bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of fresh versus effluent water irrigation on soil chemical properties of golf course greens and fairways
Authors: Isweiri Hanan , Qian Yaling , Davis Jessica G.
Published: March 2021

In arid and semiarid areas, an increase in water demand has forced urban planners to use alternative water resources for turfgrass irrigation. In this study, the soil chemical properties of push‐up greens and fairways on two golf courses that use either effluent water or fresh water were compared. The study was conducted on two golf courses in Wyoming. Golf Course A started to use effluent water for irrigation in 2007 while Golf Course B has always used fresh water. From 2003 to 2013, a total of 238 soil samples of greens (104 from Golf Course A and 134 from Golf Course B) were collected, and 90 soil samples (45 from Golf Course A and 45 from Golf Course B) were collected from fairways. The soil analyses showed that many changes occurred over time due to the use of effluent water irrigation. After 6 yr of using effluent water, soil electrical conductivity (EC) increased but remained well below the critical threshold levels for turf , whereas soil pH increased by 0.42 units. From 2007 to 2012, sodium levels increased by 2‐ to 5‐fold. The availability of micronutrients (Fe and Mn) decreased, especially on greens irrigated with effluent water. Soil phosphorus (P) and potassium (K) levels increased after using effluent water, which would be beneficial for turfgrass and lower fertilization requirements.
Interactive effects of waterlogging and salinity on perennial ryegrass and alkaligrass
Authors: Isweiri Hanan , Qian Yaling , Davis Jessica G.
Published: March 2021

A lot of salt‐affected soils in the world are also affected by compaction and waterlogging due to shallow water tables or decreased infiltration of water due to sodicity. Waterlogging and compaction cause reduced oxygen exchange (hypoxia). Research on the combined impacts of salinity and hypoxia on turfgrass growth is limited. The interactive effects of salinity and oxygen availability on nine perennial ryegrass entries (Lolium perenne L.) and one alkaligrass [Puccinellia tenuiflora (Jacq.) Parl.] cultivar were studied. In a controlled greenhouse, grasses were subjected to 4 treatments: control, salinity, hypoxia, and salinity + hypoxia for 12 weeks. All entries exhibited decreased clipping yield in both salinity and hypoxia + salinity treatments except ‘Fults’ alkaligrass. With or without hypoxia treatment, ‘Fults’ alkaligrass was the most salt tolerant grass among all entries. In general, all perennial ryegrass entries had better turf quality in control and hypoxia treatments than in salinity and salinity with hypoxia treatments. All perennial ryegrass entries were more severely affected (quality and yields) under combined hypoxia and salinity treatment compared to salinity or hypoxia only. Plant Na+ and Cl− concentrations increased under salinity and salinity + waterlogging treatments. The experimental entries (‘10.0824’ and ‘10.0825’) were able to maintain better turf quality than other perennial ryegrass cultivars under salinity and the combination of hypoxia + salinity treatments.
A field scale facility to evaluate the effect of soil organic matter content of sod‐established St. Augustinegrass lawns on nitrate‐nitrogen leaching
Authors: Park Dara M. , Cisar John L. , Snyder George H. , Fidanza Michael A. , Williams Karen E.
Published: March 2021

A field scale facility was constructed to investigate the impact of a wide range of potential management parameters on nitrate (NO3‐N) leaching from St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] turf. The facility was built to identify and quantify background NO3‐N sources and concentrations before turf cultural management factors were applied, and to examine how establishment of sod with two contrasting soil organic matter (SOM) contents influence NO3‐N concentrations in percolate and leachate. The performance of the facility's irrigation and vadose zone percolate sampling units were evaluated and found acceptable. St. Augustinegrass sod with a 2.5 cm rootzone containing either 4% or 10% SOM was installed and maintained at this facility. The NO3‐N amounts in percolate and leachate were nearly proportional to the amount of SOM associated with the sod rootzones at 4% and 10%, respectively. Based on this investigation, SOM content in the rootzone attached to sod and within the soil which sod is placed influences NO3‐N concentration in the rootzone and leachate. Therefore, SOM should be considered in best management practices for lawncare. This facility will allow for future investigations on cultural management strategies aimed at decreasing the potential for NO3‐N leaching from St. Augustinegrass lawns.
Efficacy of natural herbicides on dandelion (Taraxacum officinale G.H. Weber ex Wiggers) and white clover (Trifolium repens L.) populations
Authors: Carroll Devon Elizabeth , Kaminski J. E. , Borger J. A.
Published: March 2021

Perennial broadleaves such as dandelion (Taraxacum officinale G.H. Weber ex Wiggers) and white clover (Trifolium repens L.) are known to be pervasive weeds in stands of maintained turfgrasses. The use of synthetic herbicides is the most common and effective method of control for these weeds. As pesticide use in European countries, Canada, and the United States is becoming more scrutinized, identification of alternative weed control options may be necessary. However, few organic or natural weed control products exist. A field study was conducted to evaluate the efficacy of various fertilizers and organic and bio‐herbicides including chelated iron, ammonium nanonate, citrus oil, acetic acid, and sodium chloride on dandelion and white clover control as compared to that of two synthetic herbicides containing 2,4‐dichlorophenoxy‐acetic acid (2,4‐D), mecoprop‐p (MCPP), and dicamba. Injury to perennial ryegrass (Lolium perenne L.) was also evaluated with the objective of determining which products effectively suppressed weed populations while imposing minimal injury to desirable turfgrasses. Chelated iron was effective in controlling dandelion and white clover populations equal to that of both synthetic herbicides with minimal injury to turfgrass. Other organic and bio‐herbicide treatments provided some control of both weed populations but generally were too injurious to the turfgrass. Fertility treatments and citrus oil did not reduce populations of either weed. This research indicates that some natural products currently on the market may serve as effective alternatives to synthetic herbicides. This information will be beneficial to homeowners and turfgrass managers controlling weed populations in geographic areas with restricted pesticide use or where control with organic products is desired.
Soil surfactant use on athletic field infield surfaces
Authors: Thoms Adam W. , Lindsey Alex J. , Pease Ben W.
Published: March 2021

