bluuebunny/crossref_metadata_2025 huggingface dataset:
Strong complexation of water‐soluble betulin derivatives with (2‐hydroxypropyl)‐γ‐cyclodextrin studied by affinity capillary electrophoresis
Authors: Sursyakova Viktoria V. , Levdansky Vladimir A. , Rubaylo Anatoly I.
Published: October 2019

The complexation between (2‐hydroxypropyl)‐γ‐cyclodextrin (HP‐γ‐CD) and water‐soluble betulin derivatives, betulin 3,28‐disulfate (DSB) and betulin 3‐acetate‐28‐sulfate (ASB), belonging to the class of pentacyclic lupane triterpenoids, was studied using mobility shift ACE (ms ACE). It was found that the complexation is a high‐affinity interaction. In this case, a very low amount of HP‐γ‐CD should be added to the BGE, and triangular peaks are observed as a result of ligand deficiency in the sample zone. Le Saux et al. showed in 2005 that using the parameter a1 of the Haarhoff‐Van der Linde (HVL) function instead of the migration time measured at the peak apex eliminates the effect of ligand deficiency on effective electrophoretic mobility. Therefore, the electrophoretic mobilities of asymmetrical peaks of DSB and ASB were calculated in this way. The obtained experimental data correspond to 1:1 complexes. The calculated values of binding constants logarithms at 25°C are 6.70 ± 0.05 and 7.03 ± 0.10 for the HP‐γ‐CD complexes of DSB and ASB, respectively.
Mathematical modeling of mass transfer in supercritical fluid extraction of patchouli oil
Authors: Soh Soon Hong , Agarwal Shuchi , Jain Akshay , Lee Lai Yeng , Chin Siew Kian , Jayaraman Sundaramurthy
Published: October 2019

Patchouli oil is a high‐value essential oil used in cosmetic, food, and pharmaceutical industries. In this work, supercritical fluid extraction of patchouli oil with various operating process parameters (pressure, temperature, flow rate, and particle size) were studied and the results were modeled using the broken and intact cell model (BICM). From the experimental studies, it was found that the extraction rate was improved at higher pressures and flow rates, where the mass transfer resistances in the liquid and solid phase were decreased; however, the increase in temperature had an inverse effect on extraction rate and mass transfer. In the case of particle size, a moderate size of 0.3 to 0.6 mm gave the optimal extraction rate. The BICM predictions showed good agreements with experimental data and gave valuable insights regarding the mass transfer mechanism of the extraction process, including mass transfer coefficients and extraction periods governed by convection and diffusion.
Seismic vulnerability of offshore wind turbines to pulse and non‐pulse records
Authors: Ali Ahmer , De Risi Raffaele , Sextos Anastasios , Goda Katsuichiro , Chang Zhiwang
Published: October 2019

The increasing number of wind turbines in active tectonic regions has attracted scientific interest to evaluate the seismic vulnerability of offshore wind turbines (OWTs). This study aims at assessing the deformation and collapse susceptibility of 2MW and 5MW OWTs subjected to shallow‐crustal pulse‐like ground motions, which has not been particularly addressed to date. A cloud‐based fragility assessment is performed to quantify the seismic response for a given intensity measure and to assess the failure probabilities for pulse‐like and non‐pulse‐like ground motions. The first‐mode spectral acceleration Sa(T1) is found to be an efficient response predictor for OWTs, exhibiting prominent higher‐mode behavior, at the serviceability and ultimate conditions. Regardless of earthquake type, it is shown that records with strong vertical components may induce nonlinearity in the supporting tower, leading to potential failure by buckling in three different patterns: (i) at tower base near platform level, (ii) close to tower top, and (iii) between the upper half of the main tower and its top. Type and extent of the damage are related to the coupled excitation of vertical and lateral higher modes, for which tower top acceleration response spectra Sa,i(Top) is an effective identifier. It is also observed that tower's slenderness ratio (l/d), the diameter‐to‐thickness ratio (d/t), and the rotor‐nacelle‐assembly mass (mRNA) are precursors for evaluating the damage mode and vulnerability of OWTs under both pulse‐like and non‐pulse‐like ground motion records.
Deformation of granitic rocks within Derbugan Fault belt, Erguna Massif, Northeast China: Implication of the subduction of Mongol‐Okhotsk oceanic plate
Authors: Liang Chenyue , Liu Yongjiang , Zheng Changqing , Li Wei , Li Weimin , Neubauer Franz , Zhang Qian , Chen Zhaoxu , Zhang Duo
Published: October 2019

