bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydroxide degradation pathways for guanidimidazolium cation: A density functional theory study
Authors: Li Guang‐Lan , Yang Guoqing , Cheng Jie , Zhang Fengxiang , Hao Ce
Published: June 2018

The chemical stability of anion exchange membrane especially in strong alkaline medium under high temperature is one of the crucial challenges for the commercialization of alkaline anion exchange membrane fuel cells. Herein, the degradation mechanism of guanidimidazolium ionic group used in anion exchange membrane was calculated by density functional theory method. The whole transition states of every elemental reaction were systematically searched, and the changes of crucial bonds length were further analyzed for understanding of the reaction mechanism. It was found that the reaction pathway of OH− attacking guanidinium group of guanidimidazolium was the dominant way for the degradation of guanidimidazolium. Through comparing the energy barriers of guanidimidazolium, imidazolium, and guanidinium, it can be concluded that the electron‐inducing effect had an intimate connection with the alkali stability of ionic groups. The chemical stability of the conjugated structure groups decreased when linking with electron‐drawing groups, while it increased when linking with electron‐donating groups. This work provides theoretical basis for the design of decent alkali‐resistance and high‐performance anion exchange membrane.
Ordered Networks of Gold Nanoparticles Crosslinked by Dithiol‐Oligomers
Authors: Nayak Srikanth , Horst Nathan , Zhang Honghu , Wang Wenjie , Mallapragada Surya , Travesset Alex , Vaknin David
Published: June 2018

Controlled aggregation of nanoparticles into superlattices is a grand challenge in material science, where ligand based self‐assembly is the dominant route. Here, the self‐assembly of gold nanoparticles (AuNPs) that are crosslinked by water soluble oligo‐(ethylene glycol)‐dithiol (oEG‐dithiol) is reported and their 3D structure by small angle X‐ray scattering is determined. Surprisingly, a narrow region is found in the parameter space of dithiol linker‐length and nanoparticle size for which the crosslinked networks form short‐ranged FCC crystals. Using geometrical considerations and numerical simulations, the stability of the formed lattices is evaluated as a function of dithiol length and the number of connected nearest‐neighbors, and a phase diagram of superlattice formation is provided. Identifying the narrow parameter space that allows crystallization facilitates focused exploration of linker chemical composition and medium conditions such as thermal annealing, pH, and added solutes that may lead to superior and more robust crystals.
Advances in the Synthesis and Long‐Term Protection of Zero‐Valent Iron Nanoparticles
Authors: Mehta Joshua P. , Knappett Benjamin R. , Divitini Giorgio , Ringe Emilie , Midgley Paul A. , Fairen‐Jimenez David , Wheatley Andrew E. H.
Published: June 2018

Core@shell Fe@Fe3O4 nanoparticles (NPs) are synthesized via the thermal decomposition of iron pentacarbonyl (Fe(CO)5) in the presence either of oleylamine (OAm) or a mixture of OAm and oleic acid (OA). The heterostructured nanocomposites formed do so by a postsynthetic modification of isolated Fe seeds. This proves the versatility of the coating procedure and represents a significant advantage over previous work with Co seeds owing to the higher magnetic susceptibility, reduced toxicity, and excellent biocompatibility of Fe. Furthermore, the latter system allows the synthetic methodology to be developed from a two‐pot scenario where seeds are isolated then coated, to an easier and more efficient direct one‐pot scenario. The two‐pot method yields proportionately larger cores. However, in both cases, the monodisperse product reveals a carbonaceous interface between the Fe core and oxide shell. Meanwhile for the one‐pot synthesis, the OA:OAm ratio influences both the morphology and dispersity of the product. This is interpreted in terms of competing interactions of the ligands with the iron precursor. Superparamagnetism (SPM) is observed, and microscopic studies reveal oxidative stability of the Fe(0) cores achieved by either method for >6 months. It is proposed that the carbonaceous interface is critical to this sustained oxidative stability.
Improving Dielectric Nanoresonator Array Coatings for Solar Cells
Authors: Ha Dongheon , Zhitenev Nikolai B.
Published: June 2018

Antireflection coatings based on dielectric nanosphere arrays are discussed in application to photovoltaic materials including silicon and gallium arsenide. Macro‐ and nanoscale characterizations and finite‐difference time‐domain calculations are performed, and demonstrate the enhanced optoelectronic properties. A significant absorptivity enhancement is achieved due to the collective resonant coupling of excited whispering gallery‐like modes and thin‐film interference effects. The resonant coupling is masked in macroscale measurements by the size variation of nanospheres, but it is clearly seen through imaging photocurrent at the nanoscale with near‐field scanning photocurrent microscopy. The resonant coupling can be effectively tuned by the material, configuration, or size of nanospheres. Hybrid coatings combining nanospheres of different materials yield the highest efficiency gain of more than 30%. The impact of manufacturing defects, such as double layer formation, is also evaluated. While the performance degrades, the antireflection coating still offers marked improvement in comparison with bare cells.
A Nano‐Micro Hybrid Structure Composed of Fe7S8 Nanoparticles Embedded in Nitrogen‐Doped Porous Carbon Framework for High‐Performance Lithium/Sodium‐Ion Batteries
Authors: Liu Zhiming , Hu Fang , Xiang Juan , Yue Chuang , Lee Dongsoo , Song Taeseup
Published: June 2018

