bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Chitosan Dispersion and Microparticles on Older Streptococcus mutans Biofilms
Authors: Kawakita Erika R. H. , Ré Ana Carolina S. , Peixoto Maria Paula G. , Ferreira Maíra P. , Ricomini-Filho Antônio P. , Freitas Osvaldo , Aires Carolina P.
Published: May 2019

(1) Background: The effectiveness of chitosan to improve the action of antimicrobial compounds against planktonic bacteria and young biofilms has been widely investigated in Dentistry, where the biofilm lifecycle is a determining factor for the success of antibacterial treatment. In the present study, mature Streptococcus mutans biofilms were treated with chitosan dispersion (CD) or chitosan microparticles (CM). (2) Methods: CD at 0.25% and 1% were characterized by texture analysis, while CD at 2% was spray-dried to form CM, which were characterized with respect to particle size distribution, zeta potential, and morphology. After determining the minimum inhibitory and bactericidal concentrations, S. mutans biofilms were grown on glass slides exposed 8×/day to 10% sucrose and 2×/day to CD or CM at 0.25% and 1%. Biofilm viability and acidogenicity were determined, using appropriate control groups for each experiment. (3) Results: CD had high viscosity and CM were spherical, with narrow size distribution and positive zeta potential. CM affected bacterial viability and acidogenicity in mature S. mutans biofilms more strongly than CD, especially at 1%. (4) Conclusions: Both chitosan forms exerted antimicrobial effect against mature S. mutans biofilms. CM at 1% can reduce bacterial viability and acidogenicity more effectively than CD at 1%, and thereby be more effective to control the growth of mature biofilms in vitro.
A Strategy for Selecting “Q-Markers” of Chinese Medical Preparation via Components Transfer Process Analysis with Application to the Quality Control of Shengmai Injection
Authors: Zhao Chunxia , Liu Huan , Miao Peiqi , Wang Houen , Yu Heshui , Wang Chunhua , Li Zheng
Published: May 2019

Chinese medical preparation has complicated chemical constituents. Consequently, the proper quality control methods for these Chinese medical preparations have been great challenges to the traditional Chinese medicine modernization and internationalization. What components should be chosen for quality control is a big challenge in the development of traditional Chinese medicine. A new concept of “Quality Marker” was proposed by Liu et al. to solve this problem and established a new research paradigm for traditional Chinese medicine quality study. Several strategies were proposed by the researchers in traditional Chinese medicine, here, we used Shengmai injection as an example to discuss a strategy for selecting “Quality Markers” of Chinese medical preparation by the components transfer process analysis in the Shengmai injection manufacturing process. Firstly, a total of 87 compounds were identified or partially characterized in shengmai injection. Secondly, referenced to the quality control method in China pharmacopeia and considered the biomarkers in the original medicines and representative components in the manufacturing process, four ginsenosides in Panax ginseng (Hongshen), two compounds in Schisandra chinensis (Wuweizi), and a sugar from Ophiopogon japonicas (Maidong) were quantified. As a result, these seven representative compounds exhibited an acceptable transitivity throughout the Shengmai injection manufacturing process. Finally, combined with the active ingredients, components transfer process analysis, and comprehensive evaluation by “Spider-web” analysis, six compounds were selected as the quality markers for the quality control of Shengmai injection. Through this strategy of optimization for quality markers of Shengmai injection, we found that these six compounds could represent the main bioactive substances and be easily detected in the whole process of production. Furthermore, the quality control method was developed for quality assessment and control of these six quality markers in the Shengmai injection. The total content range of the selected quality markers in the 10 batches of the Shengmai injection is 13.844-22.557 mg/mL.
Approaching Authenticity Issues in Fish and Seafood Products by Qualitative Spectroscopy and Chemometrics
Authors: Ghidini Sergio , Varrà Maria Olga , Zanardi Emanuela
Published: May 2019

The intrinsically complex nature of fish and seafood, as well as the complicated organisation of the international fish supply and market, make struggle against counterfeiting and falsification of fish and seafood products very difficult. The development of fast and reliable omics strategies based on spectroscopy in conjunction with multivariate data analysis has been attracting great interest from food scientists, so that the studies linked to fish and seafood authenticity have increased considerably in recent years. The present work has been designed to review the most promising studies dealing with the use of qualitative spectroscopy and chemometrics for the resolution of the key authenticity issues of fish and seafood products, with a focus on species substitution, geographical origin falsification, production method or farming system misrepresentation, and fresh for frozen/thawed product substitution. Within this framework, the potential of fluorescence, vibrational, nuclear magnetic resonance, and hyperspectral imaging spectroscopies, combined with both unsupervised and supervised chemometric techniques, has been highlighted, each time pointing out the trends in using one or another analytical approach and the performances achieved.
Selective Adsorption-Based Separation of Flue Gas and Natural Gas in Zirconium Metal-Organic Frameworks Nanocrystals
Authors: Li Pengli , Shen Yongli , Wang Dandan , Chen Yanli , Zhao Yunfeng
Published: May 2019

Carbon capture from flue gas and natural gas offers a green path to construct a net-zero emissions economic system. Selective adsorption-based gas separation by employing metal-organic frameworks (MOFs) is regarded as a promising technology due to the advantages of simple processing, easy regeneration and high efficiency. We synthesized two Zirconium MOFs (UiO-66 and UiO-66-NH2) nanocrystals for selective capture and further removal of CO2 from flue gas and natural gas. In particular, UiO-66-NH2 nanocrystals have a smaller grain size, a large amount of defects, and pending –NH2 groups inside their pores which display effective CO2 selective adsorption abilities over CH4 and N2 with the theoretical separation factors of 20 and 7. This breakthrough experiment further verified the selective adsorption-based separation process of natural gas and flue gas. In one further step, we used the Monte Carlo simulation to investigate the optimized adsorption sites and energy of CO2, N2 and CH4 molecules in the gas mixture. The significantly large adsorption energy of CO2 (0.32 eV) over N2 (0.19 eV) and N2 (0.2 eV) may help us to reveal the selective adsorption mechanism.
ICAM3-Fc Outperforms Receptor-Specific Antibodies Targeted Nanoparticles to Dendritic Cells for Cross-Presentation
Authors: Cruz Luis J. , Tacken Paul J. , van der Schoot Johan M.S. , Rueda Felix , Torensma Ruurd , Figdor Carl G.
Published: May 2019