Infield skins are best managed by deep and slow additions of water, but time between games limits these applications. A two‐year study was conducted on a collegiate club softball infield skin to evaluate if applications of soil surfactants could extend soil moisture levels in infields. Seven soil surfactants treatments (Magnus at 15.9 L ha−1 and Magnus 2x at 31.8 L ha−1, Vivax at 15.9 L ha−1, Cascade at 25.5 L ha−1 and Cascade 2x at 50.9 L ha−1, Vivax Tab at 3.3 L water m−2, and Precision EZ Tab at 3.3 L water m−2), as well as a nontreated control (NTC) were applied. Linear regression analysis for soil moisture readings resulted in the Vivax Tab having greatest water loss (−0.44% h−1) along with the NTC (−0.41% h−1) in 2018, however no differences were present in 2019. Contrast statements compared the NTC to the soil surfactants and only Magnus 2x offered a lower water loss over time than NTC. Magnus 2x provided a harder surface than the NTC immediately after watering, and a lower surface hardness than all other treatments after 4 h. In 2019, only Vivax Tabs and Cascade 2x did not have lower surface hardness values than the NTC immediately after watering, and by 8 h after watering only Vivax had a lower surface hardness than NTC. Treatment affects were not consistent from year to year, but it appears increased rates may be needed to change soil moisture and hardness levels for any duration. Future research should focus on increased rates of soil surfactants for infield skins on different skin materials.
Evaluation of replica exchange with repulsive scaling approach for docking glycosaminoglycans
Authors: Maszota‐Zieleniak Martyna , Marcisz Mateusz , Kogut Małgorzata M. , Siebenmorgen Till , Zacharias Martin , Samsonov Sergey A.
Published: March 2021

Glycosaminoglycans (GAGs), long linear periodic anionic polysaccharides, are key molecules in the extracellular matrix (ECM). Therefore, deciphering their role in the biologically relevant context is important for fundamental understanding of the processes ongoing in ECM and for establishing new strategies in the regenerative medicine. Although GAGs represent a number of computational challenges, molecular docking is a powerful tool for analysis of their interactions. Despite the recent development of GAG‐specific docking approaches, there is plenty of room for improvement. Here, replica exchange molecular dynamics with repulsive scaling (REMD‐RS) recently proved to be a successful approach for protein–protein complexes, was applied to dock GAGs. In this method, effective pairwise radii are increased in different Hamiltonian replicas. REMD‐RS is shown to be an attractive alternative to classical docking approaches for GAGs. This work contributes to setting up of GAG‐specific computational protocols and provides new insights into the nature of these biological systems.
An open‐source, expert‐designed decision tree application to support accurate diagnosis of myeloid malignancies
Authors: Coats Thomas , Bean Daniel , Vatopoulou Theodora , Vijayavalli Dhanapal , El‐Bashir Razan , Panopoulou Aikaterini , Wood Henry , Wimalachandra Manujasri , Coppell Jason , Medd Patrick , Furtado Michelle , Tucker David , Kulasakeraraj Austin , Pawade Joya , Dobson Richard , Ireland Robin
Published: March 2021

Accurate, reproducible diagnoses can be difficult to make in haemato‐oncology due to multi‐parameter clinical data, complex diagnostic criteria and time‐pressured environments. We have designed a decision tree application (DTA) that reflects WHO diagnostic criteria to support accurate diagnoses of myeloid malignancies. The DTA returned the correct diagnoses in 94% of clinical cases tested. The DTA maintained a high level of accuracy in a second validation using artificially generated clinical cases. Optimisations have been made to the DTA based on the validations, and the revised version is now publicly available for use at http://bit.do/ADAtool.
Factors associated with SARS‐CoV‐2 infection in patients attending an acute hospital ambulatory assessment unit
Authors: Ronan Geoffrey , Kumar Lakshman , Davey Mary , O′Leary Catriona , McAleer Sarah , Lynch Jenny , Lavery Ros , Campion John , Ryan Joseph , O'Donoghue P. J. , Daly Aine , Shanahan Jayne , Costelloe Sean , Sadlier Corinna , McGlade Ciara , Manning Sean , Carroll Jennifer , O'Flynn Siun , Barry Patrick , Chevarria Julio
Published: March 2021

