bluuebunny/crossref_metadata_2025_split huggingface dataset:
Targeting Asexual and Sexual Blood Stages of the Human Malaria Parasite P. falciparum with 7‐Chloroquinoline‐Based 1,2,3‐Triazoles
Authors: Wadi Ishan , Prasad Davinder , Batra Neha , Srivastava Kumkum , Anvikar Anupkumar R. , Valecha Neena , Nath Mahendra 
Published: January 2019

AbstractNovel 4‐amino‐7‐chloroquinoline‐based 1,2,3‐triazole hybrids were synthesised in good yields by CuI‐catalysed Huisgen 1,3‐dipolar cycloaddition reactions of 2‐azido‐N‐(7‐chloroquinolin‐4‐ylaminoalkyl)acetamides with various terminal alkynes. These new hybrids were screened in vitro against asexual blood stages of the chloroquine‐sensitive 3D7 strain of P. falciparum. The most active compounds were further screened against asexual and sexual stages (gametocytes) of the chloroquine‐resistant RKL‐9 strain of P. falciparum. Although all compounds were less potent than chloroquine against the 3D7 strain, the three best compounds were appreciably more active than chloroquine against the RKL‐9 strain, displaying IC50 values of <100 nm, with one of them having an IC50 of 2.94 nm. Further, the lead compounds were gametocytocidal with IC50 values in the micromolar range, and were observed to induce morphological deformations in mature gametocytes. Most compounds demonstrated little or no cytotoxicity and exhibited good selectivity indices. The most active compounds represent promising candidates for further evaluation of their schizonticidal and gametocytocidal potential.
Grain Selection and Crystal Orientation in Single‐Crystal Casting: State of the Art
Authors: Raza Muhammad Huzaifa , Wasim Ahmad , Hussain Salman , Sajid Muhammad , Jahanzaib Mirza 
Published: January 2019

AbstractThe properties of single‐crystal superalloys depend highly upon crystallographic orientation and the selection of single crystal (SX) in directional solidification (DS) process. The assessment of SX selection and crystallographic orientation determines the mechanical properties of the casting. Generally, it is considered that the deviation from [001] orientation should be less than 10° for better mechanical properties. This article provides a quantitative literature review analyzing the experimental results of 30 papers that studied the effects of process parameters on crystal orientation and grain selection in SX‐casting process. Key parameters that control the SX casting during DS process include spiral selector parameters, starter block parameters, withdrawal rate, pouring temperature, and ceramic mold temperature. The analysis in this research provides a strong evidence to assist the standard operating range of each parameter. A lack of focus in the literature on alloys is found. A framework based on the key parameters is also proposed in this review.
Atomic‐Scale Direct Identification of Surface Variations in Cathode Oxides for Aqueous and Nonaqueous Lithium‐Ion Batteries
Authors: Byeon Pilgyu , Lee Hyeon Jeong , Choi Jang Wook , Chung Sung‐Yoon 
Published: January 2019

AbstractThe electrochemical (de)intercalation reactions of lithium ions are initiated at the electrode surface in contact with an electrolyte solution. Therefore, substantial structural degradation, which shortens the cycle life of cells, is frequently observed at the surface of cathode particles, including lithium–metal intermixing, phase transitions, and dissolution of lithium and transition metals into the electrolyte. Furthermore, in contrast to the strict restriction of moisture in lithium‐ion cells with nonaqueous organic electrolytes, electrode materials in aqueous‐electrolyte cells are under much more reactive environments with water and oxygen, thereby leading to serious surface chemical reactions on the cathode particles. The present article presents key results regarding structural and composition variations at the surface of oxide‐based cathodes in both high‐performance nonaqueous and recently proposed aqueous lithium‐ion batteries; in particular, focusing on direct atomic‐scale observations preformed by means of scanning transmission electron microscopy. Precise identification of surface degradation at the atomic level is thus emphasized because it can provide significant insights into overcoming the limitations of current lithium‐ion batteries.
On‐Site Purification of Copper‐Contaminated Vanadium Electrolytes by using a Vanadium Redox Flow Battery
Authors: Reynard Danick , Vrubel Heron , Dennison Christopher R. , Battistel Alberto , Girault Hubert 
Published: January 2019