Optimal targeting of nanoparticles (NP) to dendritic cells (DCs) receptors to deliver cancer-specific antigens is key to the efficient induction of anti-tumour immune responses. Poly (lactic-co-glycolic acid) (PLGA) nanoparticles containing tètanus toxoid and gp100 melanoma-associated antigen, toll-like receptor adjuvants were targeted to the DC-SIGN receptor in DCs by specific humanized antibodies or by ICAM3-Fc fusion proteins, which acts as the natural ligand. Despite higher binding and uptake efficacy of anti-DC-SIGN antibody-targeted NP vaccines than ICAM3-Fc ligand, no difference were observed in DC activation markers CD80, CD83, CD86 and CCR7 induced. DCs loaded with NP coated with ICAM3-Fc appeared more potent in activating T cells via cross-presentation than antibody-coated NP vaccines. This fact could be very crucial in the design of new cancer vaccines.
Optical Resolution of Rimantadine
Authors: Han Jianlin , Takeda Ryosuke , Sato Tatsunori , Moriwaki Hiroki , Abe Hidenori , Izawa Kunisuke , Soloshonok Vadim A.
Published: May 2019

This work discloses a new procedure for the resolution of commercially available racemic rimantadine hydrochloride to enantiomerically pure (S)-rimantadine using (R)-phenoxypropionic acid as a recyclable resolving reagent. Good chemical yields, operational ease, and low-cost structure underscore the preparative value of this method for the production of enantiomerically pure rimantadine for medicinal or synthetic studies.
RA-XII Suppresses the Development and Growth of Liver Cancer by Inhibition of Lipogenesis via SCAP-dependent SREBP Supression
Authors: Guo Di , Wang Yurong , Wang Jing , Song Lihua , Wang Zhe , Mao Bingyu , Tan Ninghua
Published: May 2019

Lipogenesis plays a critical role in the growth and metastasis of tumors, which is becoming an attractive target for anti-tumor drugs. RA-XII, one of the cyclopeptide glycosides isolated from Rubia yunnanensis, exerts anti-tumor effects on liver cancer. However, the underlying mechanisms are not clear. In the present study, the effects of RA-XII on lipogenesis were evaluated and the underlying mechanisms were investigated. The results indicated that RA-XII strongly inhibited tumor growth and lipogenesis (triglycerides and lipid droplets) in HepG2 cells, and the expression of key factors involved in lipogenesis (SREBP, SCD, FASN) was also obviously downregulated. Further investigation showed that the anti-tumor effects of RA-XII were attenuated by SREBP knockdown. Moreover, RA-XII downregulated the expression of SREBP cleavage-activating protein (SCAP), an upstream regulator of SREBP, and siRNA of SCAP prevented its restrained effects on tumor growth and lipogenesis. In addition, the in vivo experiment showed that RA-XII strongly restrained the lipogenesis and growth of liver tumor in nude mice xenograft model. Taken together, these results indicate that RA-XII suppresses the liver cancer growth by inhibition of lipogenesis via SCAP-dependent SREBP suppression. The findings reveal the potentials of RA-XII to be used in a novel therapeutic approach for treating liver cancer.
Terrestrial Microorganisms: Cell Factories of Bioactive Molecules with Skin Protecting Applications
Authors: Peyrat Laure-Anne , Tsafantakis Nikolaos , Georgousaki Katerina , Ouazzani Jamal , Genilloud Olga , Trougakos Ioannis P. , Fokialakis Nikolas
Published: May 2019

It is well known that terrestrial environments host an immense microbial biodiversity. Exposed to different types of stress, such as UV radiation, temperature fluctuations, water availability and the inter- / intra-specific competition for resources, terrestrial microorganisms have been evolved to produce a large spectrum of bioactive molecules. Bacteria, archaea, protists, fungi and algae have shown a high potential of producing biomolecules for pharmaceutical or other industrial purposes as they combine a sustainable, relatively low-cost and fast-production process. Herein, we provide an overview of the different bioactive molecules produced by terrestrial microorganisms with skin protecting applications. The high content in polyphenolic and carotenoid compounds produced by several strains, as well as the presence of exopolysaccharides, melanins, indole and pyrrole derivatives, mycosporines, carboxylic acids and other molecules, are discussed in the context of their antioxidant, photo-protective and skin-whitening activity. Relevant biotechnological tools developed for the enhanced production of high added value natural products, as well as the protecting effect of some antioxidant, hydrolytic and degrading enzymes are also discussed. Furthermore, we describe classes of microbial compounds that are used or have the potential to be used as antimicrobials, moisturizers, biosurfactants, pigments, flavorings and fragrances.
The Role of Astragaloside IV against Cerebral Ischemia/Reperfusion Injury: Suppression of Apoptosis via Promotion of P62-LC3-Autophagy
Authors: Zhang Yi , Zhang Ying , Jin Xiao-fei , Zhou Xiao-hong , Dong Xian-hui , Yu Wen-tao , Gao Wei-juan
Published: May 2019