To describe the factors associated with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection in mild‐to‐moderate patients attending for assessment. This observational study was conducted in a Model 4 tertiary referral center in Ireland. All patients referred for SARS‐CoV‐2 assessment over a 4‐week period were included. Patient demographics, presenting symptoms, comorbidities, medications, and outcomes (including length of stay, discharge, and mortality) were collected. Two hundred and seventy‐nine patients were assessed. These patients were predominantly female (62%) with a median age of 50 years (SD 16.9). Nineteen (6.8%) patients had SARS‐CoV‐2 detected. Dysgeusia was associated with a 16‐fold increased prediction of SARS‐CoV‐2 positivity (p = .001; OR, 16.8; 95% CI, 3.82–73.84). Thirteen patients with SARS‐COV‐2 detected (68.4%) were admitted, in contrast with 38.1% (99/260) of patients with SARS‐CoV‐2 non‐detectable or not tested (p = .001). Female patients were more likely to be hospitalized (p = .01) as were current and ex‐smokers (p = .05). We describe olfactory disturbance and fever as the main presenting features in SARS‐CoV‐2 infection. These patients are more likely to be hospitalized with increased length of stay; however, they make up a minority of the patients assessed. “Non‐detectable” patients remain likely to require prolonged hospitalization. Knowledge of predictors of hospitalization in a “non‐detectable” cohort will aid future planning and discussion of patient assessment in a SARS‐CoV‐2 era.
Socioeconomic, comorbidity, lifestyle, and quality of life comparisons between chronic rhinosinusitis phenotypes
Authors: Philpott Carl , Ta Ngan Hong , Hopkins Claire , Ray Jaydip , Ahmed Shazhada , Almeyda Robert , Kara Naveed , Carrie Sean , Erskine Sally E. , Cathcart Russell , Sunkaraneni Vishnu , Robertson Alasdair , Anari Shahram , Kumar Balasubrahmanyam Nirmal , Clark Allan ,   The CRES Group
Published: March 2021

Background

Chronic rhinosinusitis (CRS) is a heterogeneous group of inflammatory sinonasal disorders with key defining symptoms, but traditionally separated into phenotypes by clinical/endoscopic findings. It is not known whether the two phenotypes have differing socioeconomic, comorbidity, and lifestyle differences. This analysis of the Chronic Rhinosinusitis Epidemiology Study (CRES) database sought to analyze any key differences in the socioeconomic variables between those with CRS with nasal polyps (CRSwNPs) and those without nasal polyps (CRSsNPs). We also sought to analyze differences in comorbidities, lifestyle, and quality of life.

Methods

Patients with a confirmed diagnosis of CRS in secondary and tertiary care outpatient settings in the UK were invited to participate in a questionnaire‐based case–control study. Variables included demographics, socioeconomic factors, comorbidities, lifestyle factors, and health‐related quality of life (HRQoL) (level 3 evidence).

Results

A total of 1204 patients' data were analyzed: 553 CRSsNP and 651 CRSwNP participants. The key socioeconomic variables did not demonstrate any notable differences, nor did lifestyle variables other than alcohol consumption being higher in those with CRSwNP (P = .032), but the latter was not significant after adjusting for age and sex. Aside from confirmation of asthma being more common in CRSwNP, it was notable that this group complained less of upper respiratory tract infections (URTIs), and CRSsNP participants showed evidence of worse HRQoL scores in respect of body pain (P = .001).

Conclusions

Patients with CRSwNP experience higher rates of asthma and lower rates of URTIs; patients with CRSsNP have worse body pain scores. Otherwise, there are no demonstrable significant socioeconomic, comorbidity, lifestyle, or quality of life differences between the two phenotypes.

Level of Evidence

3 Laryngoscope, 131:2179–2186, 2021
Impact of thermal processing on levels of acrylamide in a wheat‐lentil flour matrix
Authors: Portman Drew , Maharjan Pankaj , Blanchard Chris , Naiker Mani , Panozzo Joe F.
Published: March 2021

A growing demand for plant‐based protein has seen a resurgence in the utilisation of pulses such as lentil and chickpea as a protein‐rich substrate to produce food products traditionally based on animal or cereal protein. Additionally, pulses offer metabolic benefits due to the bioactivity of compounds including phenolic acids, simple and complex carbohydrates and a more complete amino‐acid profile which is not found in cereal grains. However, there is an increasing concern in the formation of acrylamide in food which occurs when asparagine, an abundant amino acid found in pulses, forms a complex with the reducing sugars; glucose, fructose, and maltose. Recent studies in animal models have shown that acrylamide is carcinogenic and therefore is a concern for humans. High levels of acrylamide have been reported particularly in fried products, primarily due to the Maillard reaction which amplifies the formation of acrylamide. This study investigated the levels of acrylamide in bread, cookies, and extruded products prepared with wheat‐lentil composite flour. Our research found that extrusion resulted in a significantly lower concentration of acrylamide compared to traditional baking. Additionally, increasing the amount of lentil within the composite significantly increased the net concentration of acrylamide for all bread, cookies and extrudate products.
What Does Conversion Mean in Polymer Science?
Authors: Kricheldorf Hans R. , Scheliga Felix , Weidner Steffen M.
Published: March 2021

The definition of the term “conversion” is discussed for a variety of polymer syntheses. It is demonstrated that in contrast to organic and inorganic chemistry several different definitions are needed in polymer science. The influence of increasing conversion on structure and topology of homo‐ and copolymers is illustrated. Chain‐growth polymerizations, such as radical polymerization or living anionic polymerizations of vinyl monomers, condensative chain polymerization, two and three‐dimensional step‐growth polymerizations, ring–ring or chain–chain equilibration and chemical modification of polymers are considered.
Toward Largely Enhanced Toughness and Balanced Strength in PA1012/EPDM Blends via Synergistic Effect of Sacrificial Bonds and Network Structure
Authors: Sun Canchen , Wang Yuanyuan , Wang Bin , Cao Yanxia , Wang Jianfeng , Yang Yanyu , Wang Wanjie
Published: March 2021

