bluuebunny/crossref_metadata_2025 huggingface dataset:
An ICP‐AES method for routine high‐precision measurement of seawater Sr/Ca ratios to validate coral paleothermometry calibrations
Authors: Khare Agraj , Hughes Hunter P. , Kilbourne K. Halimeda , Schijf Johan
Published: May 2021

A new inductively coupled plasma atomic emission spectrometry (ICP‐AES) method is presented for rapid and routine analysis of Sr/Ca molar ratios in seawater, with a long‐term precision of < 0.2%. It is an adaptation of a method widely employed for the analysis of coral aragonite Sr/Ca ratios in marine paleothermometry studies, which are based on the assumption that the seawater Sr/Ca ratio is constant in space and time. While prior studies have shown variations of up to 1% with depth, smaller variations at the ocean surface are generally accounted for via empirical, species‐specific calibrations of coral Sr/Ca vs. temperature. We found Sr/Ca variations in some coastal waters to be even larger, with distinct periodicity, complicating this approach. Although the high precision necessary for measurements of seawater Sr/Ca has previously relied on advanced mass spectrometry, long analysis times, and expensive isotopic spikes, our method uses more accessible instrumentation and is both time‐ and cost‐saving. The intricate composition of seawater, relative to coral aragonite solutions, requires an intensity ratio calibration technique combined with rigorous normalization to a suitable seawater standard. Key aspects of our method are discussed, including the choice of wavelengths, instrument parameters, accuracy, precision, and matrix effects. Special attention is given to the need for a certified seawater Sr/Ca reference standard, which does not presently exist. Analytical validation is provided by concurrent sharp gradients in Sr/Ca and δ18O, coinciding with the Florida landfall of hurricane Irma, as recorded at near‐daily resolution in a continuous seawater sample collected with an osmotic pump.
Ring Opening Metathesis Polymerization of a New Monomer Derived from a Nitroso Diels–Alder Reaction
Authors: Subnaik Selesha , Sheridan Katya , Hobbs Christopher E.
Published: May 2021

A nitroso Diels–Alder (NDA) reaction between cyclopentadiene and an in situ generated nitroso compound leads to a new heterocyclic monomer for ring opening metathesis polymerization (ROMP) reactions. This monomer could be polymerized in the presence of Grubbs‐third generation initiator with good control over Mn and decent Ð values. The resulting isoxazolidine‐containing material could undergo further hydrogenation, deprotection, and modification with Dansyl chloride as well as ring opening to provide an amino‐and hydroxyl‐decorated “polyolefin.”
Metagenomic analysis and antimicrobial activity of two fermented milk kefir samples
Authors: Tenorio‐Salgado Silvia , Castelán‐Sánchez Hugo G. , Dávila‐Ramos Sonia , Huerta‐Saquero Alejandro , Rodríguez‐Morales Sergio , Merino‐Pérez Enrique , Roa de la Fuente Luis Fernando , Solis‐Pereira Sara E. , Pérez‐Rueda Ernesto , Lizama‐Uc Gabriel
Published: May 2021

In recent years, the fermented milk product kefir has been intensively studied because of its health benefits. Here, we evaluated the microbial consortia of two kefir samples, from Escarcega, Campeche, and Campeche (México). We considered a functional comparison between both samples, including fungal and bacterial inhibition; second, we applied shotgun metagenomics to assess the structure and functional diversity of the communities of microorganisms. These two samples exhibited antagonisms against bacterial and fungal pathogens. Bioactive polyketides and nonribosomal peptides were identified by LC‐HRMS analysis. We also observed a high bacterial diversity and an abundance of Actinobacteria in both kefir samples, and a greater abundance of Saccharomyces species in kefir of Escarcega than in the Campeche kefir. When the prophage compositions were evaluated, the Campeche sample showed a higher diversity of prophage sequences. In Escarcega, we observed a prevalence of prophage families that infect Enterobacteria and Lactobacillus. The sequences associated with secondary metabolites, such as plipastatin, fengycin, and bacillaene, and also bacteriocins like helveticin and zoocin, were also found in different proportions, with greater diversity in the Escarcega sample. The analyses described in this work open the opportunity to understand the microbial diversity in kefir samples from two distant localities.
Age‐associated variation in the gut microbiota of chinstrap penguins (Pygoscelis antarctica) reveals differences in food metabolism
Authors: Tian Jiashen , Du Jing , Zhang Shengjiu , Li Yanqiu , Gao Xianggang , Han Jiabo , Lu Zhichuang
Published: May 2021

Age is known to affect the gut microbiota in various animals; however, this relationship is poorly understood in seabirds. We investigated the temporal succession of gut microbiota in captive chinstrap penguins of different ages using high‐throughput sequencing. The gut microbiota exhibited a significant age succession pattern, reaching maturity in adults and then declining with increasing age. Only 15 amplicon sequence variants were shared among the gut microbiota in chinstrap penguins at all studied ages, and these contributed to most of the age‐related variations in total gut microbiota. Co‐occurrence networks found that these key bacteria belonged to the genera Acinetobacter, Clostridium sensu stricto, and Fusobacterium, and more species interactions were found within the same taxonomy. Functional prediction indicated that most of the metabolic functions were more abundant in the gut microbiota in adult chinstrap penguins, except for carbohydrate metabolism, which was significantly more abundant in older individuals.
Penaeid Shrimp in Chesapeake Bay: Population Growth and Black Gill Disease Syndrome
Authors: Tuckey Troy D. , Swinford Jillian L. , Fabrizio Mary C. , Small Hamish J. , Shields Jeffrey D.
Published: May 2021