Background: Ischemia/reperfusion (I/R) caused by ischemic stroke treatments leads to brain injury, and autophagy plays a role in the pathology. Astragaloside IV is a potential neuroprotectant, but its underlying mechanism on cerebral I/R injury needs to be explored. The objective of this study is to investigate the neuroprotective mechanism of Astragaloside IV against cerebral I/R injury. Methods: Middle cerebral artery occlusion method (MCAO) and oxygen and glucose deprivation/reoxygenation (OGD/R) method were used to simulate cerebral I/R injury in Sprague-Dawley (SD) rats and HT22 cells, respectively. The neurological score, 2,3,5-Triphe-nyltetrazolium chloride (TTC) staining, and transmission electron microscope were used to detect cerebral damage in SD rats. Cell viability and cytotoxicity assay were tested in vitro. Fluorescent staining and flow cytometry were applied to detect the level of apoptosis. Western blotting was conducted to examine the expression of proteins associated with autophagy. Results: This study found that Astragaloside IV could decrease the neurological score, reduce the infarct volume in the brain, and alleviate cerebral I/R injury in MCAO rats. Astragaloside IV promoted cell viability and balanced Bcl-2 and Bax expression in vitro, reduced the rate of apoptosis, decreased the expression of P62, and increased the expression of LC3II/LC3I in HT22 cells after OGD/R. Conclusions: These data suggested that Astragaloside IV plays a neuroprotective role by down-regulating apoptosis by promoting the degree of autophagy.
Study Protocol for a Pilot, Open-Label, Prospective, and Observational Study to Evaluate the Pharmacokinetics of Drugs Administered to Patients during Extracorporeal Circulation; Potential of In Vivo Cytochrome P450 Phenotyping to Optimise Pharmacotherapy
Authors: Adiraju Santosh Kumar Sreevatsav , Shekar Kiran , Tesar Peter , Naidoo Rishendran , Rapchuk Ivan , Belz Stephen , Fraser John F , Smith Maree T , Ghassabian Sussan
Published: May 2019

Pharmacokinetic alterations of medications administered during surgeries involving cardiopulmonary bypass (CPB) and extracorporeal membrane oxygenation (ECMO) have been reported. The impact of CPB on the cytochrome P450 (CYP) enzymes’ activity is the key factor. The metabolic rates of caffeine, dextromethorphan, midazolam, omeprazole, and Losartan to the CYP-specific metabolites are validated measures of in vivo CYP 1A2, 2D6, 3A4, 2C19, and 2C9 activities, respectively. The study aim is to assess the activities of major CYPs in patients on extracorporeal circulation (EC). This is a pilot, prospective, open-label, observational study in patients undergoing surgery using EC and patients undergoing laparoscopic cholecystectomy as a control group. CYP activities will be measured on the day, and 1–2 days pre-surgery/3–4 days post-surgery (cardiac surgery and Laparoscopic cholecystectomy) and 1–2 days after starting ECMO, 1–2 weeks after starting ECMO, and 1–2 days after discontinuation from ECMO. Aforementioned CYP substrates will be administered to the patient and blood samples will be collected at 0, 1, 2, 4, and 6 h post-dose. Major CYP enzymes’ activities will be compared in each participant on the day, and before/after surgery. The CYP activities will be compared in three study groups to investigate the impact of CYPs on EC.
Towards a Taxonomy for In-Vehicle Interactions Using Wearable Smart Textiles: Insights from a User-Elicitation Study
Authors: Nanjappan Vijayakumar , Shi Rongkai , Liang Hai-Ning , Lau Kim King-Tong , Yue Yong , Atkinson Katie
Published: May 2019

Textiles are a vital and indispensable part of our clothing that we use daily. They are very flexible, often lightweight, and have a variety of application uses. Today, with the rapid developments in small and flexible sensing materials, textiles can be enhanced and used as input devices for interactive systems. Clothing-based wearable interfaces are suitable for in-vehicle controls. They can combine various modalities to enable users to perform simple, natural, and efficient interactions while minimizing any negative effect on their driving. Research on clothing-based wearable in-vehicle interfaces is still underexplored. As such, there is a lack of understanding of how to use textile-based input for in-vehicle controls. As a first step towards filling this gap, we have conducted a user-elicitation study to involve users in the process of designing in-vehicle interactions via a fabric-based wearable device. We have been able to distill a taxonomy of wrist and touch gestures for in-vehicle interactions using a fabric-based wrist interface in a simulated driving setup. Our results help drive forward the investigation of the design space of clothing-based wearable interfaces for in-vehicle secondary interactions.
The Effect of an External Magnetic Field on the Electrochemical Capacitance of Nanoporous Nickel for Energy Storage
Authors: Zhang Haixia , Han Zhifei , Deng Qibo
Published: May 2019

This work investigates the effect of a magnetic field on the electrochemical performance of nanoporous nickel (np-Ni). We first compare the electrochemical capacitance of np-Ni electrodes, which were prepared using the chemical dealloying strategy under different magnetic flux densities (B = 0, 500 mT). Our experimental data show that np-Ni500 prepared under an external magnetic field of 500 mT exhibits a much better electrochemical performance, in comparison with that (np-Ni0) prepared without applying a magnetic field. Furthermore, the specific capacitance of the np-Ni0 electrode could be further enhanced when we increase the magnetic flux densities from 0 T to 500 mT, whereas the np-Ni500 electrode exhibits a stable electrochemical performance under different magnetic flux densities (B = 0 mT, 300 mT, 500 mT). This could be attributed to the change in the electrochemical impedance of the np-Ni0 electrode induced by an external magnetic field. Our work thus offers an alternative method to enhance the electrochemical energy storage of materials.
Risk Governance of Nanomaterials: Review of Criteria and Tools for Risk Communication, Evaluation, and Mitigation
Authors: Isigonis Panagiotis , Hristozov Danail , Benighaus Christina , Giubilato Elisa , Grieger Khara , Pizzol Lisa , Semenzin Elena , Linkov Igor , Zabeo Alex , Marcomini Antonio
Published: May 2019