Iron sulfides are attractive anode materials for lithium‐ion batteries (LIBs) and sodium‐ion batteries (SIBs) due to their high theoretical capacities, low cost, and eco‐friendliness. However, their real application is greatly hindered by the rapid capacity fading caused by the large volume changes and sluggish kinetics of iron sulfides during the charge and discharge processes. Combining with carbonaceous materials and tuning the structure at nanoscale are essential to address this issue. Here, a facile hydrothermal method coupled with a carbonization process is developed to synthesize a nano‐micro hybrid porous structure, which is composed of Fe7S8 nanoparticles embedded in nitrogen‐doped carbon framework (Fe7S8@NC‐PS). This hierarchical sphere is constructed by interconnected 2D nanowalls. The as‐prepared Fe7S8@NC‐PS electrodes reveal excellent rate capability and cycling stability in LIBs and SIBs. The remarkable electrochemical properties are attributed to the porous nano‐micro hybrid architecture and the high conductivity and structural stability of the nitrogen‐doped carbon framework.
Synthesis and purification of self‐assembling peptide‐oligonucleotide conjugates by solid‐phase peptide fragment condensation
Authors: Kye Mahnseok , Lim Yong‐beom
Published: June 2018

Peptide‐oligonucleotide conjugates (POCs) are interesting molecules as they covalently combine 2 of the most important biomacromolecules. Sometimes, the synthesis of POCs involves unexpected difficulties; however, POCs with self‐assembling propensity are even harder to synthesize and purify. Here, we show that solid‐phase peptide fragment condensation combined with thiol‐maleimide or copper‐catalyzed azide‐alkyne cycloaddition click chemistries is useful for the syntheses of self‐assembling POCs. We describe guidelines for the selection of reactive functional groups and their placement during the conjugation reaction and consider the cost‐effectiveness of the reaction. Purification is another important challenge during the preparation of POCs. Our results show that polyacrylamide gel electrophoresis under denaturing conditions is most suitable to recover a high yield of self‐assembling POCs. This report provides the first comprehensive study of the preparation of self‐assembling POCs, which will lay a foundation for the development of elegant and sophisticated molecular assemblies.
Linking the family context of migration during childhood to the well‐being of young adults: Evidence from the UK and France
Authors: Eremenko Tatiana , Bennett Rachel
Published: June 2018

Families often undergo separations during the migration process. A body of literature has explored the consequences of these separations for children “left behind” and, more recently, children reunified with their parents at the destination. However, little attention has been given to whether this experience during childhood is associated with well‐being into adulthood. This paper adopts a life course perspective to explore well‐being amongst youth (18–25 years) who migrated as children to the UK and France. Drawing on national household surveys, Understanding Society (UK) and Trajectories and Origins (France), we analyse whether which of the parents migrated and whether the young person migrated with them or experienced a period of separation are associated with self‐rated health (both countries) and mental well‐being (UK) or conflict with parents (France). Our findings show that whilst the majority of youth migrated with their parents (86% in the UK and 69% in France), those who did experience long‐term parental separation (6+ years) have poorer psychosocial well‐being in both destinations. This suggests that disruption to the parent–child relationship amplifies the risk of poorer outcomes in early adulthood and highlights that the context of family migration is not only important for understanding migrants' well‐being during childhood, but also as they progress into adulthood.
Negotiating mobile identity in the global nightscape
Authors: Jankowski Krzysztof Z.
Published: June 2018

Transnational and migrant identities have traditionally been theorised around axes of identity such as ethnicity or labour position; drawing on the mobilities paradigm and social geography, I discuss how representations of movement transform identity and life in the destination. This approach puts mobility at the core of transnational studies and elaborates on perspectives of space that span place to mobility. To investigate this, I conducted an ethnography in the nightlife district Lan Kwai Fong (LKF), Hong Kong. In LKF, transnational movement creates an expectation that life in Hong Kong will stand apart from home. This transforms LKF with the expectation that life is going to be better and more amazing than previously. Movement also creates the expectation of difference and novelty. Participants evaluated LKF on its merits as an exotic destination. In parallel, the curators of LKF aim to foster a sense of discovery, of finding somewhere new and different. Discovery validates movement as successful and distantiates subjects from place and into a spatial configuration of ephemerality and change. But for people living in Hong Kong, discovery has to be supplanted with a more permanent narrative of belonging without losing sight of mobility. New immobile subjects weave stories of mobility into their practices in LKF. They live mobile identities such as expatriate or exchange student, which keep the fantasy and spatial reality of mobility ongoing.
Quantitative Systems Pharmacology Modeling of Acid Sphingomyelinase Deficiency and the Enzyme Replacement Therapy Olipudase Alfa Is an Innovative Tool for Linking Pathophysiology and Pharmacology
Authors: Kaddi Chanchala D. , Niesner Bradley , Baek Rena , Jasper Paul , Pappas John , Tolsma John , Li Jing , van Rijn Zachary , Tao Mengdi , Ortemann‐Renon Catherine , Easton Rachael , Tan Sharon , Puga Ana Cristina , Schuchman Edward H. , Barrett Jeffrey S. , Azer Karim
Published: June 2018

