bluuebunny/crossref_metadata_2025 huggingface dataset:
Task shifting from general practitioners to practice assistants and nurses in primary care: a cross-sectional survey in 34 countries – RETRACTED
Authors: Groenewegen Peter P. , Boerma Wienke G. W. , Spreeuwenberg Peter , Seifert Bohumil , Schäfer Willemijn , Batenburg Ronald , van Tuyl Lilian
Published: November 2021

Aim:

To describe variation in task shifting from general practitioners (GPs) to practice assistants/nurses in 34 countries, and to explain differences by analysing associations with characteristics of the GPs, their practices and features of the health care systems.

Background:

Redistribution of tasks and responsibilities in primary care are driven by changes in demand for care, such as the growing number of patients with chronic conditions, and workforce developments, including staff shortage. The need to manage an expanding range of services has led to adaptations in the skill mix of primary care teams. However, these developments are hampered by barriers between professional domains, which can be rigid as a result of strict regulation, traditional attitudes and lack of trust.

Methods:

Data were collected between 2011 and 2013 through a cross-sectional survey among approximately 7200 GPs in 34 countries. The dependent variable ‘task shifting’ is measured through a composite score of GPs’ self-reported shifting of tasks. Independent variables at GP and practice level are: innovativeness; part-time working; availability of staff; location and population of the practice. Country-level independent variables are: institutional development of primary care; demand for and supply of care; nurse prescribing as an indicator for professional boundaries; professionalisation of practice assistants/nurses (indicated by professional training, professional associations and journals). Multilevel analysis is used to account for the clustering of GPs in countries.

Findings:

Countries vary in the degree of task shifting by GPs. Regarding GP and practice characteristics, use of electronic health record applications (as an indicator for innovativeness) and age of the GPs are significantly related to task shifting. These variables explain only little variance at the level of GPs. Two country variables are positively related to task shifting: nurse prescribing and professionalisation of primary care nursing. Professionalisation has the strongest relationship, explaining 21% of the country variation.
R-Cube-SR Test
Authors: Fehringer Benedict C. O. F.
Published: November 2021

Abstract. Visualization and spatial relations (mental rotation) are two important factors of spatial thinking. Visualization refers to complex visual-spatial transformations, whereas spatial relations refer to simple mental rotation of visualized objects. Conventional spatial relations tests, however, have been found to be highly correlated with visualization tests because solving items through mental rotation might involve visualization ability due to the complexity of the visual materials of these tests. In two studies ( N = 51, N = 109), a new computer-based test for spatial relations, the R-Cube-SR Test, was developed and validated. The R-Cube-SR Test utilizes simple, single-colored cubes as rotated visual materials. Reliability estimates of the reaction times reach ω = .87. Correlations with standard tests of spatial relations (up to r = .55) were significantly higher than with visualization tests, such as the new R-Cube-Vis Test ( Fehringer, 2020 ), which uses the same visual materials. This was supported by CFAs. It is concluded that the new R-Cube-SR Test is a valid measure of spatial relations. Both tests together, the R-Cube-Vis and R-Cube-SR, as specific tests for their respective factor, now, are able to provide a differential diagnosis of a participant’s spatial thinking ability using the same visual materials.
An Improved Tandem Neural Network Architecture for Inverse Modeling of Multicomponent Reactive Transport in Porous Media
Authors: Chen Junjun , Dai Zhenxue , Yang Zhijie , Pan Yu , Zhang Xiaoying , Wu Jichun , Reza Soltanian Mohamad
Published: November 2021

Parameter estimation for reactive transport models (RTMs) is important in improving their predictive capacity for accurately simulating subsurface hydrogeochemical processes. This paper introduces a deep learning approach called the tandem neural network architecture (TNNA), which consists of a forward network and a reverse network to estimate input parameters for RTMs. The TNNA approach has a limitation in that the approximation error from the forward network often results in biased inversion results. To solve this problem, we proposed to enhance TNNA using an adaptive updating strategy (AUS), which locally reduces the approximation error of the forward network. The developed framework updates the forward network by iteratively using local sampling and transfer learning. The TNNA‐AUS was verified by a cation exchange example. The results show that TNNA‐AUS successfully reduces the inversion bias and improves the computational efficiency and inversion accuracy, compared with the global improvement strategy of adding training samples according to the prior distribution of model parameters. After verification, the TNNA‐AUS was applied to a real‐world and well‐documented RTM problem of the Aquia aquifer, Maryland, USA. The inversion results demonstrate that the developed TNNA‐AUS algorithm is an excellent tool for us to understand the complex subsurface hydrogeochemical processes and estimate the associated reaction parameters.
Unexpected diversity among small-scale sample replicates of defined plant root compartments
Authors: Attia Sally , Russel Jakob , Mortensen Martin S , Madsen Jonas S , Sørensen Søren J
Published: November 2021

