bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and characterization of polyhydroxyalkanoates from soil bacterium Bacillus sp. PhNs9
Authors: Patil Pritam Bajirao , Sarkar Debapriya , Poddar Kasturi , Sarkar Angana
Published: April 2022

Background

Synthetic plastic pollution has increased tremendously over the past few decades. Supplanting synthetic plastics with a biodegradable alternative could save the biosphere from the drastic effects of plastic pollution. Polyhydroxyalkanoates (PHA) have been identified with the potential to become a feasible option.

Results

A bacterial strain isolated from pavement soil was investigated for its PHA production ability. The isolated strain was found to be non‐virulent, and susceptible to various antibiotics, especially cefalexin, tetracycline, chloramphenicol, norfloxacin and ofloxacin. The carbohydrate utilization profile revealed that isolated bacteria can utilize different carbohydrates with a variable rate of consumption. The 16S rRNA identification revealed that the strain was related to the Bacillus genus. The produced PHA was predicted to be polyhydroxybutyrate as suggested by differential scanning calorimetry and NMR, Fourier transform infrared and Raman spectroscopies. Moreover, the hydrophobic nature of the PHA produced was confirmed by contact angle measurement. The growth, production and substrate utilization kinetics revealed the specific growth rate of Bacillus sp. PhNs9 was 0.07 h−1, specific biomass productivity was 0.06 g L−1 h−1 and specific PHA productivity was 0.05 g L−1 h−1. The yield of PHA from biomass was found to be 0.67 g per gram of biomass.

Conclusions

The yield of PHA from the isolated strain was found to be higher than that of most earlier reports. Hence the findings of this study could catalyze the progress to completely move away from the use of synthetic plastics and replace them with an economical and sustainable solution. © 2022 Society of Chemical Industry (SCI).
Gallai–Ramsey number for K5 ${K}_{5}$
Authors: Magnant Colton , Schiermeyer Ingo
Published: April 2022

Given a graph , the ‐colored Gallai–Ramsey number is defined to be the minimum integer such that every ‐coloring of the edges of the complete graph on vertices contains either a rainbow triangle or a monochromatic copy of Fox et al. conjectured the values of the Gallai–Ramsey numbers for complete graphs. Recently, this conjecture has been verified for the first open case, when . In this paper we attack the next case, when . Surprisingly it turns out, that the validity of the conjecture depends upon the (yet unknown) value of the Ramsey number . It is known that and conjectured that . If , then Fox et al.'s conjecture is true and we present a complete proof. If, however, , then Fox et al.'s conjecture is false, meaning that exactly one of these conjectures is true while the other is false. For the case when , we show lower and upper bounds for the Gallai–Ramsey number .
Vaccination strategy for preventing the spread of SARS‐CoV‐2 in the limited supply condition: A mathematical modeling study
Authors: Lin Yi‐Fan , Li Yuwei , Duan Qibin , Lei Hao , Tian Dechao , Xiao Shenglan , Jiang Yawen , Sun Caijun , Du Xiangjun , Shu Yuelong , Zou Huachun
Published: April 2022

To mitigate SARS‐CoV‐2 transmission, vaccines have been urgently approved. With their limited availability, it is critical to distribute the vaccines reasonably. We simulated the SARS‐CoV‐2 transmission for 365 days over four intervention periods: free transmission, structural mitigation, personal mitigation, and vaccination. Sensitivity analyses were performed to obtain robust results. We further evaluated two proposed vaccination allocations, including one‐dose‐high‐coverage and two‐doses‐low‐coverage, when the supply was low. 33.35% (infection rate, 2.68 in 10 million people) and 40.54% (2.36) of confirmed cases could be avoided as the nonpharmaceutical interventions (NPIs) adherence rate rose from 50% to 70%. As the vaccination coverage reached 60% and 80%, the total infections could be reduced by 32.72% and 41.19%, compared to the number without vaccination. When the durations of immunity were 90 and 120 days, the infection rates were 2.67 and 2.38. As the asymptomatic infection rate rose from 30% to 50%, the infection rate increased 0.92 (SD, 0.16) times. Conditioned on 70% adherence rate, with the same amount of limited available vaccines, the 20% and 40% vaccination coverage of one‐dose‐high‐coverage, the infection rates were 2.70 and 2.35; corresponding to the two‐doses‐low‐coverage with 10% and 20% vaccination coverage, the infection rates were 3.22 and 2.92. Our results indicated as the duration of immunity prolonged, the second wave of SARS‐CoV‐2 would be delayed and the scale would be declined. On average, the total infections in two‐doses‐low‐coverage was 1.48 times (SD, 0.24) as high as that in one‐dose‐high‐coverage. It is crucial to encourage people in order to improve vaccination coverage and establish immune barriers. Particularly when the supply is limited, a wiser strategy to prevent SARS‐CoV‐2 is equally distributing doses to the same number of individuals. Besides vaccination, NPIs are equally critical to the prevention of widespread of SARS‐CoV‐2.
Trajectories of Change in Creative and Personal Factors in First‐Year Creative Arts Therapies Students
Authors: Diamant Adi , Orkibi Hod
Published: April 2022