Since 1991, the number of penaeid shrimp occurring in Virginia waters of Chesapeake Bay has steadily increased, prompting an interest in developing a fishery. Although development of a shrimp fishery in the Chesapeake Bay region could bring economic benefits, the fishery may be hampered by the presence of a disease syndrome known as shrimp black gill (sBG). The objectives of our study were to (1) describe the spatial distribution and abundance patterns of shrimp in Chesapeake Bay, (2) relate relative abundance of shrimp to habitat characteristics, and (3) determine the presence and seasonality of sBG to better understand disease dynamics in the region. Subadult penaeid shrimp were collected monthly from Virginia waters by trawl from 1991 to 2017, and individuals were identified to species and counted. White shrimp Litopenaeus setiferus were the most numerous species captured, followed by brown shrimp Farfantepenaeus aztecus and pink shrimp F. duorarum. Shrimp were captured primarily from July to December. White shrimp were the only species that exhibited visible signs of sBG, which was first observed in October 2016 (13.4% prevalence); the condition continued into November and recurred the following year. Shrimp with visible signs of gill disease were examined by microscopy, histology, and PCR assay and were diagnosed with infections of a histophagous apostome ciliate, presumably Hyalophysa lynni. Any impacts of sBG on shrimp survival or marketability should be considered in fishery management plans to ensure sustainability of the resource.
Decadal-Scale Variation in Mean Trophic Level in Beibu Gulf Based on Bottom-Trawl Survey Data
Authors: Su Li , Chen Zuozhi , Zhang Kui , Xu Youwei , Xu Shannan , Wang Kaili
Published: May 2021

Using bottom-trawl survey data to examine fishery resources in the Beibu Gulf, South China Sea, changes in stock density, dominant species composition, mean trophic level, and the fishing-in-balance index were comprehensively analyzed. The results show that the stock density of fishery resources declined in the gulf from 1961 to 2017. The composition of dominant species in trawl surveys from Beibu Gulf changed greatly from 1961–1962 to 2016–2017 and showed a shift from bottom species to pelagic species and from high-trophic-level species to low-trophic-level species. Catches of low-trophic-level species increased, while the dominance of high-trophic-level species declined. The mean trophic level of fish from the gulf declined from 3.90 in 1961–1962 to 3.45 in 1998–1999 at a rate of 0.13 of a trophic level per decade and then began to increase to 3.65 in 2016–2017 at a rate of 0.12 of a trophic level per decade. The fishing-in-balance index dropped to –0.96 in 1998–1999 and then slightly increased. The results indicate that fisheries resources in the Beibu Gulf have been overfished. Therefore, we recommend reducing fishing pressure and strengthening the implementation of protection measures, such as summer fishing moratoriums, enhancement, and artificial reef construction.
Age, Growth, and Mortality of Atlantic Tripletail in the North-Central Gulf of Mexico
Authors: Jefferson Amanda E. , Jargowsky Matthew B. , Schrandt Meagan N. , Cooper Pearce T. , Powers Sean P. , Dindo John J. , Drymon J. Marcus
Published: May 2021

In the southeastern USA and the Gulf of Mexico (GOM), Atlantic Tripletail Lobotes surinamensis are increasingly targeted by recreational anglers, indicating that stock status should be assessed. A critical need for such assessments is age-specific data; however, previous studies have drawn conflicting conclusions regarding the most appropriate structure for aging. Moreover, growth parameters and mortality rates for GOM Atlantic Tripletail are unknown. Therefore, the goals of this study were to (1) evaluate sagittal otoliths and first dorsal spines as aging structures; (2) model combined and sex-specific growth; and (3) estimate mortality rates for GOM Atlantic Tripletail. From 2012 to 2019, Atlantic Tripletail (N = 230, including a near-record-size specimen) were collected from the north-central GOM via hook and line and were aged using otoliths and first dorsal spines. Total length ranged from 212 to 940 mm, and age ranged from 0.07 to 5.27 years. Otoliths produced higher percent agreement (95.0%) and lower average percent error (3.0%) between readers compared to spines (82.9% and 6.5%, respectively). The von Bertalanffy growth parameters differed slightly between the otolith-based data (mean asymptotic length [L∞] = 762.42 mm, Brody growth rate coefficient [k] = 0.69 year−1, and hypothetical age at which length equals zero [t0] = −0.58 year) and spine-based data (L∞ = 718.83 mm, k = 0.79 year−1, and t0 = −0.56 year). For both otolith- and spine-based sex-specific data, the best-fitting version of the von Bertalanffy growth function permitted L∞ to vary by sex. Chapman–Robson estimates of instantaneous total mortality rate and total annual mortality rate were 1.15 and 68.66%, respectively. Based on empirical, life history-based methods, the instantaneous natural mortality rate was estimated at 0.75–0.97 and the instantaneous fishing mortality rate was estimated at 0.18–0.45, suggesting low levels of exploitation. These growth parameters and mortality estimates will provide information for future stock assessments, thereby ensuring sustainability of the GOM stock of Atlantic Tripletail.
Activity Patterns of Anadromous Fish below a Tide Gate: Observations from High-Resolution Imaging Sonar
Authors: Rillahan Christopher B. , Alcott Derrick , Castro-Santos Theodore , He Pingguo
Published: May 2021