Community assembly processes determine patterns of species distribution and abundance which are central to the ecology of microbiomes. When studying plant root microbiome assembly, it is typical to sample at the whole plant root system scale. However, sampling at these relatively large spatial scales may hinder the observability of intermediate processes. To study the relative importance of these processes, we employed millimetre-scale sampling of the cell elongation zone of individual roots. Both the rhizosphere and rhizoplane microbiomes were examined in fibrous and taproot model systems, represented by wheat and faba bean, respectively. Like others, we found that the plant root microbiome assembly is mainly driven by plant selection. However, based on variability between replicate millimetre-scale samples and comparisons with randomized null models, we infer that either priority effects during early root colonization or variable selection among replicate plant roots also determines root microbiome assembly.
A facile method to enhance the output performance of triboelectric nanogenerators based on coordination polymers by modulating terminal coordination groups
Authors: Wang Wenjie , Zhang Ying-Ying , Zhang Sheng , Huang Chao , Mi Liwei
Published: November 2021

Three isostructural Cu(i)-CPs with different terminal halogen atoms were introduced into the fabrication of TENGs, and were further applied for self-powered electrochemical cathodic protection.
Evaluation and development of a novel pre-treatment method for mulberry leaves to enhance their bioactivity via enzymatic degradation of GAL-DNJ to DNJ
Authors: Takasu Soo , Parida Isabella Supardi , Kojima Yoshihiro , Kimura Toshiyuki , Nakagawa Kiyotaka
Published: November 2021

We demonstrated the conversion of GAL-DNJ into DNJ improves mulberry leaves bioavailability and constructed a novel enzymatic-based method to induce the hydrolysis of GAL-DNJ to DNJ.
Surface engineered CoP/Co3O4 heterojunction for high-performance bi-functional water splitting electro-catalysis
Authors: Li Xintong , Liu Yizhe , Sun Qidi , Huang Wei-Hsiang , Wang Zilong , Chueh Chu-Chen , Chen Chi-Liang , Zhu Zonglong
Published: November 2021

The s-CoP/Co3O4 is employed as bi-functional catalysts towards HER and OER. A current density of 10 mA cm−2 can be achieved at an overpotential of 211 mV vs. RHE in OER and the overpotential is only 106 mV vs. RHE at a current density of −10 mA cm−2 in HER.
Asymmetric synthesis of dibenzo[b,d]azepines by Cu-catalyzed reductive or borylative cyclization
Authors: Rodríguez-Salamanca Patricia , Martín-de la Calle Rocío , Rodríguez Verónica , Merino Pedro , Fernández Rosario , Lassaletta José M. , Hornillos Valentín
Published: November 2021

Dibenzo[b,d]azepines featuring axially chiral 7-member-bridged biaryls have been prepared by asymmetric reductive or borylative cyclizations using copper catalysis.
Analysis of heating time and of temperature distributions for cylindrical geometry with the use of solution to the inverse problem
Authors: Joachimiak Magda , Joachimiak Damian
Published: November 2021

Changes in heating time of a cylinder in the furnace for thermal and thermochemical treatments depending on the given heating rate is analysed in this paper. Temperature distributions from the axis to the boundary of the cylinder were determined based on solving non-stationary and non-linear inverse problem for the heat equation. Differences between the temperature on the boundary and along the cylinder axis for processes with the given heating rates from 5 to 10ᵒC/min were calculated. Twofold increase in the heating rate allowed the heating time to be reduced significantly. Increase in the heating rate had no impact on the difference between the temperature on the boundary and on the axis of the cylinder and on the quantity of energy being consumed by heating elements.
Can Liver Ultrasound Elastography Predict the Risk of Hepatocellular Carcinoma Recurrence After Radiofrequency Ablation? A Systematic Review and Meta-Analysis
Authors: Vestito Amanda , Dajti Elton , Cortellini Fabio , Montagnani Marco , Bazzoli Franco , Zagari Rocco Maurizio
Published: November 2021

Purpose The role of liver stiffness (LS) on ultrasound elastography in the prediction of hepatocellular carcinoma (HCC) recurrence after treatment with radiofrequency ablation (RFA) is still unclear. Our aim was to perform a systematic review and meta-analysis to assess whether LS can predict the recurrence of HCC after RFA.

Materials and Methods Medline via PubMed, Embase, Scopus, and Cochrane Library databases, and abstracts of international conference proceedings were searched up to June 30, 2020. Cohort studies were included if they assessed the association between LS values measured by ultrasound elastography before RFA and HCC recurrence.

Results 9 studies including 1373 patients with HCC treated by RFA, 643 of whom developed HCC recurrence, were identified. The mean value of LS before RFA was significantly higher in patients who developed HCC recurrence than in those who did not (weighted mean difference=11.98 kPa, 95%CI: 7.60–16.35, I2=63.8%). There was a significant positive association between LS value and HCC recurrence both at univariate (unadjusted HR=1.03, 95%CI: 1.00–1.07, I2=72.7%) and multivariate analysis (adjusted HR=1.03, 95%CI: 1.02–1.04, I2=0). Patients with LS value ≥13–14 kPa or >1.5 m/s have a higher risk of both HCC recurrence (unadjusted HR=2.18, 95%CI: 1.46–3.25, I2=49.7%; adjusted HR=2.41, 95%CI: 1.53–3.79, I2=0) and overall mortality (adjusted HR=4.38; 95%CI: 2.33–8.25, I2=0) in comparison with those with LS below these cutoffs.

