bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reactivity of allenylphosphonates/allenylphosphine oxides – some new addition/cycloaddition and cyclization pathways
Authors: Swamy K. C. Kumara , Anitha Mandala , Debnath Shubham , Shankar Mallepalli 
Published: January 2019

Abstract
In this paper, we highlight some addition/cycloaddition reactions of allenylphosphonates and allenylphosphine oxides, mostly based on the work done in our laboratory. Thus the electrophilic addition of iodine monochloride (ICl) with allenylphosphine oxides affords cyclic phosphonium salts rather than γ-chloro-β-iodovinylphosphine oxides (NMR, HRMS, X-ray) that exhibit rather unusual downfield shifts in the 31P NMR spectra. These compounds undergo hydrolysis to afford γ-hydroxy-β-iodovinylphosphine oxides; the hydroxymethyl group in these compounds can be oxidized by Dess-Martin periodinane to afford the corresponding aldehyde-substituted vinylphosphine oxides. A [2+2] cycloaddition product of an allenylphosphonate has also been structurally characterized. Other reactions that are highlighted include those leading to (Z)/(E)-β-aminovinylphosphonates, β-ketophosphonates (and their utility in Horner-Wadsworth-Emmons reaction), indolyl/furanyl/isocoumaranyl/naphthyl phosphine oxides, thiophosphorylated phosphonates and azo-substituted coumarin phosphonates.
Exact solutions and conservation laws for the modified equal width-Burgers equation
Authors: Khalique Chaudry Masood , Simbanefayi Innocent 
Published: January 2019

AbstractIn this paper we study the modified equal width-Burgers equation, which describes long wave propagation in nonlinear media with dispersion and dissipation. Using the Lie symmetry method in conjunction with the (G'/G)− expansion method we construct its travelling wave solutions. Also, we determine the conservation laws by invoking the new conservation theorem due to Ibragimov. As a result we obtain energy and linear momentum conservation laws.
Elastic properties and plane acoustic velocity of cubic Sr2CaMoO6 and Sr2CaWO6 from first-principles calculations
Authors: Jia Zhenyuan , Wang Peida , Smith Willie 
Published: January 2019

Abstract
The elastic properties and plane acoustic velocity of double perovskite Sr2CaMoO6 and Sr2CaWO6 are investigated with the plane wave pseuedopotential method based on the first-principles density functional theory within the local density approximate (LDA) and the generalized gradient approximation (GGA). The calculations indicate that Sr2CaMoO6 and Sr2CaWO6 respectively have the the Mo-O and W-O stable octahedral structure. The bulk modulus B, shear modulus G, Young’s modulus E, Poisson’s ratio ν and Debye temperature were calculated based on the elastic constants. The three dimensional plane acoustic velocities and their projection are in calculated for each direction by solving the Christoffel’s equation systematically based on the theory of acoustic waves in anisotropic solids, the result shows of anisotropy of lattice vibration for Sr2CaMoO6 is stronger than Sr2CaWO6.
Fouling and fouling mitigation of calcium compounds on heat exchangers by novel colloids and surface modifications
Authors: Kazi Salim N. 
Published: January 2019

AbstractFouling is the accumulation of unwanted materials on surfaces that causes detrimental effects on its function. The accumulated materials can be composed of living organisms (biofouling), nonliving substances (inorganic and/or organic), or a combination of both of them. Mineral fouling occurs when a process uses cooling water supersaturated with mineral salt crystals (i.e. hard water). Precipitation ensues on heat transfer surfaces whenever the inversely soluble dissolved calcium salt ions are exposed to high temperature. Mineral salts, dirt, waxes, biofilms, whey proteins, etc. are common deposits on the heat exchanger surfaces, and they create thermal resistance and increase pressure drop and maintenance costs of plants. Fouling of dissolved salts and its mitigation have been studied in detail by varying process parameters, surface materials, coatings on surfaces, additives, etc. by many researchers. In the present stage, researchers have considered polymeric additives, environmental friendly nanoparticles, natural fibers, and thermal conductive coatings (metallic and polymeric) in the study of mitigation of fouling. A better understanding of the problem and the mechanisms that lead to the accumulation of deposits on surfaces will provide opportunities to reduce or even eliminate the problem in certain situations. The present review study has focused on fouling phenomena, environment of fouling, heat exchanger fouling in design, and mitigation of fouling. The findings could support in developing the improved heat exchanger material surfaces, retain efficiency of the heat exchangers, and prolong their continuous operation.
Diverse polyketides and alkaloids from Penicillium sp. KHMM: structural elucidation, biological and molecular docking studies
Authors: Hamed Abdelaaty , Ismail Mohamed , El-Metwally Mohammad M. , Frese Marcel , Ibrahim Tarek M.A. , El-Haddad Atef F. , Sewald Norbert , Shaaban Mohamed 
Published: January 2019