Here, zinc‐neutralized ethylene propylene diene monomer (EPDM) ionomers with different neutralization levels are prepared through melt blending, and are then incorporated with polyamide 1012 (PA1012) to fabricate PA1012/EPDM ionomer blends. Interestingly, complex crosslinking networks are formed in the blends due to the construction of sacrificial bonds (Zn2+‐carboxyl, Zn2+‐amide). The as‐formed network structure and sacrificial bond endow the PA/EPDM blends with largely enhanced toughness (16 times higher than that of neat PA), as well as balanced strength and stiffness. Meanwhile, the rheological behaviors of PA1012/EPDM ionomer blends indicate their relative low melting viscosity, which can avoid the processing shortcomings of plastics toughened with rubber. Moreover, PA1012/EPDM ionomer blends show obvious gelation behavior, and a maximum notched Izod impact strength exhibited at the gel point, in which unique double network structure can be observed obviously, indicating that there is a corresponding correlation between the rheological and mechanical parameters. Furthermore, the supper‐toughening mechanism of PA1012/EPDM ionomer blends at gel point is explored, which origins from the large deformation and cavitation of rubber particles and the destruction of special double network morphologies. This study provides a novel and effective strategy to fabricate PA materials with outstanding toughness and excellent strength simultaneously.
Material Design for 3D Multifunctional Hydrogel Structure Preparation
Authors: Shin Woohyeon , Kim Jun Seop , Kim Heesung , Choi Hui Ju , Lee Hee Jung , Um Moon Kwang , Choi Moon Kee , Chung Kyeongwoon
Published: March 2021

Hydrogels are recognized as one of the most promising materials for e‐skin devices because of their unique applicable functionalities such as flexibility, stretchability, biocompatibility, and conductivity. Beyond the excellent sensing functionalities, the e‐skin devices further need to secure a target‐oriented 3D structure to be applied onto various body parts having complex 3D shapes. However, most e‐skin devices are still fabricated in simple 2D film‐type devices, and it is an intriguing issue to fabricate complex 3D e‐skin devices resembling target body parts via 3D printing. Here, a material design guideline is provided to prepare multifunctional hydrogels and their target‐oriented 3D structures based on extrusion‐based 3D printing. The material design parameters to realize target‐oriented 3D structures via 3D printing are systematically derived from the correlation between material design of hydrogels and their gelation characteristics, rheological properties, and 3D printing processability for extrusion‐based 3D printing. Based on the suggested material design window, ion conductive self‐healable hydrogels are designed and successfully applied to extrusion‐based 3D printing to realize various 3D shapes.
Rapid Phenotypic Stock Identification of Chinook Salmon in Recreational Fishery Management
Authors: Jensen Alexander J. , Schreck Carl B. , Peterson James T.
Published: March 2021

Rapid phenotypic stock identification in mixed-stock fisheries can provide a useful alternative to more time-intensive methods (e.g., coded wire tags, genetics) in assessing harvest and informing management decisions. We leveraged local ecological knowledge, existing stock identification methods, and understanding of life history differences to develop rapid stock identification tools for fall-run Chinook Salmon Oncorhynchus tshawytscha encountered in the Buoy 10 recreational fishery at the mouth of the Columbia River. Specifically, we sought to differentiate between the fishery’s two dominant genetic lineages: lower river tules and upriver brights. We sampled recreationally landed Chinook Salmon in 2017, 2018, and 2019, assigned sampled individuals to functional reporting groups using a single-nucleotide-polymorphism-based genetic baseline, and collected measurements on phenotypic traits. Using traits including pigmentation patterns (e.g., spotting), fin morphology, characteristics indicative of sexual maturity, and muscle lipid content, random forest classification models provided consistently high classification success across and within genetic groups (i.e., up to 90%). Classification success remained consistent over time within fishery seasons and between years but showed meaningful bias between sexes. Based on observed classification success, we developed and evaluated a categorical visual identification guide capable of facilitating more rapid trait observations and on-site stock identification. The resulting classification key, built using classification trees and visual guide observations from 2019, achieved slightly lower classification success across and within genetic groups and had variable success among samplers. Compared with the existing use of coded wire tags in harvest assessment, phenotypic stock identification methods can provide more rapid and more numerous assignments, albeit with a greater degree of individual assignment error. Applied as a complement to standard methods like coded wire tags, the use of rapid phenotypic stock identification methods offers the potential for increased overall precision and timeliness in harvest assessments.
On (p(x), q(x))‐Laplace equations in ℝN without Ambrosetti‐Rabinowitz condition
Authors: Nastasi Antonella
Published: March 2021

In the present work, we consider a (p(x), q(x))‐elliptic equation describing the behavior of a double‐phase anisotropic problem which has relevance in electrorheological fluid applications. The analysis leads to the existence of weak (nonnegative) solutions in the special case of potential terms with critical frequency and a superlinear reaction term. In order to prove the existence result, we combine critical point theory of mountain pass type with related topological and variational methods. Basically, the approach is variational, but we do not impose any Ambrosetti‐Rabinowitz type condition for the superlinearity of the reaction. More specifically, we apply the Euler‐Lagrange functional approach to the variational formulation of the above‐mentioned model problem. We note that we work in the whole space and so we have to consider non‐compact embeddings. This aspect constitutes an additional difficulty in our study.
Novel twelve port eight element UWB‐MIMO antenna
Authors: Cheng Jun
Published: March 2021