There is little research on the transformational processes of creative arts therapies (CATs) students during training compared to other healthcare professions. CATs training relies on arts‐based experiential learning that can develop the therapist’s creative self‐beliefs, psychological mindedness, and perspective‐taking. This single group pre–post study examined the changes in these unstudied, yet essential, creative and personal factors in a sample of 191 CATs students in the first year of their master’s degree program in Israel. It was hypothesized that students would report a statistically significant increase in creative and personal measures from the beginning to the end of their first year of training, but this hypothesis was only partially supported. There were different development trajectories in each CATs discipline in terms of creative identity, creative self‐efficacy, psychological mindedness, and perspective‐taking. The discussion sheds light on these results by considering the domain‐specific differences between the CATs disciplines and their respective training approaches, and through follow‐up interview data collected from trainers in each CATs track. This study thus contributes to a better understanding of the trajectories of change of these attributes in CATs students. Training programs should consider these results when building curricula, to nurture the balance between students’ artistic and helping competencies.
Influence of different kinds of fatty acids on the behavior, structure and digestibility of high amylose maize starch–fatty acid complexes
Authors: Sun Shenglin , Hua Shuxian , Hong Yan , Gu Zhengbiao , Cheng Li , Ban Xiaofeng , Li Zhaofeng , Li Caiming , Zhou Jingwen
Published: April 2022

BACKGROUND

The formation of starch–lipid complexes is of interest to food processing and human nutrition. Fatty acid (FA) structure is important for the formation and structure of starch–FA complexes. However, there is limited research regarding the complexing behavior between amylose and different kinds of FAs, as well as the relationship between fine structures and digestibility of the formed complexes. This study aimed to investigate the behavior, fine structure, and digestibility of complexes formed between high amylose maize starch (HMS) and FA having various chain lengths and unsaturation degrees.

RESULTS

Complexes containing different FA structures showed V6III‐type crystals. Complexes containing 18‐carbon unsaturated FAs displayed significantly higher complexing index (P < 0.05) than other complexes. Complexes containing 12‐carbon FAs and 18‐carbon FAs with one unsaturation degree showed a higher degree of structural order and resistant starch (RS) content than other complexes. The 12‐carbon FAs exhibited a higher binding degree with helical cavity of amylose than other FAs. Additionally, 10‐carbon and 18‐carbon saturated FAs tended to combine with HMS outside amylose helices more than other FAs. Laser confocal micro‐Raman imaging revealed that the physically embedded 10‐carbon and 18‐carbon saturated FAs showed heterogeneous distribution in complexes, and that the complexed 18‐carbon FAs with one unsaturation degree exhibited homogeneous distribution.

CONCLUSION

The behavior, structural order and digestibility of complexes could be regulated by FA structure. The 12‐carbon FAs and 18‐carbon FAs with one unsaturation degree were more suitable for the production of HMS–FA complexes with higher structural order and RS content than other FAs. © 2022 Society of Chemical Industry.
The ideal harvest time for seed production in maize (Zea mays L.) varieties of different maturity groups
Authors: Han Dengxu , Hu Hairui , Yang Jie , Liang Xiaoling , Ai Junmin , Abula Abulaiti , Li Mingdong , Wang Yejian , Xi Haojiang , Li Li , Gu Riliang , Wang Jianhua
Published: April 2022

BACKGROUND

The correct time for harvesting is a key factor contributing to the production of high‐quality maize seeds. We conducted field experiments to harvest seeds at 11 developmental stages for 3 years, to investigate seed vigor traits in three early maturity maize varieties and two late maturity varieties in one location.

RESULTS

Significant correlations (r = 0.72 ~ 0.89) were found among six seed‐related traits: standard germination (SG), accelerated aging germination (AAG), cold test germination (CTG), hundred‐seed weight (HSW), seed moisture content (SMC), and ≥ 10 °C accumulated temperature from pollination to harvest (AT10). Analysis of variance showed that harvest stage, year, and variety had significant effects on all traits, and harvest stage displayed the greatest effect. The responses of SG, AAG, CTG, HSW and SMC to harvest stage fitted quadratic models, and AT10 fitted a linear model. From the quadratic models, an ideal harvest time (IHT, the final date to reach maximum SG, AAG, and CTG) could be calculated for each variety. The three early maturity varieties reached their IHT at 54.94–58.44 days after pollination (DAP); the two later maturity varieties reached IHT several days later (at 59.87–59.90 DAP). The early maturity varieties consistently required less AT10 to reach the IHT than the later maturity varieties. However, all of the varieties reached the IHT at similar SMC levels of about 35%.

CONCLUSION

The later maturity varieties reached the IHT at later DAPs when they acquired more AT10 than the early maturity varieties but both reached it at similar SMC levels. © 2022 Society of Chemical Industry.
A systematic study of Surface Plasmon Enhanced Electric Field in Nanoparticle Dimers for UV Plasmonics
Authors: Juneja Soniya , Agrwal Akansha , Seth Deepti
Published: April 2022

Surface plasmon mediated electric field enhancement in the dimer arrangement of Al, Ag and, Au nanoparticles using multipole spectral expansion (MSE) approach has been studied. MSE method has flexibility and simplicity in extending the approach to treat an arbitrary arrangement of nanoparticles by solving corresponding general eigenvalue problem. The field enhancement behavior of Al, Ag, and Au nanoparticle dimers has been investigated, covering UV–VIS spectral range. The role of embedding medium, particle–particle separation, and the metal type were studied. The resonance wavelength showed the red shift with increasing the dielectric constant of the ingrained material. The red shift with increasing particle size and the dielectric constant of embedded or ingrained medium has been studied. This study was used to design plasmonic nanoparticle dimer with resonant optical response at crucial wavelengths in UV–VIS spectral region.
In Vitro Studies on Protein Binding of Polyhydroxybutyrate Isolated from Rhodopseudomonas palustris KRPR02
Authors: Koyyati Rama , Kudle Karunakar Rao , Merugu Ramchander , Manthur Padigya Pratp Rudra
Published: April 2022

