bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface modifications to enhance osseointegration–Resulting material properties and biological responses
Authors: Nobles Kadie P. , Janorkar Amol V. , Williamson Randall S. 
Published: April 2021

AbstractAs 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

AbstractRecent 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

AbstractBackgroundMesenchymal 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.MethodsWe 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.ResultsMSC 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.ConclusionsMinicircles 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

AbstractExperimental 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

AbstractCurrently, 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.
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

AbstractThe 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

AbstractPolythiourea, 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

AbstractThe 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

AbstractThe 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.
Performance‐Enhanced and Washable Triboelectric Air Filter Based on Polyvinylidene Fluoride/UiO‐66 Composite Nanofiber Membrane
Authors: Hu Yijie , Wang Yulong , Tian Shidai , Yu Aifang , Wan Lingyu , Zhai Junyi 
Published: April 2021

AbstractApplying triboelectric nanogenerators (TENGs) in air filtration systems to generate electric charges through friction is a major advancement in air cleaning technology. The performance of triboelectric air filter strongly depends on the properties of triboelectric materials. In this work, a better triboelectric material, polyvinylidene fluoride (PVDF)/UiO‐66 composite nanofiber membrane (P6‐NFM), is designed and fabricated through electrospinning technology by doping UiO‐66 into PVDF matrix. As the weight ratio of UiO‐66 increases to 1%, PVDF/UiO‐66 composite nanofiber‐based TENG (P6‐TENG) achieves the maximum current, voltage, and triboelectric charge of 4.29 µA, 52.8 V, and 22.02 nC, which are 6.5 times, 5.1 times, and 8.0 times as large as those of pure PVDF‐based TENG (P‐TENG). Therefore, the triboelectric air filter based on P6‐NFM can be easily charged by slapping the fiber membrane and spun‐bond fabric. After charging, the removal efficiency of P6‐NFM is 92% for PM0.5 and 98% for PM2.5, which are 2.8 and 1.2 times those of the uncharged one. More importantly, the filtration efficiency of this air filter keeps stable after the membrane is washed four times. This method of loading UiO‐66 on the triboelectric fiber material shows tremendous potential in self‐charging and reusable air purification applications.
An Amphiphilic PEGylated Peptide Dendron‐Gemcitabine Prodrug‐Based Nanoagent for Cancer Therapy
Authors: Li Ning , Duan Zhenyu , Wang Lili , Guo Chunhua , Zhang Hu , Gu Zhongwei , Gong Qiyong , Luo Kui 
Published: April 2021

AbstractAn amphiphilic peptide dendrimer conjugated with gemcitabine (GEM), PEGylated dendron‐Gly‐Phe‐Leu‐Gly‐GEM (PEGylated dendron‐GFLG‐GEM), is developed as a nano‐prodrug for breast cancer therapy. The self‐assembled behavior is observed under a transmission electron microscopy and dynamic light scattering. The negatively charged surface and hydrodynamic size of the amphiphilic nanosized prodrug supported that the prodrug can maintain the stability of GEM during circulation and accumulate in the tumor tissue. Drug release assays are conducted to monitor the release of GEM from this nanodrug delivery system in response to the tumor microenvironment, and these assays confirm that GEM released from the nanocarrier is identical to free GEM. The GEM prodrug can prevent proliferation of tumor cells. The therapeutic effect against breast cancer is systematically investigated using an in vivo animal model. Immunohistochemical results are aligned with the significantly enhanced anticancer efficacy of GEM released from the prodrug. This self‐assembled amphiphilic drug delivery nanocarrier may broaden the application for GEM and other anticancer agents for breast cancer chemotherapy.
Evaluation of Remote Site Incubators to Incubate Wild- and Hatchery-Origin Westslope Cutthroat Trout Embryos
Authors: Shepard Bradley B. , Clancey Patrick , Nelson M. Lee , Kruse Carter G. , Al-Chokhachy Robert , Drinan Daniel , Taper Mark L. , Zale Alexander V. 
Published: April 2021