The construction of dams and tide gates on waterways has altered the physical structure of many coastal, estuarine, and freshwater systems. These changes have come at a cost to fish populations, most notably diadromous species, which rely on connectivity between marine and freshwater systems. These anthropogenic structures can have direct effects on migrating fish, such as blocking fish passage, or have more subtle effects, such as changing movement patterns. This study used a high-resolution Adaptive Resolution Imaging Sonar to examine the behavior of Striped Bass Morone saxatilis, a large coastal predator, and Alewife Alosa pseudoharengus and Blueback Herring Alosa aestivalis (collectively known as river herring), which are forage fish, below a tide gate structure on the Herring River in Wellfleet, Massachusetts, during the river herring spring spawning run. Striped Bass were persistently present downstream of the tide gate and exhibited strong diurnal and tidal patterns. Activity of Striped Bass was highest at night and during ebb tides. During peak outflow periods, river herring were observed milling downstream of the dam in a scour pool, indicating delayed upstream passage. River herring upstream migration was primarily associated with daytime and during incoming tides. Downstream-migrating river herring were primarily observed during nighttime hours. While it was documented that the tide gates provided a physical impediment to migration, their effect on predator behavior could pose an additional challenge to migrating river herring, further complicating their recovery efforts. Due to the prevalence of obstructed waterways, studying the behavior of fish around anthropogenic structures is important in understanding the full range of impacts that these systems have under varying ecological conditions and on ecological relationships.
Aggression Toward Others Misdiagnosed as Primary Tics
Authors: Kurvits Lille , Mainka Tina , Cavanna Andrea E. , Kühn Andrea A. , Ganos Christos
Published: May 2021

Background

Tics describe a wide range of sudden and repetitive behaviors. Their multifaceted clinical features may resemble other explosive behaviors, including repetitive episodes of aggression toward others (allo‐aggression) reported by subjects without tics. Here, we document 3 exemplary cases that help disentangle allo‐aggressive behaviors from tics.

Cases

We report 3 cases who presented with an array of complex repetitive behaviors, most notably allo‐aggression (eg, sudden kicking, hitting, slapping and biting others, or pushing someone off a bike), which were misdiagnosed as primary tics. In all cases, additional symptoms, such as blackouts, feeling of being controlled by different personalities, or being empowered by repetitive behaviors, and examination pointed toward different neuropsychiatric diagnoses.

Conclusions

Repetitive allo‐aggressive behaviors are not part of the range of motor manifestations of tics. This observation not only has important medico‐legal implications but is also relevant for the overall perception of Tourette syndrome and other primary tic disorders.
When should a firm set its selling price to cope with gray market trade?
Authors: Tsunoda Yushi
Published: May 2021

This study investigates the problem of timing for firms that must cope with gray market in setting its prices by applying an observable delay game. We consider a case in which a multinational firm sells a product in two countries, and a parallel importer buys the product in one country and resells it in the other country. We show that the multinational firm never sets its price at the same time when the parallel importer sets in equilibrium, and that the multinational firm's optimal timing depends on the degree of variation in consumer preferences for product quality.
Mechanisms of neuronal cell death in ischemic stroke and their therapeutic implications
Authors: Tuo Qing‐zhang , Zhang Shu‐ting , Lei Peng
Published: May 2021

Ischemic stroke caused by arterial occlusion is the most common type of stroke, which is among the most frequent causes of disability and death worldwide. Current treatment approaches involve achieving rapid reperfusion either pharmacologically or surgically, both of which are time‐sensitive; moreover, blood flow recanalization often causes ischemia/reperfusion injury. However, even though neuroprotective intervention is urgently needed in the event of stroke, the exact mechanisms of neuronal death during ischemic stroke are still unclear, and consequently, the capacity for drug development has remained limited. Multiple cell death pathways are implicated in the pathogenesis of ischemic stroke. Here, we have reviewed these potential neuronal death pathways, including intrinsic and extrinsic apoptosis, necroptosis, autophagy, ferroptosis, parthanatos, phagoptosis, and pyroptosis. We have also reviewed the latest results of pharmacological studies on ischemic stroke and summarized emerging drug targets with a focus on clinical trials. These observations may help to further understand the pathological events in ischemic stroke and bridge the gap between basic and translational research to reveal novel neuroprotective interventions.
Study of fractional integro‐differential equations under Caputo‐Fabrizio derivative
Authors: Shah Kamal , Gul Rozi
Published: May 2021

This work is devoted to study a class of fractional integro‐differential equations under Caputo‐Fabrizo derivative. Thank to Banach's and Krasnoselskii's fixed point theorems, the existence and uniqueness results are established for the considered problem. Further, we also derive some necessary conditions for Hyers‐Ulam and generalized Hyers‐Ulam type stability analysis to the considered problem. Finally, a pertinent problem is given to illustrate the main results.
Spoof plasmon polariton coupler based on the high‐order modes of reflective metasurface
Authors: Liu Xiao‐Bo , Peng Gan‐Tao , Chen Xiao‐Ming , Zhang An‐Xue
Published: May 2021

Different from previous phase gradient metasurfaces, in this letter we show that the spoof plasmon polariton conversion is dominated by the high‐order surface wave modes rather than the pre‐defined linear phase distribution. The latter becomes invalid due to the coupling between different metallic unit cells of the metasurface. To demonstrate this point, a metasurface, which includes six different H‐shaped structures in a super cell, is designed based on the high‐order surface wave modes with a nonlinear reflective phase distribution. The simulated and measured results support the proposed theory, that is, the designed metasurface can convert x‐ and y‐polarized incident waves into spoof plasmon polariton at 8.9, 10.6, and 11.9 GHz. The metasurface not only verifies the mechanism of spoof plasmon polariton conversion, but also shows great potential in realizing cloaks, flat antennas, and so on.
Radiobiological impact of gadolinium neutron capture from proton therapy and alternative neutron sources using TOPAS‐nBio
Authors: Van Delinder Kurt W. , Khan Rao , Gräfe James L.
Published: May 2021

Purpose

A multi‐scale investigation of the biological properties of gadolinium neutron capture (GdNC) therapy with applications in particle therapy is conducted using the TOPAS Monte Carlo (MC) simulation code. The simulation results are used to quantify the amount of gadolinium dose enhancement produced as a result of the secondary neutron production from proton therapy scaled by measured data.

