bluuebunny/crossref_metadata_2025 huggingface dataset:
Perfluorooctanoic acid inhibits the maturation rate of mouse oocytes cultured in vitro by triggering mitochondrial and DNA damage
Authors: Guo Conghui , Zhao Zhihong , Zhao Kun , Huang Jianhao , Ding Linshu , Huang Xiaogang , Meng Li , Li Li , Wei Hengxi , Zhang Shouquan
Published: April 2021

Background

Perfluorooctanoic acid (PFOA) is widely used in the manufacture of household and industrial products. It has certain toxicity and leaves many residues in the environment. Numerous studies have shown that PFOA exhibits endocrine disrupting properties and immunotoxicity and induces developmental defects. However, there is very little information regarding its toxicity on oocytes.

Methods

We cultured denuded oocytes in maturation medium supplemented with 0, 300, or 500 PFOA during IVM and evaluated the maturation of oocytes from the aspects of ROS(DCFH‐DA), mitochondria(MitoOrange and JC‐1), DNA damage(P‐H2AX), and cytoskeleton(β‐tubulin).

Results

Compared with the control group, the PFOA treatment group exhibited significantly reduced proportion of oocytes matutation. Furthermore, the DCFH‐DA test showed that PFOA significantly increased reactive oxygen species (ROS) levels. PFOA disrupted mitochondrial distribution and decreased mitochondrial function as assessed using MitoOrange and JC‐1. In addition, PFOA‐treated oocytes exhibited a significantly higher percentage of P‐H2AX, defective β‐tubulin, abnormal chromosome alignment, lower expression of the anti‐apoptotic gene Bcl‐2, and higher expression of the apoptotic genes caspase3 and Bax.

Conclusion

In summary, PFOA could negatively and directly affect oocyte maturation in vitro and cause oxidative stress, mitochondrial function disruption, DNA damage, cytoskeleton damage, and apoptosis.
Modeling and computation of multistep batch testing for infectious diseases
Authors: Ahn Hongshik , Jiang Haoran , Li Xiaolin
Published: April 2021

We propose a mathematical model based on probability theory to optimize COVID‐19 testing by a multistep batch testing approach with variable batch sizes. This model and simulation tool dramatically increase the efficiency and efficacy of the tests in a large population at a low cost, particularly when the infection rate is low. The proposed method combines statistical modeling with numerical methods to solve nonlinear equations and obtain optimal batch sizes at each step of tests, with the flexibility to incorporate geographic and demographic information. In theory, this method substantially improves the false positive rate and positive predictive value as well. We also conducted a Monte Carlo simulation to verify this theory. Our simulation results show that our method significantly reduces the false negative rate. More accurate assessment can be made if the dilution effect or other practical factors are taken into consideration. The proposed method will be particularly useful for the early detection of infectious diseases and prevention of future pandemics. The proposed work will have broader impacts on medical testing for contagious diseases in general.
Disorders in the Executive Performance of Children Suffering Abuse
Authors: Moreno‐Manso Juan Manuel , de la Rosa Murillo María , García‐Baamonde M.ª. Elena , Godoy‐Merino M.ª. José , Lucas‐Milán M.ª. Guadalupe , Guerrero‐Molina Mónica
Published: April 2021

Child abuse is an adverse life experience that has important physical and psychological implications. This work studies the executive functions of children who have suffered abuse and whether there are differences in the executive functioning due to the different types of child abuse. The participants included 74 children between seven and 16 years of age suffering maltreatment. The results indicate that those suffering any type of abuse have difficulties in executive performance for activities related to cognitive flexibility, behavioural organisation, and planning and attention. There is evidence of significant differences between victims who experience physical abuse and those who experience physical neglect. The victims of physical neglect have greater difficulties in mental flexibility, inhibition of responses and alternation. This research contributes to the knowledge base needed to propose interventions that are aimed at developing functional skills in the children and which would allow them to have effective executive functioning. Intervention could be aimed at working on their capacity to take initiative, organise and plan activities, establish goals, adapt to changes, be more thoughtful and be able to analyse situations before acting, and on their rigidity of thought.

‘Studies the executive functions of children who have suffered abuse and … differences … due to the different types of child abuse’

Key Practitioner Messages

The research shows the presence of alterations in the executive functions of victims of child abuse.

There is evidence of difficulties in mental flexibility, establishing goals and attention control.

The study highlights that the greatest problems in executive functions are found in victims of physical neglect.
Tandem Synthesis of ϵ‐Caprolactam from Cyclohexanone by an Acidified Metal‐organic Framework
Authors: Zhang Biying , Li Xinle , Chen Jingwen , Liu Tianqing , Cruz Andrew , Pei Yuchen , Chen Minda , Wu Xun , Huang Wenyu
Published: April 2021