Conclusion Liver ultrasound elastography appears to be a reliable tool to predict HCC recurrence and overall survival after RFA. This technique may be useful for the management of patients with HCC treated by RFA.
Planning and Setting Up of a Communication Program for Hospitalized COVID-19 Patients: Challenges and Potential Solutions in Resource Constrained Setting
Authors: Nanda Samridhi , Datta Sudip Kumar , Sagar Prem , Sharma Mona , Gupta Ranjan , Sodani Ankit , Trikha Anjan
Published: November 2021

Background The recent onset of COVID-19 pandemic has necessitated many patients to be hospitalized in the COVID-19 treating centers. Owing to the need for isolation of these patients and minimizing the risk of transmission to healthy people, COVID-19-positive patients are completely restricted from meeting their friends and families. This gives rise to anxiety amongst the patients' relatives as they are not able to monitor the progress of the patients and have to depend entirely on the healthcare staff for any updates regarding the patient. In contrast, the treating doctors are undergoing severe stress due to the unknown nature of the virus and the risks involved in treating patients. They are thoroughly exhausted after the long hours donning the personal protection equipment (PPE).

Objective To structure and form an interface for communication between the treating physician and the families, as a “communication team,” to decrease the workload on the treating physicians and minimize their contact time in a COVID-19 setting.

Results The addition of a communication team improved the physicians' efficiency of patient management and family satisfaction. Several challenges were faced during the setting up of this interface effectively. However, most of these were dealt with along the way. The communication team was instrumental in allaying the anxiety of the family with respect to their patients' clinical condition. This also ensured engagement of doctors from non-clinical and laboratory-based departments in the COVID-19 treatment process.

Conclusion Adding up a communication team for communicating clinical updates to the family in a resource-limited scenario greatly improved communication and thus family satisfaction of the COVID-19-positive patients.
Postpartum Depression Risk following Prenatal Diagnosis of Major Fetal Structural Anomalies
Authors: Herrera Christina L. , Byrne John J. , Nelson David B. , Schell Rachel C. , Dashe Jodi S.
Published: November 2021

Objectives Our primary objective was to evaluate how prenatal diagnosis of a major fetal structural anomaly and resulting pregnancy outcome affected postpartum depression risk, as assessed by the Edinburgh Postnatal Depression Scale (EPDS). Secondary objectives were to review the rate of mental health follow-up and subsequent diagnosis of postpartum depression in screen-positive women.

Study Design Singleton pregnancies with prenatal diagnosis of one or more major fetal structural anomalies were ascertained from prospectively maintained databases that included perinatal outcomes and subsequent EPDS responses from January 2010 to May 2018. EPDS scores of 13 or higher were considered positive and prompted referral for mental health follow-up, which was verified by medical record review. Statistical analyses were performed using Student's t-test, χ2, and odds ratios (ORs) with p < 0.05 considered significant.

Results A total of 1,306 women had a prenatal diagnosis of one or more major fetal structural anomalies, 896 (68%) also had a postpartum EPDS screening, and 82 (9.2%) screened positive. Positive EPDS screening was more common with anomalies of multiple organ systems (16.5 vs 7.8%, p = 0.002) and aneuploidy (17.1 vs 9.3%, p = 0.02). Pregnancies complicated by fetal death, neonatal death, and termination for anomaly were significantly more likely to screen positive than those with neonatal survival to discharge (OR, 3.1 [95% confidence interval [CI], 1.6–6.2], 3.0 [95% CI, 1.5–5.8], and 4.4 [95% CI, 2.1–8.9], respectively, p ≤ 0.002). Of the 35 (43%) screen-positive women who attended follow-up appointments with mental health providers, 18 (51%) were diagnosed with a depressive disorder, accounting overall for 22% of those with a positive EPDS screen.

Conclusion Among women with a prenatal diagnosis of a major fetal structural anomaly, those experiencing a perinatal loss or pregnancy termination have an increased risk of positive EPDS screen result compared with who have a neonate surviving to discharge. A depressive disorder was diagnosed postpartum in 22% of these women with a positive EPDS screen. Our findings highlight the mental health needs in this vulnerable population.

Key Points
Factors associated with returning to work after long term absence due to mental disorders
Authors: Rissanen Päivi , Autio Reija , Näppilä Turkka , Fröjd Sari , Pirkola Sami
Published: November 2021