Acid sphingomyelinase deficiency (ASMD) is a rare lysosomal storage disorder with heterogeneous clinical manifestations, including hepatosplenomegaly and infiltrative pulmonary disease, and is associated with significant morbidity and mortality. Olipudase alfa (recombinant human acid sphingomyelinase) is an enzyme replacement therapy under development for the non‐neurological manifestations of ASMD. We present a quantitative systems pharmacology (QSP) model supporting the clinical development of olipudase alfa. The model is multiscale and mechanistic, linking the enzymatic deficiency driving the disease to molecular‐level, cellular‐level, and organ‐level effects. Model development was informed by natural history, and preclinical and clinical studies. By considering patient‐specific pharmacokinetic (PK) profiles and indicators of disease severity, the model describes pharmacodynamic (PD) and clinical end points for individual patients. The ASMD QSP model provides a platform for quantitatively assessing systemic pharmacological effects in adult and pediatric patients, and explaining variability within and across these patient populations, thereby supporting the extrapolation of treatment response from adults to pediatrics.
Curcumin in epilepsy disorders
Authors: Dhir Ashish
Published: June 2018

Curcumin, a principal curcuminoid present in turmeric, has an antioxidant, anti‐inflammatory and neuroprotective properties. Preclinical studies have indicated its beneficial effect for the treatment of epilepsy disorders. The molecule has an anti‐seizure potential in preclinical studies, including chemical and electrical models of acute and chronic epilepsy. Curcumin also possesses an anti‐epileptogenic activity as it reduces spontaneous recurrent seizures severity in a kainate model of temporal lobe epilepsy. The antioxidant and anti‐inflammatory nature of curcumin might be responsible for its observed anti‐seizure effects; nevertheless, the exact mechanism is not yet clear. The poor availability of curcumin to the brain limits its use in clinics. The application of nanoliposome and liposome technologies has been tested to enhance its brain availability and penetrability. Unfortunately, there are no randomized, double‐blinded controlled clinical trials validating the use of curcumin in epilepsy. The present article analyzes different preclinical evidence illustrating the effect of curcumin in seizure models. The review encourages carrying out clinical trials in this important area of research. In conclusion, curcumin might be beneficial in patients with epilepsy disorders, if its bioavailability issues are resolved.
Protective effects of cinnamon bark extract against ischemia–reperfusion injury and arrhythmias in rat
Authors: Sedighi Mehrnoosh , Nazari Afshin , Faghihi Mahdieh , Rafieian‐Kopaei Mahmoud , Karimi Arash , Moghimian Maryam , Mozaffarpur Seyyed Ali , Rashidipour Marzieh , Namdari Mehrdad , Cheraghi Mostafa , Rasoulian Bahram
Published: June 2018

Cinnamomum zeylanicum (cinnamon) is a plant with potent antioxidant activity and has been used in traditional medicine for improvement of heart function. The effects of cinnamon bark ethanolic extract were investigated against ischemia‐induced arrhythmias and heart injury in an in vivo rat model of regional heart ischemia. The extract was also standardized, and its antioxidant activity was evaluated. Adult male Sprague–Dawley rats were subjected to 30 min of ischemia by occlusion of the left anterior descending coronary artery followed by 5 days of reperfusion. Thirty‐two animals were randomized to receive daily oral administration of vehicle or C. zeylanicum bark extract (intragastric, 50, 100, or 200 mg/kg) 14 days before ischemia. C. zeylanicum was standardized through HPLC analysis. Administration of cinnamon bark extract significantly improved ischemia/reperfusion‐induced myocardial injury as evidenced by reduction of the infarct size. Also, during the ischemic period, ventricular tachycardia and ventricular ectopic beats episodes decreased as compared with that of the control group. The extract stabilized the ST segment changes and QTc shortening, decreased R‐wave amplitude, and increased heart rate during ischemia. The extract also caused significant elevations in serum superoxide dismutase and glutation proxidase activities as well as a significant decrease in serum cardiac troponin I, lactate dehydrogenase, and malondialdehyde levels, 5 days after reperfusion. In HPLC analysis, the amounts of Cinamic acid, Methyl eugenol, and Cinnamaldehyde were 8.99 ± 0.5, 13.02 ± 1.8, and 14.63 ± 1.1 mg/g, respectively. The results show that the ethanolic extract of cinnamon bark is able to protect the heart against ischemia–reperfusion injury probably due to its antioxidant properties. Hence, it might be beneficial in these patients and this remedy might be used for preparation of new drugs.
A robust approach to singular spectrum analysis
Authors: Rodrigues Paulo Canas , Lourenço Vanda , Mahmoudvand Rahim
Published: June 2018

