bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Graphite Morphology on Phase, Microstructure, and Properties of Hot Dipping and Diffusion Aluminizing Coating on Flake/Spheroidal Graphite Cast Iron
Authors: Zhang Yu , Fan Yongzhe , Zhao Xue , Du An , Ma Ruina , Wu Jianjun , Cao Xiaoming
Published: April 2019

The influence of graphite morphology on the phase, microstructure and properties of hot dipping and diffusion aluminizing (HDDA) coating on flake/spheroidal graphite cast iron (FC/FCD) was investigated. The microstructure and properties of the HDDA coatings on FC/FCD were determined by the graphite morphology. The outer and inner layers of the HDDA coating comprised the Fe2Al5 and FeAl phases, respectively. The outer layer of HDDA on FCD was dense and uniform; however, some pores of different sizes were found in the outer coating on FC, resulting in looser HDDA coating. Hence, the wear resistance of the HDDA coating on FC was worse than that of the coating on FCD. During oxidation, many continuous oxidation channels were formed from the coating surface to the matrix in the HDDA coating on FC, resulting in the oxidation of graphite in the HDDA coating and the matrix. However, only exposed spheroidal graphite was oxidized in the HDDA coating on FCD. Thus, the high-temperature oxidation resistance of the HDDA coating on FC was also worse than that of the coating on FCD.
Carbonic Anhydrases in Photosynthesizing Cells of C3 Higher Plants
Authors: Ignatova Lyudmila , Rudenko Natalia , Zhurikova Elena , Borisova-Mubarakshina Maria , Ivanov Boris
Published: April 2019

The review presents data on the location, nature, properties, number, and expression of carbonic anhydrase genes in the photosynthesizing cells of C3 plants. The available data about the presence of carbonic anhydrases in plasma membrane, cytoplasm, mitochondria, chloroplast stroma and thylakoids are scrutinized. Special attention was paid to the presence of carbonic anhydrase activities in the different parts of thylakoids, and on collation of sources of these activities with enzymes encoded by the established genes of carbonic anhydrases. The data are presented to show that the consistent incorporation of carbonic anhydrases belonging to different families of these enzymes forms a coherent system of CO2 molecules transport from air to chloroplasts in photosynthesizing cells, where they are included in organic molecules in the carboxylation reaction. It is discussed that the manifestation of the activity of a certain carbonic anhydrase depends on environmental conditions and the stage of ontogenesis.
Corundum Anorthosites-Kyshtymites from the South Urals, Russia: A Combined Mineralogical, Geochemical, and U-Pb Zircon Geochronological Study
Authors: Filina Maria I. , Sorokina Elena S. , Botcharnikov Roman , Karampelas Stefanos , Rassomakhin Mikhail A. , Kononkova Natalia N. , Nikolaev Anatoly G. , Berndt Jasper , Hofmeister Wolfgang
Published: April 2019

Kyshtymites are the unique corundum-blue sapphire-bearing variety of anorthosites of debatable geological origin found in the Ilmenogorsky-Vishnevogorsky complex (IVC) in the South Urals, Russia. Their mineral association includes corundum-sapphire, plagioclase (An61–93), muscovite, clinochlore, and clinozoisite. Zircon, churchite-(Y), monazite-(Ce), and apatite group minerals are found as accessory phases. Besides, churchite-(Y) and zircon are also identified as syngenetic solid inclusions within the sapphires. In situ Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) U-Pb zircon geochronology showed the ages at about 290–330 Ma linked to the Hercynian orogeny in IVC. These ages are close to those of the syenitic and carbonatitic magmas of the IVC, pointing to their syngenetic origin, which is in agreement with the trace element geochemistry of the zircons demonstrating clear magmatic signature. However, the trace element composition of sapphires shows mostly metamorphic signature with metasomatic overprints in contrast to the geochemistry of zircons. The reason for this discrepancy can be the fact that the discrimination diagrams for sapphires are not as universal as assumed. Hence, they cannot provide an unambiguous determination of sapphire origin. If it is true and zircons can be used as traces of anorthosite genesis, then it can be suggested that kyshtymites are formed in a magmatic process at 440–420 Ma ago, most probably as plagioclase cumulates in a magma chamber. This cumulate rock was affected by a second magmatic event at 290–330 Ma as recorded in zircon and sapphire zoning. On the other hand, Ti-in-zircon thermometer indicates that processes operated at relatively lower temperature (<900 °C), which is not enough to re-melt the anorthosites. Hence, zircons in kyshtymites can be magmatic but inherited from another rock, which was re-worked during metamorphism. The most probable candidate for the anorthosite protolith is carbonatites assuming that metamorphic fluids could likely leave Al- and Si-rich residue, but removed Ca and CO2. Further, Si is consumed by the silicification of ultramafic host rocks. However, kyshtymites do not show clear evidence of pronounced metasomatic zonation and evidence for large volume changes due to metamorphic alteration of carbonatites. Thus, the obtained data still do not allow for univocal reconstruction of the kyshtymite origin and further investigations are required.
Synthesis and Characterization of Healable Waterborne Polyurethanes with Cystamine Chain Extenders
Authors: Lee Dae-Il , Kim Seung-Hyun , Lee Dai-Soo
Published: April 2019