AbstractCorrosion of carbon‐based electrodes and bipolar plates is a major hurdle and can be a cause of failure in commercial vanadium redox flow batteries (VRFBs). Carbon corrosion was found to occur in a commercial VRFB (10 kW/40 kWh), whereby cracks through bipolar plates enabled the electrolyte to leach the copper current collectors at the end of the stacks, contaminating the entire electrolyte solution. In this work, the effects of copper contaminants on the operation of a VRFB were studied. A simple and effective procedure to identify copper contamination on‐site and to purify the electrolyte was developed. The process was used to purify large quantities (6000 L) of copper‐contaminated electrolytes to levels below 1 ppm.
An efficient clustering and load balancing of distributed cloud data centers using graph theory
Authors: Devi R. Kanniga , Murugaboopathi G. 
Published: January 2019

SummaryThe prime focus of the Cloud Service Providers is enhancing the service delivery performance of the distributed cloud data centers. The clustering and load balancing of distributed cloud data centers have significant impact on its service delivery performance. Hence, this paper models distributed cloud data center environment as a network graph and proposes a two‐phase cluster‐based load balancing (CLB) algorithm based on a graph model. The first phase proposes a Cloud Data Center Clustering algorithm to cluster the distributed cloud data centers based on their proximity. The second phase proposes a Client‐Cluster Assignment algorithm to perform uniform distribution of the client requests across the clusters to enable load balancing. To assess the performance, the proposed algorithms are compared with other K‐constrained graph‐based clustering algorithms namely, graph‐based K‐means and K‐spanning tree algorithms on a simulated distributed cloud data center environment. The experimental results reveal that the proposed CLB algorithm outperforms the compared algorithms in terms of the average clustering time, load distribution, and fairness index and hence improves the service delivery performance of the distributed cloud data centers.
Investigation of the antibacterial and antifungal activity of thiolated naphthoquinones
Authors: Wellington Kevin W. , Nyoka Nomgqibelo B. P. , McGaw Lyndy J. 
Published: January 2019

AbstractThe WHO has stated that antibiotic resistance is escalating to perilously high levels globally and that traditional therapies of antimicrobial drugs are futile against infections caused by resistant microorganisms. Novel antimicrobial drugs are therefore required. We report in this study on the inhibitory activity of the 1,4‐naphthoquinone‐2,3‐bis‐sulfides and 1,4‐naphthoquinone sulfides against two bacteria and a fungus to determine their antimicrobial properties. The 1,4‐naphthoquinone sulfides have potent activity with a minimum inhibitory concentration (MIC) of 7.8 μg/mL against Staphylococcus aureus (Gram +ve), an MIC of 23.4 μg/mL against the fungus, Candida albicans, which was better than that of Amphotericin B (MIC = 31.3 μg/mL), and against Escherichia coli (Gram −ve) an MIC of 31.3 μg/mL was obtained. The 1,4‐naphthoquinone had an MIC of 11.7 μg/mL against S. aureus and the 1,4‐naphthohydroquinone also had the same activity against E. coli.

Hit, Lead & Candidate Discovery
Using multiple data sources to investigate foraging niche partitioning in sympatric obligate avian scavengers
Authors: Byrne Michael E. , Holland Amanda E. , Turner Kelsey L. , Bryan A. Lawrence , Beasley James C. 
Published: January 2019

AbstractAs carrion feeders competing for a limited and ephemeral resource, avian scavengers are ideal model organisms to study mechanisms of niche partitioning. Previous work has focused on observations of species’ interactions at carcasses, and although fruitful, the inclusion of behavior beyond that at carcasses, such as movement patterns, could yield a more comprehensive understanding of mechanisms of foraging niche partitioning. Our goal was to assess how differences in physiological, morphological, and social characteristics between sympatric black vultures (Coragyps atratus) and turkey vultures (Cathartes aura) manifest interspecific variation in movement patterns, foraging habitats, and carcass use to reduce direct competition. Both species are obligate scavengers that co‐occur across much of the New World. Turkey vultures are solitary foragers with enhanced olfactory capabilities and wings optimized for energy‐efficient low‐altitude soaring. Black vultures are aggressive, heavier bodied, and forage socially. We assessed interspecific variation in carcass exploitation using experimental carcass trials encompassing a range of habitats, carcass sizes, and seasons, and used GPS telemetry to compare how soaring conditions influenced daily space use and diurnal patterns of movement activity for each species. Turkey vultures occurred more often at small (i.e., rabbit) carcasses, and those obscured by forest cover than black vultures, and were the first vultures recorded at 94% of carcasses visited by both species. Both species increased movement rates and daily ranges when soaring conditions were favorable; however, turkey vultures had higher travel rates regardless of soaring conditions. Our results suggest the olfactory sense of turkey vultures allows them to locate smaller and visually obscured carcasses more efficiently than black vultures, facilitated by wing morphology that allows them to forage over large areas efficiently. Socially foraging black vultures appear specialized at locating larger carcasses in open habitats, which does not require as much foraging flight as turkey vultures. Our study illustrates how inclusion of movement ecology into niche partitioning studies provides a more complete understanding of the mechanisms of coexistence in avian scavenger guilds. This approach may provide important information to guide conservation efforts, such as supplemental feeding, of imperiled vulture species.
A novel solution for real‐time wireless networks: Telehealth psychological services in rural area
Authors: Luitel P. , Alsadoon Abeer , Prasad P. W. C. , Al‐Janabi Shahd , Chapagain B. , Pham Linh , Hisham Alsadoon Omar 
Published: January 2019

