bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Vivo Versus In Vitro Degradation of a 3D Printed Resorbable Device for Ligation of Vascular Tissue in Horses
Authors: Adolfsson Karin H. , Sjöberg Ida , Höglund Odd V. , Wattle Ove , Hakkarainen Minna 
Published: August 2021

AbstractA resorbable 3D printed polydioxanone (PDO) device is manufactured to facilitate ligation of vascular tissue during surgery. The device must provide sufficient mechanical performance throughout the healing period. Therefore, degradation and mechanical performance of the device are investigated as a function of in vivo and in vitro aging. During aging the PDO device released cyclic and linear water‐soluble products. In vivo aging resulted in higher relative number of linear oligomers in comparison to in vitro aging. A major loss of mechanical performance is observed after only 10 days in vivo and the Young’s modulus (E) and tensile strength at break (σb) decreased by 28% and 54%, respectively. This is in contrast to in vitro aging, where no loss of mechanical properties is observed during the same period. The in vivo aged devices exhibit clear holes in the matrices after 28 days, while apparent cracks are observed first after 140 days in vitro. These results highlight the sensitivity of the degradation process of resorbable devices with regards to the interactions of the device with the surrounding environment (tissues) and demonstrate the importance of in vivo testing as compliment to in vitro testing before clinical use of devices.
Stimuli‐Responsive Depolymerization of Poly(Phthalaldehyde) Copolymers and Networks
Authors: Soars Shafer , Kamps Joshua , Fairbanks Benjamin , Bowman Christopher 
Published: August 2021

AbstractThis article describes a stimuli‐responsive cross‐linked network based on a poly(phthalaldehyde) (PPA) self‐immolating polymer backbone which, upon removal of polymer end‐caps, becomes degradable under ambient conditions. Self‐immolating polymers (SIPs) are of particular interest due to their ability to undergo controlled depolymerization resulting in the elimination of the polymer structure and potential recovery and reuse of the original monomers. Linear copolymers of phthalaldehyde and unsymmetrical allylated‐phthalaldehyde monomers are obtained via anionic polymerization with appreciable incorporation of the allyl‐functional monomeric units. This approach enables crosslinking of the otherwise linear polymers via thiol–ene reactions with the allyl functional phthalaldehyde polymers. The polymer network thus formed unzips along the phthalaldehyde backbone to yield monomers and low molecular weight fragments in response to chemical (F−, H+) or physical (light, sonication) stimuli that remove the stabilizing functional endcaps on the phthalaldehyde polymers. Rheology is used to demonstrate gelation within 5 s of light exposure of the allylated‐phthalaldehyde polymers reacted with pentaerythritol tetrakis(3‐mercaptopropionate) and photoinitiator (3 wt%). Triggerable degelation makes this material well suited for photolithography and additive manufacturing as well as other applications that necessitate polymer network degradation or elimination. Further, a method is described for determining the degelation temperature of a self‐immolative cross‐linked network.
ABA Type Amphiphiles with Poly(2‐benzhydryl‐2‐oxazine) Moieties: Synthesis, Characterization and Inverse Thermogelation
Authors: Hahn Lukas , Keßler Larissa , Polzin Lando , Fritze Lars , Forster Stefan , Helten Holger , Luxenhofer Robert 
Published: August 2021