In this study, environmentally friendly, self-healing waterborne polyurethanes (WPUs) were prepared based on the disulfide metathesis reaction in cystamine. The cystamine acted as a chain extender in the WPU film, which showed a high mechanical strength of 19.1 MPa. The possibility of self-healing reaction was simultaneously modeled via liquid chromatography–mass spectrometry (LC-MS). WPU was confirmed to self-heal a surface crack thermally after a scratch test, and the efficiency was measured by comparing the mechanical properties before and after a cut-and-healing test. In addition, the disulfide-thiol exchange reaction was confirmed to occur in WPU with cystamine as a chain extender and 2-mercaptoethanol. Hot press tests confirmed the possibility of reprocessing the WPU. The WPU incorporating disulfide groups showed great potential as a smart self-healing material.
Determination of Barbiturates in Biological Specimens by Flat Membrane-Based Liquid-Phase Microextraction and Liquid Chromatography-Mass Spectrometry
Authors: Zhu Ruiqin , Dong Ying , Cai Xiangyang , Huang Chuixiu
Published: April 2019

The wide abuse of barbiturates has aroused extensive public concern. Therefore, the determination of such drugs is becoming essential in therapeutic drug monitoring and forensic science. Herein, a simple, efficient, and inexpensive sample preparation technique, namely, flat membrane-based liquid-phase microextraction (FM-LPME) followed by liquid chromatography-mass spectrometry (LC-MS), was used to determine barbiturates in biological specimens. Factors that may influence the efficiency including organic extraction solvent, pH, and composition of donor and acceptor phases, extraction time, and salt addition to the sample (donor phase) were investigated and optimized. Under the optimized extraction conditions, the linear ranges of the proposed FM-LPME/LC-MS method (with correlation coefficient factors ≥ 0.99) were 7.5–750 ng mL−1 for whole blood, 5.0–500 ng mL−1 for urine, and 25–2500 ng g−1 for liver. Repeatability between 5.0 and 13.7% was obtained and the limit of detection (LOD) values ranged from 1.5 to 3.1 ng mL−1, from 0.6 to 3.6 ng mL−1, and from 5.2 to 10.0 ng g−1 for whole blood, urine, and liver samples, respectively. This method was successfully applied for the analysis of barbiturates in blood and liver from rats treated with these drugs, and excellent sample cleanup was achieved.
Melittin Exerts Beneficial Effects on Paraquat-Induced Lung Injuries in Mice by Modifying Oxidative Stress and Apoptosis
Authors: El-Aarag Bishoy , Magdy Mohamed , AlAjmi Mohamed F. , Khalifa Shaden A.M. , El-Seedi Hesham R.
Published: April 2019

Melittin (MEL) is a 26-amino acid peptide with numerous biological activities. Paraquat (PQ) is one of the most widely used herbicides, although it is extremely toxic to humans. To date, PQ poisoning has no effective treatment, and therefore the current study aimed to assess for the first time the possible effects of MEL on PQ-induced lung injuries in mice. Mice received a single intraperitoneal (IP) injection of PQ (30 mg/kg), followed by IP treatment with MEL (0.1 and 0.5 mg/kg) twice per week for four consecutive weeks. Histological alterations, oxidative stress, and apoptosis in the lungs were studied. Hematoxylin and eosin (H&E) staining indicated that MEL markedly reduced lung injuries induced by PQ. Furthermore, treatment with MEL increased superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity, and decreased malonaldehyde (MDA) and nitric oxide (NO) levels in lung tissue homogenates. Moreover, immunohistochemical staining showed that B-cell lymphoma-2 (Bcl-2) and survivin expressions were upregulated after MEL treatment, while Ki-67 expression was downregulated. The high dose of MEL was more effective than the low dose in all experiments. In summary, MEL efficiently reduced PQ-induced lung injuries in mice. Specific pharmacological examinations are required to determine the effectiveness of MEL in cases of human PQ poisoning.
Optimization of Hyperglycemic Induction in Zebrafish and Evaluation of Its Blood Glucose Level and Metabolite Fingerprint Treated with Psychotria malayana Jack Leaf Extract
Authors: Benchoula Khaled , Khatib Alfi , Quzwain Fairuz M. C. , Che Mohamad Che Anuar , Wan Sulaiman Wan Mohd Azizi , Abdul Wahab Ridhwan , Ahmed Qamar Uddin , Abdul Ghaffar Majid , Saiman Mohd Zuwairi , Alajmi Mohamed F. , El-Seedi Hesham
Published: April 2019

A standard protocol to develop type 1 diabetes in zebrafish is still uncertain due to unpredictable factors. In this study, an optimized protocol was developed and used to evaluate the anti-diabetic activity of Psychotria malayana leaf. The aims of this study were to develop a type 1 diabetic adult zebrafish model and to evaluate the anti-diabetic activity of the plant extract on the developed model. The ability of streptozotocin and alloxan at a different dose to elevate the blood glucose levels in zebrafish was evaluated. While the anti-diabetic activity of P. malayana aqueous extract was evaluated through analysis of blood glucose and LC-MS analysis fingerprinting. The results indicated that a single intraperitoneal injection of 300 mg/kg alloxan was the optimal dose to elevate the fasting blood glucose in zebrafish. Furthermore, the plant extract at 1, 2, and 3 g/kg significantly reduced blood glucose levels in the diabetic zebrafish. In addition, LC-MS-based fingerprinting indicated that 3 g/kg plant extract more effective than other doses. Phytosterols, sugar alcohols, sugar acid, free fatty acids, cyclitols, phenolics, and alkaloid were detected in the extract using GC-MS. In conclusion, P. malayana leaf aqueous extract showed anti-diabetic activity on the developed type 1 diabetic zebrafish model.
Quality Control and Variability Assessment of an Eight-Herb Formulation for Hypertension Using Method Validation and Statistical Analysis
Authors: Jarouche Mariam , Suresh Harsha , Low Mitchell , Lee Samiuela , Xu Cindy , Khoo Cheang
Published: April 2019

