bluuebunny/crossref_metadata_2025_split huggingface dataset:
Size-dependent growth kinetics of struvite crystals in wastewater with calcium ions
Authors: Hutnik Nina , Stanclik Anna , Piotrowski Krzysztof , Matynia Andrzej 
Published: May 2020

AbstractKinetic parameters describing continuous reaction crystallization of struvite from aqueous solutions containing also calcium ions (from 100 to 2000 mg Ca2+/kg) were estimated. Test results were compared with kinetic data of struvite manufactured from real cattle liquid manure. Kinetic model for ideal MSMPR (Mixed Suspension Mixed Product Removal) crystallizer was used assuming dependence of crystal growth rateGon its sizeL(size-dependent growth, SDG MSMPR model). Based on nonlinear regression and statistical analysis, one from within five consideredG(L) models was selected – Rojkowski exponential (RE) model – rendering the experimental population density distributions the best. It was concluded, that calcium ions influenced all components of struvite manufacturing process disadvantageously. A rise of Ca2+concentration in a feed from 100 to 2000 mg/kg increased nucleation rateca. 160-time, whereas growth rate of nuclei up to macroscopic sizeG0decreased more than 10-time. Linear (larger) crystal growth rateG¥was nearly two-times smaller: 1.71·10–8m/s (100 mg Ca2+/kg) – 9.10·10–9m/s (2000 mg Ca2+/kg). Resulting in a product with deteriorated quality. Mean size of the crystals decreased nearly two-times (to 18.4 μm), non-homogeneity within product population enlarged and calcium fraction in the product increased. The product, beside struvite MgNH4PO4·6H2O, also contained hydrated amorphous calcium phosphate(V) Ca3(PO4)2·nH2O (ACP). It was observed, that 5-times smaller concentration of phosphate(V) ions in a feed and magnesium ions excess in relation to phosphate(V) and ammonium ions (1.2 : 1 : 1) influenced all kinetic parameters of continuous struvite reaction crystallization advantageously.
DFT calculations as an efficient tool for prediction of Raman and infra-red spectra and activities of newly synthesized cathinones
Authors: Vujović Maja , Ragavendran Venkatesan , Arsić Biljana , Kostić Emilija , Mladenović Milan 
Published: May 2020

AbstractInitially made for medical treatment for Parkinsonism, obesity, and depression, cathinones have become illegal drugs for the “recreational use”. The mechanism of action of synthetic cathinones consists of the inhibition of monoamine transporters. DFT (Density Functional Theory) calculations on the selected cathinones (3-FMC, 4-FMC, 4-MMC, Buphedrone, Butylone, Ethylone, MDPV, Methcathinone, and Methylone) were performed using B3LYP level of the Gaussian 09 program suite. The unscaled B3LYP/6–31G vibrational wavenumbers are in general larger than the experimental values, so the use of selective scaling was necessary. The calculated spectra of selected cathinones are in good correlation with the experimental spectra which demonstrates that DFT is a good tool for the prediction of spectra of newly synthesized and insufficiently experimentally characterised cathinones. Also, HOMO-LUMO (Highest Occupied Molecular Orbital-Lowest Unoccupied Molecular Orbital) analysis shows that 3-FMC possesses the minimum energy gap of 3.386 eV, and the molecule 4-FMC possesses the maximum energy gap of 4.205 eV among the investigated cathinones. It indicates that 3-FMC would be highly reactive among all the cathinones under investigation.
Study and fire test of banana fibre reinforced composites with flame retardance properties
Authors: Ortega Raquel , Monzón Mario D. , Ortega Zaida C. , Cunningham Eoin 
Published: May 2020