AbstractThermoresponsive polymers are frequently involved in the development of materials for various applications. Here, polymers containing poly(2‐ benzhydryl‐2‐oxazine) (pBhOzi) repeating units are described for the first time. The homopolymer pBhOzi and an ABA type amphiphile comprising two flanking hydrophilic A blocks of poly(2‐methyl‐2‐oxazoline) (pMeOx) and the hydrophobic aromatic pBhOzi central B block (pMeOx‐b‐pBhOzi‐b‐pMeOx) are synthesized and the latter is shown to exhibit inverse thermogelling properties at concentrations of 20 wt.% in water. This behavior stands in contrast to a homologue ABA amphiphile consisting of a central poly(2‐benzhydryl‐2‐oxazoline) block (pMeOx‐b‐pBhOx‐b‐pMeOx). No inverse thermogelling is observed with this polymer even at 25 wt.%. For 25 wt.% pMeOx‐b‐pBhOzi‐b‐pMeOx, a surprisingly high storage modulus of ≈22 kPa and high values for the yield and flow points of 480 Pa and 1.3 kPa are obtained. Exceeding the yield point, pronounced shear thinning is observed. Interestingly, only little difference between self‐assemblies of pMeOx‐b‐pBhOzi‐b‐pMeOx and pMeOx‐b‐pBhOx‐b‐pMeOx is observed by dynamic light scattering while transmission electron microscopy images suggest that the micelles of pMeOx‐b‐pBhOzi‐b‐pMeOx interact through their hydrophilic coronas, which is probably decisive for the gel formation. Overall, this study introduces new building blocks for poly(2‐oxazoline) and poly(2‐oxazine)‐based self‐assemblies, but additional studies will be needed to unravel the exact mechanism.
Catalytic Activity of Various β‐Diketiminate Zinc Complexes toward the Ring‐Opening Polymerization of Caprolactone and Derivatives
Authors: Köhler Moritz , Rinke Philipp , Fiederling Kevin , Görls Helmar , Ueberschaar Nico , Schacher Felix Helmut , Kretschmer Robert 
Published: August 2021

AbstractThe ring‐opening polymerization (ROP) of lactones is mainly catalyzed by tin(II) octanoate Sn(Oct)2, due to its efficiency and easy handling despite the toxic issues of tin. Herein, two novel dinuclear bis(β‐diketiminate) complexes with flexible alkylene bridging groups (1,2‐ethylene and 1,3‐propylene) and biocompatible zinc centers are introduced. The complexes are obtained by deprotonation of the protio‐ligands with Zn(HMDS)2 and fully characterized. Afterwards the complexes are studied regarding their catalytic activity towards the ROP of caprolactones. Briefly, ε‐caprolactone (CL), ε‐phenyl‐ε‐caprolactone (phCL) and ε‐methyl‐ε‐caprolactone (meCL) with and without benzyl alcohol (BnOH) as initiator in toluene are homopolymerized and compared to the known dinuclear 1,4‐phenylene bridged bis(β‐diketiminate) zinc catalyst and the mononuclear counterpart. Thereby, the catalysts are classified upon their efficiency by in situ IR measurements, selectivity, and polymerization control by size exclusion chromatography (SEC) of samples, which are terminated at 60% conversion. The novel zinc catalysts prevent Sn(Oct)2 typical molar mass broadening, show slower reaction rates than 1,4‐phenylene bridged bis(β‐diketiminate) and improve control compared to the mononuclear relative. However, a drastic loss of polymerization control resulting in high molar masses and polydispersities occurrs in the absence of BnOH. Furthermore, these complexes allow the ROP of phCL but are inactive for meCL.
Room‐Temperature Solid‐State Lithium Metal Batteries Using Metal Organic Framework Composited Comb‐Like Methoxy Poly(ethylene glycol) Acrylate Solid Polymer Electrolytes
Authors: Lei Zhiwen , Qiu Qi , Shen Jinlai , Ao Xiaohu , Zhang Bingqi , Guo Yuanfa , Wang Jun , Deng Yonghong , Wang Chaoyang 
Published: August 2021