Materials and methods

MC modeling was performed using the radiobiology extension TOol for PArticle Simulation TOPAS‐nBio MC simulation code to study the radiobiological effects produced from GdNC on a segment of DNA, a spherical cellular model, and from the modeling of previous experimental measurements. The average RBE values were calculated from two methods, microdosimetric kinematic (MK) and biological weighting r(y) within a 2 nm DNA segment for GdNC. The single‐strand breaks (SSBs) and double‐strand breaks (DSBs) were calculated from within the nucleus of a 20 µm diameter, spherical cell model. From a previous experimental proton therapy measurement using a spread‐out Bragg peak (SOBP) of 4.5–9.5 cm and a delivered absorbed dose of 10.4 Gy, the amount of Gd neutron captures was calculated and used to quantify the amount of GdNC absolute dose from particle therapy.

Results

The average RBE from microdosimetric kinematic and biological weighting was 1.35, and 1.70 for a 10% cell survival on HSG cell‐line and weighting function data from early intestinal tolerance of mice. From a central isotropic GdNC source, the energy deposition is found to decrease from roughly 2.7 eV per capture down to approximately 0.01 eV per capture, a drop of two orders of magnitude within 50 nm. This result suggests that Gd needs to be close to the DNA (within 10–20 nm) in order for neutron capture to induce a significant dose enhancement due to the short‐range electrons emitted after Gd neutron capture. Within a spherical cell model, the SSBs, and DSBs were determined to be 39 and 1.5 per neutron capture, respectively. From the total neutron captures produced from an experimental proton therapy measurement on a 3000 PPM Gd solution, an insignificant absolute Gd dose enhancement was quantified to be 5.4 × 10−6 Gy per Gy of administered proton dose.

Conclusion

From this study and literature review, the production of secondary thermal neutrons from proton therapy is determined to be a limiting factor and unlikely to produce a clinically useful dose enhancement for secondary neutron capture therapy. Moreover, alternative neutron sources, such as, a compact deuterium‐tritium (D‐T) neutron generator, a “high yield” deuterium‐deuterium (D‐D) generator, or an industrial strength (100 mg) 252Cf source were investigated, with the 252Cf source the most likely to be capable of producing enough neutrons for 1 Gy of localized GdNC absolute dose within a reasonable treatment time.
Protocol for magnetic resonance imaging acquisition, quality assurance, and quality check for the Accelerator program for Discovery in Brain disorders using Stem cells
Authors: Parekh Pravesh , Bhalerao Gaurav V. , Rao Rashmi , Sreeraj Vanteemar S. , Holla Bharath , Saini Jitender , Venkatasubramanian Ganesan , John John P. , Jain Sanjeev ,   ADBS Consortium
Published: May 2021

Objective

The Accelerator program for Discovery in Brain disorders using Stem cells (ADBS) is a longitudinal study on five cohorts of patients with major psychiatric disorders from genetically high‐risk families, their unaffected first‐degree relatives, and healthy subjects. We describe the ADBS protocols for acquisition, quality assurance (QA), and quality check (QC) for multimodal magnetic resonance brain imaging studies.

Methods

We describe the acquisition and QC protocols for structural, functional, and diffusion images. For QA, we acquire proton density and functional images on phantoms, along with repeated scans on human volunteer. We describe the analysis of phantom data and test–retest reliability of volumetric and diffusion measures.

Results

Analysis of acquired phantom data shows linearity of proton density signal with increasing proton fraction, and an overall stability of various spatial and temporal QA measures. Examination of dice coefficient and statistical analyses of coefficient of variation in test–retest data on the human volunteer showed consistency of volumetric and diffusivity measures at whole‐brain, regional, and voxel‐level.

Conclusion

The described acquisition and QA–QC procedures can yield consistent and reliable quantitative measures. It is expected that this longitudinal neuroimaging dataset will, upon its release, serve the scientific community well and pave the way for interesting discoveries.
Time is muscle: A recommendation for early treatment for preterm infants with spinal muscular atrophy
Authors: Lee Bo Hoon , Waldrop Megan A. , Connolly Anne M. , Ciafaloni Emma
Published: May 2021