Abstract
As a continuation of our earlier research concerning the investigation of microbial bioactive secondary metabolites from the terrestrial Penicillium sp.KH Link 1809 isolate KHMM, the fungus was re-cultivated on a large scale to explore its bioactive compounds intensively. Fifteen compounds, including seven alkaloids (1–7), one sesquiterpene (8), an acetylenic system (9), two sterols, and sphengolipid, were identified. Their structures were established on the bases of extensive one- and two-dimensional nuclear magnetic resonance and mass measurements, and by comparison with literature data. The antimicrobial activity of the fungal extract and the corresponding compounds were studied using a panel of pathogenic microorganisms, and their in vitro cytotoxicity against the human cervix carcinoma cell line (KB-3-1) was reported as well. The molecular docking of the isolated compounds showed promising affinities for the alkaloidal compounds 4–6 towards α, β tubulins.
Linear enzyme cascade for the production of (–)-iso-isopulegol
Authors: Peters Christin , Buller Rebecca 
Published: January 2019

Abstract
Biocatalysis has developed enormously in the last decade and now offers solutions for the sustainable production of chiral and highly functionalised asset molecules. Products generated by enzymatic transformations are already being used in the food, feed, chemical, pharmaceutical and cosmetic industry, and the accessible compound panoply is expected to expand even further. In particular, the combination of stereo-selective enzymes in linear cascade reactions is an elegant strategy toward enantiomeric pure compounds, as it reduces the number of isolation and purification steps and avoids accumulation of potentially unstable intermediates. Here, we present the set-up of an enzyme cascade to selectively convert citral to (–)-iso-isopulegol by combining an ene reductase and a squalene hopene cyclase. In the initial reaction step, the ene reductase YqjM from Bacillus subtilis selectively transforms citral to (S)-citronellal, which is subsequently cyclised exclusively to (–)-iso-isopulegol by a mutant of the squalene hopene cyclase from Alicyclobacillus acidocaldarius (AacSHC). With this approach, we can convert citral to an enantiopure precursor for isomenthol derivatives.
Identification of benzisoquinolinone derivatives with cytotoxicities from the leaves of Portulaca oleracea
Authors: Wei Rong-Rui , Ma Qin-Ge , Zhong Guo-Yue , Yang Ming , Sang Zhi-Pei 
Published: January 2019

Abstract
Three new benzisoquinolinones (1–3), together with seven known benzisoquinolinone derivatives (4–10), were isolated from Portulaca oleracea for the first time. The structures of the isolated compounds (1–10) had been elucidated on the basis of extensive spectroscopic methods including ultraviolet, infrared, mass spectrometry, and nuclear magnetic resonance techniques and by comparison with data reported in the references. All isolated compounds were assayed for cytotoxicities against selected human lines in vitro by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. Compounds 1, 2, 4, and 7 showed important cytotoxicities against HCT116, MCF-7, U87, and A549 cell lines with IC50 values in the range of 11.62–84.45 μM, which compared with positive control doxorubicin.
Semianalytic Weibull Model to Assess the Influence of Strength Controlling Flaws for Bimodular C-Ring Specimen
Authors: Bhushan Awani , Panda S. K. 
Published: January 2019

