bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of the Regenerative Potential of Human Bone Marrow Stem Cell-Seeded Polycaprolactone Bone Scaffolds, Fabricated Using Pneumatic Microextrusion Process
Authors: Lawrence Logan , Day James B. , Claudio Pier Paolo , Salary Roozbeh (Ross)
Published: August 2021

Pneumatic MicroExtrusion (PME) is a direct-write additive manufacturing process, which has emerged as a robust, high-resolution method for the fabrication of a broad spectrum of biological tissues and organs. However, the PME process is intrinsically complex, governed by bio-physio-chemical phenomena as well as material-process interactions. Hence, investigation of the influence of consequential factors on bone scaffold fabrication as well as investigation of cell-scaffold interactions would be an inevitable need. The objective of the work is to investigate the biocompatibility as well as the histological properties of PME-fabricated porous bone scaffolds, composed of polycaprolactone (PCL).

To achieve this objective, a media extraction of the scaffold material was tested for cytostatic or cytotoxic activity with the aim to: (i) assess the fabricated scaffolds’ feasibility of use in regenerative medicine, and (ii) determine their structural integrity in a modelled in-vivo environment. In addition, the scaffolds were inoculated with an established osteosarcoma cell line (SAOS-2) and cultured for seven days to investigate the scaffold architecture and cell integration potential. A histological examination was performed on the seeded scaffolds for further in-depth analysis of cell-scaffold interaction. Overall, the results of this study pave the way for future investigation of stem cell incorporation into PME-fabricated PCL scaffolds toward the treatment of osseous fractures and defects.
In-Situ Calibrated Digital Process Twin Models for Resource Efficient Manufacturing
Authors: Adeniji David , Schoop Julius
Published: August 2021

The chief objective of manufacturing process improvement efforts is to significantly minimize process resources such as time, cost, waste, and consumed energy while improving product quality and process productivity. This paper presents a novel physics-informed optimization approach based on artificial intelligence (AI) to generate digital process twins (DPTs). The utility of the DPT approach is demonstrated for the case of finish machining of aerospace components made from gamma titanium aluminide alloy (γ-TiAl). This particular component has been plagued with persistent quality defects, including surface and sub-surface cracks, which adversely affect resource efficiency. Previous process improvement efforts have been restricted to anecdotal post-mortem investigation and empirical modeling, which fail to address the fundamental issue of how and when cracks occur during cutting. In this work, the integration of in-situ process characterization with modular physics-based models is presented, and machine learning algorithms are used to create a DPT capable of reducing environmental and energy impacts while significantly increasing yield and profitability. Based on the preliminary results presented here, an improvement in the overall embodied energy efficiency of over 84%, 93% in process queuing time, 2% in scrap cost, and 93% in queuing cost has been realized for γ-TiAl machining using our novel approach.
A Method to Predict Fatigue Life of Additively Manufactured Metallic Parts
Authors: Zhu Hanyu , Zhao Nanzhu , Patil Sandeep , Bhasin Amit , Li Wei
Published: August 2021

Additive manufacturing (AM) of metallic parts is rapidly evolving and the fatigue behavior of AM parts has become a significant concern in both industry and academia. In this paper, a method to predict the fatigue life of additively manufactured metallic parts is presented based on the electrical resistance measurement. The damage of the AM parts is characterized by the resistance change during the fatigue process. By combining the electrical resistance measurement with a continuum damage mechanics theory, a mathematical model is developed to predict the fatigue life of the AM samples. Fatigue tests were conducted under different loading conditions with AM 316L stainless steel samples. The result showed that the electrical resistance held steady at the beginning and increased gradually with the number of fatigue loading cycles. The resistance increased dramatically as the sample approached the fracture point, and this sudden increase can be used to indicate the beginning of fracture. By converting the electrical resistance to fatigue damage, experimental data was used to estimate parameters of the fatigue life model. By comparing the model prediction with experimental data, it is shown that the change of electrical resistance can be used to predict the fatigue life of additively manufactured metallic parts.
Friction Analysis in Needle Insertion Into Soft Tissue
Authors: Hu Yingda , Li Murong , Lei Yong
Published: August 2021

As one of the preoperative diagnostic methods, needle insertion is widely used for its safety and effectiveness. Recently, robotic needle insertion systems have been under active developments. Hence needle insertion experiments are essential for system verifications, in which the interactions between needle and tissue is a major focus for needle-tissue interactive models, and the friction between the needle and tissue is an important factor. In these experiments, the friction coefficient can be affected by many factors, such as insertion speed, needle-tissue deformation and contact forces. In this paper, to study and analyze the influence of various variables on friction force and friction coefficient, three variables, i.e., tissue pressure on needle, needle insertion velocity and Young’s modulus of the tissue, are systematically studied by constructing a testbed, in which the radial surface friction is converted into equivalent plane friction based on the assumption that the distribution of the normal force and friction force on the needle is uniform for the whole needle outer surface. The experimental results show that the variation range of friction coefficient is 0.122–0.341. The friction coefficient decreases with the increase of pressure and increases with the increase of velocity, while Young’s modulus have a small effect on the friction coefficient.
Prediction of Melt-Pool Characteristics in SLM Process for Ti6Al4V Using a Semi-Analytical Model
Authors: Nandi Shubhra Kamal , Kumar Rakesh , Anubhav  , Agrawal Anupam
Published: August 2021