Implementation of newborn screening for spinal muscular atrophy (SMA) in 33 US states and increased genetic carrier screening have led to an increase in early, presymptomatic diagnosis of SMA. Early treatment is critically important and is recommended for presymptomatic infants with two to four copies of survival motor neuron 2. Currently, no specific treatment recommendations exist for preterm infants with SMA. The US Food and Drug Administration does not recommend using onasemnogene abeparvovec‐xioi in preterm infants. Some insurance companies interpret “preterm” to be less than 40 weeks gestational age (GA) instead of the commonly accepted 37 weeks GA, which can be a barrier to treatment access. Given the risk of rapid decline in some infants, we recommend treatment of preterm infants when they reach 37 weeks GA, based on the definitions of term GA from the World Health Organization and Centers for Disease Control and Prevention, assuming all other treatment criteria are met.
Versatile PVA/CS/CuO aerogel with superior hydrophilic and mechanical properties towards efficient solar steam generation
Authors: Tian Yongzhi , Wang Xiaoyang , Gu Yufei , Mu Xiaojiang , Wang Pengfei , Wei Anyun , Zhang Jiahong , Chen Yulian , Sun Zhiqiang , Jia Lingfeng , Zhao Zhongxian , Zhou Jianhua , Miao Lei
Published: May 2021

In recent years, pursuing a high evaporation rate of solar steam generation (SSG) has been the focus of research for relieving the freshwater shortage. Scientists struggled to find perfect photothermal materials while the importance of substrate during the steam generation was often overlooked. Therefore, in this work, an aerogel substrate composed of polyvinyl alcohol (PVA) and chitosan (CS) has been designed for solar steam generation. The compounded aerogels synthesized via freeze‐drying method not only retain the inherent characteristics of lightweight, porosity, and high specific surface area, but also inherit the advantages of PVA in water lock effect as well as CS in moisture absorption. The obtained PVA/CS/CuO aerogel coupling with high light absorption of CuO exhibited excellent steam generation capabilities, largely benefited from the superiority of the aerogel substrate. Under 1 sun solar illumination (1 kW m–2), it realized an evaporation rate as high as 2.14 Kg m–2 h–1, which is superior to recently reported semiconductor solar evaporation system. The solar‐to‐vapor energy conversion efficiency of 87.1% is obtained. Due to the versatility of CuO, PVA/CS/CuO aerogel not only has excellent light‐to‐heat conversion performance, but also has good effects in antibacterial.
Nursing‐sensitive quality indicators for pernicious placenta previa in obstetrics: A Delphi study based across Chinese institutions
Authors: Zhang Meng , Chen Weiping , Liu Cuiping , Sui Jing , Wang Dawei , Wang Yan , Meng Xin , Wang Yiqian , Yue Chongyu
Published: May 2021

Aim

To identify a set of scientific, systematic and clinically applicable nursing‐sensitive quality indicators for pernicious placenta previa (PPP).

Design

A modified Delphi‐Consensus Technique.

Methods

According to literature retrieval published between 2009–2019, 38 nursing‐sensitive quality indicators were chosen and a questionnaire was designed. An online survey was conducted in 20 hospitals in China, and data of experts’ opinions were collected and analysed by improved Delphi method.

Results

38 nursing‐sensitive quality indicators were identified. The response rates in the two rounds of expert consultation were 97.4% and 100%, and the authoritative coefficients were 0.89 and 0.92. The coefficients of variation ranged from 0.04–0.28. The nursing‐sensitive quality indicators were successfully constructed based on the modified Delphi technique.
Identifying the predictors of turnover intention based on psychosocial factors of nurses during the COVID‐19 outbreak
Authors: Mirzaei Alireza , Rezakhani Moghaddam Hamed , Habibi Soola Aghil
Published: May 2021

Aims

Because of the direct contact nurses have with patients, they are exposed to more stressful events during the outbreak of infectious diseases, which increases their turnover intention, highly impacting not only nurses, but also patients and organizations. The present study aimed to identify the predictors of turnover intention based on psychosocial factors in nurses of Ardabil pre‐hospital emergency and educational and medical centres during the COVID‐19 outbreak.

Design

The present descriptive‐analytical study was conducted in June, 2020.

Methods

A total of 479 nurses working in Ardabil pre‐hospital emergency and educational and medical centres to fight COVID‐19 were recruited for this study using the census method. Data were collected using the Demographic Information Questionnaire, Turnover Intention Questionnaire, Weiss & Marmar Impact of Event Scale‐Revised (IES‐R), General Health Questionnaire (12 C‐GHQ) and Job Content Questionnaire (JCQ). Data were analysed with SPSSv.22 software using correlation, t test, analysis of variance, multiple regression and descriptive tests.

Results

The mean turnover intention score of nurses was 41.73 with a standard deviation of 12.11. The results of correlation coefficient revealed a positive relationship between PTSD, general health, job demand and job strain with turnover intention (p ≤ .01) and a positive and significant relationship between social support and turnover intention (p ≤ .01). Multiple regression analysis showed that the variables of gender, marital status, work position, decision latitude, social support, job strain, general health and post‐traumatic stress disorder (PTSD) were predictors of turnover intention.

Conclusion

Job stressors during the COVID‐19 outbreak have led to an increase in nurses’ turnover intention. Identifying and managing the factors related to job stressors will make it possible to prevent nurses’ turnover intention in such critical situations.
Influence of psychological stress and coping styles in the professional identity of undergraduate nursing students after the outbreak of COVID‐19: A cross‐sectional study in China
Authors: Zhao Yanyan , Zhou Qiang , Li Jie , Luan Jiage , Wang Bingfei , Zhao Yan , Mu Xinru , Chen Haiying
Published: May 2021

Aim

To investigate the influencing factors in professional identity of undergraduate nursing students after the outbreak of COVID‐19.

Design

Cross‐sectional study.

Methods

The study covered 2,999 nursing students in six undergraduate nursing schools. Several self‐report questionnaires were used to collect the general information, psychological stress, coping styles and professional identity of the undergraduate nursing students.