Background—The quality control (QC) for commercial herbal formulations is sparse due to a lack of well-developed HPLC-ESI-MS/MS methods. Objective—This study reports the quantification of nine selected analytes for a commercial eight-herb formulation known as Qi Ju Di Huang Wan (QJDHW) used to relieve hypertension. Methods—An HPLC-ESI/MS method for the quantitation of analytes selected using the Herbal Chemical Marker Ranking System (Herb MaRS) was developed. The Herb MaRS ranking system which takes into account bioavailability, bioactivity, and physiological action related to its intended use and the commercial availability of the standard. After a method optimization, seven analytes were found to be ideal for quantitation. Results—The target analytes were identified using an electrospray ionization-tandem MS molecular breakdown comparison between the herbal peak and the commercial standard. The quantitative aspect of analyte variability of eleven samples was studied using fold variation. The fold variation of selected analytes among eleven samples ranged from 1.5 to 28.9. The qualitative aspect of variability was studied using principal component analysis (PCA) and hierarchical cluster analysis (HCA). Conclusions—There is a great degree of chemical variability in herbal formulations which are due to raw material harvesting times, storage techniques, and plant subspecies variability. Highlights—Commercial QJDHW formulations need to be standardised using HPLC-ESI-MS/MS to ensure better product quality control (QC) and product efficacy for the consumer.
Ionic Liquids as Delaminating Agents of Layered Double Hydroxide during In-Situ Synthesis of Poly (Butylene Adipate-co-Terephthalate) Nanocomposites
Authors: Beneš Hynek , Kredatusová Jana , Peter Jakub , Livi Sébastien , Bujok Sonia , Pavlova Ewa , Hodan Jiří , Abbrent Sabina , Konefał Magdalena , Ecorchard Petra
Published: April 2019

Currently, highly demanded biodegradable or bio-sourced plastics exhibit inherent drawbacks due to their limited processability and end-use properties (barrier, mechanical, etc.). To overcome all of these shortcomings, the incorporation of lamellar inorganic particles, such as layered double hydroxides (LDH) seems to be appropriate. However, LDH delamination and homogenous dispersion in a polymer matrix without use of harmful solvents, remains a challenging issue, which explains why LDH-based polymer nanocomposites have not been scaled-up yet. In this work, LDH with intercalated ionic liquid (IL) anions were synthesized by a direct co-precipitation method in the presence of phosphonium IL and subsequently used as functional nanofillers for in-situ preparation of poly (butylene adipate-co-terephthalate) (PBAT) nanocomposites. The intercalated IL-anions promoted LDH swelling in monomers and LDH delamination during the course of in-situ polycondensation, which led to the production of PBAT/LDH nanocomposites with intercalated and exfoliated morphology containing well-dispersed LDH nanoplatelets. The prepared nanocomposite films showed improved water vapor permeability and mechanical properties and slightly increased crystallization degree and therefore can be considered excellent candidates for food packaging applications.
Pressure-Dependent Confinement Effect of Ionic Liquids in Porous Silica
Authors: Wang Teng-Hui , Lin En-Yu , Chang Hai-Chou
Published: April 2019

The effect of confining ionic liquids (ILs) such as 1-ethyl-3-methylimidazolium tetrafluoroborate [C2C1Im][BF4] or 1-butyl-3-methylimidazolium tetrafluoroborate [C4C1Im][BF4] in silica matrices was investigated by high-pressure IR spectroscopy. The samples were prepared via the sol-gel method, and the pressure-dependent changes in the C–H absorption bands were investigated. No appreciable changes were observed in the spectral features when the ILs were confined in silica matrices under ambient pressure. That is, the infrared measurements obtained under ambient pressure were not sufficient to detect the interfacial interactions between the ILs and the porous silica. However, dramatic differences were observed in the spectral features of [C2C1Im][BF4] and [C4C1Im][BF4] in silica matrices under the conditions of high pressures. The surfaces of porous silica appeared to weaken the cation-anion interactions caused by pressure-enhanced interfacial IL-silica interactions. This confinement effect under high pressures was less obvious for [C4C1Im][BF4]. The size of the cations appeared to play a prominent role in the IL-silica systems.
The Roles of Nanomaterials in Conventional and Emerging Technologies for Heavy Metal Removal: A State-of-the-Art Review
Authors: Subramaniam Mahesan Naidu , Goh Pei Sean , Lau Woei Jye , Ismail Ahmad Fauzi
Published: April 2019

Heavy metal (HM) pollution in waterways is a serious threat towards global water security, as high dosages of HM poisoning can significantly harm all living organisms. Researchers have developed promising methods to isolate, separate, or reduce these HMs from water bodies to overcome this. This includes techniques, such as adsorption, photocatalysis, and membrane removal. Nanomaterials play an integral role in all of these remediation techniques. Nanomaterials of different shapes have been atomically designed via various synthesis techniques, such as hydrothermal, wet chemical synthesis, and so on to develop unique nanomaterials with exceptional properties, including high surface area and porosity, modified surface charge, increment in active sites, enhanced photocatalytic efficiency, and improved HM removal selectivity. In this work, a comprehensive review on the role that nanomaterials play in removing HM from waterways. The unique characteristics of the nanomaterials, synthesis technique, and removal principles are presented. A detailed visualisation of HM removal performances and the mechanisms behind this improvement is also detailed. Finally, the future directions for the development of nanomaterials are highlighted.
High-Fat Breakfast Meal Replacement in Overweight and Obesity: Implications on Body Composition, Metabolic Markers, and Satiety
Authors: Smith-Ryan Abbie E. , Hirsch Katie R. , Blue Malia N. M. , Mock Meredith G. , Trexler Eric T.
Published: April 2019

