bluuebunny/crossref_metadata_2025 huggingface dataset:
Milk Alternatives. What Advice should Dental Professionals be Giving?
Authors: Thalukder Imran , Torofdar Halima , Collard Mechelle
Published: May 2021

Drinking milk-like fluids made from plant-based materials, such as soya, nuts and peas, is an increasing trend within the population, and regular consumption of these non-dairy alternatives may increase the risk of developing caries. This article focuses on current research relating to caries risk and consumption of milk-like products, and also investigates the sugar content of milk alternatives available in the UK.

CPD/Clinical Relevance: Frequent sugar attacks causes caries. Dentists need to be aware of milk and milk alternatives for some may contribute to the development of caries, and this should form part of their caries risk assessment.
Radiosurgery: A Forgotten Tool?
Authors: Brown Timothy , Donachie Martin
Published: May 2021

Radiosurgery allows precise tissue cutting with simultaneous haemostasis, providing a clearer surgical field. Variation in waveform, power settings and handpiece tip shape allow for a wide variety of clinical applications, making it one of the most versatile pieces of surgical equipment in the dentist's arsenal. However, it is one of the most underused, and probably misunderstood, areas of surgery in dentistry. This may be due to conflicting literature concerning healing, overshadowing of the value of the technique by interest in dental lasers, misuse of terminology and a general lack of knowledge regarding the science underpinning its action.

CPD/Clinical Relevance: This article aims to outline the mode of action, adjustable parameters and considerations for the safe use of radiosurgery alongside clinical examples of its applications.
Redução do IPI e os reflexos nas finanças públicas dos municípios de Minas Gerais
Authors: VIEIRA MICHELLE APARECIDA , OLIVEIRA DAVID ALVES , DE ÁVILA LUCIMAR ANTÔNIO CABRAL
Published: May 2021

As desonerações do Imposto sobre Produtos Industrializados (IPI), implementadas pela União para contornar os efeitos negativos da crise financeira mundial, influenciaram significativamente a composição do Fundo de Participação dos Municípios (FPM), principal fonte de financiamento das finanças públicas municipais. Dessa forma, este estudo teve como objetivo verificar se as receitas dos municípios de Minas Gerais e seus indicadores socioeconômicos sofreram alterações significativas após a renúncia fiscal do IPI praticada pelo governo federal a partir de 2008. Os resultados evidenciam que os municípios de pequeno porte foram os que mais sofreram os efeitos negativos da redução do IPI sobre o FPM. Por outro lado, identificou-se também que para mais de 50% dos municípios analisados houve um aumento nos níveis da arrecadação tributária e também nos valores transferidos a título do FPM, em virtude do apoio financeiro concedido pela União.
An Differential Quadrature Finite Element and the Differential Quadrature Hierarchical Finite Element Methods for the Dynamics Analysis of on Board Shaft
Authors: Ahmed Saimi , Abdelhamid Hadjoui , Ismail Bensaid , Ahmed Fellah
Published: May 2021

In this paper the dynamic analysis of a shaft rotor whose support is mobile is studied. For the calculation of kinetic energy and stiffness energy, the beam theory of Euler Bernoulli was used, and the matrices of elements and systems are developed using two methods derived from the differential quadrature method (DQM). The first method is the Differential Quadrature Finite Element Method (DQFEM) systematically, as a combination of the Differential Quadrature Method (DQM) and the Standard Finite Element Method (FEM), which has a reduced computational cost for problems in dynamics. The second method is the Differential Quadrature Hierarchical Finite Element Method (DQHFEM) which is used by expressing the matrices of the hierarchical finite element method in a similar form to that of the Differential Quadrature Finite Element Method and introducing an interpolation basis on the element boundary of the hierarchical finite element method. The discretization element used for both methods is a three-dimensional beam element. In the differential quadrature finite element method (DQFEM), the mass, gyroscopic and stiffness matrices are simply calculated using the weighting coefficient matrices given by the differential quadrature (DQ) and Gauss-Lobatto quadrature rules. The sampling points are determined by the Gauss-Lobatto node method. In the Differential Quadrature Hierarchical Finite Element Method (DQHFEM) the same approaches were used, and the cubic Hermite shape functions and the special Legendre polynomial Rodrigues shape polynomial were added. The assembly of the matrices for both methods (DQFEM and DQHFEM) is similar to that of the classical finite element method. The results of the calculation are validated with the h- and hp finite element methods and also with the literature.
Finite Element Simulation of Friction Stir Welding of Inconel 718 to Nimonic 80A
Authors: Saju Tom , Velu M
Published: May 2021

This paper presents results of simulation of friction stir dissimilar welding of 5 mm thick, Nickel-based super-alloys, Inconel 718, and Nimonic 80A using Abaqus software. Four different trials were done to understand the influence of tool rotation speed on temperature distribution in weld zone while travel speed remains constant. The temperature in the weld zone was found to increase with the increase in tool rotation speed and travel speed. The temperature on the advancing side of the tool was higher than that of the retreating side. The tensile strength of weldment was found, by simulation, to be 25% more than that of base metal, Inconel 718. This may be due to grain refinement and dynamic recrystallization during FSW. The simulated bend test revealed an adequate level of ductility of weldments.
Signal-to-noise ratio of a near-infrared static wind imaging Michelson
interferometer
Authors: Zhang Chunmin , Wang Yixuan , Yan Tingyu , He Yifan , Sun Yongqiang
Published: May 2021