Singular spectrum analysis (SSA) is a nonparametric method for time series analysis and forecasting that incorporates elements of classical time series analysis, multivariate statistics, multivariate geometry, dynamical systems, and signal processing. Although this technique has shown to be advantageous over traditional model‐based methods, in particular, one of the steps of the SSA algorithm, which refers to the singular value decomposition (SVD) of the trajectory matrix, is highly sensitive to data contamination. Specifically, and because SVD decomposition is least squares based, the presence of a single outlier, if extreme, may be enough to draw the leading principal component towards itself resulting in possible misinterpretations, which may subsequently, in particular and in the case of time series analysis, lead to reduced quality of model fit and forecast accuracy. In order to alleviate this problem, a robust SSA algorithm is proposed, where a robust SVD procedure replaces the least squares based one in the original SSA procedure. The SSA and the robust SSA approaches are compared in terms of model fit quality via Monte Carlo simulations that contemplate both clean and noisy/contaminated time series. The adequacy and value of the proposed approach is then compared with the standard SSA using real data about the industrial production index.
Absolute quantitation of acetaminophen‐modified human serum albumin in acute liver failure patients by liquid chromatography/tandem mass spectrometry
Authors: Geib Timon , LeBlanc André , Shiao Tze Chieh , Roy René , Leslie Elaine M. , Karvellas Constantine J. , Sleno Lekha
Published: June 2018

Rationale

Acetaminophen (APAP) is a well‐known analgesic, deemed a very safe over‐the‐counter medication. However, it is also the main cause of acute liver failure (ALF) in the Western world, via the formation of its reactive metabolite, N‐acetyl p‐benzoquinone imine (NAPQI), and its covalent attachment to liver proteins. The aim of this study was to develop a sensitive and robust quantitative assay to monitor APAP‐protein binding to human serum albumin (HSA) in patient samples.

Methods

A combination of isotope dilution, peptic digestion and solid‐phase extraction coupled to liquid chromatography/multiple reaction monitoring (LC/MRM) was employed. An external calibration curve with surrogate modified protein spiked into blank serum was used for absolute quantitation. Samples were analyzed by LC/MRM to measure the modified active site peptide of HSA. The LC/MRM assay was validated and successfully applied to serum samples from patients suffering from APAP‐induced ALF.

Results

Accuracy ranged from 83.8–113.3%, within‐run coefficient of variation (CV) ranged from 0.3–6.9%, and total CVs from 1.6–10.6%. Patient samples ranged from 0.12–3.91 nmol/mL NAPQI‐HSA; in‐between the assay dynamic range of 0.11–50.13 nmol/mL serum. In vivo median concentrations were found to be 0.62 nmol/mL and 0.91 nmol/mL for non‐spontaneous survivors (n = 25) and individuals with irreversible liver damage (n = 10), respectively (p‐value = 0.028), demonstrating significant potential as a biomarker for ALF outcome.

Conclusions

A fast and sensitive assay was developed to accurately quantify NAPQI‐HSA as a biomarker for APAP‐related covalent binding in human serum.
Robot‐assisted percutaneous screw placement combined with pelvic internal fixator for minimally invasive treatment of unstable pelvic ring fractures
Authors: Liu Hua‐shui , Duan Sheng‐jun , Liu Shi‐dong , Jia Feng‐shuang , Zhu Li‐ming , Liu Min‐cen
Published: June 2018

Purpose

The purpose of this study was to investigate the safety and efficacy of the combination of robot‐assisted percutaneous screw placement and pelvic internal fixator (INFIX) for minimally invasive treatment of unstable anterior and posterior pelvic ring injuries.

Methods

From September 2016 to June 2017, twenty‐four patients with unstable anterior and posterior pelvic ring injuries were treated with TiRobot‐assisted percutaneous sacroiliac cannulated screw fixation on the posterior pelvic ring combined with robot‐assisted pedicle screw placement in the anterior inferior iliac spine along with INFIX on the anterior pelvic ring. The results of the treatment, including surgery duration, fluoroscopy frequency, total drilling, amount of blood loss, fracture healing time, and postoperative functional outcomes were recorded and compared with another 21 similar patients who underwent conventional manual positioning surgery.

Results

The TiRobot group incurred significantly shorter duration of surgery; less fluoroscopy frequency, intraoperative bleeding, and total drilling than in the conventional group (P < 0.05). Postoperative radiological follow‐up showed that all screws were in the safe area and no screw penetrated the cortex. All wounds healed by primary intention and no iatrogenic damage to the blood vessels, nerves, and organs occurred. Patients showed good tolerance to INFIX and reported no discomfort. The mean follow‐up duration was 5.4 months; the fractures were all healed, no loss of reduction occurred, and the mean Majeed score at the last follow‐up did not show any difference.