Nanotechnologies have been increasingly used in industrial applications and consumer products across several sectors, including construction, transportation, energy, and healthcare. The widespread application of these technologies has raised concerns regarding their environmental, health, societal, and economic impacts. This has led to the investment of enormous resources in Europe and beyond into the development of tools to facilitate the risk assessment and management of nanomaterials, and to inform more robust risk governance process. In this context, several risk governance frameworks have been developed. In our study, we present and review those, and identify a set of criteria and tools for risk evaluation, mitigation, and communication, the implementation of which can inform better risk management decision-making by various stakeholders from e.g., industry, regulators, and the civil society. Based on our analysis, we recommend specific methods from decision science and information technologies that can improve the existing risk governance tools so that they can communicate, evaluate, and mitigate risks more transparently, taking stakeholder perspectives and expert opinion into account, and considering all relevant criteria in establishing the risk-benefit balance of these emerging technologies to enable more robust decisions about the governance of their risks.
Electrical Properties and Interfacial Issues of HfO2/Ge MIS Capacitors Characterized by the Thickness of La2O3 Interlayer
Authors: Zhao Lu , Liu Hongxia , Wang Xing , Wang Yongte , Wang Shulong
Published: May 2019

Effects of the La2O3 passivation layer thickness on the interfacial properties of high-k/Ge interface are investigated systematically. In a very thin range (0~15 cycles), the increase of La2O3 passivation layer deposition cycles improves the surface smoothness of HfO2/Ge structures. The capacitance-voltage (C-V) characteristics show that the thickness of La2O3 passivation layer can affect the shift of flat band voltage (VFB), hysteretic behaviors, and the shapes of the dual-swept C-V curves. Moreover, significant improvements in the gate leakage current and breakdown characteristics are also achieved with the increase of La2O3 interlayer thickness.
Electrochemical Deposition and Investigation of Poly-9,10-Phenanthrenequinone Layer
Authors: Genys Povilas , Aksun Elif , Tereshchenko Alla , Valiūnienė Aušra , Ramanaviciene Almira , Ramanavicius Arunas
Published: May 2019

In this research, a 9,10-phenanthrenequinone (PQ) was electrochemically polymerized on a graphite rod electrode using potential cycling. The electrode modified by poly-9,10-phenanthrenequinone (poly-PQ) was studied by means of cyclic voltammetry, electrochemical impedance spectroscopy, atomic force microscopy and scanning electron microscopy. The poly-PQ shows variations in growth pattern depending on the number of potential cycles for the initiation of polymerization. Formed poly-PQ layer demonstrates good electric conductivity, great degree of electrochemical capacitance and unique oxidation/reduction properties, which are suitable for broad technological applications, including applicability in biosensors, supercapacitors and in some other electrochemical systems.
Directly Grown Multiwall Carbon Nanotube and Hydrothermal MnO2 Composite for High-Performance Supercapacitor Electrodes
Authors: Li Li , Chen Lihui , Qian Weijin , Xie Fei , Dong Changkun
Published: May 2019

MnO2–MWNT–Ni foam supercapacitor electrodes were developed based on directly grown multiwalled carbon nanotubes (MWNTs) and hydrothermal MnO2 nanostructures on Ni foam substrates. The electrodes demonstrated excellent electrochemical and battery properties. The charge transfer resistance dropped 88.8% compared with the electrode without MWNTs. A high specific capacitance of 1350.42 F·g−1 was reached at the current density of 6.5 A·g−1. The electrode exhibited a superior rate capability with 92.5% retention in 25,000 cycles. Direct MWNT growth benefits the supercapacitor application for low charge transfer resistance and strong MWNT–current collector binding.
Enhanced Antibacterial Activity of Poly (dimethylsiloxane) Membranes by Incorporating SiO2 Microspheres Generated Silver Nanoparticles
Authors: Shen Qihui , Shan Yixuan , Lü Yang , Xue Peng , Liu Yan , Liu Xiaoyang
Published: May 2019

The nonspecific adsorption of proteins and bacteria on the surface of polydimethylsiloxane (PDMS) had been a serious concern in a wide range of applications, such as medical devices. In order to improve the anti-adhesive and antibacterial capability, bare silver nanoparticles (AgNPs, ~15 nm) were generated in-situ on their surface without extra reducing and stabilizing agents. The main reason for this was that the SiO2 microspheres that are covalent bonded to the bulked PDMS could not only generate AgNPs spontaneously but also insure that no AgNPs were released to the environment. Meanwhile, the thiol-group-functionalized SiO2 microspheres self-assembled on the surface of PDMS by thiol-vinyl click reaction without any impact on their biomedical applications. After the modification of SiO2 microspheres with AgNPs, the surface of PDMS showed a smaller water contact angle than before, and the adhesion and growth of E. coli and Bacillus subtilis were effectively inhibited. When the monolayer of SiO2 microspheres with AgNPs was assembled completely on the surface of PDMS, they present improved bacterial resistance performance (living bacteria, 0%). This approach offers an antibacterial and anti-adhesive surface bearing small and well-defined quantities of in-situ generated AgNPs, and it is a novel, green, simple, and low-cost technique to generate AgNPs on soft biomedical substrates.
Aggregation-Induced Emission (AIE)-Labeled Cellulose Nanocrystals for the Detection of Nitrophenolic Explosives in Aqueous Solutions
Authors: Ye Xiu , Wang Haoying , Yu Lisha , Zhou Jinping
Published: May 2019