Wind is a key parameter to understand the dynamic behavior of the atmosphere. This paper focuses on the signal-to-noise ratio (SNR) of the near-infrared static wind imaging Michelson interferometer developed by our research group. As a physical quantity related directly to the resolution of airglow radiation, SNR is an important index to evaluate the performance of interferometers. The theoretical model of SNR is derived, and the changing rules of SNR under various physical quantities are given by computer simulation. This research provides a reliable theoretical basis for the design, development, and engineering of novel wind imaging interferometers.
Cytomembrane visualization using Stokes parameter confocal microscopy
Authors: Wang Jielin , He Yanwen , Wu Yongbo , Tang Peijun , Wang Yongsong , Tang Zhilie
Published: May 2021

A new, to the best of our knowledge, method for Stokes vector imaging is proposed to achieve imaging and dynamic monitoring of a non-labeled cytomembrane. In this work, a polarization state vector is described by a Stokes vector and expressed in chrominance space. A physical quantity called polarization chromaticity value (PCV) corresponding to a Stokes vector is used as the imaging parameter to perform Stokes vector imaging. By using the PCV imaging technique, the Stokes vector can be expressed in three-dimensional real space rather than in a Poincare sphere. Furthermore, a four-way Stokes parameter confocal microscopy system is designed to measure four Stokes parameters simultaneously and obtain micro-imaging. Label-free living onion cell membranes and their plasmolysis process are selected as the representative micro-anisotropy experimental analysis. It is proved that PCV imaging can perform visualization of cytomembranes, and further, microscopic orientation is demonstrated. The prospect of universal measurement of anisotropy details for analysis and diagnosis is provided.
Light scattering in intraocular lenses explanted 15 to 40 years after surgery
Authors: Alio Jorge L. , Arias Augusto , D’Oria Francesco , Toto Francesca , Del Barrio Jorge Alio , Duarte Raul , Artal Pablo
Published: May 2021

The optical quality of intraocular lenses (IOLs) of different materials that have been implanted from 16 to 44 years in human eyes was studied. The IOLs were explanted due to other causes than loss of transparency. The scattered light from the IOLs was assessed in two angular regimes by using dark field images (for wide angles) and the optical integration method (for narrower angles). No evident differences were found in the scattering intensities processed from the dark images. The explanted lenses presented slightly increased amounts of straylight between 1 and 5.1° when compared to a reference new unused lens.
Dynamic imaging of distant objects with ptychographical intensity interferometry
Authors: He Yuchen , Yuan Yuan , Chen Hui , Zheng Huaibin , Liu Jianbin , Xu Zhuo
Published: May 2021

As a promising lensless imaging method for distant objects, intensity interferometry imaging (III) had been suffering from the unreliable phase retrieval process, hindering the development of III for decades. Recently, the introduction of ptychographic detection in III overcame this challenge, and a method called ptychographic III (PIII) was proposed. We here experimentally demonstrate that PIII can image a dynamic distant object. A reasonable image for the moving object can be retrieved with only two speckle patterns for each probe, and only 10 to 20 iterations are needed. Meanwhile, PIII exhibits robustness to the inaccurate information of the probe. Furthermore, PIII successfully recovers the image through a fog obfuscating the imaging light path, under which a conventional camera relying on lenses fails to provide a recognizable image.
Quantifying the enhancement of two-photon absorption due to spectral-temporal entanglement
Authors: Landes Tiemo , Raymer Michael G. , Allgaier Markus , Merkouche Sofiane , Smith Brian J. , Marcus Andrew H.
Published: May 2021

When a low flux of time-frequency-entangled photon pairs (EPP) illuminates a two-photon transition, the rate of two-photon absorption (TPA) can be enhanced considerably by the quantum nature of photon number correlations and frequency correlations. We use a quantum-theoretic derivation of entangled TPA (ETPA) and calculate an upper bound on the amount of quantum enhancement that is possible in such systems. The derived bounds indicate that in order to observe ETPA the experiments would need to operate at a combination of significantly higher rates of EPP illumination, molecular concentrations, and conventional TPA cross sections than are achieved in typical experiments.
Lossy-mode-resonance sensor based on perovskite nanomaterial with high sensitivity
Authors: Wu Leiming , Xiang Yuanjiang , Qin Yuwen
Published: May 2021

Lossy-mode-resonance (LMR) is a surface plasmon resonance (SPR)-analogue optical phenomenon, which is sensitive to the surrounding environment variations and can be considered as an important detection signal in biochemical sensors. Compared with the SPR sensor which can only operate under transverse magnetic (TM)-polarized light, the LMR sensor shows a more excellent application prospect and can operate in both TM- and transverse electric (TE)-polarized light. In this work, a CH3NH3PbBr3-based LMR configuration is proposed to apply in optical sensors. When the incident light is in TM mode, the preferred way to improve the performance of the LMR sensor is optimizing the thickness of the matching layer, and the highest sensitivity of 11382 refractive index unit (RIU−1) is achieved, which is more than 200 times larger than that of the conventional Au-based SPR sensor; when the incident light is in TE mode, it is more advantageous to improve the properties of LMR sensor by optimizing the thickness of CH3NH3PbBr3 layer, and a high sensitivity of 21697 RIU−1 is obtained. With such high sensitivity, we believe that the CH3NH3PbBr3-based LMR sensor will find potential applications in biology, medicine, chemistry and other fields.
Nonlinear polarization interferometer for enhancement of laser pulse contrast and power
Authors: Khazanov Efim
Published: May 2021