AbstractSolid polymer electrolyte with good thermal stability and flexibility is an excellent candidate for solid‐state lithium metal batteries, while its low ionic conductivity caused by high crystallinity limits its application at ambient temperature. Here a metal organic framework (zeolitic imidazolate framework‐8, ZIF‐8) composited comb‐like methoxy poly(ethylene glycol) acrylate polymer electrolyte (MCPE) with high ionic conductivity (9.96 × 10−5 S cm−1 at 30 °C) is prepared by an in situ UV polymerization method. The as‐prepared MCPE exhibits improved mechanical property due to the introduction of porous ZIF‐8 nanofillers, which is beneficial to suppress the growth of lithium dendrites. Consequently, the LiFePO4||MCPE||Li cells show a high capacity of 116 mAh g−1 at 30 °C and 0.5 C, and maintain 89.4% of initial capacity after 150 cycles with the average Coulombic efficiency of 99.9%. These results demonstrate that the MCPE shows great potential in solid‐state lithium metal batteries near room temperature.
Highly Stretchable, Tough, and Conductive Ag@Cu Nanocomposite Hydrogels for Flexible Wearable Sensors and Bionic Electronic Skins
Authors: Chen Kai , Hu Yunping , Liu Mingxiang , Wang Feng , Liu Pei , Yu Yongsheng , Feng Qian , Xiao Xiufeng 
Published: August 2021

AbstractFlexible conductive materials and flexible electronic devices are driving the development of the next generation of cutting‐edge wearable electronics. However, the existing hydrogel‐based flexible conductive materials have limited tensile capacity, low toughness, and poor anti‐fatigue performance, resulting in narrow sensing area and insufficient durability. In this paper, a conductive nanocomposite hydrogel with high ductility, toughness, and fatigue resistance is prepared by combining silver coated copper (Ag@Cu) nanoparticles with gelatin followed by one‐step immersion in sodium sulfate (Na2SO4) solution. The salting‐out of gelatin in Na2SO4 solution greatly improve the mechanical properties of this gelatin‐based hydrogel. The uniform distribution of Ag@Cu nanoparticles inside the whole hydrogel endow the composite hydrogel with excellent electrical conductivity (1.35 S m−1). In addition, it displayed high and stable tensile strain sensitivity over a wide strain range (gauge factor = 2.08). Therefore, the Ag@Cu‐Gel hydrogel is sensitive and stable enough to be successfully utilized as flexible wearable sensor for detecting human motion signals in real time, such as bending of human joints, swallowing, and throat vocalization. Furthermore, this hydrogel is also suitable for application as electronic skin for bionic robots. The above results demonstrate the promising application of Ag@Cu‐Gel hydrogel for wearable electronics.
Development of MRI‐based axillary numerical models and estimation of axillary lymph node dielectric properties for microwave imaging
Authors: Godinho Daniela M. , Felício João M. , Castela Tiago , Silva Nuno A. , Orvalho Maria de Lurdes , Fernandes Carlos A. , Conceição Raquel C. 
Published: August 2021