This article presents the design of a highly integrated twelve port ultra‐wideband (UWB) antenna array for multiple‐input multiple‐output (MIMO) communications. The proposed array consists of a unit cell element constructed using a circular arc structure excited by a simple microstrip line feed terminated by an arc‐like stub. The proposed unit cell antenna covers 3–9 GHz covering most of the third, fourth, and fifth generation communication frequencies. The 3D antenna array has an overall board size of 33 × 33 × 15 mm3 consisting of one horizontal board and two vertical boards. The vertical boards are interlocked and are directly positioned above the horizontal boards. Four antennas with dual feed excitation are deployed on the horizontal board while each vertical board is printed with two elements with single port excitation. Thus, a highly integrated twelve port antenna is realized with isolation better than 15 dB between each port. The prototype antenna offers both polarization and pattern diversity leading to enhanced MIMO performance.
Motion‐compensated 3D turbo spin‐echo for more robust MR intracranial vessel wall imaging
Authors: Hu Zhehao , van der Kouwe Andre , Han Fei , Xiao Jiayu , Chen Junzhou , Han Hui , Bi Xiaoming , Li Debiao , Fan Zhaoyang
Published: March 2021

Purpose

(1) To investigate the effect of internal localized movement on 3DMR intracranial vessel wall imaging and (2) to develop a novel motion‐compensation approach combining volumetric navigator (vNav) and self‐gating (SG) to simultaneously compensate for bulk and localized movements.

Methods

A 3D variable‐flip‐angle turbo spin‐echo (ie, SPACE) sequence was modified to incorporate vNav and SG modules. The SG signals from the center k‐space line are acquired at the beginning of each TR to detect localized motion‐affected TRs. The vNavs from low‐resolution 3D EPI are acquired to identify bulk head motion. Fifteen healthy subjects and 3 stroke patients were recruited in this study. Overall image quality (0‐poor to 4‐excellent) and vessel wall sharpness were compared among the scenarios with and without bulk and/or localized motion and/or the proposed compensation strategies.

Results

Localized motion reduced wall sharpness, which was significantly mitigated by SG (ie, outer boundary of basilar artery: 0.68 ± 0.27 vs 0.86 ± 0.17; P = .037). When motion occurred, the overall image quality and vessel wall sharpness obtained with vNav‐SG SPACE were significantly higher than those obtained with conventional SPACE (ie, basilarartery outer boundary sharpness: 0.73 ± 0.24 vs 0.94 ± 0.24; P = .033), yet comparable to those obtained in motion‐free scans (ie, basilarartery outer boundary sharpness: 0.94 ± 0.24 vs 0.96 ± 0.31; P = .815).

Conclusion

Localized movements can induce considerable artifacts in intracranial vessel wall imaging. The vNav‐SG approach is capable of compensating for both bulk and localized motions.
Light‐triggered dePEGylation with decreasing the diameter of hydroxyapatite nanocarriers for enhanced cellular uptake and tumor penetration
Authors: Li Xiaojing , Xi Dongmei , Zhang Zhen , Long Saran , Chen Pengzhong , Du Jianjun , Sun Wen , Fan Jiangli , Peng Xiaojun
Published: March 2021

PEGylation of nano‐drug delivery systems (NDDSs) has been investigated to overcome the side effect of conventional chemotherapy including improving pharmacokinetics by prolonging drug circulation, reducing immune clearance and premature drug leakage. Although, PEGylation of NDDSs can also disturb the tumor penetration and cellular uptake with the diameter enhancement. Therefore, in this work, we constitute a light‐triggered dePEGylation strategy, which results in the decrease of diameter of the pH‐responsive hydroxyapatite drug nanocarriers (DOX@HAP‐PEG) for enhanced cellular uptake and tumor penetration. Under light irradiation (650 nm), PEG chains can be availably separated from the nanocarrier by cleaving the Cy linker. Moreover, the cellular uptake of DOX@HAP‐PEG and DOX@HAP‐PEG+L (DOX@HAP‐PEG under light irradiation) are explored against MCF‐7, Hela, and HepG2 cancer cells. The results show that the cellular uptake of DOX@HAP‐PEG is lower than that of DOX@HAP‐PEG+L. In addition, in 3D tumor model, DOX@HAP‐PEG+L can better penetrate into the cell spheroid than DOX@HAP‐PEG, which is demonstrated by the accumulated fluorescence signals in the cell spheroid.
Coarse‐arithmetic coordinate descent for the resolution of semidefinite linear systems
Authors: Thao Nguyen T. , Rzepka Dominik
Published: March 2021

We propose an inexact coordinate descent method to solve a consistent equation of the type Ax = b where A is a real symmetric and positive semidefinite matrix. The admissible range of inexactitude allows to reduce every multiplication present in the computation to a scaling by a signed power of 2 for the sake of hardware simplification. Although the resulting descent is nonideal, the numerical experiments show that its rate of convergence remains close to that of exact coordinate descent, whether the coordinate selection is cyclic or random. Meanwhile, our algorithm outperforms both methods with an additional low complexity “weak greedy” selection of the coordinates, also based on scaling by signed powers of 2. Our method is based on an advanced use of varying relaxation coefficients in the Gauss–Seidel iteration, with special theoretical considerations when A is singular.
Trans‐1,4‐stereospecific copolymerization of isoprene and butadiene catalyzed by TiCl4/MgCl2 Ziegler–Natta catalyst: III Effect of alkylaluminium on monomer reactivity ratios
Authors: Niu Qingtao , Zhang Junying , He Aihua
Published: March 2021