AbstractTelehealth psychological services is a time‐efficient and cost‐effective therapy solution for persons in rural areas. The high congestion resulting from these infrastructure issues, which includes low‐bandwidth wireless connections and channels prone to data loss, tends to increase video delays, thereby making real‐time video transmission during telehealth psychological services challenging. The purpose of this study is, hence, to enable the successful implementation of telehealth psychological services in rural areas by minimising end‐to‐end video transmission delay and improving bandwidth efficiency. Our proposed system uses a distortion‐aware TCP‐friendly adaptive congestion control algorithm that adapts the congestion window size according to path characteristics and quality. Indeed, evaluation results show that our algorithm—as compared to a reference—significantly improves peak signal‐to‐noise ratio and end‐to‐end delay; thus, suggesting that the adoption of an adaptive congestion window size in our system can improve network bandwidth efficiency and reduce information delay resulting from packet queuing and unnecessary packet loss. The outcome is successful high‐definition video transmission during telehealth psychological services.
Experimental studies on characteristics of fire whirl in a vertical shaft
Authors: Gao Zheming , Li Shusheng , Gao Ye , Chow Wan Ki 
Published: January 2019

SummaryAn internal fire whirl can be generated readily in a tall shaft model with appropriate gap width at one corner. Experimental study was carried out to investigate the relationship between the characteristics of an IFW and the corner gap width in a 9‐m‐tall vertical shaft model. The vertical shaft had a 2.1 m by 2.1 m square section with gasoline pool fire of different diameters burning inside. The gap width was varied to investigate its impact on fire whirl characteristics, such as flame development, swirling intensity, flame height, flame temperature, and heat release rate of the gasoline pool fire. Vigorous flame swirling motions were generated when the ratio of the gap width to the shaft section perimeter was within the range 0.16 to 0.21. From the flame streamline angle, it was observed that the swirling component was much stronger than buoyancy component near the bottom of burning region. The swirling component decreased and became roughly the same as buoyancy near the middle. Finally, it diminished to being much weaker than buoyancy near the top of the fire. These observations suggest that the Froude number Fr decreased from a large number to 1, and then continued to decrease to 0.
Electronic Raman scattering as a probe for investigating interactions between impurities in silicon
Authors: Stavrias N. , Spizzirri P.G. , Prawer S. 
Published: January 2019

AbstractElectronic Raman scattering (ERS) is investigated as a probe for interactions between impurities in silicon. We report ERS measurements of donors (P, Sb, and As) and acceptors (B) at various concentrations and measurements at various illumination wavelengths. The difference between above and below indirect band gap measurement is discussed in terms of the difficulties of using ERS as a localised probe. We extend the previous literature on impurity interactions of Si:P in the bulk to include Sb and B and demonstrate that the perturbation of the observed ERS transition energy resulting from wavefunction overlap of nearest neighbours is opposite for donors and acceptors. Finally, we model the magnitude of the shift to the first order as a function of the mean impurity atom separation.
Phase transformations of bovine serum albumin: Evidences from Rayleigh‐Brillouin light scattering
Authors: Dmitriev A.V. , Vashchenkov V.E. , Fedoseev A.I. , Lushnikov S.G. 
Published: January 2019