In present research work, isolation of the biopolymer, from the novel strain of phototrophic anoxygenic phototrophic bacteria Rhodopseudomonas palustris isolated from sugar industrial effluent, is reported. It is characterized and the efficacy of binding the biopolymer (PHB) with protein (BSA) is investigated. The strain Rp. KRPR02 is selected for the characterization and protein binding studies as it produced more amounts of PHB. The extracted biopolymer is confirmed as PHB by instrumental techniques such as UV–Visible spectroscopy, FTIR analysis, C13 NMR spectroscopy, and XRD analysis. The efficiency of PHB binding to BSA is evaluated and found that it can efficiently bind to BSA. Hence, it can be used for biomedical and pharmaceutical applications as drug carriers and also as nanocapsules to carry the micro‐ and macronutrients in agriculture.
Extracellular Synthesis of Mono and Bimetallic Nanocomposites from Novel Strains of Rhodopseudomonas palustris and Evaluation of Their Biomedical Applications
Authors: Koyyati Rama , Kudle Karunakar Rao , Nagati Veerababu , Merugu Ramchander , Padigya Pratp Rudra Manthur
Published: April 2022

In this present research work, mono and bimetallic nanoparticles are synthesized from “Rhodopseudomonas palustris KRPR01 and KRPR02.” The synthesized nanoparticles are confirmed by the color change and EDX analysis. Thus, from this study, the nanoparticle synthesized from these bacterial extracts seem to be a promising and effective antibacterial agent against bacterial strains and potent antioxidant and anticancer agents. It also acts as an anticoagulant because of its hemolytic activity. Microbial synthesis being very eco‐friendly and cost‐effective, can be used for the large‐scale integration of nanoparticles in nanotechnology processing industries and also useful in medicine, agriculture, etc.
Boron Nitride Nanosheets Reinforced Thermoplastics Nanocomposites for Thermal Management Applications: A Mini Review
Authors: Aparna Narava Divya , Tambe Pankaj
Published: April 2022

In this review, the synthesis methods and their characterization of boron nitride nanosheets (BNNs) are discussed along with their advantages and limitations. The BNNs functionalization using covalently and noncovalently routes are discussed. Further, the incorporation of BNNs in thermoplastics matrix nanocomposites on thermal properties in specific is discussed in detail. The influence of functionalization of BNNs using covalent and noncovalent modification routes on dispersion and thermal properties of thermoplastic matrix nanocomposites is discussed in detail. A brief roadmap for future research in the area of BNNs filled polymer nanocomposites is also discussed.
Effect of Sonication Time on Cellulose Nanofiber Disintegration from Locally Available Rice Straw
Authors: Ratnakumar Abirami , Samarasekara Bandu A. M. P. , Amarasinghe Shantha D. A. , Karunanayake Laleen
Published: April 2022

Ultrasonication is an important step which influences the disintegration of cellulose fibers. Ultrasonic energy is generally applied to disperse the nanoparticles. Cavitation bubbles develop and grow when high‐intensity ultrasound is applied. During the collapse of these bubbles, a considerable amount of energy is released. This creates a mechanical shock wave effect thus leads to the disruption of agglomerated particles. In this research, initially cellulose is derived from locally available rice straw varieties through a three step chemical extraction and purification process. Then, high‐intensity ultrasonication process is applied for 90 min on the chemically extracted cellulose fibers at 15 min time interval and the disintegration of cellulose nanofibers (CNFs) is studied. From the scanning electron microscopy (SEM) images, it is noticed that the high‐intensity ultrasonication process had significant effect on the disintegration of cellulose fibers. After 90 min treatment, fibrils with diameter in nanometer range are obtained whereas the lengths of the fibers are observed to be in micrometer range. Structural and thermal properties of disintegrated CNFs are also determined. From this study, it is evident that the sonication time had a greater impact on the efficiency of the disintegration of chemically extracted cellulose fibers.
Quadruple genetic variants in a sporadic ALS patient
Authors: Yilmaz Rüstem , Weishaupt Kanchi , Valkadinov Ivan , Knehr Antje , Brenner David , Weishaupt Jochen H.
Published: April 2022

Objectives

Due to upcoming gene‐specific therapy approaches for ALS patients, understanding familial and sporadic ALS genetics is becoming increasingly important. In this study, we wanted to investigate underlying genetic causes for an SALS patient.

Methods

We performed ALS gene panel sequencing and subsequent segregation analysis in the family.

Results

Genetic studies suggest that a proportion of SALS cases has an oligogenic origin due to the combination of low‐effect size mutations in several ALS genes. Maximally three mutations in different ALS disease genes have been described in isolated ALS patients. Here, we report for the first time the co‐occurrence of rare nonsynonymous variants in four known ALS genes in a SALS patient (c.859G > A/p.Gly287Ser in TARDBP, c.304G > T/p.Glu102* in NEK1, c.3446C > A/p.Gly1149Val in ERBB4, and c.1015C > T/p.Arg339Trp in VEGFA). All four variants were unique for the patient, whereas up to three of these variants were detected in the unaffected family members, all older than the patient.