Selective Laser Melting (SLM) is a powder-based layer-by-layer manufacturing technique to produce metallic customized shape components. The exceptionally high thermal gradient induces residual stress and distorts the part geometry affecting the yield quality. Computational models are instrumental in optimizing the process controls to fabricate high-quality components, and hence several such methods have been explored to simulate the thermal behavior of the process and the heat transfer in the melt-pool. Most of the practiced techniques are computationally expensive, making it infeasible to perform a parametric study. Based on closed-form exact heat conduction solution and Finite Volume Method (FVM), a pseudo-analytical thermal modeling approach has been employed to estimate the melt-pool characteristics and temperature distribution of the SLM process. A moving volumetric Gaussian heat source laser model and Green’s function have been adopted to model the heat input by conduction. The heat loss by conduction and convection has been calculated by implementing Finite Volume discretized equations on a 2-dimensional thin-walled domain with appropriate part boundary conditions. Additionally, the Alternating Direction Implicit iterative technique has been implemented for the fast convergence of the simulation. The model is used to demonstrate the influence of the process parameters and non-linear material phase change for a single-line single layer and multilayer part fabrication. The computed melt-pool dimensions and temperature distribution for varying laser-power, scanning velocity, and layer thickness for Ti6Al4V are validated with the experimental data from the literature with fair agreements.
Energy Efficient Multi-Robotic 3D Printing for Large-Scale Construction – Framework, Challenges, and a Systematic Approach
Authors: Haghighi Azadeh , Mohammed Abdullah , Wang Lihui
Published: August 2021

An emerging trend in smart manufacturing of the future is robotic additive manufacturing or 3D printing which introduces numerous advantages towards fast and efficient printing of high-quality customized products. In the case of the construction industry, and specifically in large-scale settings, multi-robotic additive manufacturing (i.e., adopting a team of 3D printer robots) has been found to be a promising solution in order to overcome the existing size limitations. Consequently, several research efforts regarding the development and control of such robotic additive manufacturing solutions have been reported in the literature. However, given the increasing environmental concerns, establishing novel methodologies for energy-efficient processing and planning of these systems towards higher sustainability is necessary. This paper presents a novel framework towards energy-efficient multi-robotic additive manufacturing and describes the overall challenges with respect to the energy efficiency. The energy module of the proposed framework is implemented in a simulation environment. In addition, a systematic approach for energy-aware robot positioning is introduced based on the novel concept of reciprocal energy map. The reciprocal energy map is established based on the original energy map calculated by the energy module and can be used for identifying the low energy zones for positioning and relocation of robots during the printing process.
Untethered Microrobots With Serpentine Actuators: The Role of Elastics Point Contact & Laser Beam Shape on Their Locomotion
Authors: Chowdhury Sri Sukanta , Yang Zhong , Clapacs Patrick W. , Popa Dan O.
Published: August 2021

FEA simulations of 7 microrobots designed from asymmetric Chevron actuators are presented with in depth analysis of their resonance behavior due to fixed, as well as elastic supports at their contact points with underlying substrate. Experimental resonance frequencies of 3 different designs identified by frequency sweep experiments, excited by a 532 nm pulse laser, are in close agreement with the simulated values. Contact stiffness is estimated by comparing simulated and experimental resonance frequencies. Both in-plane and out of plane motion due to resonance is found in all of these structures that can be used to predict the stick-slip step size (locomotion mechanism) of these robots. In addition, modeling of differential thermal expansion is conducted to optimize the laser spot size that is used to drive these microrobots. Simulations of elliptic and circular laser spots with varying size suggest that covering only the actuators of the robot is sufficient for successful actuation. Using a circular laser spot increase the thermal expansion of the overall microrobot by 3.3 nm resulting in no significant gain in step size/gait of the robotic locomotion. This finding proves that the shape and size of the laser spot are insignificant as long as the actuators are under the laser beam.
Toward Intelligent Online Scan Sequence Optimization for Uniform Temperature Distribution in LPBF Additive Manufacturing
Authors: Ramani Keval S. , Malekipour Ehsan , Okwudire Chinedum E.
Published: August 2021

Laser powder bed fusion (LPBF) is an increasingly popular approach for additive manufacturing (AM) of metals. However, parts produced by LPBF are prone to residual stresses, deformations, and other defects linked to nonuniform temperature distribution during the process. Several works have highlighted the important role (laser) scanning strategies, including laser power, scan speed, scan pattern and scan sequence, play in achieving uniform temperature distribution in LPBF. However, scan sequence continues to be determined offline based on trial-and-error or heuristics, which are neither optimal nor generalizable. To address these weaknesses, we present a framework for intelligent online scan sequence optimization to achieve uniform temperature distribution in LPBF. The framework involves the use of physics-based models for online optimization of scan sequence, while data acquired from in-situ thermal sensors provide correction or calibration of the models. The proposed framework depends on having: (1) LPBF machines capable of adjusting scan sequence in real-time; and (2) accurate and computationally efficient models and optimization approaches that can be efficiently executed online. The first challenge is addressed via a commercially available open-architecture LPBF machine. As a preliminary step towards tackling the second challenge, an analytical model is explored for determining the optimal sequence for scanning patterns in LPBF. The model is found to be deficient but provides useful insights into future work in this direction.
Multi-Agent-Based Self-Organizing Manufacturing Network Towards Mass Personalization
Authors: Qin Zhaojun , Lu Yuqian
Published: August 2021

