Ru2‐4) or 5,8‐divinylquinoxalinediyl (Ru2‐7,Ru2‐8) as bridging ligands are reported. The bridging ligands are laterally π‐extended by anellating a pyrene (Ru2‐7,Ru2‐8) or a 6,7‐benzoquinoxaline (Ru2‐3,Ru2‐4) π‐perimeter. This was done with the hope that the open π‐faces of the electron‐rich complexes will foster association with planar electron acceptors via π‐stacking. The dinuclear complexes were subjected to cyclic and square‐wave voltammetry and were characterized in all accessible redox states by IR, UV/Vis/NIR and, where applicable, by EPR spectroscopy. These studies signified the one‐electron oxidized forms of divinylphenylene‐bridged complexesRu2‐7,Ru2‐8as intrinsically delocalized mixed‐valent species, and those of complexesRu2‐3andRu2‐4with the longer divinylphenanthrenediyl linker as partially localized on the IR, yet delocalized on the EPR timescale. The more electron‐rich acac−congeners formed non‐conductive 1 : 1 charge‐transfer (CT) salts on treatment with the F4TCNQ electron acceptor. All spectroscopic techniques confirmed the presence of pairs of complex radical cations and F4TCNQ.−radical anions in these CT salts, but produced no firm evidence for the relevance of π‐stacking to their formation and properties.
Elaborated Reaction Pathway of Photothermal Catalytic CO2 Conversion with H2O on Gallium Oxide‐Decorated and ‐Defective Surfaces
Authors: Zhang Li , Li Zheng , Zhang Xu‐Han , Xu Chen‐Yu , Zhang Yan‐Wei
Published: March 2022

Ga2O3‐decorated and ‐defective surface models based on anatase TiO2 have been established. The thermodynamic reaction pathways, including protonation, deoxygenation and hydroxylation steps, during CO2 conversion with H2O to C1 products were calculated. The calculation results demonstrate that a Ga2O3 cocatalyst enhances the selective adsorption of CO2 and slightly weakens the competitive adsorption of H2O. The promotion effect of Ga2O3 on the subsequent reaction depends on the availability of protons and electrons. Free‐energy calculations revealed that the basic functional site generated by Ga2O3 not only suppresses the back reaction of the OH group after H2O directly provides protons but also maintains the surface defect oxygen vacancy (VO), which promotes the reaction thermodynamics but tends to be consumed in the process. Additionally, Ga2O3 decoration promotes VO formation, and the coexistence of Ga2O3 and VO further decreases the reaction rate‐determining step energy barrier, promoting C1 production.
Estimation of the plasma volume status of elderly patients with acute decompensated heart failure using bedside clinical, biological, and ultrasound parameters
Authors: Leahova‐Cerchez Xenia , Berthelot Emmanuelle , Genet Bastien , Hanon Olivier , Jourdain Patrick
Published: March 2022

Objective

Assessment of intravascular volume status to ensure optimization before hospital discharge could significantly reduce readmissions. It is difficult to evaluate congestion on clinical signs during an episode of acute heart failure (ADHF) in elderly patients.

Hypothesis

There is an association between various volume overload parameters in patients older than 75 years.

Methods

We performed a single‐center prospective longitudinal study of patients older than 75 years hospitalized for acute heart failure. We analyzed the association between congestion assessment based on clinical signs, inferior vena cava (IVC) diameter measured by ultrasound, biological evaluation with N terminal pro brain natriuretic peptide (NT‐proBNP), and estimated plasma volume (EPV) during decongestive therapy. We also monitored changes in renal function.

Results

Fifty consecutive ADHF patients (85.2 ± 5.9 years, 68% female) were included in the study. At admission, a dilated, noncompliant IVC was found in all patients. The strongest correlations between different parameters of volume overload estimation were found between IVC and jugular vein distention (r = .8; p < .001), then IVC and oedema (r = .6; p < .001), IVC and crackles (r = .3; p < .036), then IVC and NT‐proBNP (r = .3; p = .02). There was no correlation between EPV and signs of congestion. Patients who had no congestive signs on clinical or IVC examination at Day 2, more often presented with acute renal failure.

Conclusion

In ADHF patients older than 75 years, clinical and IVC evaluation of intravascular congestion correlate well. The concomitant assessment of clinical signs and IVC may prevent depletion‐related renal failure.
Neurodegenerative Diseases: The Value of Early Predictive End Points
Authors: Janicki Hsieh Sarah , Alexopoulou Zoi , Mehrotra Nitin , Struyk Arie , Stoch S. Aubrey
Published: March 2022

Use of early predictive biomarkers of neurodegenerative disease in phase I clinical trials may improve the translation of novel drug therapies from preclinical development through late‐stage studies. This article provides a categorical summary of promising biomarker approaches or clinical end points in molecular, cellular, metabolic, electrophysiological, or clinical function that can be used to predict or quantify the progression of neurodegenerative disorders and guide program support.
Definition‐specific prevalence estimates for sarcopenia in an Australian population: the Geelong Osteoporosis Study
Authors: Sui Sophia X. , Holloway‐Kew Kara L. , Hyde Natalie K. , Williams Lana J. , Tembo Monica C. , Leach Sarah , Pasco Julie A.
Published: March 2022

Background

We aimed to compare prevalence estimates for sarcopenia in an Australian sample of older men and women by using different criteria.

Methods

Women (n = 323) and men (n = 342) aged 60–96 years from the Geelong Osteoporosis Study were included. Handgrip strength (HGS) was measured by dynamometer (Jamar or Vernier) and appendicular lean mass (ALM) by whole‐body densitometry (Lunar). Sarcopenia definitions included European Working Group on Sarcopenia in Older People (EWGSOP) 1, EWGSOP2, and US Foundation for the National Institutes of Health (FNIH). Sarcopenia was identified as low HGS and low ALM/height2 or low muscle performance, and low HGS and low ALM/body mass index (BMI). Prevalence estimates were standardized to the Australian population and agreement between definitions assessed using the Cohen kappa statistic (κ).

Results

Low HGS was identified in 13.7–29.9% of women and 2.1–14.1% of men. Low ALM/height2 was identified in 7.1–11.8% of women and 6.0–8.4% of men, while 21.7% of women and 21.1% of men had low ALM/BMI. Mean age‐standardized prevalence estimates for sarcopenia were 5.9% (95% confidence interval 3.4–8.4) for women and 2.9% (1.9–4.0) for men (EWGSOP1), 2.3% (1.1–3.4) for women and 0.5% (0.2–0.9) for men (EWGSOP2), and 4.0% (2.1–5.8) for women and 1.1% (0.6–1.5) for men (FNIH). There was moderate agreement between EWGSOP1 and EWGSOP2 (κ = 0.58 women, 0.30 men) and poor agreement between FNIH and EWGSOP1 (κ = 0.16 women, 0.12 men) and EWGSOP2 (κ = 0.19 women, 0 men).

Conclusions

Sarcopenia prevalence differed according to definition applied. Point estimates for sarcopenia prevalence according to EWGSOP2 identified fewer individuals than EWGSOP1, with FNIH estimates between the two; however, there were overlapping 95% confidence intervals across definitions.