Abstract
The present study addresses the issues of shifting of elastic axis and elastic surface for strength scaling of bimodular C-ring specimens using a Weibull statistical model. A semianalytical weakest link theory approach has been followed to evaluate the effective volume and effective area with presumed surface and volume distributed scattered flaws in the specimen. Experimentation, semianalytic, and finite element–based numerical procedures have been pursued to iteratively evaluate the Weibull characteristic parameters for typical loading configurations. Significant asymptotic variation in these two parameters has been observed at a low Weibull modulus for a set of change in elastic modulus ratio of tension and compression in contrast to unimodular assumptions. This variation can be ascribed to the significant shifting of neutral surface from the centroidal surface, thereby exhibiting the low level of confidence in designing bimodular structures. Also, the gradients of the curve are very steep, reflecting the uncertainty in strength characteristics as compared to the unimodular case, thus causing changes in the Weibull effective volume and effective surface area. The variation in Weibull effective surface area is less in comparison to the effective volume for unimodular and bimodular thick and thin C-ring specimens. The tabulated results can be used to substitute for a large number of expensive experiments for the design and analysis of bimodular structural components.
Magnetic Field Strength and Temperature Effects on the Behavior of Oil Well Cement Slurry Modified with Iron Oxide Nanoparticles and Quantified with Vipulanandan Models
Authors: Vipulanandan C. , Mohammed A. 
Published: January 2019

Abstract
The focus of this study was to investigate the methods that could potentially be easy to adopt in field to modify cement slurry rheological properties in situ during the installation of oil and gas wells. In this study, we investigated the effects of magnetic field strengths and temperatures on the rheological properties of an oil well cement (Class H) modified with iron oxide nanoparticles (NanoFe2O3). Also, the sensitivity of using electrical resistivity in monitoring changes in the cement slurry was also investigated. The water-to-cement ratio used in this study was 0.38, since it is a popular ratio used in oil well cementing. The NanoFe2O3 contents (average particle size of 30 nm) in the cement slurry were varied up to 1 % by the weight of cement. The temperature was varied from 25°C to 85°C. The magnetic field strength was varied up to 0.6 T. The initial electrical resistivity of the cement slurry modified with NanoFe2O3 decreased by 6 % to 52 % based on the NanoFe2O3 content, temperature, and magnetic field strength. The shear thinning behavior of the cement slurry with and without NanoFe2O3 has been quantified using the Vipulanandan rheological model and compared to the Herschel-Bulkley model. The results show that the Vipulanandan rheological model predicted the shear thinning relationship between the shear stress and shear strain rate of the NanoFe2O3-modified cement slurry very well with the maximum shear stress tolerance. The rheological properties of the cement slurry modified with NanoFe2O3 under different magnetic field strengths have been correlated to the electrical resistivity of the cement slurry using a nonlinear resistivity and Vipulanandan property correlation models. Thus, the performance of the cement slurry with and without NanoFe2O3 can be characterized based on the electrical resistivity, which can be used as a real-time monitoring tool in the field.
An Enhanced Hybrid Clustering Approach for Privacy Preservation (ECPS) in Big Data using Apache Spark Framework
Authors: Swaminathan Revathy , Thangavelu Arunkumar 
Published: January 2019

Abstract
In the era of big data mining, clustering is the organization of objects into groups based on applied similarity metrics. Among those metrics, the k-means approach is considered the most popular algorithm so far. As a result of the advancement in parallel processing and distributed computation, traditional techniques are not as efficient in computing the centroid when performing clustering. Consequently, this issue has an effect on privacy preservation when it comes to processing individuals’ sensitive information. Hence, an optimal clustering technique an enhanced hybrid clustering approach for privacy preservation in the context of big data perspective as well as in the context of the preservation of individual privacy protection from background knowledge attack is proposed in this article. The first approach depicts a combination of the ant colony optimization and firefly techniques for choosing the better centroid position with the data. The next approach is about combining the differential privacy algorithm, which uses the Laplace mechanism for augmenting additional noise to the individual’s data to make privacy preservation more robust. With the evolving trends and technologies, the amount of data being generated is increasing at an overwhelming rate. Thus, the proposed approaches are designed in such a way that they can be adapted to the changing needs of big data. The proposed algorithms are efficient when compared with the existing clustering algorithms and provide better performance by guaranteeing privacy. The implementation of the proposed works is done upon the Apache Spark with the big data framework.
Shep RNA-Binding Capacity Is Required for Antagonism ofgypsyChromatin Insulator Activity
Authors: Chen Dahong , Brovkina Margarita , Matzat Leah H , Lei Elissa P 
Published: January 2019