Copolymerizations of isoprene (Ip) and butadiene (Bd) in different Bd/Ip feed ratios were carried out using the heterogeneous TiCl4/MgCl2 type Ziegler–Natta (Z‐N) catalysts activated by trimethylaluminium (AlMe3), triethylaluminium (AlEt3), triisobutylaluminium (Al(i‐Bu)3) or tri‐n‐octylaluminium (AlOct3). Monomer reactivity ratios of Ip and Bd (rIp, rBd) in the copolymerizations were calculated by the Kelen–Tödüs method and then instantaneous compositions of the copolymers were theoretically acquired based on the Mayo–Lewis equation. The effects of alkylaluminiums on copolymerization activity, copolymer microstructure, comonomer incorporation, monomer reactivity ratios and copolymer instantaneous composition were investigated. Using AlEt3 led to higher copolymerization activity and trans‐1,4 stereoselectivity compared with other trialkylaluminiums. AlOct3 with bulky n‐octyl groups showed a higher Bd monomer reactivity ratio. The theoretical copolymer composition drift based on the Mayo–Lewis equation was in good coincidence with the experimental data measured by real‐time 1H NMR during the steady polymerization stage. The nature of the discrepancy between the theoretical and measured copolymer compositions obtained in the initial polymerization stage is discussed in detail. © 2021 Society of Industrial Chemistry.
Individual participant data meta‐analysis for external validation, recalibration, and updating of a flexible parametric prognostic model
Authors: Ensor Joie , Snell Kym I. E. , Debray Thomas P. A. , Lambert Paul C. , Look Maxime P. , Mamas Mamas A. , Moons Karel G. M. , Riley Richard D.
Published: March 2021

Individual participant data (IPD) from multiple sources allows external validation of a prognostic model across multiple populations. Often this reveals poor calibration, potentially causing poor predictive performance in some populations. However, rather than discarding the model outright, it may be possible to modify the model to improve performance using recalibration techniques. We use IPD meta‐analysis to identify the simplest method to achieve good model performance. We examine four options for recalibrating an existing time‐to‐event model across multiple populations: (i) shifting the baseline hazard by a constant, (ii) re‐estimating the shape of the baseline hazard, (iii) adjusting the prognostic index as a whole, and (iv) adjusting individual predictor effects. For each strategy, IPD meta‐analysis examines (heterogeneity in) model performance across populations. Additionally, the probability of achieving good performance in a new population can be calculated allowing ranking of recalibration methods. In an applied example, IPD meta‐analysis reveals that the existing model had poor calibration in some populations, and large heterogeneity across populations. However, re‐estimation of the intercept substantially improved the expected calibration in new populations, and reduced between‐population heterogeneity. Comparing recalibration strategies showed that re‐estimating both the magnitude and shape of the baseline hazard gave the highest predicted probability of good performance in a new population. In conclusion, IPD meta‐analysis allows a prognostic model to be externally validated in multiple settings, and enables recalibration strategies to be compared and ranked to decide on the least aggressive recalibration strategy to achieve acceptable external model performance without discarding existing model information.
Analyzing the Effects of Micro‐Source Disconnection on Interactive Stability of Grid and Micro‐Grid with Series Inverters
Authors: Zhang Jinjing , Wang Xinggui , Song Wenqin , Yang Weiman
Published: March 2021

Owing to a lack of systematic mathematical models to represent the parameters related to micro‐source disconnection, the stability of interaction between a grid and a micro‐grid with series micro‐source inverters (SMSI‐MG) is difficult to analyze. In this study, the average ratio and the degree of imbalance of three‐phase micro‐source disconnection, denoted respectively by δ and ϵ, are defined, and the positive‐ and negative‐sequence impedances of the SMSI‐MG containing the two parameters are established using a combination of the harmonic linearization and the symmetrical component methods. Moreover, rules of the behavior of the SMSI‐MG after micro‐source disconnection as well as its mechanism of interaction with the grid are revealed by the impedance models. The results of analysis show that high‐frequency harmonic resonance was generated around the carrier frequency when δ ≠ 0, and both high‐ and low‐frequency harmonic resonances were generated when both δ and ϵ increased in the interactive system. Furthermore, three SMSI‐MGs containing five, 10, and 20 micro‐sources in a single phase were simulated, and the results verified the correctness, feasibility, and advantages of the simplified analysis of the impedance models. These insights can be used to apply the corresponding control strategies in a timely manner according to the given conditions of micro‐source disconnection to reduce the harmonic resonance and increase the stability of the SMSI‐MG and the grid. The results of simulations verified the effectiveness of such a control strategy. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.
A probabilistic long‐term framework for site‐specific erosion analysis of wind turbine blades: A case study of 31 Dutch sites
Authors: Shankar Verma Amrit , Jiang Zhiyu , Ren Zhengru , Caboni Marco , Verhoef Hans , van der Mijle‐Meijer Harald , Castro Saullo G.P. , Teuwen Julie J.E.
Published: March 2021

Rain‐induced leading‐edge erosion (LEE) of wind turbine blades (WTBs) is associated with high repair and maintenance costs. The effects of LEE can be triggered in less than 1 to 2 years for some wind turbine sites, whereas it may take several years for others. In addition, the growth of erosion may also differ for different blades and turbines operating at the same site. Hence, LEE is a site‐ and turbine‐specific problem. In this paper, we propose a probabilistic long‐term framework for assessing site‐specific lifetime of a WTB coating system. Case studies are presented for 1.5 and 10 MW wind turbines, where geographic bubble charts for the leading‐edge lifetime and number of repairs expected over the blade's service life are established for 31 sites in the Netherlands. The proposed framework efficiently captures the effects of spatial and orographic features of the sites and wind turbine specifications on LEE calculations. For instance, the erosion is highest at the coastal sites and for sites located at higher altitudes. In addition, erosion is faster for turbines associated with higher tip speeds, and the effects are critical for such sites where the exceedance probability for rated wind conditions are high. The study will aid in the development of efficient operation and maintenance strategies for wind farms.
Tin‐rich stannides CePd2Sn3, REPd2Sn4, Pr2Pd4Sn7 and RE3Pd6Sn10 – Crystal chemistry and 119Sn Mössbauer spectroscopy
Authors: Engelbert Simon , Klenner Steffen , Reimann Maximilian Kai , Pöttgen Rainer
Published: March 2021