Mass personalization is arriving. It requires smart manufacturing capabilities to responsively produce personalized products with dynamic batch sizes in a cost-effective way. However, current manufacturing system automation technologies are rigid and inflexible in response to ever-changing production demands and unforeseen internal system status. A manufacturing system is required to address these challenges with adaptive self-organization capabilities to achieve flexible, autonomous, and error-tolerant production. Within the context, the concept of Self-Organizing Manufacturing Network has been proposed to achieve mass personalization production. In this paper, we propose a four-layer system-level control architecture for Self-Organizing Manufacturing Network. This architecture has additional two layers (namely, Semantic Layer and Decision-Making Layer) on Physical Layer and Cyber Layer to improve communication, interaction, and distributed collaborative system automation. In this architecture, manufacturing resources are encapsulated as Semantic Twins to make interoperable peer communication in the manufacturing network. The interaction of Semantic Twins consolidates system status and manufacturing environment that enables multi-agent control technologies to optimize manufacturing operations and system performance.
Influence of Tool Runout on Force Measurement During Internal Void Monitoring for Friction Stir Welding of 6061-T6 Aluminum
Authors: Franke Daniel , Zinn Michael , Rudraraju Shiva , Pfefferkorn Frank E.
Published: August 2021

The goal of this research was to examine how altering the amount of friction stir tool eccentricity while controlling the amount of slant in the tool shoulder (drivers of oscillatory process forces) effects the generation of process force transients during sub-surface void interaction. The knowledge gained will help improve the accuracy of force-based void monitoring methods that have the potential to reduce the need for post-weld inspection. Process force transients during sub-surface void formation were examined for multiple tools with varying magnitudes of kinematic runout. The eccentric motion of the tool produced oscillations in the process forces at the tools rotational frequency that became distorted when features (flats) on the tool probe interacted with voided volumes, generating an amplitude in the force signals at three times the tool rotational frequency (for three flat tools). A larger tool eccentricity generates a larger amplitude in the force signals at the tool’s rotational frequency that holds a larger potential to create a distortion during void interaction. It was determined that once void becomes large enough to produce an interaction that generates an amplitude at the third harmonic larger than 30% of the amplitude at the rotational frequency in a weld with no interaction (amplitude solely at rotational frequency), the trailing edge of the tool shoulder cannot fully consolidate the void, i.e., it will remain in the final weld. Additionally, once the void exceeds a certain size, the amplitudes of the third harmonics saturate at 70% of the amplitude at the rotational frequency during full consolidation. The interaction between the eccentric probe and sub-surface void was isolated by ensuring any geometric imperfection in the shoulder (slant) with respect to the rotational axis was removed. The results suggest that geometric imperfections (eccentricity and slant) with respect to the tool’s rotational axis must be known when developing a void monitoring method from force transients of this nature.
Study on Non-Axisymmetric 3D Curved Surface Turning by Driven-Type Rotary Tool Synchronized With Spindle
Authors: Ishizuka Akane , Ueda Narimasa , Morimoto Yoshitaka , Hayashi Akio , Kaneko Yoshiyuki , Suzuki Naohiko
Published: August 2021

Since shifting to electric vehicles as a countermeasure against global warming is not always easy to complete, the hybrid car has been considered as another possible solution. However, based on the calculation of total CO2 emissions, all hybrid cars which will constitute 90% of all cars are expected to be equipped with an internal combustion engine even after 2030. Therefore, further efficiency improvement of the internal combustion engine is necessary. One of the key factors is the variable valve timing and variable lift with the 3D cam mechanism. Since conventional technology uses a complicated link mechanism and servo motor control, this leads a problem to set into small cars or motorcycles because they cannot afford to install the variable valve timing and variable lift with cam mechanism. To solve this problem, a cam shape with a three-dimensional curved surface has been proposed. In order to create this shape, the machining method for non-axisymmetric curved surface turning (NACS-Turning) is required. To build the new system, our research group has proposed a new machining method using a driven type rotary tool and a linear motor driven moving table to enable to achieve NACS-Turning. In this new system, a new tool rotation axis (B axis) is adopted to synchronize its rotational position with the rotational position of the spindle (C axis) holding the workpiece, the X1-, X2-, and Z-Axis positions in total. In this paper, the new hardware configuration is proposed to overcome the present machining accuracy.
Role of point-of-care ultrasound (POCUS) in the diagnosis of an abscess in paediatric skin and soft tissue infections: a systematic review and meta-analysis
Authors: Wu Jiangfeng , Ge Lijing , Wang Xiaoyun , Jin Yun
Published: August 2021