Tandem synthesis of ϵ‐caprolactam, one of the largest scaled commercial chemicals, is highly desired from the viewpoint of cost, energy, and environment. However, relevant studies have remained largely underexplored. By using a one‐pot strategy, we encapsulated phosphotungstic acid (PTA) into a chromium terephthalate metal‐organic framework (MOF), MIL‐101, for the efficient tandem conversion of cyclohexanone to ϵ‐caprolactam. The highly dispersed PTA in the MOF matrix showed a high yield of ϵ‐caprolactam through a tandem oximation‐Beckmann rearrangement reaction at 100 °C for 12 h. Moreover, MIL‐101‐PTA was recycled three times, with only a slight loss in their catalytic performance. To the best of our knowledge, this represents the first report using acidified MOF for a tandem oximation‐Beckmann rearrangement reaction.
As above, so below: Whole transcriptome profiling demonstrates strong molecular similarities between avian dorsal and ventral pallial subdivisions
Authors: Gedman Gregory , Haase Bettina , Durieux Gillian , Biegler Matthew T. , Fedrigo Olivier , Jarvis Erich D.
Published: April 2021

Over the last two decades, beginning with the Avian Brain Nomenclature Forum in 2000, major revisions have been made to our understanding of the organization and nomenclature of the avian brain. However, there are still unresolved questions on avian pallial organization, particularly whether the cells above the vestigial ventricle represent distinct populations to those below it or similar populations. To test these two hypotheses, we profiled the transcriptomes of the major avian pallial subdivisions dorsal and ventral to the vestigial ventricle boundary using RNA sequencing and a new zebra finch genome assembly containing about 22,000 annotated, complete genes. We found that the transcriptomes of neural populations above and below the ventricle were remarkably similar. Each subdivision in dorsal pallium (Wulst) had a corresponding molecular counterpart in the ventral pallium (dorsal ventricular ridge). In turn, each corresponding subdivision exhibited shared gene co‐expression modules that contained gene sets enriched in functional specializations, such as anatomical structure development, synaptic transmission, signaling, and neurogenesis. These findings are more in line with the continuum hypothesis of avian brain subdivision organization above and below the vestigial ventricle space, with the pallium as a whole consisting of four major cell populations (intercalated pallium, mesopallium, hyper‐nidopallium, and arcopallium) instead of seven (hyperpallium apicale, interstitial hyperpallium apicale, intercalated hyperpallium, hyperpallium densocellare, mesopallium, nidopallium, and arcopallium). We suggest adopting a more streamlined hierarchical naming system that reflects the robust similarities in gene expression, neural connectivity motifs, and function. These findings have important implications for our understanding of overall vertebrate brain evolution.
Lexical data mining‐based approach for the self‐enrichment ofLMFstandardized dictionaries: Case of the syntactico‐semantic knowledge
Authors: Elleuch Imen , Gargouri Bilel , Ben Hamadou Abdelmajid
Published: April 2021

The LMF ISO standard provides a large cover of lexical knowledge using a fine structure. However, like most of the electronic dictionaries, the available normalized LMF dictionaries comprise only basic morpho‐syntactic and semantic knowledge, such as the meanings of lexical entries through the definitions and the associated examples, and sometimes the indication of the synonyms and antonyms. Other sophisticated knowledge, such as the syntactic behaviors, semantic classes and syntactico‐semantic links, which are scarce, requires a high expertise and its adding to dictionaries is expensive. In fact in this paper, we propose an approach of lexical data mining of the widely available textual content associated with the meanings, notably in the normalized LMF dictionaries, in order to perform the self‐enrichment of these dictionaries. First, we contribute to the enrichment of the syntactic behaviors by linking them to the suitable meanings. Second, we focus on the enrichment of the meanings of LMF lexical entries with semantic classes based on the Gaston Gross semantic classification. Finally, we establish the syntactico‐semantic links based on the results of the syntactic and semantic enrichment processes. The proposed approach has been consolidated by an experimentation carried out on an available normalized LMF dictionary for Arabic language.
Defect Engineering of Photocatalysts towards Elevated CO2 Reduction Performance
Authors: Shen Meng , Zhang Lingxia , Shi Jianlin
Published: April 2021

Photocatalytic CO2 reduction provides a promising solution to address the crises of massive CO2 emissions and fossil energy shortages. As one of the most effective strategies to promote CO2 photoconversion, defect engineering shows great potential in modulating the electronic structure and light absorption properties of photocatalysts while increasing surface active sites for CO2 activation and conversion. This Review summarizes the recent progress in defect engineering of photocatalysts to promote CO2 reduction performances from the following four aspects: 1) Approaches to defect (mainly vacancy and dopant) generation in photocatalysts; 2) defect structure characterization techniques; 3) physical and chemical properties of defect‐engineered photocatalysts; 4) CO2 reduction performance enhancements in activity, selectivity, and stability of photocatalysts by defect engineering. This Review is expected to present readers with a comprehensive view of progress in the field of photocatalytic CO2 reduction through defect engineering for elevated CO2‐to‐fuels conversion efficiency.
Retracted: An efficient stacking model with SRPF classifier technique for intrusion detection system
Authors: Karthikeyan D. , Mohanraj V. , Suresh Y. , Senthilkumar J.
Published: April 2021