Results

The overall average score of the professional identity of nursing students (3.67 ± 0.51) has increased significantly after the outbreak of COVID‐19. The professional identity of the undergraduate nursing students was negatively correlated with psychological stress (r = −0.23, p < .001), expectation (r = −0.12, p < .001) and avoidance (r = −0.16, p < .001), but was positively correlated with solving problems (r = 0.18, p < .001) and seeking support (r = 0.12, p < .001). Academic performance, positions, grades, reasons for choosing a nursing profession, parents or relatives engaged in nursing work and the risk degree of residence were the factors influencing the professional identity score of undergraduate nursing students' (p < .001).
The mediating effect of self‐efficacy on the relationship between family functioning and quality of life among elders with chronic diseases
Authors: Yuan Yuan , Xu Hui‐wen , Zhang Song , Wang Ying , Kitayama Akio , Takashi En , Gong Wei‐juan , Liang Jing‐yan
Published: May 2021

Aim

To explore whether self‐efficacy has any positive or negative mediating effects between family functioning and quality of life among elders with chronic diseases.

Design

A cross‐sectional study.

Methods

Questionnaires were collected from 516 community‐dwelling elderly individuals with chronic diseases using a convenience sampling method. The questionnaires included the Self‐efficacy for Managing Chronic Disease Six‐Item Scale, the Family Adaptation Partnership Growth Affection Resolve Index and the MOS 36‐Item Short Form Health Survey.

Results

Family functioning and self‐efficacy impacted the quality of life of community‐dwelling elderly individuals with chronic diseases. Family functioning was mediated by self‐efficacy and had an indirect impact on quality of life. The mediating effect accounted for 62.50% of the total effect.
Predicting undergraduate nursing students’ willingness to care for older adults: A multicenter cross‐sectional study in Asia
Authors: Liu Xian‐Liang , Cheng Hui‐Lin , Lam Simon Ching
Published: May 2021

Aim

To investigate the willingness of nursing students in Hong Kong and Mainland China to care for the elderly and to identify the factors influencing their willingness.

Design

A correlational and cross‐sectional design.

Methods

A four‐part self‐administered questionnaire was utilized to collect data from the undergraduate nursing students in Hong Kong and Mainland China.

Results

The total sample consisted of 820 nursing students, with 481 students in Hong Kong and 339 students in Mainland China. The scores of willingness to care for older people of the two groups were similar (mean score 4.68 versus 4.44), and no significant difference was observed between the students in the two regions (p = .071). A very low proportion of the nursing students in Hong Kong (7.7%) and those in Mainland China (3.6%) ranked caring for older people as their first choice of work. No salient predictors of willingness to care for older people existed for the nursing students in Mainland China.
Validity of claims‐based algorithms for selected cancers in Japan: Results from the VALIDATE‐J study
Authors: de Luise Cynthia , Sugiyama Naonobu , Morishima Toshitaka , Higuchi Takakazu , Katayama Kayoko , Nakamura Sho , Chen Haoqian , Nonnenmacher Edward , Hase Ryota , Jinno Sadao , Kinjo Mitsuyo , Suzuki Daisuke , Tanaka Yoshiya , Setoguchi Soko
Published: May 2021

Purpose

Real‐world data from large administrative claims databases in Japan have recently become available, but limited evidence exists to support their validity. VALIDATE‐J validated claims‐based algorithms for selected cancers in Japan.

Methods

VALIDATE‐J was a multicenter, cross‐sectional, retrospective study. Disease‐identifying algorithms were used to identify cancers diagnosed between January or March 2012 and December 2016 using claims data from two hospitals in Japan. Positive predictive values (PPVs), specificity, and sensitivity were calculated for prevalent (regardless of baseline cancer‐free period) and incident (12‐month cancer‐free period; with claims and registry periods in the same month) cases, using hospital cancer registry data as gold standard.

Results

22 108 cancers were identified in the hospital claims databases. PPVs (number of registry cases) for prevalent/incident cases were: any malignancy 79.0% (25 934)/73.1% (18 119); colorectal 84.4% (3519)/65.6% (2340); gastric 87.4% (3534)/76.8% (2279); lung 88.1% (2066)/79.9% (1636); breast 86.4% (4959)/59.9% (3185); pancreatic 87.1% (582)/80.4% (508); melanoma 48.7% (46)/42.9% (36); and lymphoma 83.6% (1457)/77.8% (1035). Specificity ranged from 98.3% to 100% (prevalent)/99.5% to 100% (incident); sensitivity ranged from 39.1% to 67.6% (prevalent)/12.5% to 31.4% (incident). PPVs of claims‐based algorithms for several cancers in patients ≥66 years of age were slightly higher than those in a US Medicare population.