AbstractThe interest in natural fibre reinforced composites is growing in industrial applications due to natural fibres being an attractive alternative to synthetic fibres. However, it is necessary to improve the fire behaviour of the material because natural fibres have a high combustibility. The objective of this work is to evaluate the fire resistance of polymer composites reinforced with natural fibre fabric, using magnesium hydroxide as flame retardant for the polymeric matrix and alkali treatment for the fibre. The types of fabric are banana, banana with cotton and linen; and long banana fibre has been used for the formation of a nonwoven. The fire test is carried out based on ISO 9773 standard and the effect of the additive has been studied, chemical treatment, type of fabric and number of layers. Through statistical analysis, it is concluded that the flame propagation speed has a decreasing relation with respect to the percentage, but it decreases the mechanical properties considerably. In addition, the number of layers and type of fabric influence the fire properties. Finally, it is concluded that composites reinforced with linen fabric have the best mechanical properties, but banana nonwoven with 60% additive has the best fire behaviour.
Antiplasmodial Activity of Stigmastane Steroids from Dryobalanops oblongifolia Stem Bark
Authors: Indriani Indriani , Aminah Nanik Siti , Puspaningsih Ni Nyoman Tri 
Published: May 2020

AbstractThree stigmastane steroids: 6-hydroxystigmast-4-en-3-one (1), stigmast-4-en-3-one (2), and 3-hydroxystigmast-5-en-7-one (3) were successfully isolated from the acetone extract of Dryobalanps oblongifolia stem bark. The structural determination of isolated compounds was carried out on the basis of data analysis of NMR and MS spectra. In order to identify the antiplasmodial activity, the isolated compound was put to test against Plasmodium falciparum 3D7. Antiplasmodial activity of the isolated compounds showed that the IC50 values of 6-hydroxystigmast-4-en-3-one were 37.29 μg/mL while the IC50 values of stigmast-4-en-3-one were 43.54 μg/mL and the IC50 values of 3-hydroxystigmast-5-en-7-one were 13.34 μg/mL (chloroquine phosphate was used as a positive control, IC50 0.006 μg/mL). Judging from the results, the isolated compounds were proven to demonstrate mediocre antiplasmodial activity. Compound (3) indicated a better antimalarial activity than compound (1) and (2), even though there was no satisfactory activity that indicated its ability to combat chloroquine. Therefore, it might not be developed as an antimalarial drug.
Immobilization of Pseudomonas aeruginosa static biomass on eggshell powder for on-line preconcentration and determination of Cr (VI)
Authors: Rasheed Aamir , Ghous Tahseen , Mumtaz Sumaira , Zafar Muhammad Nadeem , Akhter Kalsoom , Shabir Rabia ,   Zain-ul-Abdin, Shafqat Syed Salman 
Published: May 2020

AbstractIn the present work, a novel continuous flow system (CFS) is developed for the preconcentration and determination of Cr (VI) usingPseudomonas aeruginosastatic biomass immobilized onto an effective and low-cost solid support of powdered eggshells. A mini glass column packed with the immobilized biosorbent is incorporated in a CFS for the preconcentration and determination of Cr (VI) from aqueous solutions. The method is based on preconcentration, washing and elution steps followed by colorimetric detection with 1,5-diphenyl carbazide in sulphuric acid. The effects of several variables such as pH, retention time, flow rate, eluent concentration and loaded volume are studied. Under optimal conditions, the CFS method has a linear range between 10 and 100 μg L-1and a detection limit of 6.25 μg L-1for the determination of Cr (VI). The sampling frequency is 10 samples per hour with a preconcentration time of 5 mins. Furthermore, after washing with a 0.1 M buffer (pH 3.0), the activity of the biosorbent is regenerated and remained comparable for more than 200 cycles. Scanning electron microscopy reveals a successful immobilization of biomass on eggshells powder and precipitation of Cr (VI) on the bacterial cell surface. The proposed method proves highly sensitive and could be suitable for the determination of Cr (VI) at an ultra-trace level.
Towards a Digital IUPAC
Authors: McEwen Leah R. 
Published: May 2020