Discussion

Our study suggests that SALS can be caused by the additive or synergistic action of low‐effect size mutations. Broader use of gene panel analysis or whole exome/genome sequencing may reveal a potentially treatable oligogenic causation in a higher percentage of SALS than previously thought.
Genetic testing of UGT1A1 in the diagnosis of Gilbert syndrome: The discovery of seven novel variants in the Chinese population
Authors: Gu Leilei , Han Yue , Zhang Donghua , Gong Qiming , Zhang Xinxin
Published: April 2022

Background

Genetic testing of UGT1A1 was used to facilitate the diagnosis of Gilbert syndrome, and analyze the distribution features of pathogenic variants in the Chinese population.

Methods

DNA was extracted from whole blood samples of patients with unconjugated hyperbilirubinemia, and sequencing of the UGT1A1 gene was performed after PCR amplification. After alignment with reference sequences, the known pathogenic variants were identified, the variant spectrum was analyzed, and the pathogenicity of novel variants was predicted using online mutation prediction tools.

Results

A total of 117 patients were confirmed with Gilbert syndrome by UGT1A1 genetic diagnosis, where the most common pathogenic variants included promoter A(TA)7TAA insertion and p.Gly71Arg missense variant. Following novel variants were also identified: p.Ala61Gly, p.Tyr67Phe, p.Leu166Alafs*16, p.Arg240Lys, p.Ser306Phe, p.Arg341Gln, and p.Glu424* variants.

Conclusions

Genetic testing of UGT1A1 in clinical practices could facilitate confirming Gilbert syndrome and performing differential diagnosis. The pathogenic variant spectrum in the Chinese population was similar to other Asian populations. The novel pathogenic variants identified in this study require further investigation.
Electronic portal image enhancement based on nonuniformity correction in wavelet domain
Authors: Ghaempanah Hanieh , Tavakoli Meysam , Deevband Mohammad Reza , Alvar Amin Asgharzadeh , Najafi Mohsen , Kelley Patrick
Published: April 2022

Purpose

Electronic portal images are one of the most important tools to verify the ongoing radiotherapy treatment through comparison with a reference image generated during treatment planning. In this procedure, two images are geometrically matched by means of visible bone or other landmarks of interest such as implanted fiducials. However, the intrinsically poor contrast and low spatial resolution of portal images can limit image quality.

Methods

In this study, we have provided a multiresolution approach to enhance the quality of portal images acquired from the pelvis treatment fields. The main idea behind this work aims at removing some of the image artifacts that conceal the anatomical information. For this purpose, we have applied the homomorphic filtering on the approximation sub‐band of wavelet decomposition to enhance local information. Moreover, in order to sharpen the bone edges, wavelet detail sub‐bands were weighted to amplify important image details in the reconstruction of the desired enhanced image. The most appropriate image quality measure was chosen according to the image's characteristics in the spatial domain. By considering the characteristics of portal images as the random and nonperiodic texture, high level of noise, and a nonuniform background, three suitable quality measures of images were assessed: edge content, measure of enhancement, and measure of enhancement by entropy.

Results

The higher values of these measures indicate the quality improvement in the processed images through our proposed algorithm. Moreover, the subjective evaluation results indicate that the proposed multiresolution approach significantly enhances the perceived quality of images in comparison with original and the similar approach ().

Conclusions

Our proposed wavelet‐based enhancement algorithm successfully reduced image intensity nonuniformity and enhanced anatomical featured information, which drastically improved the objective metrics values. Subjective evaluation of enhanced image confirmed this quality improvement.
Hyperpolarized 13C MRI Reveals Large Changes in Pyruvate Metabolism During Digestion in Snakes
Authors: Hansen Kasper , Hansen Esben Søvsø. S. , Jespersen Nichlas Riise V. , Bøtker Hans Erik , Pedersen Michael , Wang Tobias , Laustsen Christoffer
Published: April 2022

Purpose

Hyperpolarized 13C MRI is a powerful technique to study dynamic metabolic processes in vivo; but it has predominantly been used in mammals, mostly humans, pigs, and rodents.

Methods

In the present study, we use this technique to characterize the metabolic fate of hyperpolarized [1‐13C]pyruvate in Burmese pythons (Python bivittatus), a large species of constricting snake that exhibits a four‐ to tenfold rise in metabolism and large growth of the visceral organs within 24–48 h of ingestion of their large meals.

Results

We demonstrate a fivefold elevation of the whole‐body lactate‐to‐pyruvate ratio in digesting snakes, pointing to a large rise in lactate production from pyruvate. Consistent with the well‐known metabolic stimulation of digestion, measurements of mitochondrial respiration in hepatocytes in vitro indicate a marked postprandial upregulation of mitochondrial respiration. We observed that a low SNR of the hyperpolarized 13C produced metabolites in the python, and this lack of signal was possibly due to the low metabolism of reptiles compared with mammals, preventing quantification of alanine and bicarbonate production with the experimental setup used in this study. Spatial quantification of the [1‐13C]lactate was only possible in postprandial snakes (with high metabolism), where a statistically significant difference between the heart and liver was observed.