Machine learning process is an important part in intrusion detection system (IDS) and plays an essential role in security information. Analysts operate IDS for the study of server logs or packets of data to identify network traffic malware. IDS automates this process with machine learning‐based techniques that allow packet detection on a continuous basis without much human effort or intervention through network analyzing data. It has the following limitations on low rate of detection, false alarm rate is high, and so on, to which the conventional IDS has indicated. We proposed a stacking model that is more accurate to detect the attacks than other techniques of Random Forest, Naïve Bayes, and Decision Tree C4.5. Different researchers are exploring various techniques to classify the rules for associations. But the measure of confidence itself, as investigated in various literature, produces many times inaccurate results. So based on a recent value test called the significant rule power factor (SRPF), this paper discusses classifier. The experiments are carried out by implementation in Weka's method. Results indicate that the proposed classifier is a newly created, light weight classifier with better accuracy performance. Detection of different attacks uses NSL‐KDD dataset to train and test the data in this technique. This proposed work is measured using different performance metrics to other intrusion detection models. Compared to existing methods, our proposed model offers prominent increase in detection accuracy.
Anal cytology and high‐risk human papilloma virus testing in atypical squamous categories: Value of concurrent testing in management of high‐risk population
Authors: Cimic Adela , Saqi Anjali
Published: April 2021

Anal squamous cell carcinoma is relatively rare, but its incidence and mortality have been increasing worldwide. While anal cytology is a sensitive cancer screening modality, its specificity is low, and data for concurrent high‐risk human papilloma virus (HR‐HPV) testing are limited. At our institution, anal cancer screening consists of combined anal cytology and high‐risk human papilloma virus (HR‐HPV) testing on all specimens. The aims of the study were to correlate results of atypical cytological diagnoses [atypical squamous cells of undetermined significance (ASCUS) and atypical squamous cells cannot exclude high grade squamous intraepithelial lesion (ASC‐H)] with HR‐HPV testing and determine if co‐testing may potentially influence management. A retrospective search over 24‐months was performed for anal cytology specimens with diagnoses of ASCUS and ASC‐H. Corresponding HR‐HPV (HPV 16/18 and Other‐31/33/35/39/45/51/52/56/58/59/66/68) results were retrieved, and concordance/discordance was recorded. Cytology results were correlated with anal biopsy diagnoses, when available. A total of 139 patients, including 127 with ASCUS and 12 with ASC‐H, were identified. Of the ASCUS cases, 90/127 (70.9%) had HR‐HPV, and a squamous intraepithelial lesion (SIL) was evident in 20/39 (51.2%) of biopsies. All 12/12 (100%) ASC‐H were associated with HR‐HPV and 3/6 (50%) biopsies had a SIL. Our study supports use of concurrent cytology and HR‐HPV for anal cancer screening cytology. Co‐testing improves specificity of atypical cytology diagnoses and can identify patients requiring further intervention.
Entire university must commit to disability services
Authors: Enos Gary A.
Published: April 2021

The language around disability has transformed at the University of Mississippi, with access now framed as a civil rights issue. Stacey Reycraft, Director of Student Disability Services, discussed this redefinition and how her office acquired a seat at the table in high‐level decision‐making.
Literature review examines suicide risk during COVID‐19
Authors: Canady Valerie A.
Published: April 2021

Observing that the current pandemic presents many challenges, including the chances of a significant increase in suicide risk, vigilance and care are needed for mental health well‐being to limit the spread of suicide, say researchers of a new literature review that examines the risk factors for suicide during the pandemic. Lesser‐known mental health issues, such as post‐traumatic stress disorder, may also affect those infected with the virus and those who are not, they stated.
Transforming growth factor beta signaling: The master sculptor of fingers
Authors: Lorda‐Diez Carlos I. , Duarte‐Olivenza Cristina , Hurle Juan M. , Montero Juan A.
Published: April 2021

Transforming growth factor beta (TGFβ) constitutes a large and evolutionarily conserved superfamily of secreted factors that play essential roles in embryonic development, cancer, tissue regeneration, and human degenerative pathology. Studies of this signaling cascade in the regulation of cellular and tissue changes in the three‐dimensional context of a developing embryo have notably advanced in the understanding of the action mechanism of these growth factors. In this review, we address the role of TGFβ signaling in the developing limb, focusing on its essential function in the morphogenesis of the autopod. As we discuss in this work, modern mouse genetic experiments together with more classical embryological approaches in chick embryos, provided very valuable information concerning the role of TGFβ and Activin family members in the morphogenesis of the digits of tetrapods, including the formation of phalanxes, digital tendons, and interphalangeal joints. We emphasize the importance of the Activin and TGFβ proteins as digit inducing factors and their critical interaction with the BMP signaling to sculpt the hand and foot morphology.
Land use and management effects on soil carbon in U.S. Lake States, with emphasis on forestry, fire, and reforestation
Authors: Nave L. E. , DeLyser K. , Domke G. M. , Janowiak M. K. , Ontl T. A. , Sprague E. , Walters B. F. , Swanston C. W.
Published: April 2021