Abstract
Communicating chemical knowledge is at the core of the IUPAC mission and underlies the success of the chemistry enterprise. In the global economy of the 21st century, this involves exchange among computer systems along with the expert scientists who use them. To enable the application of IUPAC outputs in the digital environment, IUPAC must augment its efforts to enable accessibility and interpretation by machines as well as humans. The Union must adapt to a digital work culture to engage in its mission of sustainable development, common language and free exchange of scientific information. [Frey 2014, https://doi.org/10.1515/ci.2014.36.1.14]
The complexity of molecular processes in osteoarthritis of the knee
joint
Authors: Łęgosz Paweł , Sarzyńska Sylwia , Pulik Łukasz , Kotrych Daniel , Małdyk Paweł 
Published: May 2020

Abstract
Osteoarthritis (OA) is a common medical problem leading to chronic pain and physical
disability among the world’s population. Analyzing the molecular background of
the degenerative arthritis creates the potential for developing novel targeted
methods of treatment. Fifty samples of meniscus, anterior cruciate ligaments (ACLs)
and articular surfaces were collected from patients who underwent total knee
arthroplasty in 2016. Enzyme-linked immunosorbent assay was used to assess the levels
of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF), transforming growth
factor-β1 and LUMINEX for MMP-1, MMP-2, MMP-3, MMP-9 and MMP-13. The collected
data were correlated with the severity of radiological OA, demographic data and
clinical scales. Strong positive correlations in the concentration of
metalloproteinases and proinflammatory cytokines, TNF-α (MMP-2 and MMP-13) and
IL-6 (MMP-13), were identified. MMP-13 had a positive correlation with the
concentration of MMP-1, MMP-2 and MMP-9. Negative correlation coefficient exists
between clinical conditions measured with the Western Ontario and McMaster
Universities Osteoarthritis Index scale and the level of TNF-α and MMP-1. The
TNF-α concentration was lower in the cartilage of the articular surface among
patients who took non-steroidal anti-inflammatory drugs periodically. The decrease in
MMP-2 in the cartilage of the articular surface corresponded with the severity of
radiological OA on the Kellgren–Lawrence scale. Current treatment methods for
OA do not stop disease progression. Identifying signaling pathways and molecular
particles engaged in OA and their correlations with the patient’s clinical
condition brings new therapeutic possibilities.
Assessment of content and chemical forms of arsenic, copper, lead, and chromium in sewage sludge compost as affected by various bulking agents
Authors: Saffari Mahboub , Saffari Vahid Reza , Khabazzadeh Hojatollah , Naghavi Hormazd 
Published: May 2020

Abstract
In current study, the effect of various organic substances as bulking agents (BAs) including wheat straw, pistachio hull wastes, and tree leaves at different levels (10, 25, 45% v/v) were investigated on total concentration and chemical forms of Cu, Pb, Cr, and As in sewage sludge (SS) compost prepared by windrow method. According to the results, the composting process (with/without BAs), due to losses of SS mass and volume, increased the total concentration of heavy metals (HMs) compared to the un-composted SS sample (RSS). Evaluation of HMs chemical forms in prepared compost sample without BAs application (CSS) showed that the composting process reduced the mobility factor of As (from 28% to 20%), Pb (from 11.6% to 9.3%), and Cr (from 14.5% to 9.2%) compared to the RSS. Application of three BAs considerably decreased the mobility factor of As (17.5-18.8%), Pb (4.8-7.9%), and Cr (1.4-6.8%) compared to CSS and RSS. Changes of Cu mobility in prepared compost samples showed an unclear trend, however in some treatments, due to transferred organic fraction into exchangeable and carbonate fractions, increasing of this factor was obvious. Generally, the composting appeared to reduce As, Pb, and Cr availability by stabilizing the three metals and making them more stable and less mobile. In addition, the BAs application effect on HMs behavior of SS compost samples were so different and no specific kind of BAs can be recommended as a superior BAs in SS composting process.
Predicting the effect of electric and hybrid-electric aviation on acoustic pollution
Authors: Riboldi Carlo E.D. , Trainelli Lorenzo , Mariani Luca , Rolando Alberto , Salucci Francesco 
Published: May 2020