The purpose of this paper was to determine the effect of replacing breakfast with a high-fat drink on fat mass (FM), lean mass (LM), percent body fat (%BF), visceral fat (VAT), resting metabolic rate (RMR), fuel utilization (RER), blood lipids and satiety in overweight and obese adults. Healthy adults (n = 42; 21 Females; body mass index (BMI): 32.8 ± 4.6 kg·m−2) were randomized to control (CON; n = 21) or meal replacement (MRP; n = 22) groups. Body composition was measured using a four-compartment model; RMR and RER were assessed from indirect calorimetry. The MRP (70% fat) was consumed once daily for eight weeks. For males, there was no change (p > 0.05) in FM (mean difference (MD) = 0.41 ± 1.19 kg], %BF MD = 0.50 ± 1.09%, LM MD = −0.64 ± 1.79 kg, or VAT MD = −0.31 ± 1.36 cm for MRP versus CON. Similarly, no differences for females for FM MD = −0.73 ± 1.37 kg, %BF MD = −0.57 ± 1.26%, LM MD = 0.31 ± 1.37 kg, or VAT MD: −0.83 ± 1.2 cm. HDL was significantly reduced in the MRP group for females (adjusted mean change: −6.41 ± 4.44 units, p = 0.018). There was no effect on RMR or RER. Satiety increased in the afternoon for MRP (p = 0.021). Despite high fat, no negative impact on lipids resulted; increased satiety may be beneficial for controlling afternoon cravings, but does not affect body composition.
Nationwide Online Survey Enables the Reevaluation of the Safety of Coleus forskohlii Extract Intake Based on the Adverse Event Frequencies
Authors: Nishijima Chiharu , Chiba Tsuyoshi , Sato Yoko , Umegaki Keizo
Published: April 2019

The formulations of the functional ingredients of dietary supplements was studied with a small number of subjects, with a particular focus on their effectiveness, but not enough to evaluate their safety. In this regard, the reevaluation and estimation of the safe use of marketed products, with regards to their adverse event (AE) frequencies, are important. To address this issue, a post-marketing nationwide online survey was conducted for the herbal ingredient Coleus forskohlii extract (CFE), a popular weight-loss ingredient. The questionnaire included product names, adherence to the claimed amount, and AE experiences. The safe intake amount was estimated by the relationship between the claimed amount of CFE and the frequencies of AEs of each product. The number of users who experienced AEs was 75 (10.5% of all users). Gastrointestinal symptoms accounted for 92.0% (n = 69) of all AEs, and diarrhea alone accounted for 81.3% (n = 61). The amount of CFE was significantly associated with the occurrence of diarrhea (p = 0.005). The fitted curve showed that the safe intake amount of CFE was less than 250 mg/day; however, considering its effectiveness, 500 mg/day of CFE might be acceptable. In conclusion, nationwide online surveys of users enable us to confirm and reevaluate the safety of herbal supplements.
Nonperturbative Kinetic Description of Electron-Hole Excitations in Graphene in a Time Dependent Electric Field of Arbitrary Polarization
Authors: Smolyansky Stanislav A. , Panferov Anatolii D. , Blaschke David B. , Gevorgyan Narine T.
Published: April 2019

On the basis of the well-known kinetic description of e − e + vacuum pair creation in strong electromagnetic fields in D = 3 + 1 QED we construct a nonperturbative kinetic approach to electron-hole excitations in graphene under the action of strong, time-dependent electric fields. We start from the simplest model of low-energy excitations around the Dirac points in the Brillouin zone. The corresponding kinetic equations are analyzed by nonperturbative analytical and numerical methods that allow to avoid difficulties characteristic for the perturbation theory. We consider different models for external fields acting in both, one and two dimensions. In the latter case we discuss the nonlinear interaction of the orthogonal currents in graphene which plays the role of an active nonlinear medium. In particular, this allows to govern the current in one direction by means of the electric field acting in the orthogonal direction. Investigating the polarization current we detected the existence of high frequency damped oscillations in a constant external electric field. When the electric field is abruptly turned off residual inertial oscillations of the polarization current are obtained. Further nonlinear effects are discussed.
Systematic Review of Important Bacterial Zoonoses in Africa in the Last Decade in Light of the ‘One Health’ Concept
Authors: Asante Jonathan , Noreddin Ayman , El Zowalaty Mohamed
Published: April 2019