Aggregation-induced emission (AIE) active cellulose nanocrystals (TPE-CNCs) were synthesized by attaching tetraphenylethylene (TPE) to cellulose nanocrystals (CNCs). The structure and morphology of TPE-CNCs were characterized by FT-IR, XRD, ζ-potential measurements, elemental analysis, TEM, atomic force microscopy (AFM), and dynamic laser light scattering (DLS). Fluorescent properties of TPE-CNCs were also further studied. Unlike aggregation-caused quenching (ACQ), TPE-CNCs emitted weak fluorescence in the dilute suspensions, while emitting efficiently in the aggregated states. The AIE mechanism of TPE-CNCs was attributed to the restriction of an intramolecular rotation (RIR) process in the aggregated states. TPE-CNCs displayed good dispersity in water and stable fluorescence, which was reported through the specific detection of nitrophenolic explosives in aqueous solutions by a fluorescence quenching assay. The fluorescence emissions of TPE-CNCs showed quantitative and sensitive responses to picric acid (PA), 2,4-dinitro-phenol (DNP), and 4-nitrophenol (NP), and the detection limits were 220, 250, and 520 nM, respectively. Fluorescence quenching occurred through a static mechanism via the formation of a nonfluorescent complex between TPE-CNCs and nitrophenolic analytes. A fluorescence lifetime measurement revealed that the quenching was a static process. The results demonstrated that TPE-CNCs were excellent sensors for the detection of nitrophenolic explosives in aqueous systems, which has great potential applications in chemosensing and bioimaging.
Targeted Gold Nanoparticle–Oligonucleotide Contrast Agents in Combination with a New Local Voxel-Wise MRI Analysis Algorithm for In Vitro Imaging of Triple-Negative Breast Cancer
Authors: Chauhan Rajat , El-Baz Nagwa , Keynton Robert S. , James Kurtis T. , Malik Danial A. , Zhu Mingming , El-Baz Ayman , Ng Chin K. , Bates Paula J. , Malik Mohammad Tariq , O’Toole Martin G.
Published: May 2019

Gold nanoparticles (GNPs) have tremendous potential as cancer-targeted contrast agents for diagnostic imaging. The ability to modify the particle surface with both disease-targeting molecules (such as the cancer-specific aptamer AS1411) and contrast agents (such as the gadolinium chelate Gd(III)-DO3A-SH) enables tailoring the particles for specific cancer-imaging and diagnosis. While the amount of image contrast generated by nanoparticle contrast agents is often low, it can be augmented with the assistance of computer image analysis algorithms. In this work, the ability of cancer-targeted gold nanoparticle–oligonucleotide conjugates to distinguish between malignant (MDA-MB-231) and healthy cells (MCF-10A) is tested using a T1-weighted image analysis algorithm based on three-dimensional, deformable model-based segmentation to extract the Volume of Interest (VOI). The gold nanoparticle/algorithm tandem was tested using contrast agent GNP-Gd(III)-DO3A-SH-AS1411) and nontargeted c-rich oligonucleotide (CRO) analogs and control (CTR) counterparts (GNP-Gd(III)-DO3A-SH-CRO/CTR) via in vitro studies. Remarkably, the cancer cells were notably distinguished from the nonmalignant cells, especially at nanomolar contrast agent concentrations. The T1-weighted image analysis algorithm provided similar results to the industry standard Varian software interface (VNMRJ) analysis of T1 maps at micromolar contrast agent concentrations, in which the VNMRJ produced a 19.5% better MRI contrast enhancement. However, our algorithm provided more sensitive and consistent results at nanomolar contrast agent concentrations, where our algorithm produced ~500% better MRI contrast enhancement.
Dibenzyl Disulfide Adsorption on Cationic Exchanged Faujasites: A DFT Study
Authors: Hessou Etienne Paul , Ponce-Vargas Miguel , Mensah Jean-Baptiste , Tielens Frederik , Santos Juan Carlos , Badawi Michael
Published: May 2019

Although dibenzyl disulfide (DBDS) is used as a mineral oil stabilizer, its presence in electrical transformer oil is associated as one of the major causes of copper corrosion and subsequent formation of copper sulfide. In order to prevent these undesirable processes, MY zeolites (with M = Li, Na, K, Cs, Cu or Ag) are proposed to adsorb molecularly DBDS. In this study, different MY zeolites are investigated at the DFT+D level in order to assess their ability in DBDS adsorption. It was found that CsY, AgY and CuY exhibit the best compromise between high interaction energies and limited S-S bond activation, thus emerging as optimal adsorbents for DBDS.
Field Emission Characterization of MoS2 Nanoflowers
Authors: Giubileo Filippo , Grillo Alessandro , Passacantando Maurizio , Urban Francesca , Iemmo Laura , Luongo Giuseppe , Pelella Aniello , Loveridge Melanie , Lozzi Luca , Di Bartolomeo Antonio
Published: May 2019

Nanostructured materials have wide potential applicability as field emitters due to their high aspect ratio. We hydrothermally synthesized MoS2 nanoflowers on copper foil and characterized their field emission properties, by applying a tip-anode configuration in which a tungsten tip with curvature radius down to 30–100 nm has been used as the anode to measure local properties from small areas down to 1–100 µm2. We demonstrate that MoS2 nanoflowers can be competitive with other well-established field emitters. Indeed, we show that a stable field emission current can be measured with a turn-on field as low as 12 V/μm and a field enhancement factor up to 880 at 0.6 μm cathode–anode separation distance.
PEG-Poly(1-Methyl-l-Tryptophan)-Based Polymeric Micelles as Enzymatically Activated Inhibitors of Indoleamine 2,3-Dioxygenase
Authors: Huang George Lo , Tao Anqi , Miyazaki Takuya , Khan Thahomina , Hong Taehun , Nakagawa Yasuhiro , Cabral Horacio
Published: May 2019