Conclusion

We confirm the large postprandial rise in the wet mass of most visceral organs, except for the heart, and demonstrated that it is possible to image the [1‐13C]pyruvate uptake and intracellular conversion to [1‐13C]lactate in ectothermic animals.
Factors influencing the behavior of bystanders to workplace bullying in healthcare—A qualitative descriptive interview study
Authors: Jönsson Sandra , Muhonen Tuija
Published: April 2022

Workplace bullying is a severe problem that affects individuals, organizations, and society. Although there is a growing research interest in bystanders of workplace bullying, the rationale underlying bystanders' behavior in healthcare settings requires further investigation. The aim of the current study is to explore factors that influence the behavior of bystanders to workplace bullying in the healthcare sector. Qualitative semistructured interviews were conducted with 32 staff members in the healthcare sector in Sweden. Data were collected between March 2019 and September 2020 and were analyzed with thematic analysis. The participants experienced that bystanders of bullying, both colleagues and managers, were in many situations acting in a passive way. Organizational factors such as dysfunctional organizational culture and deficiencies in management affected how actively the bystanders could intervene. Additionally, a fear of negative consequences, lack of awareness of what was going on, bullying behavior being excused, and the bystander not being a member of the dominant group were social factors contributing to bystanders' passive behavior. For bystander intervention to be successful, the organization must consider bullying as a serious issue, take action, and show support for both the target and the bystander.
Digital light processing mediated 3D printing of biocomposite bone scaffolds: Physico‐chemical interactions and in‐vitro biocompatibility
Authors: Vyas Abhijit , Bandhu Ghosh Subrata , Bandyopadhyay‐Ghosh Sanchita , Agrawal Ashish Kumar , Khare Deepak , Dubey Ashutosh Kumar
Published: April 2022

This study reports development of digital light processing (DLP) mediated 3D printed customized bone scaffolds. Bioactive fluorcanasite glass ceramic was incorporated within photocurable resin matrix and the suspensions were 3D printed towards developing composite bone scaffolds. Physico‐chemical interaction in the biocomposite bone scaffolds were investigated using infrared spectroscopy, x‐ray diffraction, and field emission scanning electron microscopy. Further, the mechanical properties of the composite scaffold samples were also evaluated to understand the strengths of the samples in terms of its fracture toughness, flexural strength, and compressive strength. Infrared spectroscopy results demonstrated an active interaction between the acrylate functionalities of the polymer with the bioactive fluorcanasite glass ceramic reinforcement. This was further substantiated with x‐ray diffraction results, demonstrating rise in the bioactive crystalline peaks with corresponding increase in the fluorcanasite glass ceramic loading. Later, the samples were also evaluated for in‐vitro cellular response in terms of cell viability, proliferation, adhesion, and interaction. The surface hydrophilicity responsible for osteogenic interaction was also studied with contact angle goniometry. With increase in fluorcanasite loading in the formulation, the hydrophilicity was found to increase over the sample surface which in turn was found to enhance cell adhesion and proliferation, as revealed byin‐vitro MTT assay and also fluorescence microscopy. To establish the efficacy of DLP technique, two different porous architectural designs were 3D printed and investigated with synchrotron micro‐computed tomography. The microtomographs revealed precise microarchitecture and interconnected porosity within the scaffolds.
Erosive wear analysis of bamboo fiber‐reinforced high‐density polyethylene composites: Effect of aluminum oxide
Authors: Jiang Liangpeng , Yang Yue , Fu Jingjing , Teng Wenxiang , Wang Hao
Published: April 2022

In order to improve the erosive wear resistance of bamboo fiber‐reinforced high‐density polyethylene (HDPE) composites, the effect of aluminum oxide (Al2O3) on the erosive wear behavior of composites was investigated. The study of erosive wear was using the swirling water jet technique. The results showed that the addition of nanoscale Al2O3 could optimize the structural strength, composite structure, and erosive wear resistance of composites. The best erosive wear resistance was observed in composites containing 6/189 wt% of nanoscale Al2O3, 80/189 wt% of bamboo fiber, 100/189 wt% of HDPE, and 3/189 wt% of maleic anhydride grafted polyethylene. The composites with and without adding nanoscale Al2O3, both exhibited a maximum erosive wear rate at a shooting distance of 0.5 cm and an erosive duration of 180 s. The erosive wear mechanism of composites mainly included pulverization of bamboo fibers, brittle fracture of HDPE matrix, and increasing in oxygen content.
Machine learning to predict vasopressin responsiveness in patients with septic shock
Authors: Scheibner Aileen , Betthauser Kevin D. , Bewley Alice F. , Juang Paul , Lizza Bryan , Micek Scott , Lyons Patrick G.
Published: April 2022

Study Objectives

The objective of this study was to develop and externally validate a model to predict adjunctive vasopressin response in patients with septic shock being treated with norepinephrine for bedside use in the intensive care unit.

Design

This was a retrospective analysis of two adult tertiary intensive care unit septic shock populations.

Setting

Barnes‐Jewish Hospital (BJH) from 2010 to 2017 and Beth Israel Deaconess Medical Center (BIDMC) from 2001 to 2012.

Patients

Two septic shock populations (548 BJH patients and 464 BIDMC patients) that received vasopressin as second‐line vasopressor.