Abstract
Fish managers must weigh trade-offs among cost, speed, efficiency, and ecological adaptation when deciding how to translocate native salmonids to either establish or genetically augment populations. Remote site incubators (RSIs) appear to be a reasonable strategy, but large-scale evaluations of this method have been limited. We used 129 RSIs to incubate &gt;35,700 eyed embryos of Westslope Cutthroat Trout Oncorhynchus clarkii lewisi at eight sites within the upper 30 km of the Cherry Creek basin (Madison River, Montana) from 2007 to 2010, after using piscicides to remove all fish. We obtained gametes from 258 parental-pair crosses (164 females and 258 males) from four wild populations and two hatchery broods. All embryos were incubated to the eyed stage in two hatcheries prior to placing them in RSIs. Green-to-eyed egg survivals were higher for progeny of wild-spawned adults (median, 91.0%; 95% CI, 88.7–93.7%) than for progeny of hatchery-spawned adults (median, 81.7%; 95% CI, 74.9–88.4%), and this difference was highly significant (P &lt; 0.01). Over 26,500 fry were counted leaving RSIs. Median embryo-to-fry survival was 75.6% (95% CI, 72.2–79.0%). Fry exited individual RSIs from 8 to 45 d after embryo translocation. Fry survivals differed among years and sites, and year was more important than site in explaining variation in survival. The success of RSI fry introductions was confirmed by annual monitoring of fish abundance, which indicated that abundances of Westslope Cutthroat Trout 5 to 9 years after RSI introductions were equal to or higher than abundances of nonnative salmonids prior to their removal using piscicides.
A deep asynchronous actor‐critic learning‐based event‐triggered decentralized load frequency control of power systems with communication delays
Authors: Chen Pengcheng , Liu Shichao , Zhang Dan , Yu Li 
Published: April 2021

AbstractThis article proposes a novel asynchronous advantage actor‐critic (A3C) learning‐based dynamic event‐triggered mechanism for the decentralized load frequency regulation to alleviate the local‐area communication burden and influence of the load fluctuations. The proposed dynamic event‐triggered mechanism applies the A3C algorithm to optimally adjust the threshold of the event‐triggered function in real time. In the A3C algorithm framework, the long short‐term memory (LSTM) network is used to estimate the policy function and value function. First, for each control area, a novel model of the decentralized load frequency control (LFC) system is established to design the event‐triggered communication mechanism and deal with the communication delay simultaneously. Then, based on the Lyapunov stability theory, the controller gain parameters of the decentralized LFC system and the margins of the even‐triggering thresholds are derived by solving a series of linear matrix inequalities (LMIs). Finally, a three‐area and four‐area power systems are used to evaluate the proposed decentralized LFC method. Simulation results show that the proposed method can greatly reduce the data transmission times and preserve a satisfactory system performance.
Array‐Based Biosensors for Bacteria Detection: From the Perspective of Recognition
Authors: Yu Ting , Xianyu Yunlei 
Published: April 2021

AbstractArray‐based biosensors have shown as effective and powerful tools to distinguish intricate mixtures with infinitesimal differences among analytes such as nucleic acids, proteins, microorganisms, and other biomolecules. In array‐based bacterial sensing, the recognition of bacteria is the initial step that can crucially influence the analytical performance of a biosensor array. Bacteria recognition as well as the signal readout and mathematical analysis are indispensable to ensure the discrimination ability of array‐based biosensors. Strategies for bacteria recognition mainly include the specific interaction between biomolecules and the corresponding receptors on bacteria, the noncovalent interaction between materials and bacteria, and the specific targeting of bacterial metabolites. In this review, recent advances in array‐based bacteria sensors are discussed from the perspective of bacteria recognition relying on the characteristics of different bacteria. Principles of bacteria recognition and signal readout for bacteria detection are highlighted as well as the discussion on future trends in array‐based biosensors.