The NE–SW striking Derbugan Fault has been comprehensively accepted as a Mesozoic strike‐slip fault in Erguna Massif rather than a suture belt of Erguna and Xing'an massifs. The rocks exposed within the fault belt, which consist of Jiageda Formation and intrusions which have been multiply deformed and metamorphosed. These deformed rocks provide an ideal opportunity to understand the geodynamics of the uplift history and tectonic evolution of Derbugan Fault in Mongol‐Okhotsk regime and influence of the circum‐Pacific tectonic regime, particularly during the later stages of the Mongol‐Okhotsk Ocean collision. In this study, we report kinematics, meso‐microstructures, quartz EBSD analysis and geochronology data of the Jiageda Formation exposed within the Derbugan Fault belt in Cuogang area, Erguna Massif. The Jiageda Formation and granitic rocks have experienced regional metamorphism and deformation, and is mainly characterised by simple‐shear dominated general shearing with LS tectonites. Our new zircon U‐Pb data of mylonitic rocks from Cuogang area yielded ages between 381 to 401 Ma which was produced as a result of the subduction of the Paleo‐Asian Ocean. Deformed granitic intrusive formed in the Early Triassic (244.8 ± 5.6 Ma) was related to the southward subduction of the Mongol‐Okhotsk oceanic plate beneath the Erguna Massif. The Derbugan Fault represents a ductile to brittle deformation at decreasing crustal level due to the dominant oblique (subhorizontal) slip. The early sinistral strike‐slip deformation with a medium temperature between 450 and 550°C developed at a deep ductile regime resulted from NW–SE extension. The subsequent deformation was essentially brittle that corresponded to a low‐temperature deformation corresponded to a greenschist metamorphic facies. Crystallographic textures indicate a restricted recrystallisation of quartz mainly via dislocation creep through activation prismatic  slip and rhomb  slip system, with a later activation of basal  slip system. The Early Cretaceous extensional environment may consist with the main medium temperature deformation stage of Derbugan Fault, which was related to either delamination or upwelling of the thickened lithosphere of the Mongol‐Okhotsk tectonic regime, and rollback of the Paleo‐Pacific Plate.
NF‐E2‐related factor 2 activation boosts antioxidant defenses and ameliorates inflammatory and amyloid properties in human Presenilin‐1 mutated Alzheimer's disease astrocytes
Authors: Oksanen Minna , Hyötyläinen Ida , Trontti Kalevi , Rolova Taisia , Wojciechowski Sara , Koskuvi Marja , Viitanen Matti , Levonen Anna‐Liisa , Hovatta Iiris , Roybon Laurent , Lehtonen Šárka , Kanninen Katja M. , Hämäläinen Riikka H. , Koistinaho Jari
Published: October 2019

Alzheimer's disease (AD) is a common dementia affecting a vast number of individuals and significantly impairing quality of life. Despite extensive research in animal models and numerous promising treatment trials, there is still no curative treatment for AD. Astrocytes, the most common cell type of the central nervous system, have been shown to play a role in the major AD pathologies, including accumulation of amyloid plaques, neuroinflammation, and oxidative stress. Here, we show that inflammatory stimulation leads to metabolic activation of human astrocytes and reduces amyloid secretion. On the other hand, the activation of oxidative metabolism leads to increased reactive oxygen species production especially in AD astrocytes. While healthy astrocytes increase glutathione (GSH) release to protect the cells, Presenilin‐1‐mutated AD patient astrocytes do not. Thus, chronic inflammation is likely to induce oxidative damage in AD astrocytes. Activation of NRF2, the major regulator of cellular antioxidant defenses, encoded by the NFE2L2 gene, poses several beneficial effects on AD astrocytes. We report here that the activation of NRF2 pathway reduces amyloid secretion, normalizes cytokine release, and increases GSH secretion in AD astrocytes. NRF2 induction also activates the metabolism of astrocytes and increases the utilization of glycolysis. Taken together, targeting NRF2 in astrocytes could be a potent therapeutic strategy in AD.
Marangoni convective nanofluid flow over an electromagnetic actuator in the presence of first‐order chemical reaction
Authors: Rasool Ghulam , Shafiq Anum , Tlili Iskander
Published: October 2019

The present study aims to investigate Marangoni‐forced convective nanofluid flow over an electromagnetic actuator (Riga plate). A first‐order homogeneous chemical reaction is considered. The thermocapillary and solutocapillary Marangoni effect developed by the surface tension is considered as a driving force for the nanofluid. In addition, Grinberg‐term is accounted to involve the impact of Lorentz force impinged by the actuator in the model. A set of nonlinear ordinary differential equations is obtained via suitable transformations for a nonsimilar analysis. Series solutions are achieved through homotopy to discuss the behavior of the velocity field, thermal distribution, and concentration of the nanoparticles graphically. The variation in Nusselt and Sherwood numbers is discussed. The outcomes declared that the flow parallel to the surface of the plate is assisted by the Lorentz forces generated by electromagnetic bars of the actuator resulting in an enhancement in the fluid motion. Furthermore, the stronger Marangoni effect resulted in the declining trend of the temperature profile. The concentration of nanoparticles near the surface reduced intensive chemical reaction inside the nanofluid.
A semianalytical formula for European options under a hybrid Heston–Cox–Ingersoll–Ross model with regime switching
Authors: He Xin‐Jiang , Chen Wenting
Published: October 2019

In this paper, we consider the pricing of European options under a regime‐switching Heston–Cox–Ingersoll–Ross (CIR) hybrid model, where the mean‐reversion levels of both the stochastic volatility and interest rate are assumed to change among different states. Albeit difficult, we have still managed to derive an semianalytical pricing formula for European options after the generalized moment generating function of this particular model is worked out. Numerical experiments are also carried out to demonstrate the accuracy of the newly derived formula as well as the influence of the introduction of the regime‐switching mechanics on option prices. Finally, through a preliminary empirical study, our model is shown to be superior to the Heston‐CIR model, which demonstrates the importance of introducing the regime‐switching mechanics.
Effects of Long-Duration Spaceflight on Vertebral Strength and Risk of Spine Fracture
Authors: Burkhart Katelyn , Allaire Brett , Anderson Dennis E , Lee David , Keaveny Tony M , Bouxsein Mary L
Published: October 2019