If there is a chance for a person’s ability to work to be restored through treatment or rehabilitation, a temporary disability pension may be granted in Finland. We examined the personal, socio-economic and healthcare-related factors associated with return to work (RTW) after the receipt of temporary disability pension. The study material contains comprehensive register data of individuals who were granted a temporary disability pension due to a mental disorder (ICD10: F10–F69, F80–F99) for the first time between 2010 and 2012 (N = 8615). We applied clustering analysis in order to reveal different patterns of returning to work after receipt of temporary disability pension and utilized multinominal regression analysis to examine gender-specific determinants for RTW and partial RTW in a controlled setting. Being a lower-grade employee remarkably promoted RTW for women (OR 7.85 95% CI 5.35–11.51), as did being a manual worker for men (OR 5.47 95% CI 3.48–8.78). Moreover, both active male (OR 3.51 95% CI 2.19–5.61) and female manual workers (OR 2.44 95% CI 1.66–3.59) had a higher probability of partial RTW compared to people who were initially unemployed. In addition, psychotherapy and vocational rehabilitation were associated with an increased probability of RTW. After 3 years from the initial temporary pensioning, almost two-thirds of the study population (69% of men and 64% of women) still had a temporary or by then a permanent disability pension due to a mental disorder. This and further research could improve the ability to recognize those subjects more likely to return to work than others.
Hydrophobic halochromic aerogel capable of reversibly measuring acidic and basic vapors
Authors: Lee Jeong Hui , Park Jeeyin , Yang Jonguk , Yang Keun-Hyeok , Ju Sanghyun , Lim Taekyung , Jeong Sang-Mi
Published: November 2021

A halochromic sensor that can visually and quickly monitor the information regarding the exposure of harmful chemicals to the human body is highly valuable in the safety and industrial fields. A general halochromic sensor uses a hydrophilic matrix to increase its detection sensitivity by promoting the diffusion of foreign materials. However, it is difficult to maintain the reversibility, durability, and stability of the color change in the halochromic sensor due to the loss of halochromic dyes under continuous exposure to chemicals. This study investigates a hydrophobic halochromic aerogel sensor that is stable even when exposed to various external environments and reacts to both acids and bases. By embedding halochromic dyes in silica aerogels with a porous structure and hydrophobicity, the leaching of halochromic dyes can be prevented even when the aerogels are placed in aqueous solutions. Hydrophobic halochromic aerogels can detect vapors generated in acidic and basic solutions, and the color change in hydrophobic halochromic aerogels reacts stably even with repeated acid and base environmental changes, enabling accurate acid or base concentration detection. In addition, halochromic aerogels can be easily applied to various platforms because they can be combined with fabric, concrete blocks, pipes, and polymers such as polydimethylsiloxane to create composites. The halochromic aerogels derived in this study are expected to contribute to the development of color change sensors applicable to various work environments by greatly improving the color change reversibility, durability, and stability that are the most important characteristics of robust halochromic sensors.
A multiscale model for predicting the coefficient of thermal expansion of concrete
Authors: Cao Xiuli
Published: November 2021

The coefficient of thermal expansion (CTE) of concrete is one of the important properties that are responsible for the thermal cracking of concrete structures. To reveal the essence of thermal expansion and predict the CTE accurately, this paper establishes a multiscale model for predicting the drained and undrained CTEs of concrete according to the microstructure based on the theory of continuum micromechanics. The microstructure of concrete is quantitatively analyzed according to the raw materials and degree of hydration. The CTEs are homogenized level by level from calcium silicate hydrate to cement paste, cement mortar, and concrete. Given the initial information of concrete, the CTEs can be predicted by the model. The experimental data of concrete from the literature validated the applicability of the proposed model. The influence mechanism of factors on CTEs can be explained by the influence on the microstructure of concrete. The model has good potential in optimizing the material design of concrete to obtain a lower CTE to minimize the risk of thermal cracking.
Inertial swimming in a channel filled with a power-law fluid
Authors: Ouyang Zhenyu , Phan-Thien Nhan
Published: November 2021

We employ an immersed boundary-lattice Boltzmann (IB-LB) scheme to simulate a cylindrical (a classical self-propelled model) and a rod-shaped squirmer swimming in a channel filled with power-law fluids. The power-law index n, the channel blocking ratio κ (squirmer diameter/channel width), and the swimming Reynolds number Re are, respectively, set at 0.8 ≤ n ≤ 1.2, 0.2 ≤ κ ≤ 0.5 and 0.05 ≤ Re ≤ 5 to investigate the microswimmer' swimming speed, its power expenditure (P), and its hydrodynamic efficiency (η). The results show that increasing n yields a faster squirmer at a low Re (Re ≤ 0.5). On further increasing Re (Re ≥ 1), a larger n results in a slower pusher (a squirmer propelled from the rear), or a faster puller (a squirmer propelled from the front). Increasing the channel's width (decreasing κ) can lead to a slower puller or a puller rod squirmer. A definition of puller/pusher will be provided later. It is also found that, with shear-thinning, it is easier to unstabilize a puller than with shear-thickening, when increasing Re. Swimming in a shear-thinning fluid expends more power P than in a shear-thickening fluid, and P is scaled with Re according to P ∼ Ren-1 (0.05 ≤ Re ≤ 1). In addition, a stronger channel constraint (κ = 0.5) yields a higher η for the puller and the weak inertial pusher, whereas a weaker channel constraint (κ = 0.2) results in a higher η for the pusher with the increased fluid inertia.
A History of the Study of the Indigenous Languages of North America
Authors: Kilarski Marcin
Published: November 2021