A method for enhancing the temporal contrast of high-power femtosecond laser pulses is proposed. The suppression of low-intensity radiation and the simultaneous 100% transmission of a pulse peak are attained due to the nonlinear phase difference π between the orthogonally polarized waves, leading to a 90-degree rotation of polarization. The polarization interferometer has an in-line geometry that does not demand spatial beam separation. The output pulse compression and power enhancement are implemented as a result of self-phase modulation in the interferometer and subsequent reflection from the chirping mirrors.
3D printed long period gratings and their applications as high sensitivity shear-strain and torsion sensors
Authors: Oliveira Ricardo , Nogueira Rogério , Bilro Lúcia
Published: May 2021

In this work we demonstrate the capability to measure shear-strain and torsion loads by bonding an optical fiber to a 3D printed periodic grooved plate. The device acts as a long period grating where the resonances show loss tunability ranging from ∼0 up to ∼20 dB, achieving sensitivities values for the dip transmission ratio as function of the load of 0.12 /mε and 0.21/deg, for shear-strain and torsion loads ranging from 0–∼8 mε and 1–∼4 deg, respectively. The low wavelength drift allowed us to operate the sensor through intensity demodulation techniques, showing good tracking performance of external stimuli.
Efficient design of a dielectric metasurface with transfer learning and genetic algorithm
Authors: Xu Dong , Luo Yu , Luo Jun , Pu Mingbo , Zhang Yaxin , Ha Yinli , Luo Xiangang
Published: May 2021

Machine learning has been widely adopted in various disciplines as they offer low-computational cost solutions to complex problems. Recently, deep learning-enabled methods for metasurface design have received increasing attention in the field of subwavelength electromagnetics. However, the previous metasurface design methods based on deep learning usually use huge datasets or complex networks to make deep neural networks achieve high prediction accuracy which results in more time for dataset establishment and network training. Here, we propose an expeditious and accurate scheme for designing phase-modulating dielectric metasurface through employing the transfer learning technology and genetic algorithm. The performance of the neural network is improved distinctly by migrating knowledge between real part and imaginary part spectrum-prediction tasks. Furthermore, the target meta-atoms can be optimized readily without increasing a large dataset through transfer learning. Finally, we design two deflectors and two metalenses as a proof-of-concept demonstration to validate the ability of our proposed approach. The scheme provides an efficient and promising design method for phase-modulating metasurface.
Hierarchical semantic composition of biosimulation models using bond graphs
Authors: Shahidi Niloofar , Pan Michael , Safaei Soroush , Tran Kenneth , Crampin Edmund J. , Nickerson David P.
Published: May 2021

Simulating complex biological and physiological systems and predicting their behaviours under different conditions remains challenging. Breaking systems into smaller and more manageable modules can address this challenge, assisting both model development and simulation. Nevertheless, existing computational models in biology and physiology are often not modular and therefore difficult to assemble into larger models. Even when this is possible, the resulting model may not be useful due to inconsistencies either with the laws of physics or the physiological behaviour of the system. Here, we propose a general methodology for composing models, combining the energy-based bond graph approach with semantics-based annotations. This approach improves model composition and ensures that a composite model is physically plausible. As an example, we demonstrate this approach to automated model composition using a model of human arterial circulation. The major benefit is that modellers can spend more time on understanding the behaviour of complex biological and physiological systems and less time wrangling with model composition.
Correlation between the immuno-virological response and the nutritional profile of treatment-experienced HIV-infected patients in the East region of Cameroon
Authors: Abba Aissatou , Fokam Joseph , Kamgaing Rachel Simo , Yimga Junie Flore , Ka’e Aude Christelle , Nka Alex Durand , Tchouaket Michel Carlos Tommo , Chenwi Collins Ambe , Semengue Ezechiel Ngoufack Jagni , Ndjolo Alexis , Sosso Samuel Martin
Published: May 2021

Background

HIV management remains concerning and even more challenging in the frame of comorbidities like malnutrition that favors disease progression and mortality in resource-limited settings (RLS).

Objective

To describe the nutritional parameters of antiretroviral therapy (ART) recipients (without nutritional support) with respect to CD4 count and virological failure.

Methods

A cross-sectional study was conducted from October to December 2018 among 146 consenting participants enrolled in two health facilities of the East-Region of Cameroon. Socio-demographic data, basic clinical information and treatment history were collected; blood samples were collected by venipuncture for laboratory analysis (HIV-1 viral load, CD4 Tcells measurement and biochemical analysis) performed at the “Chantal Biya” International Reference Center”, Yaounde, Cameroon. The nutritional profile was assessed by using anthropometric and biochemical parameters. Data were analyzed using Excel 2016, Graph pad prism version 6; Spearman correlation and Kruskal-Wallis test were used; with p<0.05 considered statistically significant.