Although the negative impact of long-duration spaceflight on spine BMD has been reported, its impact on vertebral strength and risk of vertebral fracture remains unknown. This study examined 17 crewmembers with long-duration service on the International Space Station in whom computed tomography (CT) scans of the lumbar spine (L1 and L2) were collected preflight, immediately postflight and 1 to 4 years after return to Earth. We assessed vertebral strength via CT-based finite element analysis (CT-FEA) and spinal loading during different activities via subject-specific musculoskeletal models. Six months of spaceflight reduced vertebral strength by 6.1% (−2.3%, −8.7%) (median [interquartile range]) compared to preflight (p < 0.05), with 65% of subjects experiencing deficits of greater than 5%, and strengths were not recovered up to 4 years after the mission. This decline in vertebral strength exceeded (p < 0.05) the 2.2% (−1.3%, −6.0%) decline in lumbar spine DXA-BMD. Further, the subject-specific changes in vertebral strength were not correlated with the changes in DXA-BMD. Although spinal loading increased slightly postflight, the ratio of vertebral compressive load to vertebral strength for typical daily activities remained well below a value of 1.0, indicating a low risk of vertebral fracture despite the loss in vertebral strength. However, for more strenuous activity, the postflight load-to-strength ratios ranged from 0.3 to 0.7, indicating a moderate risk of vertebral fracture in some individuals. Our findings suggest persistent deficits in vertebral strength following long-duration spaceflight, and although risk of vertebral fracture remains low for typical activities, the risk of vertebral fracture is notable in some crewmembers for strenuous exercise requiring maximal effort. © 2019 American Society for Bone and Mineral Research.
miR‐98‐5p promotes apoptosis and inhibits migration and cell growth in papillary thyroid carcinoma through Bax/Caspase‐3 by HMGA2
Authors: Qiu Kai , Xie QingJi , Jiang Shan , Lin Ting
Published: October 2019

Background

The aims of this study were to investigate the function and mechanism of miRNA‐98‐5p in papillary thyroid carcinoma.

Methods

Quantitative real‐time polymerase chain reaction (qRT‐PCR) was used to measure the expression of miRNA‐98‐5p in papillary thyroid carcinoma. Western blotting and caspase‐3/9 activity levels, flow cytometric analysis, cell migration assays, DAPI assay, cell proliferation assay, and LDH activity levels were used in this study.

Results

In patient with papillary thyroid carcinoma, miRNA‐98‐5p was reduced, and HMGA2 was increased. Downregulation of miRNA‐98‐5p promoted the cell growth, inhibited apoptosis, and induced HMGA2 protein expression in papillary thyroid carcinoma cell via activation of HMGA2. Overexpression of miRNA‐98‐5p inhibited the cell growth, induced apoptosis, and suppressed HMGA2 protein expression in papillary thyroid carcinoma cell through the suppression of HMGA2. Si‐HMGA2 inhibited the effects of anti‐miRNA‐98‐5p on cell growth of papillary thyroid carcinoma.

Conclusion

Therefore, these results suggested the regulation of HMGA2 suppresses proliferation of papillary thyroid carcinoma through miRNA‐98‐5p.
Neuroserpin regulates human T cell-T cell interactions and proliferation through inhibition of tissue plasminogen activator
Authors: Loef Evert Jan , Brooks Anna E.S. , Lorenz Natalie , Birch Nigel P. , Dunbar P. Rod
Published: October 2019

T cells play a key role in mounting an adaptive immune response. T cells are activated upon recognition of cognate Ag presented by an APC. Subsequently, T cells adhere to other activated T cells to form activation clusters, which lead to directed secretion of cytokines between communicating cells. T cell activation clusters have been implicated in regulating activation, proliferation, and memory formation in T cells. We previously reported the expression of the protease inhibitor neuroserpin by human T cells and showed that expression and intracellular localization is regulated following T cell activation. To gain a better understanding of neuroserpin in the proteolytic environment postactivation we assessed its role in human T cell clustering and proliferation. Neuroserpin knockdown increased T cell proliferation and cluster formation following T cell activation. This increased cluster formation was dependent on the proteases tissue plasminogen activator (tPA) and plasmin. Furthermore, neuroserpin knockdown or plasmin treatment of T cells increased the cleavage of annexin A2, a known plasmin target that regulates the actin cytoskeleton. Live cell imaging of activated T cells further indicated a role of the actin cytoskeleton in T cell clustering. The inhibition of actin regulators myosin ATPase and Rho-associated protein kinase signaling completely reversed the neuroserpin knockdown-induced effects. The results presented in this study reveal a novel role for neuroserpin and the proteolytic environment in the regulation of T cell activation biology.
Cardiac‐Related Pulsatility in the Insula Is Directly Associated With Middle Cerebral Artery Pulsatility Index
Authors: Atwi Sarah , Robertson Andrew D. , Theyers Athena E. , Ramirez Joel , Swartz Richard H. , Marzolini Susan , MacIntosh Bradley J.
Published: October 2019

Background

Arterial stiffness in large arteries is a risk factor for cerebral small vessel disease and neurodegeneration. The challenge of accessing intracranial pulsatility noninvasively is one reason few studies provide empirical insight on the relationship between large artery and tissue pulsatility in the human brain.

Purpose

To investigate the association between the functional magnetic resonance imaging (fMRI)‐derived cardiac‐related pulsatility in the insular cortex and the ultrasound‐derived pulsatility index in the middle cerebral artery (MCA‐PI).

Study Type

Cross‐sectional.

Population

Younger adults (11; 25 ± 4 years) and older adults with and without cardiovascular risk factors (44; 70 ± 6 years).

Field Strength/Sequence

T1‐weighted, fluid attenuated inversion recovery, and T2*‐weighted blood oxygenation level‐dependent (BOLD) sequences at 3T.

Assessment

MCA‐PI and cardiac‐related pulsatility were assessed at rest by transcranial Doppler ultrasound and BOLD fMRI, respectively.