Aims: To evaluate the effect of point-of-care ultrasound (POCUS) for the diagnosis of an abscess and to compare the diagnostic accuracy of POCUS and physical examination (PE) in paediatric patients with skin and soft tissue infections (SSTI) in the emergency department.Material and methods: A comprehensive literature search was carried out to identify Englishlanguage studies on POCUS for differentiating an abscess from cellulitis in paediatric patients with SSTI. The quality of the study was assessed by the Quality Assessment of Diagnostic Accuracy Studies 2 tool, and pooled sensitivity and specificity of various POCUS findings were determined.Results: Seven studies with a total of 870 patients were included. There was significant heterogeneity across the included studies. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio for the diagnosis of abscess by POCUS were 0.90 (95% confidence interval [CI], 0.82-0.95), 0.80 (95% CI, 0.72-0.86), 4.5 (95% CI, 3.1-6.4), 0.13 (95% CI, 0.07-0.23), and 36 (95% CI, 17-75), respectively, with an area under the curve (AUC) was 0.89 (95% CI, 0.86-0.91). Four studies provided data regarding the PE method. The pooled sensitivity, specificity, and AUC of PE for the abscess were 0.84 (95% CI, 0.80-0.88), 0.69 (95% CI, 0.62-0.76), and 0.85 (95% CI, 0.81-0.88).Conclusions: POCUS is useful in identifying abscesses in paediatric patients with SSTI in emergency department, especially when PE is equivocal and outperforms PE alone.
Ascariasis, a review
Authors: Schindler-Piontek Markus , Chaubal Nitin , Dehmani Sirine , Cui Xin Wu , Dong Yi , Sharma Malay , Dietrich Christoph F
Published: August 2021

Ascariasis no longer widespread within Europe and so experience in diagnosis and treatment is limited for many specialists. On the other hand, clinicians face increasing numbers of migrants from high prevalence countries and are therefore, challenged to update in this field of infectious diseases. Here we present imaging features and current knowledge of this infection.
Social Support and Physical Activity in Older Adults: Identifying Predictors Using Data From the Canadian Longitudinal Study on Aging
Authors: Zimmer Chantelle , McDonough Meghan H.
Published: August 2021

This study examined which of nine forms of social support were the strongest predictors of physical activity in older adults, and to what degree these associations were moderated by eight demographic indicators of groups at increased risk of social isolation. Baseline data from 21,491 adults aged 65 and older who were participants of the Canadian Longitudinal Study on Aging were analyzed using multiple regression. Greater social network size, social contact with network members, and participation in community-related activities predicted greater physical activity, whereas being in a domestic partnership and perceiving more tangible support to be available were negatively associated. The strength and direction of these associations varied by sex, living arrangement, and income. Given the findings, various forms of social support should be incorporated in physical activity interventions but tailored to meet the needs of different segments of the aging population.
Risk Factors for Mobility Decline in Community-Dwelling Older Adults: A Systematic Literature Review
Authors: Nicolson Philippa J.A. , Sanchez-Santos Maria T. , Bruce Julie , Kirtley Shona , Ward Lesley , Williamson Esther , Lamb Sarah E.
Published: August 2021

Mobility is essential to maintaining independence for older adults. This systematic review aimed to summarize evidence about self-reported risk factors for self-reported mobility decline; and to provide an overview of published prognostic models for self-reported mobility decline among community-dwelling older adults. Databases were searched from inception to June 2, 2020. Studies were screened by two independent reviewers who extracted data and assessed study quality. Sixty-one studies (45,187 participants) were included, providing information on 107 risk factors. High-quality evidence and moderate/large effect sizes for the association with mobility decline were found for older age beyond 75 years, the presence of widespread pain, and mobility modifications. Moderate–high quality evidence and small effect sizes were found for a further 21 factors. Three model development studies demonstrated acceptable model performance, limited by high risk of bias. These findings should be considered in intervention development, and in developing a prediction instrument for practical application.
High-Efficiency Genome Editing Based on Endogenous CRISPR-Cas System Enhances Cell Growth and Lactic Acid Production in Pediococcus acidilactici
Authors: Liu Ling , Yang Danlu , Zhang Zhiyu , Liu Tao , Hu Guoquan , He Mingxiong , Zhao Shumiao , Peng Nan
Published: August 2021

A rapid and precise genome editing tool will promote the practical application of
Pediococcus acidilactici
, one type of lactic acid bacteria with excellent stress tolerance and probiotic characteristics. This study established a high-efficiency endogenous CRISPR-Cas system-based genome editing tool for
P. acidilactici
and achieved different genetic manipulations, including gene deletion, gene insertion, mononucleotide mutation, and endogenous plasmid depletion.
Evaluation of FASTinov Ultrarapid Flow Cytometry Antimicrobial Susceptibility Testing Directly from Positive Blood Cultures
Authors: Silva-Dias Ana , Pérez-Viso Blanca , Martins-Oliveira Inês , Gomes Rosário , Rodrigues Acácio G. , Cantón Rafael , Pina-Vaz Cidália
Published: August 2021

The FASTinov flow cytometry kit, an ultrarapid antimicrobial susceptibility test, was directly evaluated on positive blood cultures (BC) at two sites: (i) FASTinov, S.A., in Porto, Portugal, using BC spiked with well-characterized bacteria, and (ii) Ramon y Cajal University Hospital in Madrid, Spain, using positive BC from patients. Two kits were evaluated, FAST
gramneg
(
Enterobacterales
,
Pseudomonas
,
Acinetobacter
) and FAST
grampos
(
Staphylococcus
, Enterococcus
).
Virus-Like Vesicles Based on Semliki Forest Virus-Containing Rabies Virus Glycoprotein Make a Safe and Efficacious Rabies Vaccine Candidate in a Mouse Model
Authors: Zhang Chengguang , Tian Yuling , Chen Chen , Wang Zongmei , Pei Jie , Lin Chuhan , Zhou Ming , Fu Zhen F. , Zhao Ling
Published: August 2021