AbstractChromatin insulators are DNA-protein complexes that regulate chromatin structure and gene expression in a wide range of organisms. These complexes also harbor enhancer blocking and barrier activities. Increasing evidence suggests that RNA molecules are integral components of insulator complexes. However, how these RNA molecules are involved in insulator function remains unclear. The Drosophila RNA-binding protein Shep associates with the gypsy insulator complex and inhibits insulator activities. By mutating key residues in the RRM domains, we generated a Shep mutant protein incapable of RNA-binding, and this mutant lost the ability to inhibit barrier activity. In addition, we found that one of many wildtype Shep isoforms but not RRM mutant Shep was sufficient to repress enhancer blocking activities. Finally, wildtype Shep rescued synthetic lethality of shep, mod(mdg4) double-mutants and developmental defects of shep mutant neurons, whereas mutant Shep failed to do so. These results indicate that the RNA-binding ability of Shep is essential for its ability to antagonize insulator activities and promote neuronal maturation. Our findings suggest that regulation of insulator function by RNA-binding proteins relies on RNA-mediated interactions.
Cognitive Outcomes and Positional Plagiocephaly
Authors: Collett Brent R. , Wallace Erin R. , Kartin Deborah , Cunningham Michael L. , Speltz Matthew L. 
Published: January 2019

BACKGROUND:
Studies have revealed an association between positional plagiocephaly and/or brachycephaly (PPB) and development, although little is known about long-term outcomes. We examined cognition and academic achievement in children with and without PPB, testing the hypothesis that children who had PPB as infants would score lower than controls.

METHODS:
We enrolled 187 school-aged children with a history of PPB and 149 controls. Exposures were the presence or absence and severity of infancy PPB (mild, moderate to severe). Cognitive and academic outcomes were assessed by using the Differential Ability Scales, Second Edition and Wechsler Individual Achievement Test, Third Edition, respectively.

RESULTS:
Children with PPB scored lower than controls on most scales of the Differential Ability Scales, Second Edition (standardized effect sizes [ESs] = −0.38 to −0.20) and the Wechsler Individual Achievement Test, Third Edition (ESs = −0.22 to −0.17). Analyses by PPB severity revealed meaningful differences among children with moderate to severe PPB (ESs = −0.47 to −0.23 for 8 of 9 outcomes), but few differences in children with mild PPB (ESs = −0.28 to 0.14).

CONCLUSIONS:
School-aged children with moderate to severe PPB scored lower than controls on cognitive and academic measures; associations were negligible among children with mild PPB. The findings do not necessarily imply that these associations are causal; rather, PPB may serve as a marker of developmental risk. Our findings suggest a role for assessing PPB severity in clinical practice: providing developmental assessment and intervention for infants with more severe deformation and reassurance and anticipatory guidance for patients with mild deformation.
Hepatocyte Growth Factor–Secreting Mesothelial Cell Sheets Suppress Progressive Fibrosis in a Rat Model of CKD
Authors: Oka Masatoshi , Sekiya Sachiko , Sakiyama Ryoichi , Shimizu Tatsuya , Nitta Kosaku 
Published: January 2019

Significance Statement
No effective therapy is currently available to directly address a key feature of CKD progression: interstitial fibrosis leading to a loss of peritubular capillaries (PTCs). One potential antifibrotic candidate, hepatocyte growth factor (HGF), cannot be applied in clinical settings owing to its short t
1/2 in blood and elimination by other organs, such as the liver. The authors describe use of a novel HGF therapy using cell sheet technology: transplantation of transgenic HGF-secreting mesothelial cell sheets to the kidney in a CKD rat model. The HGF-secreting cell sheet directly suppresses interstitial fibrosis for 28 days and prevents loss of peritubular capillaries. Inhibition of CKD progression requires long-term suppression of fibrosis, and cell sheet therapy represents a promising strategy for achieving that goal.

Background
Although hepatocyte growth factor (HGF) has antifibrotic effects and is involved in angiogenesis and vasodilation, systemic administration of HGF to prevent kidney fibrosis is not a feasible strategy for suppressing interstitial fibrosis in patients with CKD.

Methods
We investigated a novel therapy involving HGF transgenic cell sheets grown in culture from human mesothelial cells and administered to rats with unilateral ureteral obstruction (UUO). We compared progression of fibrosis in rats with UUO that received one of five interventions: HGF-transgenic mesothelial cell sheets transplanted to the kidney surface, HGF-transgenic mesothelial cell sheets transplanted to thigh, mesotherial cell sheets transplanted to kidney, no sheets, or HGF injections.