The stannides CePd2Sn3, REPd2Sn4 (RE=Ce, Pr, Nd, Sm), Pr2Pd4Sn7 and RE3Pd6Sn10 (RE=Ce, Pr) were synthesized from the elements by arc‐melting and subsequent annealing in muffle or induction furnaces. The praseodymium, neodymium and samarium compounds are reported for the first time. The structures of PrPd2Sn4 and Pr2Pd4Sn7 were refined from single crystal X‐ray diffractometer data. The common structural building units of these stannides are condensed Pd@Sn5 square pyramids and Pd@Sn6 octahedra. The RE2Pd4Sn7 and RE3Pd6Sn10 structures are intergrowth variants of CePd2Sn3 and CePd2Sn4 related slabs. PrPd2Sn4, NdPd2Sn4 and Pr3Pd6Sn10 show Curie‐Weiss behavior with experimental magnetic moments close to the free‐ion values. Antiferromagetric ordering is detected at Néel temperatures of 8.2(1) K (PrPd2Sn4), 10.3(1) K (NdPd2Sn4) and 6.7(1) K (Pr3Pd6Sn10). The three stannides show metamagnetic transitions at low external field strengths. The stannides CePd2Sn3, REPd2Sn4 (RE=Ce, Pr, Nd) and RE3Pd6Sn10 (RE=Ce, Pr) were further characterized via their 119Sn Mössbauer spectra which reflect the different tin substructures: (i) cis‐Sn4 units, (ii) Sn2 pairs and (iii) square grids.
The inverse seesaw family: Dirac and Majorana
Authors: Chuliá Salvador Centelles , Srivastava Rahul , Vicente Avelino
Published: March 2021

Abstract

After developing a general criterion for deciding which neutrino mass models belong to the category of inverse seesaw models, we apply it to obtain the Dirac analogue of the canonical Majorana inverse seesaw model. We then generalize the inverse seesaw model and obtain a class of inverse seesaw mechanisms both for Majorana and Dirac neutrinos. We further show that many of the models have double or multiple suppressions coming from tiny symmetry breaking “μ-parameters”. These models can be tested both in colliders and with the observation of lepton flavour violating processes.
Bubble needs strings
Authors: Banerjee Souvik , Danielsson Ulf , Giri Suvendu
Published: March 2021

Abstract

In this paper, we want to emphasize the pivotal role played by strings in the model realizing de Sitter using an expanding bubble, proposed and subsequently developed in [1–3]. Contrary to the Randall-Sundrum model of brane-localized gravity, we use the end points of radially stretched strings to obtain matter sourcing gravity induced on the bubble wall. This allows us to reinterpret the possible volume divergence coming from naive dimensional reduction as mass renormalization in four dimensional particle physics. Furthermore, we argue that the residual time dependence in the bulk, pointed out by some recent work as a possible shortcoming of such models, is automatically cured in presence of these stringy sources.
Population genomics of Mediterranean oat (A. sativa) reveals high genetic diversity and three loci for heading date
Authors: Canales F. J. , Montilla-Bascón G. , Bekele W. A. , Howarth C. J. , Langdon T. , Rispail N. , Tinker N. A. , Prats E.
Published: March 2021

Key message

Genomic analysis of Mediterranean oats reveals high genetic diversity and three loci for adaptation to this environment. This information together with phenotyping and passport data, gathered in an interactive map, will be a vital resource for oat genetic improvement.

During the twentieth century, oat landraces have increasingly been replaced by modern cultivars, resulting in loss of genetic diversity. However, landraces have considerable potential to improve disease and abiotic stress tolerance and may outperform cultivars under low input systems. In this work, we assembled a panel of 669 oat landraces from Mediterranean rim and 40 cultivated oat varieties and performed the first large-scale population genetic analysis of both red and white oat types of Mediterranean origin. We created a public database associated with an interactive map to visualize information for each accession. The oat collection was genotyped with 17,288 single-nucleotide polymorphism (SNP) loci to evaluate population structure and linkage disequilibrium (LD); to perform a genome-wide association study (GWAs) for heading date, a key character closely correlated with performance in this drought-prone area. Population genetic analysis using both structure and PCA distinguished two main groups composed of the red and white oats, respectively. The white oat group was further divided into two subgroups. LD decay was slower within white lines in linkage groups Mrg01, 02, 04, 12, 13, 15, 23, 33, whereas it was slower within red lines in Mrg03, 05, 06, 11, 21, 24, and 28. Association analysis showed several significant markers associated with heading date on linkage group Mrg13 in white oats and on Mrg01 and Mrg08 in red oats.
Two-step functional screen on multiple proteinaceous substrates reveals temperature-robust proteases with a broad-substrate range
Authors: García-Moyano Antonio , Diaz Yuleima , Navarro José , Almendral David , Puntervoll Pål , Ferrer Manuel , Bjerga Gro Elin Kjæreng
Published: March 2021