VLVs have been shown to represent a more versatile and superior vaccine platform. In previous studies, VLVs containing the Semliki Forest virus replicase (SFV nsP1 to nsP4) and rabies virus glycoprotein (RABV-G) grew to relatively low titers in cells.
A Transferable IncC-IncX3 Hybrid Plasmid Cocarrying
bla
NDM-4
,
tet
(X), and
tmexCD3-toprJ3
Confers Resistance to Carbapenem and Tigecycline
Authors: Hirabayashi Aki , Dao Trung Duc , Takemura Taichiro , Hasebe Futoshi , Trang Le Thi , Thanh Nguyen Ha , Tran Hoang Huy , Shibayama Keigo , Kasuga Ikuro , Suzuki Masato
Published: August 2021

Tigecycline is important as a last-resort antimicrobial and effective against antimicrobial-resistant bacteria, such as carbapenem-producing
Enterobacterales
(CPE), whose infections are difficult to treat with antimicrobials. Since 2019, mobile tigecycline resistance genes,
tet
(X) and
tmexCD-toprJ
, and their variants have been reported mainly from China, and it has become important to understand their epidemiological situation and detailed genetic mechanisms.
Remitting seronegative symmetrical synovitis with pitting oedema following BNT162b2 mRNA COVID-19 vaccination
Authors: Parperis Konstantinos , Constantinou Maria
Published: August 2021

Remitting seronegative symmetrical synovitis with pitting oedema (RS3PE) is a rare inflammatory condition that occurs in older adults. Here, we report a case of an 80-year-old man with no history of rheumatic disease who presented with acute onset of bilateral hand pain, pitting oedema and synovitis after the second dose of the BNT162b2 mRNA C0VID-19 vaccine. Laboratory workup revealed elevated inflammatory markers and negative autoantibodies. Significant improvement was noted with prednisolone. This is the first reported case of RS3PE in an elderly patient with no previous rheumatic disease following mRNA COVID-19 vaccination.
Association between statin use and the risks of glaucoma in Australia: a 10-year cohort study
Authors: Yuan Yixiong , Wang Wei , Shang Xianwen , Xiong Ruilin , Ha Jason , Zhang Lei , Zhu Zhuoting , He Mingguang
Published: August 2021

Synopsis

In a cohort of middle-aged and elderly Australians, we found that long-term statin use was associated with a higher risk of glaucoma onset. As to subtypes of statins, the increased risk was only found in rosuvastatin users.

Purpose

To investigate the relationship between statin use and glaucoma onset in a 10-year longitudinal study.

Methods

This nested case–control study was based on data from a large-scale cohort of Australians aged over 45 years old. Medication exposure was identified by claims records from the Pharmaceutical Benefits Scheme during the follow-up period (2009–2016). The onset of glaucoma was defined as the people with at least three claims of antiglaucoma medications. Controls matched by age, gender and cardiovascular diseases were selected from participants without prescription of antiglaucoma medications. A conditional logistic regression model was used to assess the association between statin use and glaucoma onset.

Results

The proportion of statin users was higher in the case group (40.5%) than that in the control group (38.4%). After adjusting for baseline characteristics and longitudinal claims records, statin use was not associated with glaucoma onset (OR 1.04, 95% CI 0.97 to 1.11). However, an increased risk of glaucoma onset was observed in participants with a longer duration of statin use (>3 years vs <1 year: OR 1.12, 95% CI 1.04 to 1.21). With respect to specific types of statins, participants taking rosuvastatin were more likely to suffer from glaucoma (OR 1.11, 95%CI 1.01 to 1.22). The use of other statins was not significantly associated with glaucoma onset.

Conclusions

Long-term statin use was found to be associated with a higher risk of glaucoma onset in this study. Regarding specific types of statins, the increased risk of glaucoma onset was only observed in users of rosuvastatin.
Charles Bonnet syndrome in patients with Stargardt disease: prevalence and risk factors
Authors: Dhooge Patty P A , Teunisse Rob J , Liefers Bart , Lambertus Stanley , Bax Nathalie M , Hoyng Carel B , Cruysberg Johannes R M , Klevering B Jeroen
Published: August 2021

Aims

To describe the prevalence of the Charles Bonnet syndrome (CBS) and search for potential CBS risk factors in a Dutch Stargardt disease (STGD1) cohort.

Methods

Eighty-three patients with STGD1 were screened for CBS. They underwent a full eye examination. All patients completed the social functioning domain of the 36-Item Short Form Health Survey questionnaire. Participants suspected of CBS were interviewed to further evaluate their visual hallucinations.

Results

CBS prevalence was 8.4%. Six out of seven patients with CBS were women. CBS was not associated with age (p=0.279, Mann-Whitney). Patients with CBS had a significant lower social functioning score (p<0.05, Mann-Whitney). All seven patients with CBS were in the category of vision impairment (visual acuity <6/12, but ≥3/60). Moreover, first hallucinations manifested after a drop in visual acuity. The retinal atrophic area of the worst eye tended to be lower in the CBS group (range 0.11–9.86 mm2) as compared with controls (range 0–180 mm2). There was no relation between the position of the scotoma and the location of the visual hallucinations.