Results

Median [IQR] age was 42 [33–51] years, 76.0% (111/146) were female and median [IQR] duration on ART was 54 [28–86] months. Of these participants, 11.6% (17/146) were underweight based on the body mass index and 4.7% (7/146) were at the stage of advanced weight loss. According to immunovirological responses, 44.5% (65/146) were immunocompromised (CD4<500 cell/μl) and 75.3% (110/146) had an undetectable viremia (<40 copies/mL). CD4 count inversely correlated with total protein concentration (r = -0.18, p = 0.005**). Viremia was inversely correlated with albumin (r = -0.21; p = 0.047*), nutritional risk index (r = -0.28; p = 0.013*), total cholesterol (r = -0.27; p = 0.007**), and positively correlated with total protein (r = 0.27; p<0.001**) concentrations.

Conclusion

In this RLS, with patients having about five years of ART-experience, malnutrition appears to be driven mainly by a poor BMI, indicating that about one of ten patients falls within this severe condition. However, the largely normal nutritional profiles should be interpreted with caution, considering local realities and food support programs in place. The present outcomes highlight the need for monitoring nutritional status of people receiving ART in RLS, toward the design of optimal food interventions.
Who infects whom?—Reconstructing infection chains of Mycobacterium avium ssp. paratuberculosis in an endemically infected dairy herd by use of genomic data
Authors: Nigsch Annette , Robbe-Austerman Suelee , Stuber Tod P. , Pavinski Bitar Paulina D. , Gröhn Yrjö T. , Schukken Ynte H.
Published: May 2021

Recent evidence of circulation of multiple strains within herds and mixed infections of cows marks the beginning of a rethink of our knowledge on Mycobacterium avium ssp. paratuberculosis (MAP) epidemiology. Strain typing opens new ways to investigate MAP transmission. This work presents a method for reconstructing infection chains in a setting of endemic Johne’s disease on a well-managed dairy farm. By linking genomic data with demographic field data, strain-specific differences in spreading patterns could be quantified for a densely sampled dairy herd. Mixed infections of dairy cows with MAP are common, and some strains spread more successfully. Infected cows remain susceptible for co-infections with other MAP genotypes. The model suggested that cows acquired infection from 1–4 other cows and spread infection to 0–17 individuals. Reconstructed infection chains supported the hypothesis that high shedding animals that started to shed at an early age and showed a progressive infection pattern represented a greater risk for spreading MAP. Transmission of more than one genotype between animals was recorded. In this farm with a good MAP control management program, adult-to-adult contact was proposed as the most important transmission route to explain the reconstructed networks. For each isolate, at least one more likely ancestor could be inferred. Our study results help to capture underlying transmission processes and to understand the challenges of tracing MAP spread within a herd. Only the combination of precise longitudinal field data and bacterial strain type information made it possible to trace infection in such detail.
Heavy metal accumulation by roadside vegetation and implications for pollution control
Authors: Altaf Rubina , Altaf Sikandar , Hussain Mumtaz , Shah Rahmat Ullah , Ullah Rehmat , Ullah Muhammad Ihsan , Rauf Abdul , Ansari Mohammad Javed , Alharbi Sulaiman Ali , Alfarraj Saleh , Datta Rahul
Published: May 2021

Vehicular emissions cause heavy metal pollution and exert negative impacts on environment and roadside vegetation. Wild plants growing along roadsides are capable of absorbing considerable amounts of heavy metals; thus, could be helpful in reducing heavy metal pollution. Therefore, current study inferred heavy metal absorbance capacity of some wild plant species growing along roadside. Four different wild plant species, i.e., Acacia nilotica L., Calotropis procera L., Ricinus communis L., and Ziziphus mauritiana L. were selected for the study. Leaf samples of these species were collected from four different sites, i.e., Control, New Lahore, Nawababad and Fatehabad. Leaf samples were analyzed to determine Pb2+, Zn2+, Ni2+, Mn2+ and Fe3+ accumulation. The A. nilotica, Z. mauritiana and C. procera accumulated significant amount of Pb at New Lahore site. Similarly, R. communis and A. nilotica accumulated higher amounts of Mn, Zn and Fe at Nawababad and New Lahore sites compared to the rest of the species. Nonetheless, Z. mauritiana accumulated higher amounts of Ni at all sites compared with the other species included in the study. Soil surface contributed towards the uptake of heavy metals in leaves; therefore, wild plant species should be grown near the roadsides to control heavy metals pollution. Results revealed that wild plants growing along roadsides accumulate significant amounts of heavy metals. Therefore, these species could be used to halt the vehicular pollution along roadsides and other polluted areas.
Student perspectives of preparedness characteristics for clinical learning within a fully distributed veterinary teaching model
Authors: Saadeh Khalil , Aitken Joanna B. , Paramasivam Sharmini Julita , Cockcroft Peter , Jeevaratnam Kamalan
Published: May 2021