The languages indigenous to North America are characterized by a remarkable genetic and typological diversity. Based on the premise that linguistic examples play a key role in the origin and transmission of ideas within linguistics and across disciplines, this book examines the history of approaches to these languages through the lens of some of their most prominent properties. These properties include consonant inventories and the near absence of labials in Iroquoian languages, gender in Algonquian languages, verbs for washing in the Iroquoian language Cherokee and terms for snow and related phenomena in Eskimo-Aleut languages. By tracing the interpretations of the four examples by European and American scholars, the author illustrates their role in both lay and professional contexts as a window onto unfamiliar languages and cultures, thus allowing a more holistic view of the history of language study in North America.
Ad hoc categorization in linguistic interaction
Authors: Mauri Caterina
Published: November 2021

The aim of this paper is to describe and explain the
role that linguistic interaction plays in category construction and
communication, by looking at naturally occurring data of spoken
language. First, it will be argued that there is a way of building
categories that is inherently interactional and indexical, namely ad
hoc categorization. Ad hoc categorization will be defined as a
bottom-up exemplar driven process, that is dependent on context for
both its construction and its interpretation, and crucially relies on
non-exhaustivity and exemplification. After a brief overview of the
linguistic strategies that may encode ad hoc categorization, we will
concentrate on linguistic interaction, taking the perspective of
so-called languaging. It will be shown that categorization is
frequently instrumental to intersubjective aims, such as mutual
agreement, negotiation, and the general management of the speakers’
reciprocal positioning. In turn, it is collaboration between the interlocutors
that allows to fine-tune categorization and achieve mutual
understanding. Finally, we will focus on the incrementality of ad hoc
categorization in interaction along two dimensions, namely, the
identification of the category borders and the progressive anchoring
of the category to the interlocutors’ experience.
Exemplification in interaction
Authors: Barotto Alessandra , Lo Baido Maria Cristina
Published: November 2021

The aim of this paper is to examine how
exemplification is used in real-time interactions to make reference to
conceptual categories. Based on real occurrences of spoken Italian, it
is shown that in conversations exemplification is used cooperatively
by different participants to perform several functions. Not only can
exemplification be used to present or expand the reference to a
category by both speaker and addressee, but it can also contribute to
the creation of a mutually accepted common ground (examples can be
employed to communicate that alignment has been reached or to
communicate how such alignment could be reached). Finally, we argue
that examples are part of a bigger picture of cooperative reference
construction, where speakers collaborate reformulating the reference
using different types of strategies.
Encoding ad hoc categories in Georgian
Authors: Kikvidze Zaal
Published: November 2021

The chapter is a discussion of Georgian echo-word
constructions (non-prototypical reduplication) as a linguistic
encoding of ad hoc categories. Based on the empirical data (published
texts, corpora, elicited examples), I present a classification of
Georgian echo-word constructions into three types with their
respective formal and semantic features. With respect to possible
parameters of base/reduplicant combinations, such as (a) free/bound
form, (b) kind and direction of copying, (c) meaning of resulting
formation, the following three types were identified: Type 1:
Turkish-like m-reduplication; Type 2: Initial
C/cluster deletion; Type 3: Fossilized echo-pairs. Notwithstanding a
type, they all, to a certain extent, participate in the encoding of ad
hoc categories in Georgian.
Why it’s hard to construct ad hoc number concepts
Authors: Ariel Mira
Published: November 2021

Lexical meanings are routinely adjusted in order to
evoke ad hoc concepts. But number words pose a unique challenge. Carston (2002) discusses two
relevant interpretative processes in this connection. Broadening (as
in metaphorical uses) introduces an ad hoc concept by incorporating
interpretations that fall outside the lexeme’s linguistic meaning, and
narrowing (e.g., interpreting finger as ‘index
finger’) restricts the lexical meaning to a subset of its senses. I
here argue that number words impose restrictions on the construction
of such ad hoc concepts: (i) (nonround) number words cannot undergo
narrowing, and (ii) when broadened (interpreted as ‘approximately N’),
number words typically require explicit marking (e.g., about
N). Both restrictions stem from a single fact: Number
words lack a prototype category structure (Lakoff 1972; Rosch & Mervis 1975). I support these
claims with corpus analyses (The Santa Barbara Corpus of Spoken
American English, The Longman Corpus of Spoken American English and
the British National Corpus).
Asymptotic structure with vanishing cosmological constant
Authors: Fernández-Álvarez Francisco , Senovilla José M M
Published: November 2021

This is the first of two papers (Fernández-Álvarez F and Senovilla J M M 2021 Class. Quant. Grav
39 165012) devoted to the asymptotic structure of space-time in the presence of a non-negative cosmological constant Λ. This first paper is concerned with the case of Λ = 0. Our approach is fully based on the tidal nature of the gravitational field and therefore on the ‘tidal energies’ built with the Weyl curvature. In particular, we use the (radiant) asymptotic supermomenta computed from the rescaled Weyl tensor at infinity to provide a novel characterisation of radiation escaping from, or entering into, the space-time. Our new criterion is easy to implement and shown to be fully equivalent to the classical one based on the news tensor. One of its virtues is that its formulation can be easily adapted to the case with Λ > 0 covered in the second paper. We derive the general energy–momentum-loss formulae including the matter terms and all factors associated to the choices of arbitrary foliation and of super-translation. We also revisit and present a full reformulation of the traditional peeling behaviour with a neat geometrical construction that leads, in particular, to an asymptotic alignment of the supermomenta in accordance with the radiation criterion.
Dynamic behaviours of double-ended tuning fork based comb-driven microelectromechanical resonators for modulating magnetic flux synchronously
Authors: Liu Zhenxi , Chen Jiamin , Yang Wuhao , Zheng Tianyi , Jiao Qifeng , Zou Xudong
Published: November 2021