To support the bio-based industry in development of environment-friendly processes and products, an optimal toolbox of biocatalysts is key. Although functional screen of (meta)genomic libraries may potentially contribute to identifying new enzymes, the discovery of new enzymes meeting industry compliance demands is still challenging. This is particularly noticeable in the case of proteases, for which the reports of metagenome-derived proteases with industrial applicability are surprisingly limited. Indeed, proteolytic clones have been typically assessed by its sole activity on casein or skim milk and limited to mild screening conditions. Here, we demonstrate the use of six industry-relevant animal and plant by-products, namely bone, feather, blood meals, gelatin, gluten, and zein, as complementary substrates in functional screens and show the utility of temperature as a screening parameter to potentially discover new broad-substrate range and robust proteases for the biorefinery industry. By targeting 340,000 clones from two libraries of pooled isolates of mesophilic and thermophilic marine bacteria and two libraries of microbial communities inhabiting marine environments, we identified proteases in four of eleven selected clones that showed activity against all substrates herein tested after prolonged incubation at 55 °C. Following sequencing, in silico analysis and recombinant expression in Escherichia coli, one functional protease, 58% identical at sequence level to previously reported homologs, was found to readily hydrolyze highly insoluble zein at temperatures up to 50 °C and pH 9–11. It is derived from a bacterial group whose ability to degrade zein was unknown. This study reports a two-step screen resulting in identification of a new marine metagenome-derived protease with zein-hydrolytic properties at common biomass processing temperatures that could be useful for the modern biorefinery industry.

Key points

• A two-step multi-substrate strategy for discovery of robust proteases.

• Feasible approach for shortening enzyme optimization to industrial demands.

• A new temperature-tolerant protease efficiently hydrolyzes insoluble zein.
No effect of passive stretching on neuromuscular function and maximum force-generating capacity in the antagonist muscle
Authors: Cè Emiliano , Coratella Giuseppe , Doria Christian , Rampichini Susanna , Borrelli Marta , Longo Stefano , Esposito Fabio
Published: March 2021

Purpose

The present study investigated whether or not passive stretching increases the force-generating capacity of the antagonist muscle, and the possible neuromuscular mechanisms behind.

Methods

To this purpose, the neuromuscular function accompanying the force-generating capacity was assessed in 26 healthy male volunteers after passive stretching and in a control session. Before and after passive intermittent static stretching of the plantar flexors consisting of five sets × 45 s + 15 s-rest, maximum voluntary isometric contraction (MVC) and surface electromyographic root mean square (sEMG RMS) were measured in the tibialis anterior (the antagonist muscle). Additionally, evoked V wave, H-reflex, and M wave were elicited by nerve stimulation at rest and during MVC. Ankle range of motion (ROM) and plantar flexors MVC and EMG RMS were measured to check for the effectiveness of the stretching manoeuvre.

Results

No change in MVC [p = 0.670; effect size (ES) − 0.03] and sEMG RMS/M wave during MVC (p = 0.231; ES − 0.09) was observed in the antagonist muscle after passive stretching. Similarly, no change in V wave (p = 0.531; ES 0.16), H-reflex at rest and during MVC (p = 0.656 and 0.597; ES 0.11 and 0.23, respectively) and M wave at rest and during MVC (p = 0.355 and 0.554; ES 0.04 and 0.01, respectively) was observed. An increase in ankle ROM (p < 0.001; ES 0.55) and a decrease in plantar flexors MVC (p < 0.001; ES − 1.05) and EMG RMS (p < 0.05; ES − 1.72 to − 0.13 in all muscles) indicated the effectiveness of stretching protocol.

Conclusion

No change in the force-generating capacity and neuromuscular function of the antagonist muscle after passive stretching was observed.
Testing olfactory dysfunction in acute and recovered COVID-19 patients: a single center study in Italy
Authors: Pasquini Jacopo , Maremmani Carlo , Salvadori Stefano , Silani Vincenzo , Ticozzi Nicola
Published: March 2021

Background

Olfactory dysfunction in coronavirus disease 2019 (COVID-19) is common during acute illness and appears to last longer than other symptoms. The aim of this study was to objectively investigate olfactory dysfunction in two cohorts of patients at two different stages: during acute illness and after a median recovery of 4 months.

Methods

Twenty-five acutely ill patients and 26 recovered subjects were investigated. Acute patients had a molecular diagnosis of COVID-19; recovered subjects had a positive antibody assay and a negative molecular test. A 33-item psychophysical olfactory identification test tailored for the Italian population was performed.

Results

Median time from symptoms onset to olfactory test was 33 days in acute patients and 122 days in recovered subjects. The former scored a significantly higher number of errors at psychophysical testing (median [IQR]: 8 [13] vs 3 [2], p < 0.001) and were more frequently hyposmic (64% vs 19%, p = 0.002). Recovered subjects reported a variable time to subjective olfactory recovery, from days up to 4 months. Participants included in the study reported no significant nasal symptoms at olfactory testing. Among recovered subject who reported olfactory loss during acute COVID-19, four (27%) were still hyposmic. Demographic and clinical characteristics did not show significant associations with olfactory dysfunction.

Conclusion

Moderate-to-severe hospitalized patients showed a high level and frequency of olfactory dysfunction compared to recovered subjects. In the latter group, subjects who reported persisting olfactory dysfunction showed abnormal scores on psychophysical testing, indicating that, at least in some subjects, persistent hyposmia may represent a long-term sequela of COVID-19.