The transition into the clinical environment is challenging and associated with significant stress and anxiety. This study aimed to examine the perspectives of students on the characteristics important for preparedness for clinical learning and the influence of gender, age, and graduate status on those perspectives. This descriptive, questionnaire-based study of 62 characteristics categorised into six themes was conducted within the Surrey School of Veterinary Medicine completed by 139 students commencing their final clinical year. The Friedman test and post-hoc Wilcoxon signed rank sum test explored for differences in ranking across the themes. Ordinal logistic regression and Mann-Whitney U pairwise comparisons were utilised to investigate for effects of gender, age, and graduate status on theme ranking. There was a significant difference (P <0.05) between medians for themes of preparedness characteristics with comparisons revealing willingness and communication and interaction as the most highly rated characteristics. Knowledge and understanding were viewed as the least important characteristic. Regression and pairwise Mann-Whitney U comparisons confirmed no significant effects (P >0.05) of gender, age or graduate status on student rating of preparedness characteristics. Integrating learning opportunities of those preparedness characteristics in the pre-clinical curriculum may improve students’ preparedness for the clinical environment.
The natural sequence of events in larval settlement and metamorphosis of Hydroides elegans (Polychaeta; Serpulidae)
Authors: Hadfield Michael G. , Freckelton Marnie L. , Nedved Brian T.
Published: May 2021

The broadly distributed serpulid worm Hydroides elegans has become a model organism for studies of marine biofouling, development and the processes of larval settlement and metamorphosis induced by surface microbial films. Contrasting descriptions of the initial events of these recruitment processes, whether settlement is induced by (1) natural multi-species biofilms, (2) biofilms composed of single bacterial species known to induce settlement, or (3) a bacterial extract stimulated the research described here. We found that settlement induced by natural biofilms or biofilms formed by the bacterium Pseudoalteromonas luteoviolacea is invariably initiated by attachment and secretion of an adherent and larva-enveloping primary tube, followed by loss of motile cilia and ciliated cells and morphogenesis. The bacterial extract containing complex tailocin arrays derived from an assemblage of phage genes incorporated into the bacterial genome appears to induce settlement events by destruction of larval cilia and ciliated cells, followed by attachment and primary-tube formation. Similar destruction occurred when precompetent larvae of H. elegans or larvae of a nudibranch gastropod were exposed to the extract, although neither of them metamorphosed. We argue that larvae that lose their cilia before attachment would be swept away from the sites that stimulated settlement by the turbulent flow characteristic of most marine habitats.
Attitudes of health care providers regarding female genital mutilation and its medicalization in Guinea
Authors: Balde Mamadou Dioulde , O’Neill Sarah , Sall Alpha Oumar , Balde Mamadou Bailo , Soumah Anne Marie , Diallo BoubacarAlpha , Pallitto Christina Catherine
Published: May 2021

Background

Guinea has a high prevalence of female genital mutilation (FGM) (95%) and it is a major concern affecting the health and the welfare of women and girls. Population-based surveys suggest that health care providers are implicated in carrying out the practice (medicalization). To understand the attitudes of health care providers related to FGM and its medicalization as well as the potential role of the health sector in addressing this practice, a study was conducted in Guinea to inform the development of an intervention for the health sector to prevent and respond to this harmful practice.

Methodology

Formative research was conducted using a mixed-methods approach, including qualitative in-depth interviews with health care providers and other key informants as well as questionnaires with 150 health care providers. Data collection was carried out in the provinces of Faranah and Labé and in the capital, Conakry.

Results

The majority of health care providers participating in this study were opposed to FGM and its medicalization. Survey data showed that 94% believed that it was a serious problem; 89% felt that it violated the rights of girls and women and 81% supported criminalization. However, within the health sector, there is no enforcement or accountability to the national law banning the practice. Despite opposition to the practice, many (38%) felt that FGM limited promiscuity and 7% believed that it was a good practice.

Conclusion

Health care providers could have an important role in communicating with patients and passing on prevention messages that can contribute to the abandonment of the practice. Understanding their beliefs is a key step in developing these approaches.
A fast MR-thermometry method for quantitative assessment of temperature increase near an implanted wire
Authors: Delcey Marylène , Bour Pierre , Ozenne Valéry , Ben Hassen Wadie , Quesson Bruno
Published: May 2021

Purpose

To propose a MR-thermometry method and associated data processing technique to predict the maximal RF-induced temperature increase near an implanted wire for any other MRI sequence.

Methods

A dynamic single shot echo planar imaging sequence was implemented that interleaves acquisition of several slices every second and an energy deposition module with adjustable parameters. Temperature images were processed in real time and compared to invasive fiber-optic measurements to assess accuracy of the method. The standard deviation of temperature was measured in gel and in vivo in the human brain of a volunteer. Temperature increases were measured for different RF exposure levels in a phantom containing an inserted wire and then a MR-conditional pacemaker lead. These calibration data set were fitted to a semi-empirical model allowing estimation of temperature increase of other acquisition sequences.

Results

The precision of the measurement obtained after filtering with a 1.6x1.6 mm2 in plane resolution was 0.2°C in gel, as well as in the human brain. A high correspondence was observed with invasive temperature measurements during RF-induced heating (0.5°C RMSE for a 11.5°C temperature increase). Temperature rises of 32.4°C and 6.5°C were reached at the tip of a wire and of a pacemaker lead, respectively. After successful fitting of temperature curves of the calibration data set, temperature rise predicted by the model was in good agreement (around 5% difference) with measured temperature by a fiber optic probe, for three other MRI sequences.