Statistical Tests

Multivariate analyses of covariance between MCA‐PI and cardiac‐related pulsatility. Analysis of variance was used to assess regional differences.

Results

MCA‐PI was associated with cardiac‐related insular pulsatility (P = 0.037), but not whole‐brain pulsatility (P = 0.81). Left insular pulsatility was higher than right insular pulsatility (P < 0.01) and was associated with diastolic blood pressure (P = 0.028).

Data Conclusion

We show a correlation between ultrasound and fMRI measures of cerebrovascular pulsatility. This association provides insight into the transmission of pulsatile energy from large basal arteries at the Circle of Willis to downstream cerebrovascular beds and has implications for the utility of cardiac‐related pulsatility as a potential marker for cerebral small vessel disease.

Level of Evidence: 4

Technical Efficacy: Stage 3

J. Magn. Reson. Imaging 2020;51:1454–1462.
Study of the noncovalent interactions of ginsenosides and amyloid‐β‐peptide by CSI‐MS and molecular docking
Authors: Zhou Yanan , Chen Su , Qiao Jinping , Cui Yanyun , Yuan Chang , He Lan , Ouyang Jin
Published: October 2019

Noncovalent interactions between drugs and proteins play significant roles for drug metabolisms and drug discoveries. Mass spectrometry has been a commonly used method for studying noncovalent interactions. However, the harsh ionization process in electrospray ionization mass spectrometry (ESI‐MS) is not conducive to the preservation of noncovalent and unstable biomolecular complexes compared with the cold spray ionization mass spectrometry (CSI‐MS). A cold spray ionization providing a stable solvation‐ionization at low temperature is milder than ESI, which was more suitable for studying noncovalent drug‐protein complexes with exact stoichiometries. In this paper, we apply CSI‐MS to explore the interactions of ginsenosides toward amyloid‐β‐peptide (Aβ) and clarify the therapeutic effect of ginsenosides on Alzheimer's disease (AD) at the molecular level for the first time. The interactions of ginsenosides with Aβ were performed by CSI‐MS and ESI‐MS, respectively. The ginsenosides Rg1 bounded to Aβ at the stoichiometries of 1:1 to 5:1 could be characterized by CSI‐MS, while dehydration products are more readily available by ESI‐MS. The binding force depends on the number of glycosyls and the type of ginsenosides. The relative binding affinities were sorted in order as follows: Rg1 ≈ Re > Rd ≈ Rg2 > Rh2, protopanaxatriol by competition experiments, which were supported by molecular docking experiment. CSI‐MS is expected to be a more appropriate approach to determine the weak but specific interactions of proteins with other natural products especially polyhydroxy compounds.
Predictability of the rainy season onset date in Central Highlands of Vietnam
Authors: Pham‐Thanh Ha , van der Linden Roderick , Ngo‐Duc Thanh , Nguyen‐Dang Quang , Fink Andreas H. , Phan‐Van Tan
Published: October 2019

In this study, different criteria to determine the rainy season onset date (RSOD) and its predictability in the Central Highlands (CH) of Vietnam are investigated. Using daily rainfall amounts from 10 meteorological stations for the period 1981–2015, four criteria to determine the RSOD were tested in order to select the one that most reasonably depicts the climatology of the RSOD over the CH. Results show that the RSOD varies strongly from year to year. In the long‐term mean, the onset starts first in southern parts of the CH and then progresses to the northern parts. The earliest onset date is around the beginning of April, and the latest in the second half of May. The average RSOD is on 28 April with a standard deviation of 14 days. Thus, the RSOD is distinct from the summer monsoon onset, namely, leading the mean summer monsoon onset by about 3 weeks in some years. In terms of remote influences, the RSOD in the CH has a high correlation with the El Niño–Southern Oscillation phenomenon, with most RSODs being later during El Niño years, while being earlier during La Niña years. The RSOD in the CH also shows high correlations with sea surface temperatures (SSTs), 850‐hPa zonal winds (U850) and mean sea level pressures (PMSL) over certain regions of the Pacific and Indian Oceans. Building on these relationships, the RSOD can be successfully predicted using large‐scale fields of SST, U850 and PMSL as predictors in two different approaches, namely the field mean and principal component analysis. This suggests that the overall approach can also be applied in predicting the RSOD in the CH on sub‐seasonal to seasonal timescales.
The significance of surgically modifying soft tissue phenotype around fixed dental prostheses: An American Academy of Periodontology best evidence review
Authors: Lin Guo‐Hao , Curtis Donald A. , Kapila Yvonne , Velasquez Diego , Kan Joseph Y.K. , Tahir Peggy , Avila‐Ortiz Gustavo , Kao Richard T.
Published: October 2019

Background

This systematic review endeavored to investigate the effect of soft tissue phenotype modification therapy (PhMT‐s) at sites with a tooth or an implant supported fixed dental prosthesis.

Methods

A comprehensive literature search was conducted by two independent examiners to identify relevant studies reporting differences in clinical, esthetic, or radiographic outcomes of interest between sites underwent PhMT‐s and sites that remained untreated. Risk of bias assessment was calculated for all included studies. Meta‐analyses involving endpoints of interest were performed when feasible.