There is growing need to quantify and communicate how land use and management activities influence soil organic carbon (SOC) at scales relevant to, and in the tangible control of landowners and forest managers. The continued proliferation of publications and growth of data sets, data synthesis and meta‐analysis approaches allows the application of powerful tools to such questions at ever finer scales. In this analysis, we combined a literature review and effect‐size meta‐analysis with two large, independent, observational databases to assess how land use and management impact SOC stocks, primarily with regards to forest land uses. We performed this work for the (Great Lakes) U.S. Lake States, which comprise 6% of the land area, but 7% of the forest and 9% of the forest SOC in the United States, as the second in a series of ecoregional SOC assessments. Most importantly, our analysis indicates that natural factors, such as soil texture and parent material, exert more control over SOC stocks than land use or management. With that for context, our analysis also indicates which natural factors most influence management impacts on SOC storage. We report an overall trend of significantly diminished topsoil SOC stocks with harvesting, consistent across all three data sets, while also demonstrating how certain sites and soils diverge from this pattern, including some that show opposite trends. Impacts of fire grossly mirror those of harvesting, with declines near the top of the profile, but potential gains at depth and no net change when considering the whole profile. Land use changes showing significant SOC impacts are limited to reforestation on barren mining substrates (large and variable gains) and conversion of native forest to cultivation (losses). We describe patterns within the observational data that reveal the physical basis for preferential land use, e.g., cultivation of soils with the most favorable physical properties, and forest plantation establishment on the most marginal soils, and use these patterns to identify management opportunities and considerations. We also qualify our results with ratings of confidence, based on their degree of support across approaches, and offer concise, defensible tactics for adapting management operations to site‐specific criteria and SOC vulnerability.
Modeling of a shake‐table tested retrofitted wood‐frame building subjected to subduction ground motions
Authors: Pan Yuxin , Ventura Carlos E. , Bebamzadeh Armin , Motamedi Mehrtash
Published: April 2021

In 2004 , the provincial government of British Columbia in Canada initiated a seismic retrofit program to quantify the seismic risk and to implement a seismic mitigation plan over 750 school buildings located in high seismic hazard regions of the province. The current phase of the program focuses on conducting a series of full‐scale shake‐table tests of a retrofitted two‐story wood‐frame school building prototype as part of the performance‐based Seismic Retrofit Guidelines (SRG). This paper presents the numerical modeling and seismic assessment of the tested building. A detailed two‐dimensional model and a computationally efficient three‐dimensional model were developed. By performing nonlinear dynamic analyses, both models predicted the building responses accurately when compared with the experimental tests in terms of roof drift, energy dissipation, and global hysteresis behavior. The retrofitted school building showed a large overstrength that mainly came from the unblocked walls. Empirical equations based on the FEMA P‐807 guidelines and a simplified method developed in the SRG, called Toolbox Approach were investigated for estimating its overstrength and ultimate capacity. Finally, following a performance‐based tri‐hazard probabilistic methodology proposed in the SRG, the seismic risk of the building was assessed by performing incremental dynamic analysis using 30 ground motion records that were selected based on a multiple event‐based conditional mean spectrum (CMS) approach. The results indicated that the subduction motions posed higher probability of drift exceedance and collapse risk of the retrofitted school building than crustal and subcrustal motions.
Exergo‐economic assessment by a specific exergy costing method for an experimental thermochemical hydrogen production system
Authors: Farsi Aida , Dincer Ibrahim , Naterer Greg F.
Published: April 2021

In this article, an exergo‐economic study of an experimental lab‐scale integrated copper‐chlorine (Cu‐Cl) cycle of hydrogen production is conducted. The analysis is performed based on a specific exergy costing (SPECO) method to determine the influences of various design criteria on the costs and then identify possible improvements for more cost effective approaches. The article includes an exergy analysis, economic study, exergy costing and exergo‐economic evaluation. Also, a scale‐up analysis is performed to predict the cost of a larger scale facility of 1000 kg per day of hydrogen production. The results of the exergo‐economic and scale‐up analysis are expected to assist in the design, optimization and improvement of a scaled‐up Cu‐Cl thermochemical cycle. Furthermore, the results of this study show that for a large‐scale Cu‐Cl cycle plant with a capacity of 1000 kg/day H2, the cost of hydrogen production, excluding the treatment of side reactions, is predicted at about 3.91 $/kg H2.
Unilateral versus bilateral nodal irradiation: Current evidence in the treatment of squamous cell carcinoma of the head and neck
Authors: Nuyts Sandra , Bollen Heleen , Eisbruch Avrahram , Corry June , Strojan Primoz , Mäkitie Antti A. , Langendijk Johannes A. , Mendenhall William M. , Smee Robert , DeBree Remco , Lee Anne W. M. , Rinaldo Alessandra , Ferlito Alfio
Published: April 2021

Cancers of the head and neck region often present with nodal involvement. There is a long‐standing convention within the community of head and neck radiation oncology to irradiate both sides of the neck electively in almost all cases to include both macroscopic and microscopic disease extension (so called elective nodal volume). International guidelines for the selection and delineation of the elective lymph nodes were published in the early 2000s and were updated recently. However, diagnostic imaging techniques have improved the accuracy and reliability of nodal staging and as a result, small metastases that used to remain undetected and were thus in the past included in the elective nodal volume, will now be included in high‐dose volumes. Furthermore, the elective nodal areas are situated close to the parotid glands, the submandibular glands and the swallowing muscles. Therefore, irradiation of a smaller, more selected volume of the elective nodes could reduce treatment‐related toxicity. Several researchers consider the current bilateral elective neck irradiation strategies an overtreatment and show growing interest in a unilateral nodal irradiation in selected patients. The aim of this article is to give an overview of the current evidence about the indications and benefits of unilateral nodal irradiation and the use of SPECT/CT‐guided nodal irradiation in squamous cell carcinomas of the head and neck.
Using system traps to understand and potentially prevent human resource development intervention failure
Authors: Blackman Deborah , Buick Fiona , Johnson Samantha , Rooney James , Ilahee Nabil
Published: April 2021