Conclusion

This method proposes a rapid and reliable quantification of the temperature rise near an implanted wire. Calibration data set and resulting fitting coefficients can be used to estimate temperature increase for any MRI sequence as function of its power and duration.
Data-driven model reduction of agent-based systems using the Koopman generator
Authors: Niemann Jan-Hendrik , Klus Stefan , Schütte Christof
Published: May 2021

The dynamical behavior of social systems can be described by agent-based models. Although single agents follow easily explainable rules, complex time-evolving patterns emerge due to their interaction. The simulation and analysis of such agent-based models, however, is often prohibitively time-consuming if the number of agents is large. In this paper, we show how Koopman operator theory can be used to derive reduced models of agent-based systems using only simulation data. Our goal is to learn coarse-grained models and to represent the reduced dynamics by ordinary or stochastic differential equations. The new variables are, for instance, aggregated state variables of the agent-based model, modeling the collective behavior of larger groups or the entire population. Using benchmark problems with known coarse-grained models, we demonstrate that the obtained reduced systems are in good agreement with the analytical results, provided that the numbers of agents is sufficiently large.
Improvement of renal function after transcatheter aortic valve replacement in patients with chronic kidney disease
Authors: Lemes da Silva Michel V. , Nunes Filho Antonio C. B. , Rosa Vitor E. E. , Caixeta Adriano , Lemos Neto Pedro A. , Ribeiro Henrique B. , Almeida Breno O. , Mariani José , Campos Carlos M. , Abizaid Alexandre A. C. , Mangione José A. , Sampaio Roney O. , Caramori Paulo , Sarmento-Leite Rogério , Tarasoutchi Flávio , Franken Marcelo , de Brito Fábio S.
Published: May 2021

Background

Chronic kidney disease is commonly found in patients with aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) and has marked impact in their prognosis. It has been shown however that TAVR may improve renal function by alleviating the hemodynamic barrier imposed by AS. Nevertheless, the predictors of and clinical consequences of renal function improvement are not well established.

Our aim was to assess the predictors of improvement of renal function after TAVR.

Methods

The present work is an analysis of the Brazilian Registry of TAVR, a national non-randomized prospective study with 22 Brazilian centers. Patients with baseline renal dysfunction (estimated glomerular filtration rate [eGFR] < 60mL/min/1.73m2) were stratified according to renal function after TAVR: increase >10% in eGFR were classified as TAVR induced renal function improvement (TIRFI); decrease > 10% in eGFR were classified as acute kidney injury (AKI) and stable renal function (neither criteria).

Results

A total of 819 consecutive patients with symptomatic severe AS were included. Of these, baseline renal dysfunction (estimated glomerular filtration rate [eGFR] < 60mL/min/1.73m2) was present in 577 (70%) patients. Considering variance in renal function between baseline and at discharge after TAVR procedure, TIRFI was seen in 197 (34.1%) patients, AKI in 203 (35.2%), and stable renal function in 177 (30.7%).

The independent predictors of TIRFI were: absence of coronary artery disease (OR: 0.69; 95% CI 0.48–0.98; P = 0.039) and lower baseline eGFR (OR: 0.98; 95% CI 0.97–1.00; P = 0.039). There was no significant difference in 30-day and 1-year all-cause mortality between patients with stable renal function or TIRFI. Nonetheless, individuals that had AKI after TAVR presented higher mortality compared with TIRFI and stable renal function groups (29.3% vs. 15.4% vs. 9.5%, respectively; p < 0.001).

Conclusions

TIRFI was frequently found among baseline impaired renal function individuals but was not associated with improved 1-year outcomes.
Teenage pregnancy as a risk factor for placental abruption: Findings from the prospective Japan environment and children’s study
Authors: Kyozuka Hyo , Murata Tsuyoshi , Fukusda Toma , Yamaguchi Akiko , Kanno Aya , Yasuda Shun , Sato Akiko , Ogata Yuka , Endo Yuta , Hosoya Mitsuaki , Yasumura Seiji , Hashimoto Koichi , Nishigori Hidekazu , Fujimori Keiya ,   the Japan Environment and Children’s Study (JECS) Group
Published: May 2021

Objective

Placental abruption is a significant obstetric complication that affects both maternal and neonatal mortality and morbidity. The present study examined the effect of maternal age on the incidence of placental abruption.

Methods

We used data of singleton pregnancies from the Japan Environment and Children’s Study, which was a prospective birth cohort study conducted between January 2011 and March 2014 across 15 regional centers in Japan. A multiple regression model was used to identify whether maternal age (<20 years, 20–24 years, 25–29 years, 30–34 years, and ≥35 years) is a risk factor for placental abruption. The analyses were conducted while considering the history of placental abruption, assisted reproductive technology, number of previous deliveries, smoking during pregnancy, body mass index before pregnancy, and chronic hypertension.

Results

A total of 94,410 Japanese women (93,994 without placental abruption and 416 with placental abruption) were recruited. Herein, 764, 8421, 25915, 33517, and 25793 women were aged <20 years, 20–24 years, 25–29 years, 30–34 years, and ≥35 years, respectively. Besides advanced maternal age (≥35 years; adjusted odds ratio: 1.7, 95% confidence interval: 1.1–2.5), teenage pregnancy was also a risk factor for placental abruption (adjusted odds ratio: 2.8, 95% confidence interval: 1.2–6.5) when the maternal age of 20–24 years was set as a reference.