Conclusion

TiRobot‐assisted percutaneous screw placement combined with INFIX for the anterior and posterior pelvic ring injuries is accurate, safe, less invasive, and shows satisfactory efficacy, suggesting it is a better method for minimally invasive treatment of unstable pelvic ring fractures.
Distributed optimal resource allocation of second‐order multiagent systems
Authors: Deng Zhenhua , Liang Shu , Yu Weiyong
Published: June 2018

In this paper, the resource allocation problems of multiagent systems are investigated. Different from the well‐studied resource allocation problems, the dynamics of agents are taken into account in our problem, which results that the problem could not be solved by most of existing resource allocation algorithms. Here, the agents are in the form of second‐order dynamics, which causes the difficulties in designing and analyzing distributed resource allocation algorithms. Based on gradient descent and state feedback, two distributed resource allocation algorithms are proposed to achieve the optimal allocation, and their convergence are analyzed by constructing suitable Lyapunov functions. One of the two algorithms can ensure that the decisions of all agents asymptotically converge to the exact optimal solution, and the other algorithm achieves the exponential convergence. Finally, numerical examples about the economic dispatch problems of power grids are given to verify the effectiveness of the obtained results.
A robust economic MPC for changing economic criterion
Authors: D' Jorge Agustina , Anderson Alejandro , González Alejandro H. , Ferramosca Antonio
Published: June 2018

This note presents a robust economic model predictive control controller suitable for changing economic criterion. The proposal ensures feasibility under any change of the economic criterion, thanks to the use of artificial variables and a relaxed terminal constraint, and robustness in presence of additive bounded disturbances. The resulting robust formulation considers a nominal prediction model and restricted constraints (in order to account for the effect of additive disturbances). The controlled system under the proposed controller is shown to be input‐to‐state stable in the sense that it is asymptotically steered to an invariant region around the best admissible steady state. An illustrative example shows the benefits and the properties of the proposed controller.
Nonlinear variable selection with continuous outcome: A fully nonparametric incremental forward stagewise approach
Authors: Yu Tianwei
Published: June 2018

We present a method of variable selection for the sparse generalized additive model. The method does not assume any specific functional form, and can select from a large number of candidates. It takes the form of incremental forward stagewise regression. Given no functional form is assumed, we devised an approach termed “roughening” to adjust the residuals in the iterations. In simulations, we show the new method is competitive against popular machine learning approaches. We also demonstrate its performance using some real data sets. The method is available as a part of the nlnet package on CRAN (
https://cran.r‐project.org/package=nlnet).
Polyaniline‐ZnO Hybrid Nanocomposites with Enhanced Photocatalytic and Electrochemical Performance
Authors: Qin Runhua , Hao Lingyun , Liu Yi , Zhang Yueling
Published: June 2018

In this paper, polyaniline‐zinc oxide (PANI‐ZnO) nanocomposites (NCPs) were prepared by in‐situ chemical polymerization process. The prepared PANI‐ZnO was characterized by FTIR, XRD, SEM, laser size tester, XPS, UV‐Vis DRS and PL. The photocatalytic ability was evaluated for the degradation of methylene blue (MB) under visible light irradiation. The results indicated that the addition of PANI effectively enhanced the photocatalytic activity of bare ZnO. PANI‐ZnO exhibited significantly enhanced photocatalytic properties, the reaction rate constant (0.01944 min−1) is higher than that of bare ZnO (0.00245 min−1) and PANI (0.00585 min−1). Scavenger test was used to determine the role of active species, combining the analysis results of UV‐Vis DRS and PL, accordingly the photocatalytic mechanism of PANI‐ZnO was proposed. Meanwhile, the as‐prepared PANI‐ZnO NCPs were used to decorate glassy carbon electrode (GCE), and the electrochemical properties of bare GCE and PANI‐ZnO/GCE have been investigated by cyclic voltammetry (CV). The results indicated that the addition of PANI‐ZnO effectively enhanced the electrochemical property of bare GCE. The maximum current density of PANI‐ZnO/GCE is 0.698 mA cm−2, which is higher than that of bare GCE (0.312 mA cm−2). Herein, the surface modification layer of PANI‐ZnO plays a critical role in enhancing current output.
Nanocrystalline Pyrite for Photovoltaic Applications
Authors: Khalid Sadia , Ahmed Ejaz , Khan Yaqoob , Riaz Khalid Nadeem , Malik Mohammad Azad
Published: June 2018

Transition metal sulfides (TMSs) are of special interest in energy conversion and storage devices. Amongst all sulfides, fool's gold or iron pyrite (FeS2) is potentially an attractive candidate for photovoltaic applications. Iron pyrite has risen to prominence due to its distinct properties and abundance in nature to meet the large scale needs. It is considered as environmentally benign solar absorber material with high absorption coefficient, α > 6 x105 cm−1 for λ ≥ 700 nm and suitable energy bandgap (Eg=0.95 eV). Numerous physical and chemical methods have been employed to deposit nanocrystalline pyrite thin films directly from source materials or indirectly by sulfuration. This review gives an overview of pyrite as a low cost photovoltaic absorber material for contemporary solar cell structures. In addition, practical approaches like the rational design of nanocomposites, band gap engineering and nanostructure synthesis of pyrite for improving its properties particularly photovoltaic properties are also deliberated. Moreover, limitations, challenges, remedies and prospects of pyrite as potential photovoltaic material are also reviewed to further advance the development of pyrite‐based solar cell configurations.
Changes in Emission Properties by π‐Stacking and Conformation Adjustment of an Imidazole‐Tethered Naphthalimide Derivative
Authors: Singh Munendra Pal , Tarai Arup , Baruah Jubaraj Bikash
Published: June 2018