Zoonoses present a major public health threat and are estimated to account for a substantial part of the infectious disease burden in low-income countries. The severity of zoonotic diseases is compounded by factors such as poverty, living in close contact with livestock and wildlife, immunosuppression as well as coinfection with other diseases. The interconnections between humans, animals and the environment are essential to understand the spread and subsequent containment of zoonoses. We searched three scientific databases for articles relevant to the epidemiology of bacterial zoonoses/zoonotic bacterial pathogens, including disease prevalence and control measures in humans and multiple animal species, in various African countries within the period from 2008 to 2018. The review identified 1966 articles, of which 58 studies in 29 countries met the quality criteria for data extraction. The prevalence of brucellosis, leptospirosis, Q fever ranged from 0–40%, 1.1–24% and 0.9–28.2%, respectively, depending on geographical location and even higher in suspected outbreak cases. Risk factors for human zoonotic infection included exposure to livestock and animal slaughters. Dietary factors linked with seropositivity were found to include consumption of raw milk and locally fermented milk products. It was found that zoonoses such as leptospirosis, brucellosis, Q fever and rickettsiosis among others are frequently under/misdiagnosed in febrile patients seeking treatment at healthcare centres, leading to overdiagnoses of more familiar febrile conditions such as malaria and typhoid fever. The interactions at the human–animal interface contribute substantially to zoonotic infections. Seroprevalence of the various zoonoses varies by geographic location and species. There is a need to build laboratory capacity and effective surveillance processes for timely and effective detection and control of zoonoses in Africa. A multifaceted ‘One Health’ approach to tackle zoonoses is critical in the fight against zoonotic diseases. The impacts of zoonoses include: (1) Humans are always in contact with animals including livestock and zoonoses are causing serious life-threatening infections in humans. Almost 75% of the recent major global disease outbreaks have a zoonotic origin. (2) Zoonoses are a global health challenge represented either by well-known or newly emerging zoonotic diseases. (3) Zoonoses are caused by all-known cellular (bacteria, fungi and parasites) and noncellular (viruses or prions) pathogens. (4) There are limited data on zoonotic diseases from Africa. The fact that human health and animal health are inextricably linked, global coordinated and well-established interdisciplinary research efforts are essential to successfully fight and reduce the health burden due to zoonoses. This critically requires integrated data from both humans and animals on zoonotic diseases.
Insights into the Molecular Mechanisms of Eg5 Inhibition by (+)-Morelloflavone
Authors: Ogunwa Tomisin Happy , Laudadio Emiliano , Galeazzi Roberta , Miyanishi Takayuki
Published: April 2019

(+)-Morelloflavone (MF) is an antitumor biflavonoid that is found in the Garcinia species. Recently, we reported MF as a novel inhibitor of ATPase and microtubules-gliding activities of the kinesin spindle protein (Eg5) in vitro. Herein, we provide dynamical insights into the inhibitory mechanisms of MF against Eg5, which involves binding of the inhibitor to the loop5/α2/α3 allosteric pocket. Molecular dynamics simulations were carried out for 100 ns on eight complexes: Eg5-Adenosine diphosphate (Eg5-ADP), Eg5-ADP-S-trityl-l-cysteine (Eg5-ADP-STLC), Eg5-ADP-ispinesib, Eg5-ADP-MF, Eg5-Adenosine triphosphate (Eg5-ATP), Eg5-ATP-STLC, Eg5-ATP-ispinesib, and Eg5-ATP-MF complexes. Structural and energetic analyses were done using Umbrella sampling, Molecular Mechanics Poisson–Boltzmann Surface Area (MM/PBSA) method, GROMACS analysis toolkit, and virtual molecular dynamics (VMD) utilities. The results were compared with those of the known Eg5 inhibitors; ispinesib, and STLC. Our data strongly support a stable Eg5-MF complex, with significantly low binding energy and reduced flexibility of Eg5 in some regions, including loop5 and switch I. Furthermore, the loop5 Trp127 was trapped in a downward position to keep the allosteric pocket of Eg5 in the so-called “closed conformation”, comparable to observations for STLC. Altered structural conformations were also visible within various regions of Eg5, including switch I, switch II, α2/α3 helices, and the tubulin-binding region, indicating that MF might induce modifications in the Eg5 structure to compromise its ATP/ADP binding and conversion process as well as its interaction with microtubules. The described mechanisms are crucial for understanding Eg5 inhibition by MF.
Design of Poly(lactic-co-glycolic Acid) (PLGA) Nanoparticles for Vaginal Co-Delivery of Griffithsin and Dapivirine and Their Synergistic Effect for HIV Prophylaxis
Authors: Yang Haitao , Li Jing , Patel Sravan Kumar , Palmer Kenneth E. , Devlin Brid , Rohan Lisa C.
Published: April 2019

Long-acting topical products for pre-exposure prophylaxis (PrEP) that combine antiretrovirals (ARVs) inhibiting initial stages of infection are highly promising for prevention of HIV sexual transmission. We fabricated core-shell poly(lactide-co-glycolide) (PLGA) nanoparticles, loaded with two potent ARVs, griffithsin (GRFT) and dapivirine (DPV), having different physicochemical properties and specifically targeting the fusion and reverse transcription steps of HIV replication, as a potential long-acting microbicide product. The nanoparticles were evaluated for particle size and zeta potential, drug release, cytotoxicity, cellular uptake and in vitro bioactivity. PLGA nanoparticles, with diameter around 180–200 nm, successfully encapsulated GRFT (45% of initially added) and DPV (70%). Both drugs showed a biphasic release with initial burst phase followed by a sustained release phase. GRFT and DPV nanoparticles were non-toxic and maintained bioactivity (IC50 values of 0.5 nM and 4.7 nM, respectively) in a cell-based assay. The combination of drugs in both unformulated and encapsulated in nanoparticles showed strong synergistic drug activity at 1:1 ratio of IC50 values. This is the first study to co-deliver a protein (GRFT) and a hydrophobic small molecule (DPV) in PLGA nanoparticles as microbicides. Our findings demonstrate that the combination of GRFT and DPV in nanoparticles is highly potent and possess properties critical to the design of a sustained release microbicide.
Collagen Type I Containing Hybrid Hydrogel Enhances Cardiomyocyte Maturation in a 3D Cardiac Model
Authors: Edalat Sam G. , Jang Yongjun , Kim Jongseong , Park Yongdoo
Published: April 2019