Conclusion

The relative high CBS prevalence in STGD1 suggests that CBS may be more prevalent in younger ophthalmic patients than currently presumed. In this specific group of patients, we established social isolation and acquired vision impairment as risk factors for CBS. There was a female preponderance among patients with CBS. Age and retinal pigment epithelium atrophy were not identified as significant risk factors. We should actively diagnose CBS in patients of any age who fulfil the criteria for the category vision impairment, especially in cases where social isolation is suspected.
Trends in the co-use of alcohol and tobacco among Japanese adolescents: periodical nationwide cross-sectional surveys 1996–2017
Authors: Fujii Maya , Kuwabara Yuki , Kinjo Aya , Imamoto Aya , Jike Maki , Otsuka Yuichiro , Itani Osamu , Kaneita Yoshitaka , Minobe Ruriko , Maesato Hitoshi , Higuchi Susumu , Yoshimoto Hisashi , Kanda Hideyuki , Osaki Yoneatsu
Published: August 2021

Objectives

This study aimed to assess trends in the prevalence of alcohol use depending on smoking behaviours and that of smoking depending on drinking behaviours among Japanese adolescents.

Design

This was a retrospective study using Japanese school-based nationwide surveys conducted between 1996 and 2017.

Setting

Surveyed schools, both junior and senior high schools, considered representative of the entire Japanese population, were sampled randomly.

Participants

We enrolled 11 584–64 152 students from 179 to 103 schools yearly. They completed a self-reported and anonymous questionnaire on smoking and drinking behaviour.

Results

Since 1996, the prevalence of alcohol use and smoking among adolescents decreased in each survey (p<0.01). The prevalence of alcohol use in the non-smokers group was 29.0% in 1996 and 4.0% in 2017, and in the smokers group, it was 73.3% in 1996 and 57.4% in 2017. The reduction rate (the difference in prevalence between 1996 and 2017 divided by the prevalence in 1996) was 0.86 in the non-smokers group and 0.22 in the smokers group. The prevalence of smoking in the non-drinkers group was 6.7% in 1996 and 0.7% in 2017, while that in the drinkers group was 32.5% in 1996 and 18.9% in 2017. The reduction rate was 0.90 in the non-drinkers group and 0.42 in the drinkers group. Therefore, downward trends differed among the groups. In a subanalysis of senior high school students, we divided students into three groups according to their intention to pursue further education. Between 1996 and 2017, there was a consistent difference in the prevalence of alcohol use and smoking among these groups.

Conclusions

Alcohol use and smoking among Japanese adolescents seem to have reduced. However, certain groups showed poor improvements, and health risk behaviour disparity exists, which may widen further. We need to focus on high-risk groups and implement appropriate measures or interventions accordingly.
Developing a recovery-focused therapy for older people with bipolar disorder: a qualitative focus group study
Authors: Tyler Elizabeth , Lobban Fiona , Long Rita , Jones Steven H
Published: August 2021

Objectives

As awareness of bipolar disorder (BD) increases and the world experiences a rapid ageing of the population, the number of people living with BD in later life is expected to rise substantially. There is no current evidence base for the effectiveness of psychological interventions for older adults with BD. This focus group study explored a number of topics to inform the development and delivery of a recovery-focused therapy (RfT) for older adults with BD.

Design

A qualitative focus group study.

Setting

Three focus groups were conducted at a university in the North West of England.

Participants

Eight people took part in the focus groups; six older adults with BD, one carer and one friend.

Results

Participant’s responses clustered into six themes: (1) health-related and age-related changes in later life, (2) the experience of BD in later life, (3) managing and coping with BD in later life, (4) recovery in later life, (5) seeking helping in the future and (6) adapting RfT for older people.

Conclusions

Participants reported a range of health-related and age-related changes and strategies to manage their BD. Participants held mixed views about using the term ‘recovery’ in later life. Participants were in agreement that certain adaptations were needed for delivering RfT for older adults, based on their experience of living with BD in later life. The data collected as part of the focus groups have led to a number of recommendations for delivering RfT for older adults with BD in a randomised controlled trial (Clinical Trial Registration:ISRCTN13875321).
Physician adherence to acute rhinosinusitis antibiotic treatment guidelines
Authors: Levi Esther , Ronen Ohad
Published: August 2021

Antibiotic treatment guidelines promote proper diagnosis and treatment and optimize antibiotic treatment, minimizing both antimicrobial resistance to antibiotics and financial expenditure. This study aimed to investigate whether community physicians and emergency department (ED) physicians diagnose and treat acute rhinosinusitis according to accepted guidelines. This was a retrospective study of medical records and referrer letters of patients admitted to the medical center between 2014 and 2015. Physician adherence to antibiotic guidelines regarding indication, type and duration of treatment was assessed. Overall, the study included 84 patients diagnosed with acute rhinosinusitis and admitted to the ED. Fewer than 20% of doctors treating patients with rhinosinusitis at our institution followed the current recommended guidelines. In most cases, the type of treatment administered by ED physicians and by community physicians complied with the guidelines (90% and 96%, respectively, p=0.564). The duration of treatment prescribed by the ED physicians aligned with the guidelines in 37.7% of the cases. There was insufficient compliance with acute rhinosinusitis treatment guidelines among all treating physicians in this study, which was characterized by excessive antibiotic treatment. Therefore, ways to increase understanding and adherence to clinical guidelines, and to provide optimal settings in the clinics to carry out the guidelines should be investigated.
Complications of Nasal SARS-CoV-2 Testing: A Review
Authors: Clark James H , Pang Sharon , Naclerio Robert M , Kashima Matthew
Published: August 2021