Solid state self‐assemblies of 2,4‐dinitrophenolate, 2,4,6‐trinitrophenolate salts of N‐(3‐imidazol‐1‐yl‐propyl)‐1,8‐naphthalimide (abbreviated as imidanap) have distinguishable π‐stacking patterns, each stack influences fluorescence emission causing fluorescence quenching. It is found that the solid sample of nitrate or bromide salt of imidanap retains fluorescence properties of the parent compound. Photo‐induced electron transfer process in solution gets prominence upon interactions of imidanap with hydrobromic as well as nitric acid but in the nitrophenolate salts the effect of π‐interactions over‐ride the effect of protonation of imidazole to change intensity of fluorescence emission. DFT calculations using B3LYP functional with 6–31+G (d,p) as basis set have revealed LUMO in the imidanap and in the respective nitrophenolate salts are localized on the naphthalimide unit whereas HOMO in each case is localization differently over the rings other than the naphthalimide ring. Studies based on 1H NMR suggest that water causes conformation adjustments of imidanap by forming hydrogen bonds. This enhances photo‐induced electron transfer (PET) emission of the imidanap until a limiting concentration of water is reached, beyond which increase in amount of water causes quenching of emission. The PET‐ON state of imidanap generated by addition of water to an acetonitrile solution is quenched by 2,4,6‐trinitrophenol due to charge‐transfer interactions.
Synthesis of New Heteroaryl α‐Aminophosphonates and Evaluation of Their Cytotoxicity against Human Breast Cancer MCF‐7 Cell Lines
Authors: Kuruva Chandra S. , Gandavaram Syam P. , Kadiam Venkata S. , Valluru Lokanatha , Chamarthi Naga R.
Published: June 2018

Breast cancer has a rate of occurrence of one in nine. Aromatase also named estrogen synthase which is found to be associated with breast cancer and it has also been one of the targets for treatment and the current work explores the potentiality of a new heteroaryl α‐aminophosphonates 9 a‐j. The new heteroaryl α‐aminophosphonates 9 a‐j were synthesized using the reactions involving 2‐aminobenzothiazole (6), various heteroaryl aldehydes 7 a‐j and 2,3‐dihydro[1, 3,2]oxazaphospholo[4, 5‐b]pyridine‐2‐oxide (5). The QSAR (quantitative structure activity relationship) descriptors, PreADMET (adsorption, distribution, metabolism, excretion and toxicity) analysis and binding interaction simulation studies with X‐Ray crystallographic structure of Aromatase have positively forwarded us for the cytotoxicity evaluation of the title compounds by Morphological study, Cell proliferation inhibition assay (MTT), Lactate dehydrogenase (LDH) assay and Hoechst staining (apoptosis). An improved apoptotic cell number was observed in Hoechst staining using compounds 9 e and 9 h further corroborated by LDH assay. Current work supports to conclude the promising ability of the title compounds to induce apoptosis through nuclear fragmentation of breast cancer cells by regulating their metabolic functions.
An Electrochemical Comparison of Single‐Walled and Multi‐Walled Carbon Nanotubes Utilizing Paeonol as the Model Drug
Authors: Mane Suyash , Chatterjee Sanghamitra
Published: June 2018

Herein, we report the development of a selective and highly sensitive electrochemical sensing of paeonol at carbon nanotubes modified glassy carbon electrode (GCE). Trace amount of paeonol was quantitated by employing square wave voltammetry technique for the first time based on the electrochemical oxidation of the analyte at the modified electrodes. The single walled carbon nanotubes (SWNTs) based sensor exhibited higher recognition ability of paeonol in comparison with the multi walled carbon nanotubes (MWNTs) based sensor. The linear dynamic range was found to be 100 nM – 25 μM for SWNTs modified GCE and 1–25 μM for MWNTs modified GCE. The sensitivity at SWNTs modified GCE was ∼ 3.5 times more than that at MWNTs modified GCE. The limit of detection was estimated to be 9.57 nM and 0.63 μM corresponding to SWNTs and MWNTs modified GCE respectively. The influence of experimental parameters affecting sensor response was optimized. The stability, reproducibility tests and interference effects were demonstrated to confirm the reliability of the proposed sensor. The applicability of the developed sensor was successfully assessed through convenient measurements of paeonol in biological samples and Cortex moutan which exhibits anticancer effect.
High‐Performance Red/Near‐IR Carbon Dots as Fluorescence Probes for Tumor Imaging In Vivo
Authors: Yang Sheng‐Tao , Liu Jia‐Hui , Wang Ping , Yang Shengnan , Ge Lin , Yan Sijia , Sun Ya‐Ping
Published: June 2018