Indoleamine 2,3-dioxygenase (IDO) is an immunomodulating enzyme that is overexpressed in many cancers with poor prognosis. IDO suppresses T cell immunity by catabolizing tryptophan into kynurenine (KYN), which induces apoptosis in T effector cells and enhances T regulatory cells, providing a powerful immunosuppressive mechanism in tumors. Thus, major efforts for developing IDO inhibitors have been undertaken. Among them, 1-Methyl-l-Tryptophan (MLT) and 1-Methyl-d-Tryptophan (MDT) effectively inhibit IDO in preclinical tumor models and the latter is under clinical evaluation. However, both MLT and MDT present poor pharmacokinetics, with the maximum serum concentration being below their 50% inhibitory concentration value. Herein, we have developed polymeric IDO inhibitors based on MLT, which can release active MLT after enzymatic degradation, toward establishing superior antitumor immunotherapies. These polymers were prepared by ring opening polymerization of an N-phenyl carbamate (NPC) derivative of MLT that was synthesized by carbamylation with diphenyl carbonate. By using ω-amino-poly(ethylene glycol) (PEG-NH2) as the macroinitiator, we prepared amphiphilic PEG-poly(MLT) block copolymers, which self-assembled into polymeric micelles in aqueous conditions. The PEG-poly(MLT) block copolymers could be readily degraded by chymotrypsin and the micelles were able to reduce the levels of KYN in activated macrophages. These results provide a strong rationale for pursuing MLT-based polymeric micelles as tumor-targeted prodrug systems.
Enhanced Photocatalytic Degradation of Organic Dyes via Defect-Rich TiO2 Prepared by Dielectric Barrier Discharge Plasma
Authors: Li Yanqin , Wang Wei , Wang Fu , Di Lanbo , Yang Shengchao , Zhu Shengjie , Yao Yongbin , Ma Cunhua , Dai Bin , Yu Feng
Published: May 2019

The dye wastewater produced in the printing and dyeing industry causes serious harm to the natural environment. TiO2 usually shows photocatalytic degradation of dye under the irradiation ultravilet light rather than visible light. In this work, a large number of oxygen vacancies and Ti3+ defects were generated on the surface of the TiO2 nanoparticles via Ar plasma. Compared with pristine TiO2 nanoparticles, the as-obtained Ar plasma-treated TiO2 (Ar-TiO2) nanoparticles make the energy band gap reduce from 3.21 eV to 3.17 eV and exhibit enhanced photocatalytic degradation of organic dyes. The Ar-TiO2 obtained exhibited excellent degradation properties of methyl orange (MO); the degradation rate under sunlight irradiation was 99.6% in 30 min, and the photocatalytic performance was about twice that of the original TiO2 nanoparticles (49%). The degradation rate under visible light (λ > 400 nm) irradiation was 89% in 150 min, and the photocatalytic performance of the Ar-TiO2 was approaching ~4 times higher than that of the original TiO2 nanoparticles (23%). Ar-TiO2 also showed good degradation performance in degrading rhodamine B (Rho B) and methylene blue (MB). We believe that this plasma strategy provides a new method for improving the photocatalytic activity of other metal oxides.
First-Principles Analysis of Vibrational Properties of Type II SiGe Alloy Clathrates
Authors: Xue Dong , Myles Charles W.
Published: May 2019

We have mostly performed vibrational studies of Type-II silicon-germanium clathrate alloys, namely, Si136-xGex (0 < x ≤ 128), using periodic density functional theory (DFT). Our computed lattice constant for various stoichiometric amount, namely, x, of Ge agrees to some extent with the observed X-ray diffraction (XRD) data, along with monotonically increasing dependence on x. According to our bandgap energy calculation via Vienna ab initio simulation package (VASP), Si128Ge8 has a “nearly-direct” bandgap of approximately 1.27 eV, which agrees well with the previously calculated result (~1.23 eV), which was obtained using the Cambridge sequential simulation total energy package (CASTEP). Most of our first-principles calculations focus on exploring the low-energy transverse acoustic (TA) phonons that contribute dominantly to the induction of negative thermal expansion (NTE) behavior. Moreover, our work has predicted that the Si104Ge32 framework exhibits NTE in the temperature range of 3–80 K, compared to the temperature regime (10–140 K) of NTE observed in such pure Si136. It is posited that the increased number of Ge–Ge bonds may weaken the NTE effect substantially, as the composition, which is denoted as x, in Si136-xGex is elevated from 32 (or 40) to 96 (or 104).
A Novel Polymeric Adsorbent Embedded with Phase Change Materials (PCMs) Microcapsules: Synthesis and Application
Authors: Li Xingang , Sun Lingyu , Sui Hong , He Lin , Yuan Wei , Han Zhenwei
Published: May 2019

The heat released during the industrial gas adsorption (e.g., volatile organic compounds (VOCs)) on adsorbents (e.g., activated carbon) would lead to the risks of fire and explosion in the adsorption column. Herein, a novel highly-porous Vinylbenzyl chloride-Divinylbenzene (VBC-DVB) polymeric adsorbent was synthesized with embedded microcapsules (Hypercrosslinked VBC-DVB Beads (HVPM)). These microcapsules have a polydivinylbenzene-phase change materials (DVB-PCMs) core-shell structure. Paraffin wax was used as PCM filling in the spherical capsule. This microcapsules-embedded polymeric adsorbent HVPM (Φ1.5–2.0 mm) is found to possess a high specific surface area (~665 m²/g) and micropore-dominant structure. It also has heat storage capability indicated by DSC (Differential Scanning Calorimetry) analysis (11.1 J/g heat of fusion between 35.0 and 48.2 °C) for the encapsulated paraffin wax. The lab adsorption tests proved the capabilities of HVPM in adsorbing VOCs (toluene, 0.21 g/g) and controlling the temperature inside the adsorption column during the dynamic adsorption process, in which the temperature rise was lowered by 62.5%, relatively.
Whole Genome Sequencing of the First H3N8 Equine Influenza Virus Identified in Malaysia
Authors: Gahan Jacinta , Garvey Marie , Asmah Abd Samad Rozanah , Cullinane Ann
Published: May 2019