Adopting human resource development (HRD) activities can lead to improved organizational outcomes, such as improved performance and innovation. However, while the implementation of HRD strategies is widespread, there are concerns that they have failed to support the learning and skill acquisition required to support both individual learning and improved organizational outcomes. Having established that HRD is a systems level issue, this paper applies Meadows's (2008) system traps to suggest that adopting this lens could explain why extensive HRD interventions have failed to deliver desired system outcomes. Qualitative data is analyzed to consider why HRD interventions fail to result in increased capability development in the Australian public sector. The findings demonstrate four system traps were present in HRD interventions, which help explain the ongoing failure of HRD interventions to support required learning or improve organizational performance: (1) shifting the burden to the intervenor; (2) seeking the wrong goal; (3) policy resistance; and (4) drift to low performance. We argue that the presence of these traps suggest that HRD subsystems will need to be reconceptualized for there to be a real improvement. To this end, we apply Meadows's (2008) suggestions to overcome the traps, identifying potential strategies for HRD practitioners to act as system intervenors. Our paper contributes to knowledge through focusing on a specific aspect of systems thinking to help explain why HRD intervention failure occurs.
Incidences of aligned magnetic field on unsteady MHD flow past a parabolic accelerated inclined plate in a porous medium
Authors: Endalew Mehari Fentahun , Sarkar Subharthi
Published: April 2021

An exact analysis of a radiative hydromagnetic flow behavior over a tilted parabolic plate through a permeable medium along with variable species concentration and fluid temperature in the presence of a slanted magnetic field parameter, chemical reaction, and heat generation has been carried out in this study. Closed‐form analytical benchmark solutions for flow‐governing equations are obtained by using the Laplace transform method. Thereafter, the incidences of different important physical entities on the nondimensional velocity field, temperature distribution, and species concentration are presented using graphs, whereas impacts of various physical entities on wall shear stress, heat and mass transfer rates are presented in tables. It is worth noting that an increase in the magnetic field and its inclination angle causes the reduction in the fluid velocity. However, wall shear stress increases with the increase of magnetic field and its inclination angle. The novel results in this article can be used to improve quicker cooling and producing miniaturized heat flow systems with upgraded efficiency and cost‐effectiveness.
Biochemical impact of solar radiation exposure on human keratinocytes monitored by Raman spectroscopy; effects of cell culture environment
Authors: Lopez‐Gonzalez Ulises , Casey Alan , Byrne Hugh J.
Published: April 2021

Understanding and amelioration of the effects of solar radiation exposure are critical in preventing the occurrence of skin cancer. Towards this end, many studies have been conducted in 2D cell culture models under simplified and unrealistic conditions. 3D culture models better capture the complexity of in vivo physiology, although the effects of the 3D extracellular matrix have not been well studied. Monitoring the instantaneous and resultant cellular responses to exposure, and the influence of the 3D environment, could provide an enhanced understanding of the fundamental processes of photocarcinogenesis. This work presents an analysis of the biochemical impacts of simulated solar radiation (SSR) occurring in immortalised human epithelial keratinocytes (HaCaT), in a 3D skin model, compared to 2D culture. Cell viability was monitored using the Alamar Blue colorimetric assay (AB), and the impact of the radiation exposure, at the level of the biomolecular constituents (nucleic acids and proteins), were evaluated through the combination of Raman microspectroscopy and multivariate statistical analysis. The results suggest that SSR exposure induces alterations of the conformational structure of DNA as an immediate impact, whereas changes in the protein signature are primarily seen as a subsequent response.
Surface modifications to enhance osseointegration–Resulting material properties and biological responses
Authors: Nobles Kadie P. , Janorkar Amol V. , Williamson Randall S.
Published: April 2021

As life expectancy and the age of the general population increases so does the need for improved implants. A major contributor to the failure of implants is poor osseointegration, which is typically described as the direct connection between bone and implant. This leads to unnecessary complications and an increased burden on the patient population. Modification of the implant surfaces through novel techniques, such as varying topography and/or applying coatings, has become a popular method to enhance the osseointegration capability of implants. Recent research has shown that particular surface features influence how bone cells interact with a material; however, it is unknown which exact features achieve optimal bone integration. In this review, current methods of modifying surfaces will be highlighted, and the resulting surface characteristics and biological responses are discussed. Review of the current strategies of surface modifications found that many coating types are more advantageous when used in combination; however, finding a surface modification that utilizes the mutual beneficial effects of important surface characteristics while still maintaining commercial viability is where future challenges exist.
Genetic discrimination views in online discussion forums: Perspectives from Canadian forumites
Authors: Dalpé Gratien , Pinkesz Miriam , Oliviero Elisabeth , Tolymbek Maria , Joly Yann
Published: April 2021