Conclusions

VALIDATE‐J demonstrated high specificity and modest‐to‐moderate sensitivity for claims‐based algorithms of most malignancies using Japanese claims data. Use of claims‐based algorithms will enable identification of patient populations from claims databases, while avoiding direct patient identification. Further research is needed to confirm the generalizability of our results and applicability to specific subgroups of patient populations.
Tunable helical structures formed by blending ABC triblock copolymers and C homopolymers in nanopores
Authors: Chen Ka , Wang Feng , Liu Meijiao , Wang Xinping
Published: May 2021

ABC triblock copolymers with frustrated interactions of χACN ≪ χABN ~ χBCN confined in nanopores with A‐block‐attracting surfaces can self‐assemble into helical morphologies, where the B blocks form helical domains wrapping around C‐core cylinders within the A shell. It has been suggested that the number of helical strands (m) increases as the volume fraction of C block (fC) decreases, while the increasing m is restricted because C blocks forming domains cannot maintain a cylindrical shape as fC gradually decreases, and the B block domains transform from helical structures to toroidal domains. To prevent the restriction of increasing m, in the current study we added C homopolymers into nanopores. For a given triblock copolymer with (χABN, χBCN, χACN) = (80, 80, 20) and (fA, fB, fC) = (0.7, 0.1, 0.2), varying the concentration (ϕH) and the chain length (γ) of the C homopolymers, as well as the diameter (D) of the nanopores, we constructed different two‐dimensional phase diagrams with respect to two of these control parameters using self‐consistent field theory. A number of helical structures with strands ranging from 1 to 6 are predicted. Our calculations indicate that m increases with increasing γ and D and decreasing ϕH. The theoretical results demonstrate that blending of homopolymer with one given triblock terpolymer could provide an efficient route to fabricate different complex helical nanostructures. © 2021 Society of Industrial Chemistry.
All‐organic polymer blend dielectrics of poly (arylene ether urea) and polyimide: Toward high energy density and high temperature applications
Authors: Ahmad Aftab , Tong Hui , Fan Tao , Xu Ju
Published: May 2021

The development of high‐performance dielectric films with high energy density and temperature stability is extremely desired for modern electronics and power systems. Herein, a simple and low‐cost approach is proposed to fabricate all‐organic blend films prepared from poly (arylene ether urea) (PEEU) and polyimide (PI) via solution casting and thermal imidization process. The incorporation of PEEU in PI matrix significantly improved dielectric breakdown strength and dielectric constant of PI. More precisely, blend film with 15 wt% PEEU exhibited highest energy density 5.14 J/cm3 at 495.65 MV/m, with enhanced dielectric constant of 4.73 and very low dissipation factor of 0.299%. Furthermore, the dielectric properties of the PEEU/PI blend displayed wonderful temperature stability in the range of − 50–+ 250°C, and great frequency stability between 10 and 106 Hz. The blend film also exhibited excellent heat resistance and presented valuable potential in thin film capacitors for high voltage direct current system.
Edible mycorrhizal fungi of the world: What is their role in forest sustainability, food security, biocultural conservation and climate change?
Authors: Pérez‐Moreno Jesús , Guerin‐Laguette Alexis , Rinaldi Andrea C. , Yu Fuqiang , Verbeken Annemieke , Hernández‐Santiago Faustino , Martínez‐Reyes Magdalena
Published: May 2021

Societal Impact Statement

Edible mycorrhizal fungi (EMF) have been consumed since ancestral times by humans either as food, medicine or for ceremonial use. Nowadays, they are a non‐timber forest product and a diverse genetic resource with great ecological, sociocultural, economic, medicinal and biotechnological relevance around the world. Therefore, they have a paramount role to play in meeting the United Nations global sustainable development goals 2030. EMF may promote forest sustainability, biodiversity conservation, mitigation of greenhouse gas emissions through the maintenance of forest masses, human nutrition and health, economic development, conservation of biocultural heritages, women empowerment and hunger mitigation. We provide a worldwide review of the knowledge, biodiversity, novel approaches, future challenges and perspectives in the post‐COVID era of this important genetic resource whose relevance has usually received marginal attention despite its strategic global significance.

Ectomycorrhizal fungi play a key role in the structure and functioning of forest ecosystems. They have a paramount importance in nutrient cycling, plant protection against pathogens and abiotic stress, and establishment of underground networks that connect trees and other plants in nature, therefore being the wood wide web, the ‘internet’ of the forests. According to our literature review, globally 970 mycorrhizal fungal species (including both mushrooms and truffles) are edible, and they have enormous relevance either as a source of subsistence in low‐income human groups around the world or as an important economic component whose international commerce is worth billions of American dollars annually. Since edible mycorrhizal fungi (EMF) are a non‐timber forest product, their sustainable use and management is crucial in order to maintain forest stands and to provide well‐being to the human communities surrounding the forested areas where they grow. In different parts of the world, different cultures have developed a traditional knowledge of EMF over millennia. Their knowledge might play an important role in food supply and food security in the future, hence contributing towards the “zero hunger” global goal. The biotechnological development of EMF has also been crucial in the establishment of plantations, or successful reforestation and ecosystem restoration, which contribute to climate change mitigation by reducing greenhouse gas emissions. Here, a worldwide review of how EMF might contribute to forest sustainability, food supply, biocultural conservation, and hunger and climate change mitigation is addressed by analysing the similarities, contrasts and challenges in all five continents.
Comparison of dosimetric characteristics between flattening filter‐free and flattening filter mode volumetric‐modulated arc therapy plans in rectal cancer
Authors: Ding Zhen , Xiang Xiaoyong , Kang Kailian , Zeng Qi , Yuan Qingqing , Xu Meiling
Published: May 2021

Objective

We aimed to compare the dosimetric characteristics of 6‐MV flattening filter mode (FF) and flattening filter‐free mode (FFF) volumetric‐modulated arc therapy (VMAT) plans in preoperative radiotherapy for rectal cancer using an Edge linear accelerator.

Methods

Two‐arc FF‐VMAT and FFF‐VMAT plans were generated for 15 patients with rectal cancer using the Philips Pinnacle treatment planning system (version 9.10). The homogeneity index, conformity index, planning target volume covered by 105% isodose lines, organ‐at‐risk dosimetry characteristics, and monitor units (MUs) were compared between the plans. The results were analyzed using paired t‐tests.