Abstract
In the quest for the reduction of noise pollution, novel hybrid-electric or fully-electric power-trains promise to provide a substantial contribution. Especially closer to airfields, where acceptability issues tend to limit air operations with conventional fuel-burning engines, such novel power-trains allow to fly terminal maneuvers with a dramatically reduced impact on pollution. Considering the General Aviation (GA) field, where such new types of propulsion are more likely to gain a significant market share thanks to their favorable characteristics for this weight category, the reduction of the noise impact on ground may increase the infrastructural value of smaller airfields, often located in densely populated areas. This in turn would help in making novel power-train technologies economically advantageous at a system level. Despite these evident advantages, a methodology to quantify noise emissions of a novel type of power-train has not been identified yet – a fundamental step towards the assessment of the potential contribution of hybrid-electric or fully-electric aircraft to the global scenario of future aviation. This work introduces and discusses a possible procedure to provide such estimation. While mainly focused on the field of propeller-driven GA aircraft, the procedure presented herein can be easily scaled to cope with the specific features of heavier categories.
A Time-Updated, Parsimonious Model to Predict AKI in Hospitalized Children
Authors: Sandokji Ibrahim , Yamamoto Yu , Biswas Aditya , Arora Tanima , Ugwuowo Ugochukwu , Simonov Michael , Saran Ishan , Martin Melissa , Testani Jeffrey M. , Mansour Sherry , Moledina Dennis G. , Greenberg Jason H. , Wilson F. Perry 
Published: May 2020

Significance StatementBecause AKI in hospitalized children is associated with poor outcomes, a tool allowing early identification of children at risk of developing AKI may facilitate timely interventions. The authors describe various machine learning techniques used to build a parsimonious model predictive of pediatric AKI. From an initial pool of 720 potential variables, they evaluated multiple feature selection techniques to create a ten-feature logistic regression model that could predict, in time-updated fashion, the risk of AKI in the next 48 hours. A machine learning-based genetic algorithm (reflecting the process of natural selection) was the best variable selection method, using ten factors extracted from electronic health records to use for AKI prediction. Risk-stratifying hospitalized children might allow clinicians to implement targeted and timely interventions prior to AKI development.BackgroundTimely prediction of AKI in children can allow for targeted interventions, but the wealth of data in the electronic health record poses unique modeling challenges.MethodsWe retrospectively reviewed the electronic medical records of all children younger than 18 years old who had at least two creatinine values measured during a hospital admission from January 2014 through January 2018. We divided the study population into derivation, and internal and external validation cohorts, and used five feature selection techniques to select 10 of 720 potentially predictive variables from the electronic health records. Model performance was assessed by the area under the receiver operating characteristic curve in the validation cohorts. The primary outcome was development of AKI (per the Kidney Disease Improving Global Outcomes creatinine definition) within a moving 48-hour window. Secondary outcomes included severe AKI (stage 2 or 3), inpatient mortality, and length of stay.ResultsAmong 8473 encounters studied, AKI occurred in 516 (10.2%), 207 (9%), and 27 (2.5%) encounters in the derivation, and internal and external validation cohorts, respectively. The highest-performing model used a machine learning-based genetic algorithm, with an overall receiver operating characteristic curve in the internal validation cohort of 0.76 [95% confidence interval (CI), 0.72 to 0.79] for AKI, 0.79 (95% CI, 0.74 to 0.83) for severe AKI, and 0.81 (95% CI, 0.77 to 0.86) for neonatal AKI. To translate this prediction model into a clinical risk-stratification tool, we identified high- and low-risk threshold points.ConclusionsUsing various machine learning algorithms, we identified and validated a time-updated prediction model of ten readily available electronic health record variables to accurately predict imminent AKI in hospitalized children.
The Choice Between Public and Private Debt by Russian Companies at Different Stages of the Life Cycle
Authors: Rossokhin Vladimir , Ryabova Elena 
Published: May 2020