Conclusions

In the Japanese general population, besides advanced maternal age, teenage pregnancy was associated with placental abruption. Recently, the mean maternal age has been changing in Japan. Therefore, it is important for obstetric care providers to provide proper counseling to young women based on up-to-date evidence.
Men’s and women’s knowledge of danger signs relevant to postnatal and neonatal care-seeking: A cross sectional study from Bungoma County, Kenya
Authors: Roney Emma , Morgan Christopher , Gatungu Daniel , Mwaura Peter , Mwambeo Humphrey , Natecho Alice , Comrie-Thomson Liz , Gitaka Jesse N.
Published: May 2021

Background

Neonatal and maternal mortality rates remain high in Kenya. Knowledge of neonatal danger signs may reduce delay in deciding to seek care. Evidence is emerging on the influential role of male partners in improving maternal and newborn health. This study analysed the factors that determine men’s and women’s knowledge and practices in postnatal and neonatal care-seeking, in order to inform design of future interventions.

Methods

A quantitative, cross-sectional study was undertaken in Bungoma County, Kenya. Women who had recently given birth (n = 348) and men whose wives had recently given birth (n = 82) completed questionnaires on knowledge and care-seeking practices relating to the postnatal period. Univariate and multivariate logistic regression analyses were performed to investigate associations with key maternal and newborn health outcomes.

Results

51.2% of women and 50.0% of men knew at least one neonatal danger sign, however women knew more individual danger signs than men. In the univariate model, women’s knowledge of a least one neonatal danger sign was associated with attending antenatal care ≥4 times (OR 4.46, 95%CI 2.73–7.29, p<0.001), facility birth (OR 3.26, 95%CI 1.89–5.72, p<0.001), and having a male partner accompany them to antenatal care (OR 3.34, 95%CI 1.35–8.27, p = 0.009). Higher monthly household income (≥10,000KSh, approximately US$100) was associated with facility delivery (AOR 11.99, 95%CI 1.59–90.40, p = 0.009).

Conclusion

Knowledge of neonatal danger signs was low, however there was an association between knowledge of danger signs and increased healthcare service use, including male partner involvement in antenatal care. Future interventions should consider the extra costs of facility delivery and the barriers to men participating in antenatal and postnatal care.
Nurse-sensitive outcomes in district nursing care: A Delphi study
Authors: Veldhuizen Jessica D. , van den Bulck Anne O. E. , Elissen Arianne M. J. , Mikkers Misja C. , Schuurmans Marieke J. , Bleijenberg Nienke
Published: May 2021

Objectives

To determine nurse-sensitive outcomes in district nursing care for community-living older people. Nurse-sensitive outcomes are defined as patient outcomes that are relevant based on nurses’ scope and domain of practice and that are influenced by nursing inputs and interventions.

Design

A Delphi study following the RAND/UCLA Appropriateness Method with two rounds of data collection.

Setting

District nursing care in the community care setting in the Netherlands.

Participants

Experts with current or recent clinical experience as district nurses as well as expertise in research, teaching, practice, or policy in the area of district nursing.

Main outcome measures

Experts assessed potential nurse-sensitive outcomes for their sensitivity to nursing care by scoring the relevance of each outcome and the ability of the outcome to be influenced by nursing care (influenceability). The relevance and influenceability of each outcome were scored on a nine-point Likert scale. A group median of 7 to 9 indicated that the outcome was assessed as relevant and/or influenceable. To measure agreement among experts, the disagreement index was used, with a score of <1 indicating agreement.

Results

In Delphi round two, 11 experts assessed 46 outcomes. In total, 26 outcomes (56.5%) were assessed as nurse-sensitive. The nurse-sensitive outcomes with the highest median scores for both relevance and influenceability were the patient’s autonomy, the patient’s ability to make decisions regarding the provision of care, the patient’s satisfaction with delivered district nursing care, the quality of dying and death, and the compliance of the patient with needed care.

Conclusions

This study determined 26 nurse-sensitive outcomes for district nursing care for community-living older people based on the collective opinion of experts in district nursing care. This insight could guide the development of quality indicators for district nursing care. Further research is needed to operationalise the outcomes and to determine which outcomes are relevant for specific subgroups.
Deep reinforcement learning approaches for global public health strategies for COVID-19 pandemic
Authors: Kwak Gloria Hyunjung , Ling Lowell , Hui Pan
Published: May 2021

Background

Unprecedented public health measures have been used during this coronavirus 2019 (COVID-19) pandemic to control the spread of SARS-CoV-2 virus. It is a challenge to implement timely and appropriate public health interventions.

Methods and findings

Population and COVID-19 epidemiological data between 21st January 2020 to 15th November 2020 from 216 countries and territories were included with the implemented public health interventions. We used deep reinforcement learning, and the algorithm was trained to enable agents to try to find optimal public health strategies that maximized total reward on controlling the spread of COVID-19. The results suggested by the algorithm were analyzed against the actual timing and intensity of lockdown and travel restrictions. Early implementations of the actual lockdown and travel restriction policies, usually at the time of local index case were associated with less burden of COVID-19. In contrast, our agent suggested to initiate at least minimal intensity of lockdown or travel restriction even before or on the day of the index case in each country and territory. In addition, the agent mostly recommended a combination of lockdown and travel restrictions and higher intensity policies than the policies implemented by governments, but did not always encourage rapid full lockdown and full border closures. The limitation of this study was that it was done with incomplete data due to the emerging COVID-19 epidemic, inconsistent testing and reporting. In addition, our research focuses only on population health benefits by controlling the spread of COVID-19 without balancing the negative impacts of economic and social consequences.