In vitro maturation of cardiomyocytes in 3D is essential for the development of viable cardiac models for therapeutic and developmental studies. The method by which cardiomyocytes undergoes maturation has significant implications for understanding cardiomyocytes biology. The regulation of the extracellular matrix (ECM) by changing the composition and stiffness is quintessential for engineering a suitable environment for cardiomyocytes maturation. In this paper, we demonstrate that collagen type I, a component of the ECM, plays a crucial role in the maturation of cardiomyocytes. To this end, embryonic stem-cell derived cardiomyocytes were incorporated into Matrigel-based hydrogels with varying collagen type I concentrations of 0 mg, 3 mg, and 6 mg. Each hydrogel was analyzed by measuring the degree of stiffness, the expression levels of MLC2v, TBX18, and pre-miR-21, and the size of the hydrogels. It was shown that among the hydrogel variants, the Matrigel-based hydrogel with 3 mg of collagen type I facilitates cardiomyocyte maturation by increasing MLC2v expression. The treatment of transforming growth factor β1 (TGF-β1) or fibroblast growth factor 4 (FGF-4) on the hydrogels further enhanced the MLC2v expression and thereby cardiomyocyte maturation.
Highly Porous Organic Polymers for Hydrogen Fuel Storage
Authors: Cousins Kimberley , Zhang Renwu
Published: April 2019

Hydrogen (H2) is one of the best candidates to replace current petroleum energy resources due to its rich abundance and clean combustion. However, the storage of H2 presents a major challenge. There are two methods for storing H2 fuel, chemical and physical, both of which have some advantages and disadvantages. In physical storage, highly porous organic polymers are of particular interest, since they are low cost, easy to scale up, metal-free, and environmentally friendly. In this review, highly porous polymers for H2 fuel storage are examined from five perspectives: (a) brief comparison of H2 storage in highly porous polymers and other storage media; (b) theoretical considerations of the physical storage of H2 molecules in porous polymers; (c) H2 storage in different classes of highly porous organic polymers; (d) characterization of microporosity in these polymers; and (e) future developments for highly porous organic polymers for H2 fuel storage. These topics will provide an introductory overview of highly porous organic polymers in H2 fuel storage.
Upper Critical Solution Temperature (UCST) Behavior of Coacervate of Cationic Protamine and Multivalent Anions
Authors: Kim Hyungbin , Jeon Byoung-jin , Kim Sangsik , Jho YongSeok , Hwang Dong Soo
Published: April 2019

Complex coacervation is an emerging liquid/liquid phase separation (LLPS) phenomenon that behaves as a membrane-less organelle in living cells. Yet while one of the critical factors for complex coacervation is temperature, little analysis and research has been devoted to the temperature effect on complex coacervation. Here, we performed a complex coacervation of cationic protamine and multivalent anions (citrate and tripolyphosphate (TPP)). Both mixtures (i.e., protamine/citrate and protamine/TPP) underwent coacervation in an aqueous solution, while a mixture of protamine and sodium chloride did not. Interestingly, the complex coacervation of protamine and multivalent anions showed upper critical solution temperature (UCST) behavior, and the coacervation of protamine and multivalent anions was reversible with solution temperature changes. The large asymmetry in molecular weight between positively charged protamine (~4 kDa) and the multivalent anions (<0.4 kDa) and strong electrostatic interactions between positively charged guanidine residues in protamine and multivalent anions were likely to contribute to UCST behavior in this coacervation system.
Acoustic Emission-Based Study to Characterize the Crack Initiation Point of Wood Fiber/HDPE Composites
Authors: Guo Yong , Zhu Shiliu , Chen Yuxia , Liu Dian , Li Dagang
Published: April 2019

The crack initiation point can be regarded as a sign of composite failure and plays a vital role in the evaluation of fracture toughness. Wood-plastic composites (WPCs) are viscoelastic materials and the evaluation of fracture mechanism and toughness has a great significance in their applications. Therefore, we used the acoustic emission (AE) technique to measure the crack initiation point of the WPCs and evaluate their fracture toughness. The results show that the novel AE-based methods were more effective than the conventional standard methods for characterization of the crack initiation point. Using the relationship of cumulative AE events with time and load, the critical failure load was quickly determined, and then the critical stress intensity factor and fracture toughness were calculated. The fracture toughness of the WPCs increased with an increase in the wood fiber content.
Universal Relationships in Hyperbranched Polymer Architecture for Batch and Continuous Step Growth Polymerization of AB2-Type Monomers
Authors: Tobita Hidetaka
Published: April 2019

Design and control of hyperbranched (HB) polymer architecture by way of reactor operation is key to a successful production of higher-valued HB polymers, and it is essential in order to clarify the fundamental structural characteristics formed in representative types of reactors. In this article, the irreversible step growth polymerization of AB2 type monomer is investigated by a Monte Carlo simulation method, and the calculation was conducted for a batch and a continuous stirred-tank reactor (CSTR). In a CSTR, a highly branched core region consisting of units with large residence times is formed to give much more compact architecture, compared to batch polymerization. The universal relationships, unchanged by the conversion levels and/or the reactivity ratio, are found for the mean-square radius of gyration Rg2, and the maximum span length LMS. For batch polymerization, the g-ratio of Rg2 of the HB molecule to that for a linear molecule conforms to that for the random branched polymers represented by the Zimm-Stockmayer equation. A single linear equation represents the relationship between Rg2 and LMS, both for batch and CSTR. Appropriate process control in combination with the chemical control of the reactivity of the second B-group promises to produce tailor-made HB polymer architecture.
More than a Toxin: Protein Inventory of Clostridium tetani Toxoid Vaccines
Authors: Möller Jens , Kraner Max Edmund , Burkovski Andreas
Published: April 2019