Results
HGF transgenic cell sheets transplanted to the kidney strongly suppressed the induction of myofibroblasts and collagen in the kidney for 28 days; other interventions did not. Additionally, the HGF-secreting cell sheets ameliorated loss of peritubular capillaries and maintained renal blood flow.

Conclusions
These findings suggest that cell sheet therapy is a novel and promising strategy for inhibiting progressive fibrosis in CKD.
The Effects of Fracture Penetration Ratio and Fracture Conductivity on the Performance of Hydraulic Fractured Vertical Wells in Gas Reservoirs
Authors: Kamal Babar , Malekzadeh Darren 
Published: January 2019

Abstract
Predicting the effects of the fracture penetration ratio and fracture conductivity in hydraulically- fractured vertical wells in dry-gas and wet-gas reservoirs is important in determining the well performance in a given formation. A fracture length and conductivity which provide the highest ultimate gas recovery factor at the earliest time to reach abandonment conditions is the proper fracture type which has to be selected for developing the reservoir.
A three dimensional reservoir simulation model is used to evaluate the performance of hydraulic fractured vertical wells as a function of fracture penetration ratio and fracture conductivity. Accurate determination of initial gas reserves, average reservoir pressure at abandonment time, and the time to reach abandonment conditions is very important to the petroleum industry. Material balance technique and volumetric method, currently used in the petroleum industry to determine the reserves, which do not consider well performance and, as a result, predict a very high recovery factor at abandonment pressure for hydraulic fractured vertical wells in volumetric dry-gas and wet-gas reservoirs.
Well performance in hydraulic fractured vertical wells depends on fracture penetration ratio and fracture conductivity. A comparison with horizontal wells of same penetration ratio is also provided in this paper as an alternative to hydraulic fracturing. A number of simulation runs were performed on a square shape reservoir of horizontal permeability 0.01 md, 0.1 md and 1 md with a penetration ratio of 0.2, 0.4 and 0.8. Our results quantify and show that the ultimate recovery factor and abandonment time are function of fracture penetration ratio regardless of fracture conductivity. In addition, our results shows that in low permeability reservoirs a hydraulic fractured vertical well of similar penetration ratio to a horizontal well perform twice in terms of recovery factor and abandonment time. The effects of formation thickness, well parameters and reservoir rock properties on the average reservoir pressure at abandonment time and on the time to reach the economic limit are also presented in this paper. Based on the results of fracture penetration ratio and fracture conductivity in volumetric dry-gas and wet-gas reservoirs, this paper presents recommendations regarding the proper well type with which the reservoir should be developed.
Terrestrial Non-Parasitic Nematode Assemblages associated With Glyphosate-tolerant and Conventional Soybean-Based Cropping Systems
Authors: Mbatyoti Akhona , Daneel Mieke Stefanie , Swart Antoinette , de Waele Dirk , Fourie Hendrika 
Published: January 2019

Abstract
Information about the effects of glyphosate on nematodes is limited and contradictory, while none existing for South African agricultural fields. The abundance and identity of non-parasitic nematodes in the rhizospheres of commercial glyphosate-tolerant and conventional (non-glyphosate-tolerant), soybean cultivars from cultivated fields, and adjacent natural vegetation (reference system) were obtained for two growing seasons. The impact of glyphosate was also investigated on non-parasitic nematodes in a 2-year soybean-maize cropping system. Thirty-two non-parasitic nematode genera were identified from soils of the three field ecosystems, with most of the genera occurring in natural vegetation (28), and less in conventional (23) and glyphosate-tolerant soybean (21). Bacterivores had the greatest diversity in soils of all three ecosystems during both seasons, while fungivores tended to be more abundant in glyphosate-tolerant soybean fields especially during the second season. Soils from the three ecosystems were disturbed and degraded with low abundance and diversity of omnivores and predators. Of the 14 genera identified from the soybean-maize cropping experiment, bacterivores dominated in terms of diversity in non-treated, and fungivores in glyphosate-treated plots. Soils from glyphosate-treated plots were degraded, less enriched and fungal-mediated, while those from non-treated plots were disturbed, enriched, and bacterial-mediated.