AbstractPurposeMicrowave imaging (MWI) has been studied as a complementary imaging modality to improve sensitivity and specificity of diagnosis of axillary lymph nodes (ALNs), which can be metastasized by breast cancer. The feasibility of such a system is based on the dielectric contrast between healthy and metastasized ALNs. However, reliable information such as anatomically realistic numerical models and matching dielectric properties of the axillary region and ALNs, which are crucial to develop MWI systems, are still limited in the literature. The purpose of this work is to develop a methodology to infer dielectric properties of structures from magnetic resonance imaging (MRI), in particular, ALNs. We further use this methodology, which is tailored for structures farther away from MR coils, to create MRI‐based numerical models of the axillary region and share them with the scientific community, through an open‐access repository.MethodsWe use a dataset of breast MRI scans of 40 patients, 15 of them with metastasized ALNs. We apply image processing techniques to minimize the artifacts in MR images and segment the tissues of interest. The background, lung cavity, and skin are segmented using thresholding techniques and the remaining tissues are segmented using a K‐means clustering algorithm. The ALNs are segmented combining the clustering results of two MRI sequences. The performance of this methodology was evaluated using qualitative criteria. We then apply a piecewise linear interpolation between voxel signal intensities and known dielectric properties, which allow us to create dielectric property maps within an MRI and consequently infer ALN properties. Finally, we compare healthy and metastasized ALN dielectric properties within and between patients, and we create an open‐access repository of numerical axillary region numerical models which can be used for electromagnetic simulations.ResultsThe proposed methodology allowed creating anatomically realistic models of the axillary region, segmenting 80 ALNs and analyzing the corresponding dielectric properties. The estimated relative permittivity of those ALNs ranged from 16.6 to 49.3 at 5 GHz. We observe there is a high variability of dielectric properties of ALNs, which can be mainly related to the ALN size and, consequently, its composition. We verified an average dielectric contrast of 29% between healthy and metastasized ALNs. Our repository comprises 10 numerical models of the axillary region, from five patients, with variable number of metastasized ALNs and body mass index.ConclusionsThe observed contrast between healthy and metastasized ALNs is a good indicator for the feasibility of a MWI system aiming to diagnose ALNs. This paper presents new contributions regarding anatomical modeling and dielectric properties' characterization, in particular for axillary region applications.
Defect distribution index: A novel metric for functional lung MRI in cystic fibrosis
Authors: Valk Anne , Willers Corin , Shahim Kamal , Pusterla Orso , Bauman Grzegorz , Sandkühler Robin , Bieri Oliver , Wyler Florian , Latzin Philipp 
Published: August 2021

PurposeLung impairment from functional MRI is frequently assessed as defect percentage. The defect distribution, however, is currently not quantified. The purpose of this work was to develop a novel measure that quantifies how clustered or scattered defects in functional lung MRI appear, and to evaluate it in pediatric cystic fibrosis.TheoryThe defect distribution index (DDI) calculates a score for each lung voxel categorized as defected. The index increases according to how densely and how far an expanding circle around a defect voxel contains more than 50% defect voxels.MethodsFractional ventilation and perfusion maps of 53 children with cystic fibrosis were previously acquired with matrix pencil decomposition MRI. In this work, the DDI is compared to a visual score of 3 raters who evaluated how clustered the lung defects appear. Further, spearman correlations between DDI and lung function parameters were determined.ResultsThe DDI strongly correlates with the visual scoring (r = 0.90 for ventilation; r = 0.88 for perfusion; P < .0001). Although correlations between DDI and defect percentage are moderate to strong (r = 0.61 for ventilation; r = 0.75 for perfusion; P < .0001), the DDI distinguishes between patients with comparable defect percentage.ConclusionThe DDI is a novel measure for functional lung MRI. It provides complementary information to the defect percentage because the DDI assesses defect distribution rather than defect size. The DDI is applicable to matrix pencil MRI data of cystic fibrosis patients and shows very good agreement with human perception of defect distributions.
Evaluation of Supplemental Crappie Stocking in Small Southern Reservoirs
Authors: Haley Bryant M. , Wesley Neal J. 
Published: August 2021

Abstract
Supplemental stocking of crappie is a primary management strategy in many small southern reservoirs, but survival and contribution to the year-class in these systems is not known. We assessed the contribution of hatchery fish to the age-1 year-class within established crappie populations in four reservoirs ranging 29–74 ha in surface area. Chemically marked White Crappie Pomoxis annularis and magnolia crappie (Black Crappie Pomoxis nigromaculatus × ♀White Crappie) were stocked at 125 fish/ha in 2015 and 2016, respectively. We also stocked a renovated reservoir (40 ha) with White Crappie in 2015 to serve as a reference without intraspecific competition and to provide an estimate of marking efficacy and mark retention. The total length of wild age-0 fish at the time of stocking averaged 52–60 mm larger than that of their hatchery conspecifics. We only recaptured 11 marked crappie, 10 of which were from the reference reservoir. The recovery of only one hatchery fish from the supplemental stockings yielded a combined stocking contribution of 0.59%, or 0.71% when adjusted for marking efficacy (at least 83%). We concluded that supplemental stocking of crappie in smaller reservoirs is not effective under current the stocking protocols, as contributions &lt;1% cannot justify hatchery and personnel costs. It may be possible to modify the stocking procedures, and potential modifications are discussed.
Combination and development of carbon filament tows: Application of coextrusion with long fiber‐reinforced thermoplastics
Authors: Lin Mei‐Chen , Lin Jia‐Horng , Bao Limin 
Published: August 2021