Microelectromechanical system (MEMS) resonators have been widely used in the magneto-resistive (MR) sensor for modulating the magnetic flux to enhance the detection limit. However, the manufacturing tolerances in MEMS fabrication processes make it challenging to fabricate the identical resonators with the same vibration frequency, which greatly decreases the detection limit of the MR sensor. To synchronize the MEMS resonators and improve the performance of the MR sensor, the double-ended tuning fork (DETF) based comb-driven MEMS resonators is proposed in this paper, making the system operate at the out-of-phase mode to complete the synchronization. The dynamic behaviour of the resonators is investigated through theoretical analysis, numerical solution based on MATLAB code and Simulink, and experimental verification. The results show that the transverse capacitances in the comb will significantly affect the resonance frequency due to the second-order electrostatic spring constant. It is the first time to observe the phenomenon that the resonant frequency increases with the increase of the bias, and it can also decrease with increasing the bias through adjusting the initial space between the fixed finger and the moving mass, they are different from the model about spring softening and spring hardening. Besides, the proposed DETF based comb-driven resonators can suppress the in-phase and out-of-phase mode through adjusting the driving and sensing ports, and sensing method, meanwhile make the magnetic flux modulation fully synchronized, and maximize the modulation efficiency, and minimize the detection limit. These characteristics are appropriate for the MR sensor, even other devices that need to adjust the resonance frequency and vibration amplitude. Furthermore, the model and the design can also be extended to characteristic the single end tuning fork based MEMS resonator and other MEMS-based MR sensors.
Femtosecond x-ray absorption spectroscopy of pyrazine at the nitrogen K-edge: on the validity of the Lorentzian limit
Authors: Freibert Antonia , Mendive-Tapia David , Huse Nils , Vendrell Oriol
Published: November 2021

We calculate the femtosecond x-ray absorption spectrum of pyrazine at the nitrogen K-edge including the wavepacket dynamics in both the valence and core-excited state manifolds. We do not invoke the widely used short-time (or Lorentzian) approximation which neglects the nuclear dynamics after the x-ray probe excitation. Instead, we calculate the x-ray-induced polarization in the time-domain where the optical pump as well as x-ray probe pulses are explicitly described. While the non-adiabatic population transfer following the optical excitation is well reproduced in the Lorentzian limit the transient x-ray absorption spectra obtained under this approximation lack some vibronic features, even when considering the short core-hole lifetime of nitrogen. We further demonstrate the effect of an increasingly longer pulse on the observed photo-triggered wavepacket dynamics which are blurred to the point that the x-ray probe response becomes effectively time-independent.
Efficient arbitrary polarized light focusing by silicon cross-shaped metaatoms
Authors: Bazouband Fatemeh , Bazouband Elaheh , Golestanizade Tahereh , Jabbar Sadooni Amirhossein , Mousavifard Maryam , Karimullah Affar S , Kumar Reddy Andra Naresh , Hashemi Mahdieh
Published: November 2021

The functionality of most of the metasurfaces that have been investigated so far, especially in illuminations with arbitrarily linearly polarized incident light, are restricted to x- or y-polarized incoming light. In particular, filtering out one of the two orthogonal polarizations of the incoming electromagnetic wave loses the incident light energy and limits the potential performance of the metasurface. In this study, by utilizing the cross-shaped silicon metaatoms that support the simultaneous excitation of electric and magnetic dipoles under the illumination of both x- and y- orthogonal polarizations, we overcome the polarization-restricted functionality of the metalenses. By selecting the metaatoms arrangement in the metalens structure, which follows the hyperbolic phase profiles for both x- and y-polarized incoming light waves at the same time, we obtain the light intensity distribution with the extended depth of focus (EDOF) or enhanced intensities at the focal spot with the focusing efficiency 65% for the numerical aperture of 0.7. Utilizing metaatoms with the ability to control the two orthogonal incoming polarizations develops a new methodology for using the full potential and intensity of the arbitrary polarized incoming light. The present design concept of metaatoms has several advantages that are not limited to metalenses alone but can be applied in all metasurfaces realized to have good efficiency. Finally, the proposed metalenses are suitable for imaging, optical tweezers and lithography applications, where subwavelength light intensity distributions with EDOF are the most desirable property.
Role of inelastic couplings in 4He + 208Pb elastic scattering in a wide energy range
Authors: Chamon L C , Gasques L R , Zamora J C
Published: November 2021