Recent advancements in genetic technologies have made genetic information increasingly sought out in a wide range of non‐therapeutic contexts, which has increased the risk that such information be used to discriminate against individuals. Frequently, it is genetic counselors who have to respond to questions about genetic discrimination (GD) from worried patients. Here, we examine the general Canadian public's knowledge, attitudes, and concerns about GD through a comprehensive analysis and categorization of posts from selected Canadian online discussion forums. Overall, we collected 1,638 posts, from which we coded 694 posts originating from newspaper comment sections and Reddit posts that were categorized to yield 6 main themes that consistently concerned Canadian users on the topics of GD: (a) discussions centered around how insurance business practices can be affected by genetic information; (b) issues in employment; (c) ‘fear’ of genetic testing and eugenics; (d) preventive approaches such as law and human rights instruments; (e) the predictive value and privacy that should be conferred to genetic information; and (f) other ethical issues. Overall, discussions addressed risk stratification models applied to genetic information and personal insurance underwriting. We find that many forum users (aka forumites) fear GD in insurance and employment, consider genetic information private, and strongly support different legal approaches to prevent GD. However, we find dissension among forumites that may represent different advocacy groups such as insurers and employers. From these important concerns and social conceptions, we discuss issues that should be taken into consideration for the development of future policies and information campaigns addressing GD in Canada and other countries.
Minicircle‐based expression of vascular endothelial growth factor in mesenchymal stromal cells from diverse human tissues
Authors: Serra Joana , Alves Cláudia P. A. , Cabral Joaquim M. S. , Monteiro Gabriel A. , da Silva Cláudia L. , Prazeres Duarte Miguel F.
Published: April 2021

Background

Mesenchymal stromal cells (MSC) have been exploited for the treatment of ischemic diseases given their angiogenic potential. Despite bone marrow (BM) being the most studied tissue source, cells with similar intrinsic properties can be isolated from adipose tissue (AT) and umbilical cord matrix (UCM). The present study aims to compare the angiogenic potential of MSC obtained from BM, AT and UCM that were genetically modified with vascular endothelial growth factor (VEGF)‐encoding minicircle (MC) vectors. The overexpression of VEGF combined with the intrinsic properties of MSC could represent a promising strategy towards angiogenic therapies.

Methods

We established a microporation‐based protocol to transfect human MSC using VEGF‐encoding MC (MC‐VEGF). VEGF production levels were measured by an enzyme‐linked immunosorbent assay and a quantitative polymerase chain reaction. Thein vitroangiogenic potential of transfected cells was quantified using cell tube formation and migration functional studies.

Results

MSC isolated from BM, AT or UCM showed similar levels of VEGF secretion after transfection with MC‐VEGF. Those values were significantly higher when compared to non‐transfected cells, indicating an effective enhancement of VEGF production. Transfected cells displayed higherin vitroangiogenic potential than non‐transfected controls, as demonstrated by functionalin vitroassays. No significant differences were observed among cells from different sources.

Conclusions

Minicircles can be successfully used to transiently overexpress VEGF in human MSC, regardless of the cell tissue source, representing an important advantage in a clinical context (i.e., angiogenic therapy) because a standard protocol might be applied to MSC of different tissue sources, which can be differentially selected according to the application (e.g., autologous versus allogeneic settings).
Biomechanical, histological, and molecular characterization of a new posttraumatic model of arthrofibrosis in rats
Authors: Owen Aaron R. , Dagneaux Louis , Limberg Afton K. , Bettencourt Jacob W. , Bayram Banu , Bolon Brad , Berry Daniel J. , Morrey Mark E. , Sanchez‐Sotelo Joaquin , van Wijnen Andre J. , Abdel Matthew P.
Published: April 2021

Experimental analyses of posttraumatic knee arthrofibrosis utilize a rabbit model as a gold standard. However, a rodent model of arthrofibrosis offers many advantages including reduced cost and comparison with other models of organ fibrosis. This study aimed to characterize the biomechanical, histological, and molecular features of a novel posttraumatic model of arthrofibrosis in rats. Forty eight rats were divided into two equal groups. An immobilization procedure was performed on the right hind limbs of experimental rats. One group was immobilized for 4 weeks and the other for 8 weeks. Both groups were remobilized for 4 weeks. Limbs were studied biomechanically via assessment of torque versus degree of extension, histologically via whole knee specimen, and molecularly via gene expression of posterior capsular tissues. Significant differences were observed between experimental and control limbs at 4 N‐cm of torque in the 4‐week (knee extension: 115° ± 8° vs. 169° ± 17°, respectively; p = 0.007) and 8‐week immobilization groups (knee extension: 99° ± 12° vs. 174° ± 9°, respectively; p = 0.008). Histologically, in each group experimental limbs demonstrated increased posterior capsular thickness and total area of tissue when compared to control limbs (p < 0.05). Gene expression values evaluated in each group were comparable. This study presents a novel rat model of arthrofibrosis with severe and persistent knee contractures demonstrated biomechanically and histologically. Statement of clinical significance: Arthrofibrosis is a common complication following contemporary total knee arthroplasties. The proposed model is reproducible, cost‐effective, and can be employed for translational investigations studying the pathogenesis of arthrofibrosis and efficacy of neoadjuvant pharmacologic agents.
A systematic review and meta‐analyses on animal models used in bone adhesive research
Authors: Van Erk Machteld , Van Luijk Judith , Yang Fang , Leeuwenburgh Sander C. G. , Sánchez‐Fernández María J. , Hermans Erik , Félix Lanao Rosa P. , Van Goor Harry
Published: April 2021