AbstractIn this study, long fiber‐reinforced thermoplastics (LFT) and coextrusion are applied to wrap carbon fiber tows in a thermoplastic polyurethane (TPU) outer layer. In this way, the proposed wrapped yarns have a sheath–core structure. Scanning electron microscopy observation reveals that TPU and carbon fiber tows form a physical combination that allows TPU to further enhance the tensile strength of carbon fiber tows by 35.87%, which is 19.62 ± 1.88 MPa. The tensile strain of carbon fiber tows also improves. LFT and coextrusion are performed to produce successive carbon fiber tows that can be successfully fabricated into textiles, possessing good fabric flexibility. The technique of carbon fiber tows can be applied to mass production feasibility for the field of carbon fiber composites.
Registration of three Arkot 0908 cotton germplasm lines
Authors: Bourland Fred M. , Chee Peng , Jones Don C. 
Published: August 2021

AbstractArkot 0908‐52 (Reg. no. GP‐1091, PI 697035), Arkot 0908‐56 (Reg. no. GP‐1090, PI 697034), and Arkot 0908‐60 (Reg. no. GP‐1089, PI 697033) are conventional cotton (Gossypium hirsutum L.) germplasm lines released by the Arkansas Agricultural Experiment Station in October 2020. The lines are high performing, early maturing germplasm derived from parents (‘GA 230’ and ‘UA222’) having contrasting backgrounds and maturity. The lines produced higher lint yields than UA222 and ‘UA48’ over 5 yr and at four test sites in Arkansas, producing similar relative lint yields across all test sites and about 15 and 25% higher than lint yields of UA222 and UA48, respectively. Additionally, they had smaller seed while producing more seed per area and more or equal amount of lint per seed than UA222 or UA48. Arkot 0908‐52 and Arkot 0908‐60 performed well in the 2017 Regional High Quality Test and the 2017 Regional Breeders Network Test, respectively. Leaf pubescence and bract trichome density of Arkot 0908‐56 were greater than Arkot 0908‐52, Arkot 0908‐60, and UA48. Stem pubescence density of Arkot 0908‐52 and Arkot 0908‐56 was similar to UA48 and UA222 but greater than Arkot 0908‐60. All three lines displayed high resistance to bacterial blight and were similar to UA222 and UA48 in their response to other diseases. Arkot 0908‐56 and Arkot 0908‐60 were more resistant to tarnished plant bug than Arkot 0908‐52 and UA48, but all were more susceptible to tarnished plant bug than UA222. Fiber quality of Arkot 0908‐52 and Arkot 0908‐56 was similar to UA48, while fiber quality of Arkot 0908‐60 was similar to UA222.
Modulating Endogenous Oxygen Consumption Enhanced AIEgens‐Mediated Photodynamic Therapy against Advanced Bladder Tumor
Authors: Hao Jiange , Yin Haoli , Lu Wenfeng , Zhuang Junlong , Chen Mengxia , Gao Jie , Zhu Guanchen , Cao Wenmin , Kan Yansheng , Lu Yingqiang , Guo Hongqian 
Published: August 2021