In August 2015, Malaysia experienced an outbreak of acute respiratory disease in racehorses. Clinical signs observed were consistent with equine influenza (EI) infection. The index cases were horses recently imported from New Zealand. Rapid control measures, including temporary cancellation of racing, were implemented to minimize the impact of the outbreak. By November, the disease outbreak was resolved, and movement restrictions were lifted. The aim of this study was to confirm the clinical diagnosis and characterize the causal virus. A pan-reactive influenza type A real-time RT-PCR was used for confirmatory diagnosis. Antigenic characterization by haemagglutinin inhibition using a panel of specific ferret antisera indicated that the causal virus belonged to clade 1 of the H3N8 Florida sub-lineage. The genetic characterization was achieved by the whole genome sequencing of positive nasal swabs from clinically affected animals. Pylogenetic analysis of the haemagglutinin (HA) and neuraminidase (NA) genes demonstrated ≥99% homology with several EI strains that had recently circulated in the USA and Japan. The antigenic and genetic characterization did not indicate that the current World Organisation for Animal Health (OIE) recommendations for EI vaccine composition required modification.
Hepatitis B Virus Molecular Epidemiology, Host-Virus Interaction, Coinfection, and Laboratory Diagnosis in the MENA Region: An Update
Authors: Al-Sadeq Duaa W. , Taleb Sara A. , Zaied Roan E. , Fahad Sara M. , Smatti Maria K. , Rizeq Balsam R. , Al Thani Asmaa A. , Yassine Hadi M. , Nasrallah Gheyath K.
Published: May 2019

Hepatitis B virus (HBV) is an enveloped partial double-stranded DNA virus that can cause acute and chronic hepatitis. According to the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC), 257 million people are living with HBV. Moreover, 20,900 acute hepatitis B cases were reported in 2016. Hepatitis B is highly prevalent in the African, Western Pacific, Eastern Mediterranean, South-East Asia, and European regions, respectively. Due to the high mutational rate of HBV and lack of reverse transcriptase proofreading activity, ten different genotypes with different geographical distributions have been identified. HBV pathogenesis and severity of infection depend on several host and viral factors, particularly, the genetic variability of both the host and virus. Although HBV infection is a global health concern, there is a lack of adequate studies and reports in the Middle East and North Africa (MENA) region. Here, we provide a review on HBV epidemiology, pathogenesis, host–pathogen interactions, coinfection with selected viruses, and laboratory diagnosis, focusing on studies conducted in the MENA region to determine the current situation of the HBV infection and outline the future study areas.
Piper betel Compounds Piperidine, Eugenyl Acetate, and Chlorogenic Acid Are Broad-Spectrum Anti-Vibrio Compounds that Are Also Effective on MDR Strains of the Pathogen
Authors: Acosta-Smith Erika , Leon-Sicairos Nidia , Tiwari Sandeep , Flores-Villaseñor Hector , Canizalez-Roman Adrian , Kumavath Ranjith , Ghosh Preetam , Azevedo Vasco , Barh Debmalya
Published: May 2019

The natural population of the aquatic environment supports a diverse aquatic biota and a robust seafood industry. However, this environment also provides an appropriate niche for the growth of pathogenic bacteria that cause problems for human health. For example, species of the genus Vibrio inhabit marine and estuarine environments. This genus includes species that are pathogenic to aquaculture, invertebrates, and humans. In humans, they can cause prominent diseases like gastroenteritis, wound infections, and septicemia. The increased number of multidrug resistant (MDR) Vibrio strains has drawn the attention of the scientific community to develop new broad-spectrum antibiotics. Hence, in this paper we report the bactericidal effects of compounds derived from Piper betel plants: piperidine, chlorogenic acid, and eugenyl acetate, against various strains of Vibrio species. The different MIC90 values were approximately in a range of 2–6 mg/mL, 5–16 mg/mL, 5–20 mg/mL, and 30–80 mg/mL, for piperidine, chlorogenic acid, and eugenyl acetate, respectively. Piperidine showed the best anti-Vibrio effect against the five Vibrio species tested. Interestingly, combinations of sub-inhibitory concentrations of piperidine, chlorogenic acid, and eugenyl acetate showed inhibitory effects in the Vibrio strains. Furthermore, these compounds showed synergism or partial synergism effects against MDR strains of the Vibrio species when they were incubated with antibiotics (ampicillin and chloramphenicol).
Sex-Dependence in the Effect of Pharmaceutical Excipients: Polyoxyethylated Solubilising Excipients Increase Oral Drug Bioavailability in Male but Not Female Rats
Authors: Mai Yang , Dou Liu , Madla Christine M. , Murdan Sudaxshina , Basit Abdul W.
Published: May 2019

It is known that males and females respond differently to medicines and that differences in drug behaviour are due to inter-individual variability and sex specificity. In this work, we have examined the influence of pharmaceutical excipients on drug bioavailability in males and females. Using a rat model, we report that a portfolio of polyoxyethylated solubilising excipients (polyethylene glycol 2000, Cremophor RH 40, Poloxamer 188 and Tween 80) increase ranitidine bioavailability in males but not in females. The in vivo sex and excipient effects were reflected in vitro in intestinal permeability experiments using an Ussing chamber system. The mechanism of such an effect on drug bioavailability is suggested to be due to the interaction between the excipients and the efflux membrane transporter P-glycoprotein (P-gp), whose expression in terms of gene and protein levels were inhibited by the solubilising agents in male but not in female rats. In contrast, the non-polyoxyethylated excipient, Span 20, significantly increased ranitidine bioavailability in both males and females in a non-sex-dependent manner. These findings have significant implications for the use of polyoxyethylated solubilising excipients in drug formulation in light of their sex-specific modulation on the bioavailability of drugs that are P-gp substrates. As such, pharmaceutical research is required to retract from a ‘one size fits all’ approach and to, instead, evaluate the potential impact of the interplay between excipients and sex on drug effect to ensure effective pharmacotherapy.
Nanoemulsion Based Vehicle for Effective Ocular Delivery of Moxifloxacin Using Experimental Design and Pharmacokinetic Study in Rabbits
Authors: Shah Jigar , Nair Anroop B. , Jacob Shery , Patel Rakesh K. , Shah Hiral , Shehata Tamer M. , Morsy Mohamed Aly
Published: May 2019