The phenomenological strengths of the real part of the optical potential, obtained from elastic scattering data analyses within the optical model (OM) approach, present significant energy-dependence. This behavior has been associated with the intrinsic energy-dependence of the effective nucleon–nucleon interaction. However, in earlier works, we proposed that at least part of this dependence can arise from the effect of couplings to inelastic states of the nuclei. In order to deepen this study, in this paper we present extensive data analyses for the elastic scattering and inelastic excitation of 111 states of 208Pb, for the 4He + 208Pb system in a wide energy range. For the purpose of comparison, the theoretical cross sections are obtained using different approaches for the imaginary part of the potential, and within both contexts: OM (distorted wave Born approximation) and coupled-channel calculations.
Epitaxial growth of bilayer Bi(110) on two-dimensional ferromagnetic Fe3GeTe2
Authors: Xi Yilian , Zhao Mengting , Feng Haifeng , Sun Ying , Man Xingkun , Xu Xun , Hao Weichang , Dou Shixue , Du Yi
Published: November 2021

Heterostructures of two-dimensional (2D) layered materials with selective compositions play an important role in creating novel functionalities. Effective interface coupling between 2D ferromagnet and electronic materials would enable the generation of exotic physical phenomena caused by intrinsic symmetry breaking and proximity effect at interfaces. Here, epitaxial growth of bilayer Bi(110) on 2D ferromagnetic Fe3GeTe2 (FGT) with large magnetic anisotropy has been reported. Bilayer Bi(110) islands are found to extend along fixed lattice directions of FGT. The six preferred orientations could be divided into two groups of three-fold symmetry axes with the difference approximately to 26°. Moreover, dI/dV measurements confirm the existence of interface coupling between bilayer Bi(110) and FGT. A variation of the energy gap at the edges of bilayer Bi(110) is also observed which is modulated by the interface coupling strengths associated with its buckled atomic structure. This system provides a good platform for further study of the exotic electronic properties of epitaxial Bi(110) on 2D ferromagnetic substrate and promotes potential applications in the field of spin devices.
Structural design and performance analysis of a self-driven articulated arm coordinate measuring machine
Authors: Yang Hongtao , Shen Mei , Zhang Mengyao , Cheng Jingjing , Hu Tingting , Hu Yi
Published: November 2021

In order to solve the problem that a traditional articulated arm coordinate measuring machine (AACMM) cannot measure automatically, a self-driven AACMM is proposed. Based on the self-driven AACMM design indicators, the length of the connecting rods of the self-driven AACMM was allocated. The self-driven AACMM virtual prototype was designed and assembled based on joint module selection and joint component design, and its measurement space range was also verified. The key components of the structural optimized design and dynamic performance analysis of motion parameters are adopted, respectively, to correct the positioning error of the self-driven AACMM’s probe caused by static and dynamic deformations. The static deformation of the structure caused by the self-driven AACMM’s weight was analyzed. The influence of the dynamic flexible deformation on the positioning error of the probe of the self-driven AACMM during the variable-speed approach and the constant-speed touch measurement stage was studied. The results show that the measurement space range of the self-driven AACMM designed in this paper can meet the design index of the measuring radius. The probe position error caused by static deformation of the measuring machine after structural optimization is reduced by an order of magnitude, and the equivalent stress of the mechanical structure of the self-driven AACMM is within the allowable stress of the material. The positioning error of the probe caused by the dynamic deformation of the self-driven AACMM structure meets the positioning accuracy index. During the stage of self-driven AACMM constant-speed touch measurement, the instantaneous position error of the probe changes linearly with the touch time and the optimal touch speed (6.6 mm s−1, 6.4 mm s−1) exists to minimize the probe positioning error. During the variable-speed approach stage, the influence of the angular acceleration and the angular velocity of each joint on the positioning error of the probe is negligible when the self-driven AACMM is in the typical posture. In the extreme posture, with the optimal joint angular acceleration (

0.00055
∘

s

−
2

) and angular velocity (

0.0185
∘

s

−
1

), the inertial force of the measuring machine structure and the instantaneous position error of the probe are the smallest, and the movement stability is the best. The structural optimization design and motion parameter performance analyses of the self-driven AACMM can provide a theoretical research foundation for subsequent motion parameter optimization and dynamic error compensation modeling.
Designing of a pH-activatable carbon dots as a luminescent nanoprobe for recognizing folate receptor-positive cancer cells
Authors: Rashidi Elham , Esfandiari Neda , Ranjbar Zahra , Alvandi Nikta , Fatahi Zahra
Published: November 2021

During recent years, cancer has been recognized as a well-known disorder all over the world. One of the important factors to tackle this problem better than past decades is early diagnosis that takes into practice by state-of-the-art visual equipment for detection cancer cells. Herein, in this research, we synthesized carbon dots with pH-dependent behavior from a green source by hydrothermal method with high quantum yield and blue fluorescence. Folic acid-conjugated carbon dots by an efficient and optimal conjugation method were set upped which determined cancer cells visually. These synthesized and conjugated nanoparticles entered into the cancer cells more comprehensive than normal cells by receptor-mediated endocytosis and could distinguish cancer cells from normal ones by fluorescence imaging. Ultimately, synthesized nanoparticles in this research can be considered as an efficient fluorescent nanoprobe for cancer pre-diagnosis.
Biocompatibility of electrospun cell culture scaffolds made from balangu seed mucilage/PVA composites
Authors: Allafchian Alireza , Saeedi Shiva , Jalali Seyed Amir Hossein
Published: November 2021