AbstractRayleigh‐Brillouin light‐scattering studies of a high‐concentration solution of bovine serum albumin (BSA, pH = 7.45, C = 100 mg/ml) in a sodium phosphate buffer in the temperature range 300–370 K are presented. It is shown that the temperature dependences of relative changes in the Brillouin shift and half width at half maximum and intensity of the Brillouin doublet and intensity of Rayleigh components exhibit anomalies in the vicinity of 335, 345, and 363 K. Analysis of the literature data allowed us to construct a phase diagram showing a sequence of BSA phase transformations in the temperature range from 300 to 375 K and to correlate the anomalies in the scattering spectra to the regions of phase transformations. The anomalies in the behavior of the light‐scattering spectra in the vicinity of Tm = 335 K are attributable to the melting temperature and the formation of BSA self‐assembled aggregates. The formation of a phase with oriented β‐sheet rich mature fibrils at Tm < T < 347 K is confirmed by elastic light scattering experiments. This phase passes into a gel‐like phase in which the aggregates are rearranged and a polymer network, which is finally converted to a gel in the vicinity of 363 K is formed. Thus, the Rayleigh‐Brillouin scattering experiments demonstrated the evolution of the structure, which manifested itself in the anomalous temperature behavior of the intensities of the Rayleigh and Brillouin components in the light‐scattering spectra. The anomalous low‐frequency dynamics of the BSA solution at denaturing and transition into a gel phase was clearly observed in the anomalous Brillouin shift behavior in the vicinity of 335 and 363 К. The sequence of phase transformations in BSA at heating from 300 to 375 K in the phase diagram correlates well with the anomalies observed in the evolution of Rayleigh‐Brillouin light scattering.
Variation of heavy metal contamination between mushroom species in the Copperbelt province, Zambia: are the people at risk?
Authors: Chungu Donald , Mwanza Alstone , Ng'andwe Phillimon , Chungu Bertha Chitala , Maseka Kenneth 
Published: January 2019

AbstractBACKGROUNDHeavy metal contamination in mushrooms and the associated health risk are unknown in Zambia. We studied seven heavy metals and 23 mushroom species and interviewed 400 people.RESULTSMushrooms were found to contain substantial concentrations of Cu (894.4 ± 267.9 µg g−1) and Fe (998.4 ± 454.0 µg g−1). Significant differences in transfer factors of metals occurred between mushroom species (F11,66 = 5.36, P < 0.001). The most efficient were L. kabansus (for Zn and Ni), A. miomboensis (for Cu and Fe) and T. clypeatus (for Mn, Pb and Co). These species were also among the most preferred mushrooms for consumption based on the interviews conducted. Although 60% of the mushrooms observed were edible, only 20% were frequently consumed during the mushroom season. High positive correlations observed between soils and mushrooms suggest that contamination in mushrooms increases with soil pollution. The estimated daily intake of metals and the target hazard quotient through mushroom consumption were found to be significantly influenced by mushroom species (F11,66 = 38.8, P < 0.001) suggesting that the level of exposure to heavy metals depends on the species of mushroom consumed.CONCLUSIONSThe study has revealed that heavy metal concentrations in mushrooms exceed permissible limits and vary between species. Transfer efficiency also varies between mushroom species and contamination in mushrooms increases with soil pollution. The fact that concentrations of metals in soil were significantly high, the risk of exposure through mushroom consumption and possibly soil ingestion is even higher. © 2019 Society of Chemical Industry
Application of the Hepatic Transit Time (HTT) in Evaluation of Portal Vein Pressure in Gastroesophageal Varices Patients
Authors: Lin Yuan‐Qiang , Jiang Bo , Li He‐Qun , Jin Chun‐Xiang , Wang Hui 
Published: January 2019