Nanoemulsion is one of the potential drug delivery strategies used in topical ocular therapy. The purpose of this study was to design and optimize a nanoemulsion-based system to improve therapeutic efficacy of moxifloxacin in ophthalmic delivery. Moxifloxacin nanoemulsions were prepared by testing their solubility in oil, surfactants, and cosurfactants. A pseudoternary phase diagram was constructed by titration technique and nanoemulsions were obtained with four component mixtures of Tween 80, Soluphor® P, ethyl oleate and water. An experiment with simplex lattice design was conducted to assess the influence of formulation parameters in seven nanoemulsion formulations (MM1–MM7) containing moxifloxacin. Physicochemical characteristics and in vitro release of MM1–MM7 were examined and optimized formulation (MM3) was further evaluated for ex vivo permeation, antimicrobial activity, ocular irritation and stability. Drug pharmacokinetics in rabbit aqueous humor was assessed for MM3 and compared with conventional commercial eye drop formulation (control). MM3 exhibited complete drug release in 3 h by Higuchi diffusion controlled mechanism. Corneal steady state flux of MM3 (~32.01 µg/cm2/h) and control (~31.53 µg/cm2/h) were comparable. Ocular irritation study indicated good tolerance of MM3 and its safety for ophthalmic use. No significant changes were observed in the physicochemical properties of MM3 when stored in the refrigerator for 3 months. The greater aqueous humor concentration (Cmax; 555.73 ± 133.34 ng/mL) and delayed Tmax value (2 h) observed in MM3 suggest a reduced dosing frequency and increased therapeutic efficacy relative to control. The area under the aqueous humor concentration versus time curve (AUC0–8 h) of MM3 (1859.76 ± 424.51 ng·h/mL) was ~2 fold higher (p < 0.0005) than the control, suggesting a significant improvement in aqueous humor bioavailability. Our findings suggest that optimized nanoemulsion (MM3) enhanced the therapeutic effect of moxifloxacin and can therefore be used as a safe and effective delivery vehicle for ophthalmic therapy.
Effect of Poly(styrene-ran-methyl acrylate) Inclusion on the Compatibility of Polylactide/Polystyrene-b-Polybutadiene-b-Polystyrene Blends Characterized by Morphological, Thermal, Rheological, and Mechanical Measurements
Authors: Wang Bocheng , Tu Zheng , Wu Chonggang , Hu Tao , Wang Xiaotao , Long Shijun , Gong Xinghou
Published: May 2019

A poly(styrene-ran-methyl acrylate) (S-MA) (75/25 mol/mol), synthesized by surfactant-free emulsion copolymerization, was used as a compatibilizer for polystyrene-b-polybutadiene-b-polystyrene (SBS)-toughened polylactide (PLA) blends. Upon compatibilization, the blends exhibited a refined dispersed-phase morphology, a decreased crystallinity with an increase in their amorphous interphase, improved thermal stability possibly from the thicker, stronger interfaces insusceptible to thermal energy, a convergence of the maximum decomposition-rate temperatures, enhanced magnitude of complex viscosity, dynamic storage and loss moduli, a reduced ramification degree in the high-frequency terminal region of the Han plot, and an increased semicircle radius in the Cole–Cole plot due to the prolonged chain segmental relaxation times from increases in the thickness and chain entanglement degree of the interphase. When increasing the S-MA content from 0 to 3.0 wt %, the tensile properties of the blends improved considerably until 1.0 wt %, above which they then increased insignificantly, whereas the impact strength was maximized at an optimum S-MA content of ~1.0 wt %, hypothetically due to balanced effects of the medium-size SBS particles on the stabilization of preexisting crazes and the initiation of new crazes in the PLA matrix. These observations confirm that S-MA, a random copolymer first synthesized in our laboratory, acted as an effective compatibilizer for the PLA/SBS blends.
Preparation of Thermoplastic Polyurethane (TPU) Perforated Membrane via CO2 Foaming and Its Particle Separation Performance
Authors: Ge Chengbiao , Zhai Wentao , Park Chul B.
Published: May 2019

The way in which a perforated structure is formed has attracted much interest in the porous membrane research community. This novel structure gives materials an excellent antifouling property as well as a low operating pressure and other benefits. Unfortunately, the current membrane fabrication methods usually involve multi-step processes and the use of organic solvents or additives. Our study is the first to offer a way to prepare perforated membrane by using a physical foaming technique with CO2 as the blowing agent. We selected thermoplastic polyurethane (TPU) as the base material because it is a biocompatible elastomer with excellent tensility, high abrasion resistance, and good elastic resilience. Various processing parameters, which included the saturation pressure, the foaming temperature, and the membrane thickness, were applied to adjust the TPU membrane’s perforated morphology. We proposed a possible formation mechanism of the perforated membrane. The as-prepared TPU membrane had good mechanical properties with a tensile strength of about 5 MPa and an elongation at break above 100%. Such mechanical properties make this novel membrane usable as a self-standing filter device. In addition, its straight-through channel structure can separate particles and meet different separation requirements.