Carbon dots (CDots) are brightly fluorescent, especially in the same green spectral region overlapping that of the green fluorescent protein, and also benign and nontoxic. For imaging in vivo, however, red/near‐IR probes are required for the high optical transmittance through tissues and the contrast against interference from autofluorescence background. Herein, high‐performance red/near‐IR CDots are designed and prepared by modifying the core carbon nanoparticles in CDots with the incorporation of selected dye species into the nanoparticle structure. The representative modified CDots thus obtained are used as fluorescence probes in the in vivo imaging of normal and tumor‐bearing nude mice via various exposure pathways. The results suggest that these red/near‐IR CDots are indeed excellent probes for fluorescence imaging in vivo, especially with their enhanced tumor uptake. The potentially far‐reaching implications of being able to design and synthesize the modified CDots of strong optical absorptions and bright fluorescence emissions in the red/near‐IR are discussed in terms of their broad applicability to in vivo imaging and theranostics.
Enhancing Bifunctional Catalytic Activity of Oxygen Reduction and Evolution Reaction via One‐Pot Formation of MnO2‐Carbon Hybrid Nanocomposite
Authors: Kim Hye‐min , Saito Nagahiro , Kim Dae‐wook
Published: June 2018

While manganese dioxide (MnO2) is a promising bifunctional electrocatalyst for oxygen reduction and evolution reaction (ORR/OER) in alkaline media, electrochemical performance of bulk MnO2 limited by their poor electrical conductivity. Herein, we fabricate a MnO2‐carbon nanoparticle hybrid composite (MO‐CNP) by applying the plasma discharge in the single precursor of purple benzene. This synthesis route facilitates a simultaneous formation of MnO2 and carbon, which induced a homogeneously mixed and firmly anchored hybrid composite. As a result, as‐obtained MO‐CNP‐1 shows more than 12 times higher electrical conductivity than that of prepared conventionally. Thus, formation of MO‐CNP could be accompanied by a synergy between MnO2 and CNP as electrocatalyst, and consequently, electrochemical properties were significantly improved. In comparison with CNP, the ORR potential of MO‐CNP‐1 was positively shifted from –0.28 to –0.23 V (vs. Ag/AgCl), and current density has increased more than 2 times. Although the ORR activity of MO‐CNP‐1 was still far a little short of the commercial Pt/C, the MO‐CNP‐1 indicated significant higher OER activity, which demonstrated excellent overall catalytic capability of MO‐CNP‐1 as bifunctional catalyst.
Formation of N‐rich Hierarchically Porous Carbon via Direct Growth ZIF‐8 on C3N4 Nanosheet with Enhancing Electrochemical Performance
Authors: Tan Bin , Luo Huan , Xie Zailai
Published: June 2018

Presented here are the synthesis of series N‐rich hierarchically porous carbons via disposition of ZIF‐8 on g‐C3N4 nanosheets and their uses as electrode materials in oxygen reduction reaction (ORR) and supercapacitor. Electron microscopy images show the successful formation of 2D carbon structures through using layered C3N4 as a novel template and ZIF‐8 as carbon precursor. The meso and macropores of the ZIF‐8 derived carbons are significantly developed with g‐C3N4 incorporation. Electrochemical measurements demonstrate that the resulting 2D carbons exhibit enhancing performance of supercapacitance up to 159.0 F/g at a current density of 1 A/g, meanwhile the optimized electrocatalytic activity for ORR in O2 saturated 0.1 M KOH electrolyte, with a distinct oxygen reduction peak at 0.71 V that was comparable to the value of the referenced Pt/C catalyst. Notably, this is the first investigation of layered g‐C3N4 supported ZIF‐8 derived carbons for ORR and supercapacitance. This work may offer a new way to prepare novel electrocatalysts by effective integration of ZIF‐8 derived carbon and the g‐C3N4 skeleton.
The Application of Graphite in the Preparation of Cathode Material Li3V2(PO4)3/C
Authors: Bai Guoliang , Wang Chunhua , Yang Yifu , Shao Ms. Huixia
Published: June 2018

Graphite and citric acid are simultaneously employed as carbon sources to prepare Li3V2(PO4)3/C (LVP/C) cathode material by a sol‐gel method. The effects of graphite on the structure and electrochemical performance of LVP/C are investigated by X‐ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer‐Emmett‐Teller (BET) method, and electrochemical measurements. The XRD patterns indicate that graphite influences the rate and the direction of the LVP crystal growth. The SEM results show that the sample has a unique porous wafer‐like morphology. The sample has initial discharge capacities of 128.7 and 124 mAh g−1 at 0.2 and 5 C rates in the potential range of 3.0‐4.3 V, respectively. The capacity retentions are 99.8% and 93.3% after 100 circles. In addition, a simple method for the determination of carbon content of LVP/C sample is put forward.
Halide‐Modulated Functionality of Wide Band Gap Zinc Oxide Semiconductor Nanoparticle
Authors: Maji Tuhin Kumar , Kar Prasenjit , Mandal Harahari , Bhattacharya Chinmoy , Karmakar Debjani , Pal Samir Kumar
Published: June 2018