Intervention

Patients who were vasopressin responsive were compared with those who were nonresponsive. Vasopressin response was defined as survival with at least a 20% decrease in maximum daily norepinephrine requirements by one calendar day after vasopressin initiation, without a third‐line vasopressor.

Measurements

Two supervised machine learning models (gradient‐boosting machine [XGBoost] and elastic net penalized logistic regression [EN]) were trained in 1000 bootstrap replications of the BJH data and externally validated in the BIDMC data to predict vasopressin responsiveness.

Main Results

Vasopressin responsiveness was similar among each cohort (BJH 45% and BIDMC 39%). Mortality was lower for vasopressin responders compared with nonresponders in the BJH (51% vs. 73%) and BIDMC (45% vs. 83%) cohorts, respectively. Both models demonstrated modest discrimination in the training (XGBoost area under receiver operator curve [AUROC] 0.61 [95% confidence interval (CI) 0.61–0.61], EN 0.59 [95% CI 0.58–0.59]) and external validation (XGBoost 0.68 [95% CI 0.63–0.73], EN 0.64 [95% CI 0.59–0.69]) datasets.

Conclusion

Vasopressin nonresponsiveness is common and associated with increased mortality. The models' modest performances highlight the complexity of septic shock and indicate that more research will be required before clinical decision support tools can aid in anticipating patient‐specific responsiveness to vasopressin.
Extraction of Electromechanical Coefficients from Capacitance–Voltage Measurements of Unannealed Solution‐Processed KNN Thin Films: Effects of Frequency and Electrostatic and Mechanical Deformation
Authors: Deol Rajinder Singh , Batra Nitika , Bhattacharya Kritika , Devi Henam Sylvia , Mitra Bhaskar , Singh Madhusudan
Published: April 2022

A solution‐processed piezoceramic thin‐film MπM parallel‐plate capacitor structure to determine electromechanical coefficient using capacitance–voltage measurements is demonstrated. Electrical loading is applied to the capacitor to stimulate out‐of‐plane longitudinal and transverse elongation. The piezoelectric coefficient (d33) is estimated using the spatial deviation of thin‐film dimensions as a function of the applied electric field. The results are validated using finite element method‐based modeling and compared with several measurements in literature, including piezoresponse force microscopy‐based measurements, which are generally considered unreliable due to strong electrostatic interactions between the tip‐cantilever, and the charged sample surface, wherein such artifacts result in the overestimation of the electromechanical response of the material under investigation.
Process to separate per‐ and polyfluoroalkyl substances from water using colloidal gas aphrons
Authors: Kulkarni Poonam R. , Aranzales Diana , Javed Hassan , Holsen Thomas M. , Johnson Nicholas W. , Richardson Stephen D. , Mededovic Thagard Selma , Newell Charles J.
Published: April 2022

Current ex situ per‐ and polyfluoroalkyl substances (PFAS) remediation strategies often involve the treatment of large volumes of PFAS‐impacted water via separation processes to concentrate PFAS for subsequent treatment or disposal. This study presents a new method for concentrating PFAS that relies on colloidal gas aphrons (CGAs), unusual microstructures composed of water, multilayers of surfactants, and air, that can be used for separation via electrostatic and hydrophobic sorption. This study successfully demonstrates the efficacy of CGAs in removing ionic dyes (as PFAS surrogates) (81%–91%), as well as ultra‐short and short‐chain PFAS (60%–90%) and perfluorooctanoic acid (PFOA, 88%) within 10 min. However, poor removal of perfluorooctane sulfonic acid (PFOS, 0%) was observed within 10 min of treatment. Compared to bubbling with nitrogen alone, and nitrogen with cetrimonium bromide (CTAB) in bulk solution, CGAs demonstrate significantly higher removal of perfluorobutanoic acid, a short‐chain PFAS (0% for N2, 11% for N2 + CTAB, and 90% for CGAs). These results suggest that CGAs may serve as a promising new separation and concentration technology for removing a suite of PFAS from water, particularly for difficult to remove short‐chained compounds.
A scoping review of international mindedness and related concepts in music education, 2000–2020
Authors: Norman Timothy David
Published: April 2022

International mindedness (IM) is a term often used by the International Baccalaureate (IB), international schools and researchers in the field of international education. However, within the discipline of music education, this concept remains relatively unexplored. Conducted as a scoping review, using Arksey and O’Malley's (2005) framework, this study charts the research literature that explores IM and its related concepts within music education settings. A broad definition of music education was adopted, incorporating both formal and informal learning environments. Related concepts to IM, used as search terms, were taken from two IB commissioned reports (that is, Castro, Lundgren and Woodin, 2013; Singh and Qi, 2013). Only primary studies, with a publication date between 2000 and 2020, were included. In total, 218 studies satisfied the inclusion criteria, the majority of which addressed the concepts of multicultural education, intercultural competence, cultural awareness and social inclusion. No primary studies were included for the concepts of common humanity, human rights education, language rights, omniculturalism, transcultural competence and world mindedness/citizenship. Only four primary studies were found that address IM, conducted by the same two researchers, leading the author to question whether future research exploring IM in music education settings is a worthwhile endeavour. In sum, although a significant amount of literature was found through this scoping review, several concepts remain underdeveloped, or completely unexplored, within the field of music education.
Improving the performance of Bayesian logistic regression model with overdose control in oncology dose‐finding studies
Authors: Zhang Hongtao , Chiang Alan Y. , Wang Jixian
Published: April 2022