ObjectivesTo analyze the clinical significance of using hepatic transit time (HTT) to evaluate portal vein pressure in gastroesophageal varices patients.MethodsFor the observation group, we enrolled 50 gastroesophageal varices patients who had received esophagogastric variceal embolization in our hospital between January 2015 and February 2018. Patients without liver disease populated the control group and were recruited during the same time period. All patients underwent contrast‐enhanced sonography. In the observation group, free portal pressure (FPP) was detected during esophagogastric variceal embolization with ultrasound guidance. Differences in hepatic artery–hepatic vein transit time (HA‐HVTT), portal vein–hepatic vein transit time (PV‐HVTT), and parenchyma–hepatic vein transit time (PA‐HVTT) were compared between groups. Correlations between HA‐HVTT, PV‐HVTT, PA‐HVTT, and FPP in the observation group were analyzed using the Pearson coefficient and linear regression analysis.ResultsHA‐HVTT (t = 5.078; P < .001), PV‐HVTT (t = 12.163; P < .001), and PA‐HVTT (t = 2.649; P = .009) within the observation group were significantly lower than those of the control group. The areas under the curve of HTT were 0.771 (HA‐HVTT), 0.951 (PV‐HVTT), and 0.652 (PA‐HVTT), and the sensitivity and specificity of PV‐HVTT at 7.99 seconds were 86.0% and 88.0%, respectively. The HA‐HVTT (r = –0.799; P < .001), PV‐HVTT (r = –0.554; P < .001), and PA‐HVTT (r = –0.735; P < .001) negatively correlated to FPP in the observation group. Linear regression analysis showed y = –0.410x + 7.254 (HA‐HVTT and FPP), y = –0.335x + 4.983 (PV‐HVTT and FPP), and y = –0.566x + 4.997 (PA‐HVTT and FPP) in the observation group.ConclusionCompared with the control patients, the HTT of patients with portal hypertension–esophagogastric varices was significantly shorter, and showed an inverse relationship with FPP.
Investigation of Radiofrequency Ultrasound‐Based Fibrotic Tissue Strain Imaging Method Employing Endogenous Motion
Authors: Sakalauskas Andrius , Jurkonis Rytis , Gelman Sigita , Lukoševičius Arūnas , Kupčinskas Limas 
Published: January 2019

ObjectivesThe paper presents the results of an initial clinical study, which were obtained using the strain elastography imaging method based on radio frequency ultrasound signal analysis.MethodsThe technique employs endogenous motion of the liver induced by beating heart and vascular pulsatility as an excitation source of tissue microdisplacement. The potential for fibrotic tissue characterization was demonstrated using a clinical data set of radio frequency ultrasound signals (23 healthy controls, 21 subjects with hepatitis, and 16 subjects with liver cirrhosis). Parametric maps, which represent the tissue strain, were derived from the gradient of the integrated spectral coefficient parameter, and correlations with the stage of liver disease were evaluated. Average endogenous strain derived from the gradient of the integrated spectral coefficient parameter and variability (standard deviation) of the strain were evaluated in the rectangular regions of interest (sizes, 1 × 1 and 2 × 2 cm) defined by the observer. The assessment of strain was performed in different frequency subbands of endogenous motion (0–10 Hz and 10–20 Hz).ResultsThe best distinction between the groups was observed for the average strain derived from the gradient of the integrated spectral coefficient parameter: the controls, 13.30 ± 6.62; hepatitis, 7.12 ± 7.45; cirrhosis, 3.95 ± 2.44 μm/cm (region of interest, 1 × 1 cm; frequency subband 0–10 Hz), and 10.48 ± 6.02, 8.27 ± 5.41, 3.89 ± 2.07 μm/cm, respectively (2 × 2 cm, 0–10 Hz).ConclusionThe investigated strain parameters showed statistically significant differences (P < .001) for the different stages of liver fibrosis in most of the cases and proved this method to be feasible.
To tell or not to tell? The roles of perceived norms and self‐consciousness in understanding consumers' willingness to recommend online secondhand apparel shopping
Authors: Lo Carolyn J. , Tsarenko Yelena , Tojib Dewi 
Published: January 2019

AbstractSecondhand apparel shopping resides in a domain characterized by used goods traditionally associated with financially marginalized consumers. Acknowledging the elusive psychological barriers associated with preowned apparel, this study explores mechanisms that facilitate consumers' willingness to recommend online secondhand apparel shopping. Results from three experimental studies and a cross‐sectional survey of online secondhand shoppers in the United States reveal that hedonic and ethical benefits influence recommendation behavior via perceived norms, whereas economic benefit directly influences consumers' willingness to recommend. Moderated mediation analyses further demonstrate that self‐consciousness alters the strength of the indirect effects, such that consumers with lower self‐consciousness displayed greater willingness to recommend compared to highly self‐conscious consumers. Findings contribute to a greater theoretical understanding of the roles perceived norms and self‐consciousness play in facilitating or inhibiting recommendation behavior in a context that implicitly involves self‐disclosure of one's secondhand purchase behavior. Managerial implications offer insights on salient benefits that can be leveraged to influence word‐of‐mouth recommendation.