Clostridium tetani is the etiological agent of tetanus, a life-threatening bacterial infection. The most efficient protection strategy against tetanus is a vaccination with the C. tetani neurotoxin, which is inactivated by formaldehyde-crosslinking. Since we assumed that besides the tetanus toxin, other proteins of C. tetani may also be present in toxoid preparations, we analyzed commercially available vaccines from different countries in respect to their protein content using mass spectrometry. In total 991 proteins could be identified in all five analyzed vaccines, 206 proteins were common in all analyzed vaccines and 54 proteins from the 206 proteins were potential antigens. The additionally present proteins may contribute at least partially to protection against C. tetani infection by supporting the function of the vaccine against the devastating effects of the tetanus toxin indirectly. Two different label-free protein quantification methods were applied for an estimation of protein contents. Similar results were obtained with a Total Protein Approach (TPA)-based method and Protein Discoverer 2.2 software package based on the minora algorithm. Depending on the tetanus toxoid vaccine and the quantification method used, tetanus neurotoxin contributes between 14 and 76 % to the total C. tetani protein content and varying numbers of other C. tetani proteins were detected.
Set Thine House in Order: Black Feminism and the Sermon as Sonic Art in The Amen Corner
Authors: Hill Melanie R.
Published: April 2019

In The Souls of Black Folk, W.E.B. DuBois discusses the historical and cultural beginnings of the black preacher as “the most unique personality developed on American soil.” He writes, “[the black preacher] found his functions as the healer of the sick, the interpreter of the Unknown, the comforter of the sorrowing, the supernatural avenger of wrong…Thus as bard, physician, judge, and priest within the narrow limits allowed by the slave system rose the Negro preacher.” Far from being a monolith, the preacher figure embodies many complexities and variances on how the preached Word can be delivered. This begs the question, in what ways can we reimagine DuBois’s black preacher figure in his words, “the most unique personality developed on American soil,” as a black woman? What remains to be seen in scholarship of the mid-twentieth century is an articulation of the black woman preacher in African American literature. By reimagining and refiguring a response to DuBois’s assertion above, how is the role of the black woman preacher and impact of her sermons portrayed in African American literature? Using the art of the sermon, the intersection of music, and James Baldwin’s The Amen Corner as a central text, this article examines the black woman preacher in character and African American women’s spirituality in twentieth century literature. I argue that the way in which Margaret Alexander, as a black woman preacher in the text, creates sermonic spaces of healing and restoration (exegetically and eschatologically) for herself and others outside of the church becomes a new mode of social and cultural resistance. This article works to re-envision the black woman and reposition her in the center of religious discourse on our way to unearthing the modes of transfiguration black women preachers evoke in and out of the pulpit.
Kālavañcana in the Konkan: How a Vajrayāna Haṭhayoga Tradition Cheated Buddhism’s Death in India
Authors: Mallinson James
Published: April 2019

In recent decades the relationship between tantric traditions of Buddhism and Śaivism has been the subject of sustained scholarly enquiry. This article looks at a specific aspect of this relationship, that between Buddhist and Śaiva traditions of practitioners of physical yoga, which came to be categorised in Sanskrit texts as haṭhayoga. Taking as its starting point the recent identification as Buddhist of the c.11th-century Amṛtasiddhi, which is the earliest text to teach any of the methods of haṭhayoga and whose teachings are found in many subsequent non-Buddhist works, the article draws on a range of textual and material sources to identify the Konkan site of Kadri as a key location for the transition from Buddhist to Nāth Śaiva haṭhayoga traditions, and proposes that this transition may provide a model for how Buddhist teachings survived elsewhere in India after Buddhism’s demise there as a formal religion.
Beyond Belief: Chance, Authorship, and the Limits of Comprehension in Gerhard Richter’s Strip
Authors: Romaine James
Published: April 2019

For nearly six decades, Gerhard Richter has challenged the conceptual and visual limits of contemporary painting. His 2011 work Strip overloads the viewer’s visual perception. Richter created this unique digital print using a process that deliberately employs chance to circumvent the artist’s authorship. This article examines the history of Richter’s skepticism of creative authority and the strategies he has developed to realize an art that exceeds the limits of human skill and imagination. Although he remains an atheist, Richter frames his pursuit of an incomprehensible art in terms of a longing for a belief in God.
Defining Geographical Rating Territories in Auto Insurance Regulation by Spatially Constrained Clustering
Authors: Xie Shengkun
Published: April 2019

Territory design and analysis using geographical loss cost are a key aspect in auto insurance rate regulation. The major objective of this work is to study the design of geographical rating territories by maximizing the within-group homogeneity, as well as maximizing the among-group heterogeneity from statistical perspectives, while maximizing the actuarial equity of pure premium, as required by insurance regulation. To achieve this goal, the spatially-constrained clustering of industry level loss cost was investigated. Within this study, in order to meet the contiguity, which is a legal requirement on the design of geographical rating territories, a clustering approach based on Delaunay triangulation is proposed. Furthermore, an entropy-based approach was introduced to quantify the homogeneity of clusters, while both the elbow method and the gap statistic are used to determine the initial number of clusters. This study illustrated the usefulness of the spatially-constrained clustering approach in defining geographical rating territories for insurance rate regulation purposes. The significance of this work is to provide a new solution for better designing geographical rating territories. The proposed method can be useful for other demographical data analysis because of the similar nature of the spatial constraint.
Treatment Level and Store Level Analyses of Healthcare Data
Authors: Wang Kaiwen , Ding Jiehui , Lidwell Kristen R. , Manski Scott , Lee Gee Y. , Esposito Emilio Xavier
Published: April 2019