Results

No controlled studies pertaining to tooth sites were identified. A total of six articles reporting on the outcomes of buccal soft tissue phenotype modification around implants were selected, of which, five were included in the meta‐analyses. Quantitative analyses showed a weighted mean difference (WMD) of 0.98 mm (95% CI = 0.25 to 1.72 mm, P = 0.009) for change of tissue thickness; a WMD of −4.87% (95% CI = −34.27 to 24.53%, P = 0.75) for bleeding on probing (BOP); a WMD of 0.36 mm (95% CI = 0.12 to 0.59 mm, P = 0.003) for mucosal recession (MR); a WMD of 0.13 mm (95% CI = −0.11 to 0.36 mm, P = 0.30 for probing depth (PD); a WMD of 1.08 (95% CI = −0.39 to 2.55, P = 0.15) for pink esthetic score (PES), and a WMD of 0.40 mm (95% CI = −0.34 to 1.14 mm, P = 0.28) for marginal bone loss (MBL).

Conclusions

Surgical modification of peri‐implant soft tissue phenotype via PhMT‐s may decrease the amount of MR. Future clinical trials are needed to warrant the clinical benefits of modifying soft tissue phenotype around tooth‐supported restorations.
Chicken Tallow, a Renewable Source for the Production of Biosurfactant by Yarrowia lipolytica MTCC9520, and its Application in Silver Nanoparticle Synthesis
Authors: Radha Panjanathan , Suhazsini Priya , Prabhu Keerthana , Jayakumar Anjali , Kandasamy Ramani
Published: October 2019

The present study is focused on the production of a biosurfactant using Yarrowia lipolytica MTCC 9520 by employing inexpensive lipid waste, chicken tallow from slaughterhouses. Plackett–Burman and Box–Behnken Design analyses were adopted for preliminary screening of medium variables and further optimization. The maximal yield of 4.4 g L−1 of the biosurfactant was obtained from the optimized medium. The highest emulsification activity was found to be 55%, and the surface tension decreased to 37 mN m−1 at the end of 96 h. The critical micelle concentration of the biosurfactant was calculated as 1.2%. The produced biosurfactant was characterized as cationic lipoprotein in type, and the proteins present in the biosurfactant were observed to have molecular weights between 75 and 100 kDa. The fatty acids composition of the biosurfactant was detected by gas chromatography–mass spectrometry (GC–MS) analysis. Fourier transform infra red (FTIR) and nuclear magnetic resonance (NMR) analysis confirmed the lipoprotein nature of the extracted biosurfactant. Thermogravimetric (TG) and differential scanning calorimetry (DSC) analysis revealed the thermostable nature of the extracted biosurfactant. Surface plasmon resonance vibration peak at 421 nm was observed for the surfactant‐stabilized silver nanoparticles (AgNP) through UV–Vis spectrophotometry. The average particle size of the synthesized AgNP was calculated as 7.2 ± 0.4 nm from transmission electron microscopy (TEM) analysis. Energy dispersive x‐ray (EDX) spectroscopy exhibited the presence of silver in the synthesized nanoparticles. The zeta potential value of the synthesized AgNP was measured as −22.2 mV, and the polydispersity index was found as 2.3 through dynamic light scattering (DLS) analysis.
Effect of Fe:ligand ratios on hydroponic conditions and calcareous soil in Solanum lycopersicum L. and Glycine max L. fertilized with heptagluconate and gluconate
Authors: Islas‐Valdez Samira , López‐Rayo Sandra , Arcos Jessica , Menéndez Nieves , Lucena Juan J.
Published: October 2019

BACKGROUND

The environmental risk from the application of synthetic chelates has led to the use of biodegradable complexes to correct Fe deficiency in plants. In this article, the Fe oxidation state, the Fe:ligand ratio, and the molecular weight distribution for heptagluconate (G7) and gluconate (G6) are considered as key factors for the efficacy of complexes as fertilizers. Complexes with different Fe:ligand ratios were prepared and analyzed by gel filtration chromatography (GFC). The ability of Fe:ligand ratios to provide Fe to tomato in hydroponics and soybean in calcareous soil was tested and compared with synthetic chelates (Fe3+:HBED and Fe3+:EDTA).

RESULTS

G7 presented greater capacity to complex both Fe(II) and Fe(III) than G6, but the Fe(II) complexes exhibited poor stability at pH 9 and oxidation in solution. Gel filtration chromatography demonstrated the polynuclear nature of the Fe3+:G7 at various ratios. The effectiveness of the Fe fertilizers depend on the Fe3+:ligand ratio and the ligand type, the Fe3+:G7 (1:1 and 1:2) being the most effective. Fe3+:G7 (1:1) also presented a better response for the uptake of other micronutrients.

CONCLUSION

Fe3+:G7 molar ratios have been shown to be critical for plant Fe uptake under hydroponic conditions and with calcareous soil. Thus, the Fe3+:G7 at equimolar ratio and 1:2 molar ratio can be an environmentally friendly alternative to less degradable synthetic chelates to correct Fe chlorosis in strategy I plants. © 2019 Society of Chemical Industry
Overcoming latency with motion prediction in directional autostereoscopic displays
Authors: Zhang Hantao , Chen Mingjun , Li Xiaoke , Li Kunyang , Chen Xuehao , Wang Jiahui , Liang Haowen , Zhou Jianying , Liang Weitang , Fan Hang , Ding Ruijie , Wang Shuying , Deng Dongyan
Published: October 2019

Imaging delivering to correct retina assisted with tracking technique is a common practice for autostereoscopic displays with stereo two‐view data format. Due to various latencies produced in camera buffering, computer processing, data transmission, and illumination refreshing, delayed image delivery will give rise to a substantial degradation of the 3D display experience. This is particularly obvious for directional backlight 3D displays where significant flickering is resulted as a result of the inherent latency. This work systematically analyzes the source of latency by quantitatively measuring the exact latency value in a typical directional backlight autostereoscopic display. Based on accurate measurement, a motion prediction solution is proposed to improve the synchronization between the backlight illumination and viewer's eye location. Motion prediction helps overcome the lag between the center of illumination and viewer's eye, providing a flicker‐free viewing experience for both a stationary and a moving viewer.
Chromatographic identification of “green capping agents” extracted from Nasturtium officinale (Brassicaceae) leaves for the synthesis of MoO3 nanoparticles
Authors: Shaheen Irum , Ahmad Khuram Shahzad
Published: October 2019