Currently, steel implants are used for osteosynthesis of (comminuted) fractures and intra‐articular bone defects. These osteosyntheses can sometimes be complicated procedures and can have several drawbacks including stress shielding of the bone. A bone glue might be a safe and effective alternative to current materials. Despite numerous animal studies on bone adhesives, no such material is clinically applied yet. We have conducted a systematic review to summarize the evidence in experimental animal models used in research on bone adhesive materials for trauma and orthopedic surgery. Additionally, we analysed the efficacy of the different bone adhesives for different experimental designs. A heterogeneity in experimental parameters including animal species, defect types, and control measurements resulted in a wide variety in experimental models. In addition, no standard outcome measurements could be identified. Meta‐analysis on bone regeneration between adhesive treatment and nonadhesive treatment showed a high heterogeneity and no statistically significant overall effect (M: −0.71, 95% confidence interval [CI]: −1.63–0.21, p = 0.13). Besides, currently there is not enough evidence to draw conclusions based on the effectiveness of the individual types of adhesives or experimental models. A positive statistically significant effect was found for the adhesive treatment in comparison with conventional osteosynthesis materials (M: 2.49, 95% CI: 1.20–3.79, p = 0.0002). To enhance progression in bone adhesive research and provide valuable evidence for clinical application, more standard experimental parameters and a higher reporting quality in animal studies are needed. Statement of Clinical Significance: Current materials restoring anatomical alignments of bones have several drawbacks. A (biodegradable) adhesive for fixating bone defects can be a treatment breakthrough. Although numerous bone adhesives have been researched, most seemed to fail at the preclinical stage. An overview in this field is missing. This systematic review highlights the relevant parameters for design of experimental bone adhesive studies. It demonstrates evidence regarding benefit of bone adhesives but also that the quality of reporting and the risk of bias in studies need to be improved. The results will aid in designing better quality animal studies for bone adhesive research with higher translational value.
Echogenic Surface Enhancements for Improving Needle Visualization in Ultrasound
Authors: Hovgesen Caroline Harder , Wilhjelm Jens E. , Vilmann Peter , Kalaitzakis Evangelos
Published: April 2021

Optimal visualization of needles in clinical ultrasound imaging is important and challenging, especially at steep angles. Improvement of visualization has been attempted with various techniques, for example, coatings and dimples. This systematic review summarizes enhancement techniques and identifies superior echogenic surface enhancements. Twenty‐four papers were identified providing visibility measures for 33 different echogenic needles. These were grouped according to surface characteristics and ranked. Echogenic needles ranked higher than standard needles especially at steeper angles. Among the echogenic needles, coated needles were seemingly better visualized “in vivo” than noncoated needles, despite heterogeneity in study conditions. No unambiguous comparison revealed which needle was best visualized.
Applying Administrative Data‐Based Coding Algorithms for Frailty in Patients With Cirrhosis
Authors: Louissaint Jeremy , Murphy Susan L. , Sonnenday Christopher J. , Lok Anna S. , Tapper Elliot B.
Published: April 2021

Frailty is a powerful prognostic tool in cirrhosis. Claims‐based frailty scores estimate the presence of frailty without the need for in‐person evaluation. These algorithms have not been validated in cirrhosis. Whether they measure true frailty or perform as well as frailty in outcome prediction is unknown. We evaluated 2 claims‐based frailty scores—Hospital Frailty Risk Score (HFRS) and Claims‐Based Frailty Index (CFI)—in 3 prospective cohorts comprising 1100 patients with cirrhosis. We assessed differences in neuromuscular/neurocognitive capabilities in those classified as frail or nonfrail based on each score. We assessed the ability of the indexes to discriminate frailty based on the Fried Frailty Index (FFI), chair stands, activities of daily living (ADL), and falls. Finally, we compared the performance of claims‐based frailty measures and physical frailty measures to predict transplant‐free survival using competing risk regression and patient‐reported outcomes. The CFI identified neuromuscular deficits (balance, chair stands, hip strength), whereas the HFRS only identified poor chair‐stand performance. The CFI had areas under the receiver operating characteristic curve (AUROCs) for identifying frailty as measured by the FFI, ADL, and falls of 0.57, 0.60, and 0.68, respectively; similarly, the AUROCs were 0.66, 0.63, and 0.67, respectively, for the HFRS. Claims‐based frailty scores were associated with poor quality of life and sleep but were outperformed by the FFI and chair stands. The HFRS, per 10‐point increase (but not the CFI) predicted survival of patients in the liver transplantation (subdistribution hazard ratio [SHR], 1.08; 95% confidence interval [CI], 1.03‐1.12) and non–liver transplantation cohorts (SHR, 1.13; 95% CI, 1.05‐1.22). Claims‐based frailty scores do not adequately associate with physical frailty but are associated with important cirrhosis‐related outcomes.
Evaluating Poly(Acrylamide‐co‐Acrylic Acid) Hydrogels Stress Relaxation to Direct the Osteogenic Differentiation of Mesenchymal Stem Cells
Authors: Prouvé Emilie , Drouin Bernard , Chevallier Pascale , Rémy Murielle , Durrieu Marie‐Christine , Laroche Gaétan
Published: April 2021