An accurately identified maximum tolerated dose (MTD) serves as the cornerstone of successful subsequent phases in oncology drug development. Bayesian logistic regression model (BLRM) is a popular and versatile model‐based dose‐finding design. However, BLRM with original overdose control strategy has been reported to be safe but “excessively conservative.” In this article, we investigate the reason for conservativeness and point out that a major reason could be the lack of appropriate underdose control. We propose designs that balance overdose and underdose control to improve the performance over the original BLRM. Simulation results reveal that the new designs have better accuracy and treat more patients at MTD.
Efficient Flexible Perovskite Solar Cells with Reduced Hysteresis Employing Cobalt Nitrate Treated SnO2
Authors: Wu Donghui , Ai Zhenhai , Li Sheng , Chen Junjun , Zhao Yue , Ma Tianshu , Wang Huayang , Wang Changlei , Li Xiaofeng
Published: April 2022

Flexible perovskite solar cells (PSCs) have great potential for portable electronics, however, suffer from large hysteresis in regular structure. Insufficient charge extraction in commonly used tin dioxide (SnO2) electron transporting layer (ETL) is regarded as one possible origin of hysteresis due to the low crystallinity and energy level mismatching. Here, the hysteresis of flexible PSCs is suppressed by synthesizing cobalt‐modified SnO2 ETLs, which improve electron extraction capability due to the high carrier mobility and well‐aligned energy levels. Moreover, cobalt modification passivates the defects on the ETL surface, facilitates sequential perovskite film growth, and inhibits carrier recombination. As a result, flexible PSCs with efficiencies exceeding 20% are obtained with significantly reduced hysteresis and enhanced illumination stability. Comprehensive optoelectronic simulations are conducted to unveil the deep mechanisms of eliminated hysteresis. The proposed work provides an efficient and facile strategy for the fabrication of high‐performance flexible PSCs upon future commercialization.
Grain Coarsening of a Powder Metallurgical High‐Speed Steel After Sliding Wear
Authors: Lyu Cheng , Yao Yao , Zhang Xianglin , Luo Yiyuan
Published: April 2022

The microstructure of a powder metallurgical high‐speed steel (PM HSS) after sliding wear is investigated by using electron backscattering diffraction (EBSD) and transmission electron microscope (TEM). Part of martensite blocks become coarsened as the fine blocks can still be seen after sliding wear. The texture, nanolamellar structure, and twin martensite are observed, which suggests that grain rotation and grain boundary migration are driven by plastic deformation and are the main factors for grain growth. However, grain rotation and grain boundary migration are also blocked by carbides and alloy elements segregation, resulting in discontinuous grain growth.
Evolution of Passive Film on 304 Stainless Steel During Nitric Acid Passivation
Authors: Yue Yingying , Liu Chengjun , Jiang Maofa
Published: April 2022

The corrosion resistance of 304 stainless steel is dominated by the passive film on its surface. The main purpose of the present study is to validate the critical factor determining the corrosion resistance of the passive film and identify the optimized passivating time in nitric acid under chemical oxidation. The electrochemical results show that the passive film consists of an outer layer behaving as a p‐type semiconductor and an inner layer behaving as an n‐type semiconductor. The film thickness and film resistance increase to maximum values after 2.67 h with the lowest carrier densities. Afterward, the properties of the passive film reach a steady state with higher carrier densities. The X‐Ray photoelectron spectroscopy results indicate that the gradual dissolution of FeOOH and further oxidation of Fe2+ species in nitric acid contribute to the decrease of corrosion resistance of the passive film. The thickness of the passive film is accurately predicted according to electrochemical impedance spectroscopy data based on the Hsu‐Mansfeld (H–S) model.
Development of a Porous Solid Model for the Direct Reduction of Iron Ore Pellets
Authors: Fradet Quentin , Ali Mohammed Liaket , Riedel Uwe
Published: April 2022

The direct reduction of iron ore pellets with syngas or hydrogen is a promising technology to reduce the CO2 emissions of the iron and steel industry. The conversion rate of single iron ore pellets to iron is extensively investigated. In most of these studies, a shrinking core model is employed to reproduce the experimental observations. However, this model presents an inherent bias by assuming a sharp separation between a fully converted region and a fully unreacted one. Herein the present study, an improved porous solid model is proposed. This model solves the mass balances of the individual gas species and the solid ones assuming spherical symmetry. The governing equations, the main algorithm, and validation cases are presented. The present model also offers wide flexibility to incorporate complex phenomena such as porosity changes or carbon deposition. Furthermore, the proposed model is integrated into a computational fluid dynamics (CFD) environment. It is verified that identical input parameters yield almost identical results in both frameworks, opening the gate toward reliable CFD simulations of industrial‐scale reactors.
Effect of Grain Size and Cooling Rate on the Martensite Start Temperature of Stainless Steel
Authors: Liu Chengcheng , Huang Minping , Ren Qiang , Ren Ying , Zhang Lifeng
Published: April 2022