A low‐temperature, efficient and effective method was investigated for phytochemical hydroethanolic extraction of Nasturtium officinale (Brassicaceae). The phytocompounds of the selected plant leaves were identified by high‐performance liquid chromatography, gas chromatography with mass spectroscopy, Fourier transform infrared spectroscopy, and ultraviolet‐visible spectroscopy. Acetic acid, d‐alanine, octodrine, decanoic acid, and cyclohexylethylamine were the major phytocompounds identified in N. officinale leaves with high similarity match and spectral purity. The reducing and stabilizing potential of the extracted phytochemicals was demonstrated by synthesizing the metal oxide nanoparticles (MoO3) by treating ammonium heptamolybdate tetrahydrate (H4MO7N6O24.4H2O) aqueous complex with bioactive compounds of the leaves. The bio‐synthesized MoO3 nanoparticles were characterized by ultraviolet‐visible spectroscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, energy dispersive X‐ray spectroscopy, field emission‐scanning electron microscopy, and gas chromatography with mass spectroscopy. Gas chromatography‐mass spectroscopy identified acetic acid, d‐alanine, and octodrine as stabilizing agents in the synthesis of MoO3 nanoparticles.
Distribution of sapogenins in morphological Medicago sativa L. parts: Comparison of various extraction techniques
Authors: Kiełbasa Anna , Krakowska‐Sieprawska Aneta , Kowalkowski Tomasz , Rafińska Katarzyna , Buszewski Bogusław
Published: October 2019

Saponins in plant extracts were indirectly determined by estimation of the content of sapogenins. The first step of determination is extraction with high efficiency. One conventional extraction technique (maceration) and two modern ones (accelerated solvent extraction and supercritical fluid extraction) were compared. Methanol and ethanol were used as solvents or co‐solvents. The results were supported by statistical analysis. Saponins were extracted from leaves, roots, and sprouts of Medicago sativa. Acid hydrolysis, purification, and determination by high‐performance liquid chromatography with evaporative light scattering detector were used. The content of sapogenins was the highest in the roots. Smaller amounts of sapogenins were found in sprouts and the smallest ones in leaves. The main ingredient was medicagenic acid with mean concentration of 621.8 µg/g in roots, 456.7 µg/g in sprouts, and 471.3 µg/g in leaf extract. The highest content of sapogenins in extract was obtained after maceration with methanol; however, this method is nonselective in relation to biologically active compounds. Due to the possibility of using the obtained extracts with sapogenins in the cosmetic or pharmaceutical industry, the selection of extraction techniques and solvents is a very important aspect. Additionally, the chosen technique should be considered eco‐friendly and consistent with the assumptions of “green chemistry.”
The membrane topology of immunity proteins for the two‐peptide bacteriocins carnobacteriocin XY, lactococcin G, and lactococcin MN shows structural diversity
Authors: Britton Angelle P. , van der Ende Sarah R. , van Belkum Marco J. , Martin‐Visscher Leah A.
Published: October 2019

The two‐peptide bacteriocins produced by Gram‐positive bacteria require two different peptides, present in equimolar amounts, to elicit optimal antimicrobial activity. Producer organisms are protected from their bacteriocin by a dedicated immunity protein. The immunity proteins for two‐peptide bacteriocins contain putative transmembrane domains (TMDs) and might therefore be associated with the membrane. The immunity protein CbnZ for the two‐peptide bacteriocin carnobacteriocin XY (CbnXY) was identified by heterologously expressing the cbnZ gene in sensitive host strains. Using protein topology prediction methods and the dual pho‐lac reporter system, we mapped out the membrane topology of CbnZ, along with those of the immunity proteins LagC and LciM for the two‐peptide bacteriocins lactococcin G and lactococcin MN, respectively. Our results reveal wide structural variety between these immunity proteins that can contain as little as one TMD or as many as four TMDs.
Co‐dynamics of Symbiodiniaceae and bacterial populations during the first year of symbiosis with Acropora tenuis juveniles
Authors: Quigley Kate M. , Alvarez Roa Carlos , Torda Greg , Bourne David G. , Willis Bette L.
Published: October 2019

Interactions between corals and their associated microbial communities (Symbiodiniaceae and prokaryotes) are key to understanding corals' potential for and rate of acclimatory and adaptive responses. However, the establishment of microalgal and bacterial communities is poorly understood during coral ontogeny in the wild. We examined the establishment and co‐occurrence between multiple microbial communities using 16S rRNA (bacterial) and ITS2 rDNA (Symbiodiniaceae) gene amplicon sequencing in juveniles of the common coral, Acropora tenuis, across the first year of development. Symbiodiniaceae communities in juveniles were dominated by Durusdinium trenchii and glynnii (D1 and D1a), with lower abundances of Cladocopium (C1, C1d, C50, and Cspc). Bacterial communities were more diverse and dominated by taxa within Proteobacteria, Cyanobacteria, and Planctomycetes. Both communities were characterized by significant changes in relative abundance and diversity of taxa throughout the year. D1, D1a, and C1 were significantly correlated with multiple bacterial taxa, including Alpha‐, Deltra‐, and Gammaproteobacteria, Planctomycetacia, Oxyphotobacteria, Phycisphaerae, and Rhizobiales. Specifically, D1a tended to associate with Oxyphotobacteria and D1 with Alphaproteobacteria, although these associations may represent correlational and not causal relationships. Bioenergetic modeling combined with physiological measurements of coral juveniles (surface area and Symbiodiniaceae cell densities) identified key periods of carbon limitation and nitrogen assimilation, potentially coinciding with shifts in microbial community composition. These results demonstrate that Symbiodiniaceae and bacterial communities are dynamic throughout the first year of ontology and may vary in tandem, with important fitness effects on host juveniles.
Spatial price competition in the Manhattan hotel market: The role of location, quality, and online reputation
Authors: Rezvani Erfan , Rojas Christian
Published: October 2019