Transnasal swab testing for the detection of SARS-CoV-2 is well established. The Centers for Disease Control and Prevention advocates swabbing either of the anterior nares, middle turbinate, or nasopharynx for specimen collection depending on available local resources. The purpose of this review is to investigate complications related to transnasal SARS-CoV-2 testing with specific attention to specimen collection site and swab approach. The literature demonstrates that while nasopharyngeal swabbing is associated with an increased risk of complications, it should remain the gold-standard test due to greater diagnostic accuracy relative to anterior nasal and middle turbinate swabs.
Predominant learning approaches of medical students in Saudi Arabia
Authors: AlOmar Reem S , AlShamlan Nouf A , AlAmer Naheel A , Albrahim Nouf I , Alshulah Zainab Z , Kalalah Zahra A , Almoaibed Danah M , Alshulah Hawra Z , AlRashid Musaad R , Althumairi Abdulaziz A , Althunyan Abdullatif K
Published: August 2021

Purpose of the study

This study aims at identifying the predominant learning approaches by Saudi medical students across Saudi Arabia and assess its possible associations with sociodemographic and educational characteristics.

Study design

A cross-sectional study design using the Approaches and Study Skills Inventory for Students questionnaire. The questionnaire gives rise to three possible learning approaches; deep, strategic and surface approaches. Bivariate analyses were performed through independent samples t-test and χ2 tests where appropriate. A multinominal regression analysis was performed to obtain risk estimates and 95% CIs.

Results

A total of 3767 students participated and were included in the analysis. The predominant learning approach was the deep approach, followed by the strategic and surface approaches (40.59%, 37.81% and 21.60%, respectively). Males and students belonging to private medical schools were more likely to adopt a strategic rather than a deep one (relative risk ratio (RRR) 1.22, 95% CI 1.06 to 1.42 and RRR 1.32, 95% CI 1.05 to 1.65, respectively). Students with an A grade point average (GPA) were less likely to adopt a surface approach, whereas those with a C GPA were more likely to adopt it (RRR=0.67, 95% CI 0.54 to 0.83 and RRR=1.29, 95% CI 1.02 to 1.61, respectively).

Conclusion

The findings from this study show that medical students predominantly favour the deep learning approach. Results from this study encourage the continuous adaptation of clinical teaching in medical schools to optimise students’ learning experiences.
Spin-1 resonances
Authors: De Curtis Stefania , Dominici Daniele
Published: August 2021

Spin-1 resonances are naturally present in composite Higgs frameworks. We first review a model independent approach to parameterize a single additional heavy triplet and then we consider more realistic models arising in composite Higgs scenarios where a larger number of spin-1 resonances is expected. In these cases, finite width and interference effects can heavily affect the bounds extracted from the data.
Declarative Machine Learning Systems
Authors: Molino Piero , Ré Christopher
Published: August 2021

The people training and using ML models now are typically experienced developers with years of study working within large organizations, but the next wave of ML systems should allow a substantially larger number of people, potentially without any coding skills, to perform the same tasks. These new ML systems will not require users to fully understand all the details of how models are trained and used for obtaining predictions, but will provide them a more abstract interface that is less demanding and more familiar. Declarative interfaces are well-suited for this goal, by hiding complexity and favoring separation of interest, and ultimately leading to increased productivity.
Hostile Takeover: How Viruses Reprogram Prokaryotic Metabolism
Authors: Jacobson Tyler B. , Callaghan Melanie M. , Amador-Noguez Daniel
Published: August 2021

To reproduce, prokaryotic viruses must hijack the cellular machinery of their hosts and redirect it toward the production of viral particles. While takeover of the host replication and protein synthesis apparatus has long been considered an essential feature of infection, recent studies indicate that extensive reprogramming of host primary metabolism is a widespread phenomenon among prokaryotic viruses that is required to fulfill the biosynthetic needs of virion production. In this review we provide an overview of the most significant recent findings regarding virus-induced reprogramming of prokaryotic metabolism and suggest how quantitative systems biology approaches may be used to provide a holistic understanding of metabolic remodeling during lytic viral infection.
Sleep and Diet: Mounting Evidence of a Cyclical Relationship
Authors: Zuraikat Faris M. , Wood Rebecca A. , Barragán Rocío , St-Onge Marie-Pierre
Published: August 2021