The problems of formation of the company’s capital structure to date have already been studied well. A large number of theoretical papers and empirical studies devoted to this issue have been published. However, managers are confronted not only with the question of the optimal balance between equity and debt capital, but also with the choice of debt structure in the presence of several of its sources, such as public and private debt. This is a new paradigm in corporate finance. On the one hand, companies are not always ready to issue listed securities at the initial stages of their activity. On the other hand, raising funds in open markets has several advantages. With the help of public debt, one can attract a sufficiently large amount of financial resources with a lower cost in comparison with private borrowing. At the same time, as a rule, the public debt is not secured by the assets in the proper amount.
According to the author’s opinion, in dealing with this question, companies can take into account not only the current state of the company and its financial indicators, but also the stages of the life cycle, since each of them has its own development features. The purpose of this study is to analyze whether life cycle stages and other financial indicators of a company affect the choice of a source of borrowed capital (private or public debt), thereby to contribute to the development of this research direction. The objects of study are Russian companies. In the empirical part of the study, the binary choice model had been applied.
The sample size is 1,818 companies, the financial statements for three years were used. The stages of the organization’s life cycle were calculated by the method of V. Dickinson. A number of control variables were also included in the model. The results of empirical analysis indicate that the company decides to issue public debt, regardless of the stage of the life cycle. This allows us to conclude that the company, when conceptually resolving the question about the structure of borrowed capital, relies on economic indicators such as profitability, size of the company, structure of assets and financial leverage. Understanding this fact can also help potential investors in making investment decisions to form conservative portfolios.
Metabolomic profiling in patients with metabolic syndrome
Authors: Korobkova E. O. , Kozhevnikova M. V. , Ilgisonis I. S. , Shakaryants G. A. , Appolonova S. A. , Kukharenko A. V. , Larcova E. V. , Maltseva A. A. , Khabarova N. V. , Belenkov Yu. N. 
Published: May 2020

Objective. To identify biomarkers, which are most specific for patients with metabolic syndrome (MS) using metabolomic profiling.Materials and Methods. Metabolomic profiling of patients with MS and comparison of their profile with the profile of volunteers was performed using high-performance liquid chromatography-mass-spectrometry.Results. The metabolomic profile of MS patients differed in several amino acids, including choline, cysteine, and serine and in the acylcarnitine group (р<0.05 for all comparisons).Conclusion. The metabolites most specific for MS patients were identified. Increased concentrations of a combination of amino acids and carnitines can be considered as possible additional risk factors for cardiovascular diseases.
Comparative study of outcomes of type-1 tympanoplasty with temporalis fascia only and with cartilage slice reinforcement
Authors: Rathaur Shiv Kumar 
Published: May 2020

<p class="abstract"><strong>Background:</strong> Tympanoplasty is a surgical procedure performed to eradicate infection and restore the function of middle ear. Cartilage slice support offers an extremely reliable method for reconstruction of tympanic membrane in cases of high-risk perforation. The purpose of this study was to evaluate the graft uptake and auditory outcomes of type I tympanoplasty using temporalis muscle fascia only and with cartilage slice reinforcement.</p><p class="abstract"><strong>Methods:</strong> This prospective study was conducted at the Department of Otorhinolaryngology, Government Medical College, Jalaun, Uttar Pradesh, India from November 2016 to November 2019. There were total of 100 patients, divided in two groups, 50 patients in each group, tympanoplasty type-1 using only temporalis fascia (group-A) and tympanoplasty type-1 using temporalis fascia with cartilage slice reinforcement (group-B). The result was measured on graft uptake and hearing outcome at 6 months postoperatively. </p><p class="abstract"><strong>Results:</strong> Overall graft uptake rate in group-A was 94%, whereas that in group-B was 100%. The age and sex had no significant effect on the success rate of surgery (p&gt;0.05) in group-A. The average air bone gap (ABG) decreased from 28.3 dB to 10 dB, in group-B, the average ABG was 28.3 dB preoperatively and reached 16.6 dB after surgery. The difference between the rates of ABG improvement in the two groups was significant (p&lt;0.01).</p><p class="abstract"><strong>Conclusions:</strong> Hearing improvements is better in tympanoplasty type-1 with a temporalis graft only then with cartilage slice reinforcement. However, the graft uptake rate is higher in cartilage reinforcement compare with temporalis muscle fascia only.</p><p class="abstract"> </p>