Herein, the transformation process of the martensitic stainless steel under different austenite temperatures, holding times, and cooling rates were in situ observed using the confocal laser scanning microscope. The grain boundary migration energy of the austenite grain was 241.51 kJ mol−1. The grain size at different temperatures and holding times was predicted, agreeing well with measured values. The relationship between the martensite start temperature and the grain size is proposed. The martensitic start temperature was significantly influenced by the cooling rate. With the increase of the cooling rate, the martensitic start temperature first decreased then rose up due to the quenching vacancy and internal stress, respectively.
Toward Eco‐Friendly Lead‐Free Low‐Dimensional Perovskites
Authors: Gao Xinying , Luo Jiawei , Wu Yilei , Lu Aini , Ju Ming-Gang , Wang Jinlan
Published: April 2022

Lead halide perovskites are regarded as potential successor of traditional perovskites, due to their variable structures and excellent optoelectronic properties. However, its large‐scale commercialization is impeded by the inherent instability and toxicity. In this regard, lead‐free low‐dimensional perovskites (LFLDPs) have emerged as promising alternatives to the traditional 3D components, due to their structural tunability and environmental friendliness and stability. The structure–property characteristics of LFLDPs endow them with a unique combination of optoelectronic efficiency and versatile functionality, which has led to their impressive employment in the optoelectronic devices. In this perspective, a brief description of recent progress on the various LFLDPs, and especially from theoretical perspective, is presented. First, the general types of LFLDPs are introduced and the metal elements that have been used to date in the exploitation of LFLDPs are collected. This is followed by a discussion of fundamental understanding of the structure–property relationship for different dimensional perovskites in the view of connectivity and element composition. Finally, luminescence mechanism of relevant LFLDPs and the key frontiers and challenges for further developing LFLDP materials is discussed.
Sustainable chemical upcycling of waste polyolefins by heterogeneous catalysis
Authors: Chu Mingyu , Tu Weilin , Yang Shuangqiao , Zhang Congyang , Li Qingye , Zhang Qiao , Chen Jinxing
Published: April 2022

The mass production of disposable polyolefin products has led to serious plastic pollution and an imbalance between manufacturing and recycling. Given these challenges, the chemical upcycling of waste polyolefins has attracted extensive attention due to its high efficiency and economic benefits. Herein, we review the development of polyolefin chemical upcycling in heterogeneous catalysis. The status quo of polyolefin recycling is first discussed. We then introduce the advanced strategies for chemical upcycling in the view of different value‐added products and discuss their challenges and prospects. Our in‐depth analysis centers on the catalytic mechanism and the design principle of heterogeneous catalysts. Finally, we outlook the promising directions to facilitate the degradation process via polymer and catalyst design and optimized catalytic engineering. Innovative strategies are expected to promote the chemical upcycling of polyolefins, bringing great promise for the sustainable development of society.
Recent Advances in Carbon and Metal Based Supramolecular Technology for Supercapacitor Applications
Authors: Hasan Md. Mahedi , Islam Tamanna , Shah Syed Shaheen , Awal Abdul , Aziz Md. Abdul , Ahammad A. J. Saleh
Published: April 2022

As the world moves towards renewable and sustainable energy sources, the need for systems that can quickly and safely store this energy is also rising. Supercapacitors (SCs) are among the most promising alternatives to conventional lithium‐ion batteries. SCs are more stable, have higher‐power densities, and can be charged much faster. However, SCs have their issues, and three of the main drawbacks of current SCs are 1) lower energy densities, 2) high cost of production, and 3) safety concerns in wearable devices. In this review, we discuss recent progress made in supramolecule‐based SCs (SSCs). In supramolecular systems, molecules are held stable using non‐covalent‐type bonds. This allows for a flexible system in which the molecular interaction sites can easily break and reform at low energy, allowing for exposure of highly active sites and self‐healing. When heterometal atoms are introduced into these supramolecular systems, this allows for further activation of the metal sites through the metal‐metal interaction along with the metal‐ligand interactions. This review discusses different types of SSCs (carbon‐based and metal‐incorporated) that have been utilized in recent years depending on their synthesis process. The working principle of SSCs and the utilization of different supramolecular elements that enhance the performance of SCs have also been discussed.
Age‐related miRNAs dysregulation and abnormal BACE1 expression following Pb exposure in adolescent mice
Authors: Wang Ruike , Wu Zuntao , Liu Rundong , Bai Lin , Lin Yan , Ba Yue , Huang Hui
Published: April 2022

Numbers of emerging evidence suggest that lead (Pb) exposure contributes to cognitive decline and might also increase the risk of Alzheimer's disease (AD) dementia in the elderly by increasing the beta‐amyloid burden. Here, we aimed to characterize the effects of Pb on the post‐transcriptional regulators, microRNAs (miRNAs), which may participate in AD pathogenesis. At first, early chronic Pb exposure on neuronal miRNAs expression with increasing aging was profiled to elucidate the association of three selected miRNAs with β‐site APP‐cleaving enzyme 1(BACE1), a rate‐limiting enzyme for β‐amyloid (Aβ) production. Next, we verified changes in BACE1 were observed by regulating miRNAs expression in vitro. While Pb promoted BACE1 levels, BACE1 levels were reduced in SH‐SY5Y cells with miR‐124‐3p mimic, suggesting for the first time that miR‐124‐3p/BACE1 pathway modulation is critically involved in Pb‐induced AD‐like amyloidogenic processing. Findings from this study could provide new insight into the molecular mechanisms of Pb‐associated neurodegenerative pathogenesis from an epigenetic perspective.