Interpretation

Compared to actual government implementation, our algorithm mostly recommended earlier intensity of lockdown and travel restrictions. Reinforcement learning may be used as a decision support tool for implementation of public health interventions during COVID-19 and future pandemics.
Antiviral kinetics of tenofovir alafenamide and tenofovir disoproxil fumarate over 24 weeks in women of childbearing potential with chronic HBV
Authors: Pan Calvin Q. , Chang Ting-Tsung , Bae Si Hyun , Brunetto Maurizia , Seto Wai-Kay , Coffin Carla S. , Tan Susanna K. , Mo Shuyuan , Flaherty John F. , Gaggar Anuj , Nguyen Mindie H. , Çelen Mustafa Kemal , Thompson Alexander , Gane Edward J.
Published: May 2021

Background/Purpose

Use of tenofovir disoproxil fumarate (TDF) improves patient outcomes in preventing mother-to-child transmission (pMTCT) of the hepatitis B virus (HBV) in mothers with chronic HBV and high viral loads. Given the lack of data for tenofovir alafenamide (TAF) in pMTCT, rates of early viral suppression with TAF and TDF were evaluated in women of childbearing potential (WOCBP) participating in 2 randomized, double-blind, Phase 3 studies in chronic HBV.

Methods

In a patient subset meeting WOCBP criteria and with baseline HBV DNA >200,000 IU/mL, rates of viral suppression with TAF or TDF in achieving the target of HBV DNA <200,000 IU/mL at weeks 12 and 24 were assessed. Multivariate logistic regression was used to identify factors predictive of failure to suppress HBV DNA to the target level.

Results

In 275 of 1298 (21%) patients meeting WOCBP criteria with high viral load, 93% and 96% had HBV DNA <200,000 IU/mL at weeks 12 and 24, respectively. Results for TAF (n = 194) vs TDF (n = 81) treatment were similar at weeks 12 and 24 (94% vs. 90% and 97% vs. 93%), respectively. High baseline HBV DNA level, genotype D infection, and prior interferon (week 24 only) were predictive of failure to achieve the target level. Both treatments were well tolerated with TAF showing less impact on renal and bone parameters.

Conclusions

In WOCBP with high VL, no differences were found between TAF and TDF in reducing HBV DNA to levels associated with lower transmission risk. These data support ongoing studies of TAF for pMTCT.
Phenome-wide association of 1809 phenotypes and COVID-19 disease progression in the Veterans Health Administration Million Veteran Program
Authors: Song Rebecca J. , Ho Yuk-Lam , Schubert Petra , Park Yojin , Posner Daniel , Lord Emily M. , Costa Lauren , Gerlovin Hanna , Kurgansky Katherine E. , Anglin-Foote Tori , DuVall Scott , Huffman Jennifer E. , Pyarajan Saiju , Beckham Jean C. , Chang Kyong-Mi , Liao Katherine P. , Djousse Luc , Gagnon David R. , Whitbourne Stacey B. , Ramoni Rachel , Muralidhar Sumitra , Tsao Philip S. , O’Donnell Christopher J. , Gaziano John Michael , Casas Juan P. , Cho Kelly ,   on behalf of the VA Million Veteran Program COVID-19 Science Initiative
Published: May 2021

Background

The risk factors associated with the stages of Coronavirus Disease-2019 (COVID-19) disease progression are not well known. We aim to identify risk factors specific to each state of COVID-19 progression from SARS-CoV-2 infection through death.

Methods and results

We included 648,202 participants from the Veteran Affairs Million Veteran Program (2011-). We identified characteristics and 1,809 ICD code-based phenotypes from the electronic health record. We used logistic regression to examine the association of age, sex, body mass index (BMI), race, and prevalent phenotypes to the stages of COVID-19 disease progression: infection, hospitalization, intensive care unit (ICU) admission, and 30-day mortality (separate models for each). Models were adjusted for age, sex, race, ethnicity, number of visit months and ICD codes, state infection rate and controlled for multiple testing using false discovery rate (≤0.1). As of August 10, 2020, 5,929 individuals were SARS-CoV-2 positive and among those, 1,463 (25%) were hospitalized, 579 (10%) were in ICU, and 398 (7%) died. We observed a lower risk in women vs. men for ICU and mortality (Odds Ratio (95% CI): 0.48 (0.30–0.76) and 0.59 (0.31–1.15), respectively) and a higher risk in Black vs. Other race patients for hospitalization and ICU (OR (95%CI): 1.53 (1.32–1.77) and 1.63 (1.32–2.02), respectively). We observed an increased risk of all COVID-19 disease states with older age and BMI ≥35 vs. 20–24 kg/m2. Renal failure, respiratory failure, morbid obesity, acid-base balance disorder, white blood cell diseases, hydronephrosis and bacterial infections were associated with an increased risk of ICU admissions; sepsis, chronic skin ulcers, acid-base balance disorder and acidosis were associated with mortality.

Conclusions

Older age, higher BMI, males and patients with a history of respiratory, kidney, bacterial or metabolic comorbidities experienced greater COVID-19 severity. Future studies to investigate the underlying mechanisms associated with these phenotype clusters and COVID-19 are warranted.