Results

The conformity index of the FF‐VMAT plan and FFF‐VMAT plan were (0.93 ± 0.01) and (0.92 ± 0.02), and the homogeneity index of the two groups were (0.07 ± 0.03) and (0.08 ± 0.01), the differences were not statistically significant (both P > 0.05). The volume covered by 105% isodose lines of the FFF‐VMAT plan was significantly higher than that of the FF‐VMAT plan. The FFF‐VMAT plan required a higher monitor unit (t = 11.49, P = 0.002) and shorter beam‐on time (t = 5.78, P = 0.001) compared with the FF‐VMAT plan. There were no significant differences in the absolute volume receiving 30 Gy and 40 Gy of the bladder between the plans. The absolute volume receiving 30 Gy and absolute volume receiving 40 Gy of the intestine and colon in the FFF‐VMAT plan increased by 5.5% and 2.1% compared with those in the FF‐VMAT plans that increased by 7.2% and 2.2%, respectively (both P > 0.05). The absolute volume receiving 20 Gy of the left and right femoral head in the FFF‐VMAT plan decreased by 3.7% and 4.9% compared with those in the FF‐VMAT plans (P > 0.05).

Conclusion

Both FF‐VMAT and FFF‐VMAT plans met the clinical requirements.
Evidence for the preferential reuse of sub‐domain motifs in primordial protein folds
Authors: Heizinger Leonhard , Merkl Rainer
Published: May 2021

A comparison of protein backbones makes clear that not more than approximately 1400 different folds exist, each specifying the three‐dimensional topology of a protein domain. Large proteins are composed of specific domain combinations and many domains can accommodate different functions. These findings confirm that the reuse of domains is key for the evolution of multi‐domain proteins. If reuse was also the driving force for domain evolution, ancestral fragments of sub‐domain size exist that are shared between domains possessing significantly different topologies. For the fully automated detection of putatively ancestral motifs, we developed the algorithm Fragstatt that compares proteins pairwise to identify fragments, that is, instantiations of the same motif. To reach maximal sensitivity, Fragstatt compares sequences by means of cascaded alignments of profile Hidden Markov Models. If the fragment sequences are sufficiently similar, the program determines and scores the structural concordance of the fragments. By analyzing a comprehensive set of proteins from the CATH database, Fragstatt identified 12 532 partially overlapping and structurally similar motifs that clustered to 134 unique motifs. The dissemination of these motifs is limited: We found only two domain topologies that contain two different motifs and generally, these motifs occur in not more than 18% of the CATH topologies. Interestingly, motifs are enriched in topologies that are considered ancestral. Thus, our findings suggest that the reuse of sub‐domain sized fragments was relevant in early phases of protein evolution and became less important later on.
A novel encapsulation of Streptomyces fulvissimus Uts22 by spray drying and its biocontrol efficiency against Gaeumannomyces graminis, the causal agent of take‐all disease in wheat
Authors: Saberi‐Riseh Roohallah , Moradi‐Pour Mojde
Published: May 2021

BACKGROUND

Wheat is a valuable food source that is exposed to many diseases that reduce its quantity and quality. One of the most important diseases affecting wheat is take‐all, caused by Gaeumannomyces graminis var. tritici. The application of bacterial inoculants into the soil can increase plant nutrient absorption and enhance the efficiency of probiotic bacteria. For increased beneficial bacteria efficiency, the encapsulation technique has been used in agriculture.

RESULTS

The results of Fourier transform infrared (FTIR) and X‐ray diffraction analysis (XRD) indicated that the prepared formulation is a mixture of gellan and chitosan. Using SEM, the spherical structure of the microcapsules was confirmed. It was observed that the increase in bacterial release was gradual, and the highest amount of bacteria was released (109 CFU mL–1) on the 50th day. Greenhouse experiments showed that plants treated with S. fulvissimus Uts22 microcapsules had the highest efficiency with 90% disease control. Moreover, the highest fresh and dry weights of roots and shoots were observed in this treatment.

CONCLUSION

In this study, a new type of formulation aiming at controlling wheat take‐all disease was developed through bacterial and nanoparticles loaded chitosan‐ gellan gum microcapsules with spray drying method. This formulation has many advantages, such as a large surface area and high internal porosity and increased water‐holding capacity, while it also provides a proper habitat for bacteria to increase colonization rates and offers protection of the soil. © 2021 Society of Chemical Industry.
Monte Carlo Simulation of a Mixed Spin‐1/2 and Spin‐3/2 Ising Ferrimagnetic System with Site Dilution
Authors: Sánchez-Villalobos Carlos A. , Buendía Gloria M.
Published: May 2021

A study of the magnetic behavior of a mixed Ising system on a square lattice, where spins are located on alternating sites with spins , is presented. The change in the magnetic behavior of the system when empty sites are introduced in one of the sublattices or in both is analyzed. This system can be thought of as a site‐diluted ferrimagnet or as a system with nonmagnetic impurities. The Hamiltonian of the model contains an exchange interaction between nearest neighbors S–σ, next‐nearest‐neighbors , and a crystal field. The dependence of the total magnetization, the sublattice magnetizations, and the specific heat, with dilution is calculated. It is found that the behavior of the critical and compensation temperatures is strongly affected by dilution and where it is located. There is critical dilution, above which the compensation temperature disappears.