We investigate whether and to what extent price competition among hotels in Manhattan is driven by geographic location, quality, and online reputation. We investigate (a) which of the three product differentiation dimensions matters most for hotels' pricing decisions and (b) whether and to what extent competition is localized. Results show that hotel quality and geographic location matter the most for price competition. Whereas hotels of similar reputation also react to each other's prices, the effect is less important. Also, results indicate that hotels' prices react most aggressively to prices set by the four nearest hotels in the area.
Flow topology in an L‐shaped cavity with lids moving in the same directions
Authors: Deliceoğlu Ali , Bozkurt Deniz , Çelik Ebutalib
Published: October 2019

Flow development and eddy structure in an L‐shaped cavity with lids moving in the same directions have been investigated using both tools from topological and numerical methods. In particular, structural bifurcation near a nonsimple degenerate point is investigated by making a local analysis of the velocity field based on a Taylor series expansion. The streamlines of a Hamiltonian vector field system are simplified by using the homotopy invariance of the index theory. A series of bifurcation curves are constructed to determine the sequence of flow structures by which eddies are generated in the L‐shaped cavity.
Finite difference/Galerkin finite element methods for a fractional heat conduction‐transfer equation
Authors: Li Can , Li Min‐Min , Sun Xiaorui
Published: October 2019

In this paper, we develop and compare four kinds of fully discrete continuous Galerkin finite element methods for a fractional heat transport equation describing the deep underground unsteady flow. We adopt continuous Galerkin finite element methods for the spatial discretization and the backward Euler together with linear interpolation (L1), second‐order backward differentiation formula (BDF2), weighted and shifted Grünwald difference (WSGD), and Crank‐Nicolson (CN) time‐stepping methods for time discretization. We derive the stability estimates and a priori error estimates for the semidiscrete and fully discrete finite element schemes. Finally, numerical comparisons of the four families of fully discrete finite element methods are presented to illustrate the effectiveness of the studied numerical schemes.
Duck Egg White–Derived Peptide VSEE (Val‐Ser‐Glu‐Glu) Regulates Bone and Lipid Metabolisms by Wnt/β‐Catenin Signaling Pathway and Intestinal Microbiota
Authors: Guo Danjun , Liu Weiwei , Zhang Xing , Zhao Mengge , Zhu Biyang , Hou Tao , He Hui
Published: October 2019

Scope

Val‐Ser‐Glu‐Glu (VSEE), identified from duck egg white peptides, has been proven to facilitate calcium absorption in a previous study. Since prevention of osteoporosis is important, it might act as a potential cofactor in osteoporosis prevention. Therefore, the aim of this study is to investigate the regulation of VSEE on osteoporosis and abnormal lipid metabolisms.

Methods and results

MC3T3‐E1 cell and ovariectomized (OVX) rat model are used to evaluate VSEE on regulation of bone and lipid metabolisms. Differentiation and matrix mineralization of preosteoblast are significantly increased by VSEE (p <0.05), which attributed to stimulating calcium influx, then to activating Wnt/β‐catenin signaling pathway and regulating runt‐related transcription factor 2 and osteoprotegerin. VSEE can cross Caco‐2/HT‐29 co‐cultured monolayer via paracellular pathway and peptide transporter 1 (PepT1), and can be detected in blood and maximum concentration is 122.84 ± 3.68 mg L−1 at 60 min. Additionally, VSEE reverses bone loss and regulate dyslipidemia through Wnt/β‐catenin signaling pathway in OVX rats. Firmicutes phylum, Veillonellaceae, Prevotellaceae and six genera in VSEE group are significantly different compared with the Model group (p < 0.05).

Conclusion

VSEE promotes bone growth and inhibit abnormal lipid metabolism in an OVX model through the regulation of intestinal microbiota compositions and Wnt/β‐catenin signal pathway.
Epigenetics Predicts Serum 25‐Hydroxyvitamin D Response to Vitamin D3 Supplementation in African Americans
Authors: Chen Li , Dong Yanbin , Chen Jie , Huang Ying , Zhu Haidong
Published: October 2019

Scope

The effects of vitamin D3 supplementations on circulating 25‐hydroxyvitamin D [25(OH)D] are varied. The hypothesis that the baseline DNA methylation plays a role in the serum 25(OH)D response to vitamin D3 supplementation is tested.

Methods and results

A randomized clinical trial is first conducted among 64 African Americans, who are randomly assigned to a placebo or a 16‐week treatment of 600, 2000, and 4000 IU d–1 of vitamin D3 supplements. Expected serum 25(OH)D concentrations at posttest are estimated by intervention, age, gender, body mass index, baseline 25(OH)D concentrations, and seasonal variations. The 25(OH)D response is categorized into a high‐response group when the actual 25(OH)D concentrations at posttest are higher than expected, and a low‐response group otherwise. The 25(OH)D response is associated with baseline methylation levels of CYP family and VDR genes (raw p < 0.05). At a genome‐wide level, the baseline methylation level of cg07873128 (OSBPL5) that regulates cholesterol balance and calcium homeostasis is higher in the low‐response group (false discovery rate = 0.028).