AbstractPhotodynamic therapy (PDT) plays an important role in tumor therapy. However, PDT outcomes remain poor due to the insufficient reactive oxygen species (ROS) yield of the photosensitizer and the aggravation of hypoxia in the tumor microenvironment through PDT. To solve this issue, a puissant PDT nanoparticles (NPs) platform is developed to defeat tumors by employing powerful PDT in an oxygen‐enriched tumor microenvironment and by inhibiting tumor migration through regulating hypoxia‐related pathways. Specifically, TFM, as a previously reported AIEgen, does not emit brightly but instead makes use of its nonradiative relaxation for ROS generation, along with oxygen regulator doxycycline (DOXY), both of which are encapsulated in NPs that can specifically penetrate deep into tumor tissue. After released from the NPs, TFM functions as a powerful ROS generator, and DOXY reduces endogenous oxygen consumption via regulating mitochondrial cytochrome oxidase 1, further enhancing TFM‐mediated PDT efficacy. Meanwhile, reoxygenation is observed to reduce the expression of hypoxia inducible factor‐1α and M2 macrophages induced by PDT. The amplified PDT not only strongly killed tumor but, along with the downregulated hypoxia related pathways during the post‐PDT process, inhibited tumor migration. In summary, such NPs exhibit potent anti‐tumor effects for advanced bladder cancer therapy.
An overview on the seven pathogenic human coronaviruses
Authors: Kesheh Mina Mobini , Hosseini Parastoo , Soltani Saber , Zandi Milad 
Published: August 2021

SummaryTo date, seven human coronaviruses (HCoVs) have been detected: HCoV‐NL63, HCoV‐229E, HCoV‐HKU1, HCoV‐OC43, severe acute respiratory syndrome coronavirus (SARS‐CoV), Middle East respiratory syndrome coronavirus (MERS‐CoV) and SARS‐CoV‐2. Four of these viruses, including HCoV‐NL63, ‐229E, ‐HKU1 and ‐OC43, usually cause mild‐to‐moderate respiratory diseases with a seasonal pattern. Since 2000, three new HCoVs have emerged with a significant mortality rate. Although SARS‐CoV and MERS‐CoV caused an epidemic in some countries, SARS‐CoV‐2 escalated into a pandemic. All HCoVs can cause severe complications in the elderly and immunocompromised individuals. The bat origin of HCoVs, the presence of intermediate hosts and the nature of their viral replication suggest that other new coronaviruses may emerge in the future. Despite the fact that all HCoVs share similarities in viral replication, they differ in their accessory proteins, incubation period and pathogenicity. This study aims to review these differences between the seven HCoVs.
Systematic review of host genetic association with Covid‐19 prognosis and susceptibility: What have we learned in 2020?
Authors: Ferreira de Araújo João Locke , Menezes Diego , Saraiva‐Duarte Julia Maria , de Lima Ferreira Luciana , Santana de Aguiar Renato , Pedra de Souza Renan 
Published: August 2021

SummaryBiomarker identification may provide strategic opportunities to understand disease pathophysiology, predict outcomes, improve human health, and reduce healthcare costs. The highly heterogeneous Covid‐19 clinical manifestation suggests a complex interaction of several different human, viral and environmental factors. Here, we systematically reviewed genetic association studies evaluating Covid‐19 severity or susceptibility to SARS‐CoV‐2 infection following PRISMA recommendations. Our research comprised papers published until December 31st, 2020, in PubMed and BioRXiv databases focusing on genetic association studies with Covid‐19 prognosis or susceptibility. We found 20 eligible genetic association studies, of which 11 assessed Covid‐19 outcome and 14 evaluated infection susceptibility (five analyzed both effects). Q‐genie assessment indicated moderate quality. Five large‐scale association studies (GWAS, whole‐genome, or exome sequencing) were reported with no consistent replication to date. Promising hits were found on the 3p21.31 region and ABO locus. Candidate gene studies examined ACE1, ACE2, TMPRSS2, IFITM3, APOE, Furin, IFNL3, IFNL4, HLA, TNF‐ɑ genes, and ABO system. The most evaluated single locus was the ABO, and the most sampled region was the HLA with three and five candidate gene studies, respectively. Meta‐analysis could not be performed. Available data showed the need for further reports to replicate claimed associations.