The presented research discusses general approaches to analyze and model healthcare data at the treatment level and at the store level. The paper consists of two parts: (1) a general analysis method for store-level product sales of an organization and (2) a treatment-level analysis method of healthcare expenditures. In the first part, our goal is to develop a modeling framework to help understand the factors influencing the sales volume of stores maintained by a healthcare organization. In the second part of the paper, we demonstrate a treatment-level approach to modeling healthcare expenditures. In this part, we aim to improve the operational-level management of a healthcare provider by predicting the total cost of medical services. From this perspective, treatment-level analyses of medical expenditures may help provide a micro-level approach to predicting the total amount of expenditures for a healthcare provider. We present a model for analyzing a specific type of medical data, which may arise commonly in a healthcare provider’s standardized database. We do this by using an extension of the frequency-severity approach to modeling insurance expenditures from the actuarial science literature.
Building Extraction from High-Resolution Aerial Imagery Using a Generative Adversarial Network with Spatial and Channel Attention Mechanisms
Authors: Pan Xuran , Yang Fan , Gao Lianru , Chen Zhengchao , Zhang Bing , Fan Hairui , Ren Jinchang
Published: April 2019

Segmentation of high-resolution remote sensing images is an important challenge with wide practical applications. The increasing spatial resolution provides fine details for image segmentation but also incurs segmentation ambiguities. In this paper, we propose a generative adversarial network with spatial and channel attention mechanisms (GAN-SCA) for the robust segmentation of buildings in remote sensing images. The segmentation network (generator) of the proposed framework is composed of the well-known semantic segmentation architecture (U-Net) and the spatial and channel attention mechanisms (SCA). The adoption of SCA enables the segmentation network to selectively enhance more useful features in specific positions and channels and enables improved results closer to the ground truth. The discriminator is an adversarial network with channel attention mechanisms that can properly discriminate the outputs of the generator and the ground truth maps. The segmentation network and adversarial network are trained in an alternating fashion on the Inria aerial image labeling dataset and Massachusetts buildings dataset. Experimental results show that the proposed GAN-SCA achieves a higher score (the overall accuracy and intersection over the union of Inria aerial image labeling dataset are 96.61% and 77.75%, respectively, and the F1-measure of the Massachusetts buildings dataset is 96.36%) and outperforms several state-of-the-art approaches.
Exploring Weighted Dual Graph Regularized Non-Negative Matrix Tri-Factorization Based Collaborative Filtering Framework for Multi-Label Annotation of Remote Sensing Images
Authors: Zhang Juli , Zhang Junyi , Dai Tao , He Zhanzhuang
Published: April 2019

Manually annotating remote sensing images is laborious work, especially on large-scale datasets. To improve the efficiency of this work, we propose an automatic annotation method for remote sensing images. The proposed method formulates the multi-label annotation task as a recommended problem, based on non-negative matrix tri-factorization (NMTF). The labels of remote sensing images can be recommended directly by recovering the image–label matrix. To learn more efficient latent feature matrices, two graph regularization terms are added to NMTF that explore the affiliated relationships on the image graph and label graph simultaneously. In order to reduce the gap between semantic concepts and visual content, both low-level visual features and high-level semantic features are exploited to construct the image graph. Meanwhile, label co-occurrence information is used to build the label graph, which discovers the semantic meaning to enhance the label prediction for unlabeled images. By employing the information from images and labels, the proposed method can efficiently deal with the sparsity and cold-start problem brought by limited image–label pairs. Experimental results on the UCMerced and Corel5k datasets show that our model outperforms most baseline algorithms for multi-label annotation of remote sensing images and performs efficiently on large-scale unlabeled datasets.
Change Analysis in Urban Areas Based on Statistical Features and Temporal Clustering Using TerraSAR-X Time-Series Images
Authors: Yuan Jili , Lv Xiaolei , Dou Fangjia , Yao Jingchuan
Published: April 2019

The existing unsupervised multitemporal change detection approaches for synthetic aperture radar (SAR) images based on the pixel level usually suffer from the serious influence of speckle noise, and the classification accuracy of temporal change patterns is liable to be affected by the generation method of similarity matrices and the pre-specified cluster number. To address these issues, a novel time-series change detection method with high efficiency is proposed in this paper. Firstly, spatial feature extraction using local statistical information on patches is conducted to reduce the noise and for subsequent temporal grouping. Secondly, a density-based clustering method is adopted to categorize the pixel series in the temporal dimension, in view of its efficiency and robustness. Change detection and classification results are then obtained by a fast differential strategy in the final step. The experimental results and analysis of synthetic and realistic time-series SAR images acquired by TerraSAR-X in urban areas demonstrate the effectiveness of the proposed method, which outperforms other approaches in terms of both qualitative results and quantitative indices of macro F1-scores and micro F1-scores. Furthermore, we make the case that more temporal change information for buildings can be obtained, which includes when the first and last detected change occurred and the frequency of changes.