The aim of this study is to investigate polyacrylamide‐based hydrogels stress relaxation and the subsequent impact on the osteogenic differentiation of human mesenchymal stem cells (hMSCs). Different hydrogels are synthesized by varying the amount of cross‐linker and the ratio between the monomers (acrylamide and acrylic acid), and characterized by compression tests. It has been found that hydrogels containing 18% of acrylic acid exhibit an average relaxation of 70%, while pure polyacrylamide gels show an average relaxation of 15%. Subsequently, hMSCs are cultured on two different hydrogels functionalized with a mimetic peptide of the bone morphogenetic protein‐2 to enable cell adhesion and favor their osteogenic differentiation. Phalloidin staining shows that for a constant stiffness of 55 kPa, a hydrogel with a low relaxation (15%) leads to star‐shaped cells, which is typical of osteocytes, while a hydrogel with a high relaxation (70%) presents cells with a polygonal shape characteristic of osteoblasts. Immunofluorescence labeling of E11, strongly expressed in early osteocytes, also shows a dramatically higher expression for cells cultured on the hydrogel with low relaxation (15%). These results clearly demonstrate that, by fine‐tuning hydrogels stress relaxation, hMSCs differentiation can be directed toward osteoblasts, and even osteocytes, which is particularly rare in vitro.
Thioureas Bridged Polysiloxanes for Ultrafast Detection of Cr6+ and Applications
Authors: Wang Xiaoni , Gou Zhiming , Zuo Yujing
Published: April 2021

Polythiourea, as a kind of seductive material, has been widely applied in various fields. However, the design strategy of polythiourea remains a strong challenge mainly owing to synthesis process is cumbersome and noble metals participate in the reaction. In this report, a new synthetic method is presented to construct poly (siloxane‐thioureas) (PTUs) via a simple and economic “one‐pot” method. The optical properties of PTUs are mainly investigated by the ultraviolet absorption spectrum and fluorescence spectrum. Noteworthly, PTUs display ultrafast response rate to Cr6+. In addition, PTUs also possess excellent photostability and biocompatibility. A paper sensor based on PTUs is also prepared by visual fluorescence change to achieve the purpose of detection of Cr6+. Herein, it is desired that, as a new type of polythiourea material, PTUs could extend the applications in the bioimaging field.
Low Dielectric Polyimide/Fluorinated Ethylene Propylene (PI/FEP) Nanocomposite Film for High‐Frequency Flexible Circuit Board Application
Authors: Cheng Tangjian , Lv Genpin , Li Yitao , Yun Hao , Zhang Lingfei , Deng Yongmao , Lin Liping , Luo Xiangjun , Nan Junmin
Published: April 2021

The low dielectric polymer films have drawn great attention to the application as the dielectric insulating materials in high‐frequency circuit boards, while the weak adhesion to the copper foils and the poor processability resulted from the fluorinated or rigid structures limited their high‐frequency application. In this work, the low dielectric and high adhesive polyimide/fluorinated ethylene propylene (PI/FEP) nanocomposite film for high‐frequency flexible circuit board application is developed. It is indicated that the fluorocarbon surfactants can significantly improve the dispersion of FEP in PI substrate, and thus, the PI/FEP nanocomposite film exhibits excellent mechanical properties, including the tensile strength increases to 46.6 MPa and the elongation at the break increases to 13.7%. Importantly, at the high‐frequency of 10 GHz, the 60 wt% FEP filled PI nanocomposite film displays an ultralow dielectric loss (0.006) and a reduced dielectric constant (2.69). In addition, the high‐frequency flexible circuit board with the PI/FEP film as the dielectric insulating layer has a high peel strength of 0.75 N mm−1, indicating this PI/FEP nanocomposite film can meet the requirements of the high‐frequency flexible circuit board application.
Importance of Low‐Temperature Melt‐Mixing on the Construction of Stereocomplex Crystallites with Superior Nucleation Efficiency in Asymmetric Poly(l‐lactide)/Poly(d‐lactide) Blends
Authors: Yao Ju , Zeng Zhen , Bai Hongwei , Zhang Qin , Fu Qiang
Published: April 2021

The nucleation efficiency (NE) of stereocomplex crystallites (SCs) formed in asymmetric poly(L‐lactide)/poly(D‐lactide) (PLLA/PDLA) blends is generally unsatisfactory because the competition between stereocomplexation and chain mixing involved in the melt‐mixing process can cause low formation efficiency and even severe aggregation of SCs. Herein, it is attempted to achieve high‐efficient formation of finely dispersed SCs particles by designing a unique melt‐mixing procedure, where the mixing of PLLA with 0.75 wt% PDLA is first performed at elevated temperatures (far above the melting temperature of SCs) to allow the homogeneous mixing of PLLA/PDLA chains and then at a low temperature (slightly above that of homocrystallites) to permit the full stereocomplexation of the premixed chains. It is found that the SCs formed in the blends exhibit unexpectedly low NEs (e.g., 54.5%), much inferior to that (73.6%) in the counterpart without undergoing premixing. This is because the introduction of premixing leads to a remarkable deterioration in the amount of SCs particles formed, despite decreased particle size, highlighting that the direct mixing at low temperatures of 170–180 °C (about 20–30 °C lower than that used in common melt‐processing of PLA) is more effective for the construction of SCs with superior NE. The mechanisms for these striking findings are discussed.