Conclusions

The baseline methylation levels of CYP family and VDR modulate 25(OH)D response. In addition, the hypermethylation of cg07873128 at the baseline, which is located in the imprinted gene OSBPL5, may reduce the serum 25(OH)D response to vitamin D3 supplementation.
Rapid and motion‐robust volume coverage using cross‐sectional real‐time MRI
Authors: Voit Dirk , Kalentev Oleksandr , van Zalk Maaike , Joseph Arun A. , Frahm Jens
Published: October 2019

Purpose

To develop a rapid and motion‐robust technique for volumetric MRI, which is based on cross‐sectional real‐time MRI acquisitions with automatic advancement of the slice position.

Methods

Real‐time MRI with a frame‐by‐frame moving cross‐section is performed with use of highly undersampled radial gradient‐echo sequences offering spin density, T1, or T2/T1 contrast. Joint reconstructions of serial images and coil sensitivity maps from spatially overlapping sections are accomplished by nonlinear inversion with regularization to the preceding section—formally identical to dynamic real‐time MRI. Shifting each frame by 20% to 25% of the section thickness ensures 75% to 80% overlap of successive sections. Acquisition times of 40 to 67 ms allow for rates of 15 to 25 sections per second, while volumes are defined by the number of cross‐sections times the section shift.

Results

Preliminary realizations at 3T comprise studies of the human brain, carotid arteries, liver, and prostate. Typically, coverage of a 90‐ to 180‐mm volume at 0.8‐ to 1.2‐mm in‐plane resolution, 4‐ to 6‐mm section thickness, and 0.8‐ to 1.5‐mm section shift is accomplished within total measuring times of 4 to 6 seconds and a section speed of 15 to 37.5 mm per second. However, spatiotemporal resolution, contrast including options such as fat saturation and total measuring time are highly variable and may be adjusted to clinical needs. Promising volumetric applications range from fetal MRI to dynamic contrast‐enhanced MRI.

Conclusion

The proposed method allows for rapid and motion‐robust volume coverage in a variety of imaging scenarios.
Artificial neural network for myelin water imaging
Authors: Lee Jieun , Lee Doohee , Choi Joon Yul , Shin Dongmyung , Shin Hyeong‐Geol , Lee Jongho
Published: October 2019

Purpose

To demonstrate the application of artificial neural network (ANN) for real‐time processing of myelin water imaging (MWI).

Methods

Three neural networks, ANN‐IMWF, ANN‐IGMT2, and ANN‐II, were developed to generate MWI. ANN‐IMWF and ANN‐IGMT2 were designed to output myelin water fraction (MWF) and geometric mean T2 of intra‐ and extra‐cellular water signal (GMT2,IEW), respectively, whereas ANN‐II generates a T2 distribution. For the networks, gradient and spin echo data from 18 healthy controls (HC) and 26 multiple sclerosis patients (MS) were utilized. Among them, 10 HC and 12 MS had the same scan parameters and were used for training (6 HC and 6 MS), validation (1 HC and 1 MS), and test sets (3 HC and 5 MS). The remaining data had different scan parameters and were applied to exam effects of the scan parameters. The network results were compared with those of conventional MWI in the white matter mask and regions of interest.

Results

The networks produced highly accurate results, showing averaged normalized root‐mean‐squared error under 3% for MWF and 0.4% for GMT2,IEW in the white matter mask of the test set. In the region of interest analysis, the differences between ANNs and conventional MWI were less than 0.1% in MWF and 0.1 ms in GMT2,IEW (no statistical difference and R2 > 0.97). Datasets with different scan parameters showed increased errors. The average processing time was 0.68 s in ANNs, gaining 11,702 times acceleration in the computational speed (conventional MWI: 7,958 s).

Conclusion

The proposed neural networks demonstrate the feasibility of real‐time processing for MWI with high accuracy.
Explicit dynamics in impact simulation using a NURBS contact interface
Authors: Otto Peter , De Lorenzis Laura , Unger Jörg F.
Published: October 2019

In this paper, the impact problem and the subsequent wave propagation are considered. For the contact discretization an intermediate non‐uniform rational B‐spline (NURBS) layer is added between the contacting finite element bodies, which allows a smooth contact formulation and efficient element‐based integration. The impact event is ill‐posed and requires a regularization to avoid propagating stress oscillations. A nonlinear mesh‐dependent penalty regularization is used, where the stiffness of the penalty regularization increases upon mesh refinement. Explicit time integration methods are well suited for wave propagation problems, but are efficient only for diagonal mass matrices. Using a spectral element discretization in combination with a NURBS contact layer the bulk part of the mass matrix is diagonal.
The governance of China's foreign aid system: Evolution and path dependence
Authors: Zhao Jianzhi , Jing Yijia
Published: October 2019

As China become a major donor in international development, there is an urgent need to improve its capacity to govern its aid policy and management system. This study provides a comprehensive review of China's aid governance system and its evolution along the time, showing its changes and nonchanges. Path dependence effects are used to explain such evolution and are further illustrated by the consistent central role of the Ministry of Commerce in the aid system and by the central–provincial arrangement of development finance. Further, by exploiting limited yet novel evidence of the newly established State International Development Cooperation Agency, we argue that path dependence effects make it difficult to achieve the goal to comprehensively restructure the aid governance system by establishing State International Development Cooperation Agency. The study offers a useful perspective to understand the functioning and future evolution of China's aid governance system.