Synthesis of Balangu (Lallemantia royleana) seed mucilage (BSM) solutions combined with polyvinyl alcohol (PVA) was studied for the purpose of producing 3D electrospun cell culture scaffolds. Production of pure BSM nanofibers proved to be difficult, yet integration of PVA contributed to a facile and successful formation of BSM/PVA nanofibers. Different BSM/PVA ratios were fabricated to achieve the desired nanofibrous structure for cell proliferation. It is found that the optimal bead-free ratio of 50/50 with a mean fiber diameter of ≈180 nm presents the most desirable scaffold structure for cell growth. The positive effect of PVA incorporation was approved by analyzing BSM/PVA solutions through physiochemical assays such as electrical conductivity, viscosity and surface tension tests. According to the thermal analysis (TGA/DSC), incorporation of PVA enhanced thermal stability of the samples. Successful fabrication of the nanofibers is verified by FT-IR spectra, where no major chemical interaction between BSM and PVA is detected. The crystallinity of the electrospun nanofibers is investigated by XRD, revealing the nearly amorphous structure of BSM/PVA scaffolds. The MTT assay is employed to verify the biocompatibility of the scaffolds. The cell culture experiment using epithelial Vero cells shows the affinity of the cells to adhere to their nanofibrous substrate and grow to form continuous cell layers after 72 h of incubation.
The CMB bispectrum from bouncing cosmologies
Authors: Delgado Paola C. M. , Durrer Ruth , Pinto-Neto Nelson
Published: November 2021

In this paper we compute the CMB bispectrum for bouncing models motivated by Loop Quantum Cosmology. Despite the fact that the primordial bispectrum of these models is decaying exponentially above a large pivot scale, we find that the cumulative signal-to-noise ratio of the bispectrum induced in the CMB from scales ℓ<30 is larger than 10 in all cases of interest and therefore can, in principle, be detected in the Planck data.
A gauge theory for two-band model of Chern insulators and induced topological defects
Authors: Chang Zhi-Wen , Hao Wei-Chang , Liu Xin
Published: November 2021

In this paper a gauge theory is proposed for the two-band model of Chern insulators. Based on the so-called ’t Hooft monopole model, a U(1) Maxwell electromagnetic sub-field is constructed from an SU(2) gauge field, from which arise two types of topological defects, monopoles and merons. We focus on the topological number in the Hall conductance

σ

xy

=

e

2

h

C

, where C is the Chern number. It is discovered that in the monopole case C is indeterminate, while in the meron case C takes different values, due to a varying on-site energy m. As a typical example, we apply this method to the square lattice and compute the winding numbers (topological charges) of the defects; the C-evaluations we obtain reproduce the results of the usual literature. Furthermore, based on the gauge theory we propose a new model to obtain the high Chern numbers ∣C∣ = 2, 4.
A 515-nm laser-pumped idler-resonant femtosecond BiB3O6 optical parametric oscillator
Authors: Yang Jinfang , Wang Zhaohua , Song Jiajun , Lv Renchong , Wang Xianzhi , Zhu Jiangfeng , Wei Zhiyi
Published: November 2021

We report on an idler-resonant femtosecond optical parametrical oscillator (OPO) based on BiB3O6 (BiBO) crystal, synchronously pumped by a frequency-doubled, mode-locked Yb:KGW laser at 515 nm. The idler wavelengths of OPO can be tuned from 1100 nm to 1540 nm. At a repetition rate of 75.5 MHz, the OPO generates as much as 400 mW of idler power with 3.1 W of pump power, the corresponding pulse duration is 80 fs, which is 1.04 times of Fourier transform-limited (FTL) pulse duration at 1305 nm. In addition, the OPO exhibits excellent beam quality with M
2 < 1.8 at 1150 nm. To the best of our knowledge, this is the first idler-resonant femtosecond OPO pumped by 515 nm.
MOS-based model of four-transistor CMOS image sensor pixels for photoelectric simulation
Authors: Zhang Bing , Hu Congzhen , Xin Youze , Li Yaoxin , Guo Zhuoqi , Xue Zhongming , Dong Li , Yu Shanzhe , Wang Xiaofei , Lei Shuyu , Geng Li
Published: November 2021

By using the MOS-based model established in this paper, the physical process of photoelectron generation, transfer, and storage in the four-transistor active pixel sensor (4T-APS) pixels can be simulated in SPICE environment. The variable capacitance characteristics of double junctions in pinned photodiodes (PPDs) and the threshold voltage difference formed by channel nonuniform doping in transfer gates (TGs) are considered with this model. The charge transfer process of photogenerated electrons from PPDs to the floating diffusion (FD) is analyzed, and the function of nonuniform doping of TGs in suppressing charge injection back to PPDs is represented with the model. The optical and electrical characteristics of all devices in the pixel are effectively combined with the model. Moreover, the charge transfer efficiency and the voltage variation in PPD can be described with the model. Compared with the hybrid simulation in TCAD and the Verilog-A simulation in SPICE, this model has higher simulation efficiency and accuracy, respectively. The effectiveness of the MOS-based model is experimentally verified in a 3 μm test pixel designed in 0.11 μm CIS process.