Two factors intrinsic to health are diet and sleep. These two behaviors may well influence one another. Indeed, that insufficient sleep adversely impacts dietary intakes is well documented. On the other hand, diet may influence sleep via melatonin and its biosynthesis from tryptophan. Experimental data exist indicating that provision of specific foods rich in tryptophan or melatonin can improve sleep quality. Whole diets rich in fruits, vegetables, legumes, and other sources of dietary tryptophan and melatonin have been shown to predict favorable sleep outcomes. Although clinical trials are needed to confirm a causal impact of dietary patterns on sleep and elucidate underlying mechanisms, available data illustrate a cyclical relation between these lifestyle factors. We recommend adopting a healthful diet to improve sleep, which may further promote sustained favorable dietary practices.
Face Recognition by Humans and Machines: Three Fundamental Advances from Deep Learning
Authors: O'Toole Alice J. , Castillo Carlos D.
Published: August 2021

Deep learning models currently achieve human levels of performance on real-world face recognition tasks. We review scientific progress in understanding human face processing using computational approaches based on deep learning. This review is organized around three fundamental advances. First, deep networks trained for face identification generate a representation that retains structured information about the face (e.g., identity, demographics, appearance, social traits, expression) and the input image (e.g., viewpoint, illumination). This forces us to rethink the universe of possible solutions to the problem of inverse optics in vision. Second, deep learning models indicate that high-level visual representations of faces cannot be understood in terms of interpretable features. This has implications for understanding neural tuning and population coding in the high-level visual cortex. Third, learning in deep networks is a multistep process that forces theoretical consideration of diverse categories of learning that can overlap, accumulate over time, and interact. Diverse learning types are needed to model the development of human face processing skills, cross-race effects, and familiarity with individual faces.
Endothelial cell PHD2-HIF1α-PFKFB3 contributes to right ventricle vascular adaptation in pulmonary hypertension
Authors: Kassa Biruk , Kumar Rahul , Mickael Claudia , Sanders Linda , Vohwinkel Christine , Lee Michael H. , Gu Sue , Poth Jens M. , Stenmark Kurt R. , Zhao You-Yang , Tuder Rubin M. , Graham Brian B.
Published: August 2021

Humans and animals with pulmonary hypertension (PH) show right ventricular (RV) capillary growth, which positively correlates with overall RV hypertrophy. However, molecular drivers of RV vascular augmentation in PH are unknown. Prolyl hydroxylase (PHD2) is a regulator of hypoxia-inducible factors (HIFs), which transcriptionally activates several proangiogenic genes, including the glycolytic enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3). We hypothesized that a signaling axis of PHD2-HIF1α-PFKFB3 contributes to adaptive coupling between the RV vasculature and tissue volume to maintain appropriate vascular density in PH. We used design-based stereology to analyze endothelial cell (EC) proliferation and the absolute length of the vascular network in the RV free wall, relative to the tissue volume in mice challenged with hypoxic PH. We observed increased RV EC proliferation starting after 6 h of hypoxia challenge. Using parabiotic mice, we found no evidence for a contribution of circulating EC precursors to the RV vascular network. Mice with transgenic deletion or pharmacological inhibition of PHD2, HIF1α, or PFKFB3 all had evidence of impaired RV vascular adaptation following hypoxia PH challenge. PHD2-HIF1α-PFKFB3 contributes to structural coupling between the RV vascular length and tissue volume in hypoxic mice, consistent with homeostatic mechanisms that maintain appropriate vascular density. Activating this pathway could help augment the RV vasculature and preserve RV substrate delivery in PH, as an approach to promote RV function.
Alamandine but not angiotensin-(1–7) produces cardiovascular effects at the rostral insular cortex
Authors: Marins Fernanda Ribeiro , Oliveira Aline Cristina , Qadri Fatimunnisa , Motta-Santos Daisy , Alenina Natalia , Bader Michael , Fontes Marco Antonio Peliky , Santos Robson Augusto Souza
Published: August 2021

Experiments aimed to evaluate the tissue distribution of Mas-related G protein-coupled receptor D (MrgD) revealed the presence of immunoreactivity for the MrgD protein in the rostral insular cortex (rIC), an important area for autonomic and cardiovascular control. To investigate the relevance of this finding, we evaluated the cardiovascular effects produced by the endogenous ligand of MrgD, alamandine, in this brain region. Mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA) were recorded in urethane anesthetized rats. Unilateral microinjection of equimolar doses of alamandine (40 pmol/100 nL), angiotensin-(1–7), angiotensin II, angiotensin A, and Mas/MrgD antagonist d-Pro7-Ang-1-7 (50 pmol/100 nL), Mas antagonist A779 (100 pmol/100 nL), or vehicle (0.9% NaCl) were made in different rats ( n = 4–6/group) into rIC. To verify the specificity of the region, a microinjection of alamandine was also performed into intermediate insular cortex (iIC). Microinjection of alamandine in rIC produced an increase in MAP (Δ = 15 ± 2 mmHg), HR (Δ = 36 ± 4 beats/min), and RSNA (Δ = 31 ± 4%), but was without effects at iIC. Strikingly, an equimolar dose of angiotensin-(1–7) at rIC did not produce any change in MAP, HR, and RSNA. Angiotensin II and angiotensin A produced only minor effects. Alamandine effects were not altered by A-779, a Mas antagonist, but were completely blocked by the Mas/MrgD antagonist d-Pro7-Ang-(1–7). Therefore, we have identified a brain region in which alamandine/MrgD receptor but not angiotensin-(1–7)/Mas could be involved in the modulation of cardiovascular-related neuronal activity. This observation also suggests that alamandine might possess unique effects unrelated to angiotensin-(1–7) in the brain.