Surface modification of inorganic nanomaterials using different ions is well‐known to induce significant modulation in functionality of the nanoparticles (NP), which improves tuning their relevant properties for suitable applications in the field of nanotechnology. Here, we report synthesis and surface modification of a model inorganic wide bandgap semiconductor ZnO NP by halide ions by simple precipitation method and demonstrate that proximity of various halide ions to the NP modifies their electronic properties. It is interesting to note that such surface modulation has little impact on its morphology, while significantly influencing their applications in photocatalytic activity or magnetism. Indeed, the halide attached ZnO NP displays a large reduction of defect state emission. Various microscopic and spectroscopic tools (including picosecond resolved technique) were used to characterize and understand the key role of the halide ions to modulate the light induced charge separation in ZnO NP. Picosecond resolved fluorescence spectra unveil a significant quenching, implying an electronic cross‐talking between the NP and the attached halide ions. Magnetic measurements indicate that attachment of a suitable halide ion introduces room temperature ferromagnetism in this system. Finally, the photocatalytic activity of the ZnO NP for the photodegradation of a model pollutant, methyl orange was evaluated under UV light irradiation. Halide ZnO is anticipated to be a very promising photocatalytic agent; hence it can be used to cleanup environmental pollution. First principles analysis has been performed to understand the modulation of electronic properties like photocatalysis and magnetism in halide attached nanosystem. The experimental behavior resembles nicely with theoretical results.
Multi‐Color Excitonic Emissions in Chemical Dip‐Coated Organolead Mixed‐Halide Perovskite
Authors: Tanveer Karim Al Momin M. , Rahman M. Azizar , Hossain M. S. , Khan M. K. R. , Rahman M. Mozibur , Kamruzzaman M. , Ton‐That Cuong
Published: June 2018

Organolead mixed‐halide perovskites capable of emitting multiple colors not only allow the fabrication of compact devices but also improves the functionality of light emitting devices beyond conventional displays. Here we demonstrate a cost‐effective chemical dip‐coating technique to grow highly reproducible methylammonium‐lead‐halide perovskite film, which exhibits highly efficient multi‐color emissions of red, green and ultraviolet. The power‐ and temperature‐resolved cathodoluminescence analyses reveal that these emissions are attributed to localized excitions with thermal activation energies of 27, 29 and 57 meV. The non‐linear fitting of these emission band widths within the frame work of Boson model reveals that excitons are strongly coupled to the lattice with energy of 28 meV, which is consistent with the Raman measurement. This work presents an effective method for the deposition of high‐quality and large‐area perovskite film, which could be useful for high‐performance multi‐color display devices.
Oxidative Dehydrogenation of But‐1‐ene at Low Temperature with Copper Ferrite Catalysts
Authors: Kiyokawa Takayasu , Ikenaga Naoki
Published: June 2018

Oxidative dehydrogenation (ODH) reactions of but‐1‐ene with copper and iron oxide catalysts were carried out with a fixed‐bed flow reactor in a temperature range of 230–350 °C at 1‐C4H8(mL/min)/O2(mL/min) flow ratios of 5/1, 5/2.5, 5/4, and 5/5 for 100 min. When CuFe2O4/AC prepared in the presence of activated carbon at a molar ratio of Cu/Fe=1/2 was used for the ODH under reaction conditions of 270 °C and 1‐C4H8/O2=5/5, the highest BD (buta‐1,3‐diene) yield of 15% for 100 min was achieved. When the usability of the CuFe2O4 structure was evaluated, it was clarified that the ODH and complete oxidation proceeded on copper oxides. In addition, CuFe2O4/AC mainly advanced the ODH, while CuO and Cu2O promoted the complete oxidation. CuFe2O4/AC catalyst showed the good catalytic performance in the ODH of but‐1‐ene at a low temperature of 270 °C. According to XRD and XPS analyses of CuFe2O4/AC, CuO/AC, and Cu2O before and after the reaction, most of the crystalline CuO phase changed to the Cu2O phase during the ODH, and the Cu2O phase was maintained in the ODH. These results indicated that complete oxidation occurred with the Cu2O phase. In the case of CuFe2O4/AC, although Cu species in CuFe2O4 were also reduced to Cu2O, many CuFe2O4 structures and Cu2+ species were maintained. This suggested that the maintenance of the CuFe2O4 structure and Cu2+ species is important in the production of BD.
Electrochemical Corrosion of Ag Electrode in the Silver Grid Electrode‐Based Flexible Perovskite Solar Cells and the Suppression Method
Authors: Wang Jie , Chen Xiaolian , Jiang Fangyuan , Luo Qun , Zhang Lianping , Tan Mingxi , Xie Menglan , Li Yan‐Qing , Zhou Yinhua , Su Wenming , Li Yuanjie , Ma Chang‐Qi
Published: June 2018

The Ag grid electrode is a candidate for use as a transparent conductive electrode in large‐area flexible thin‐film photovoltaics due to its high conductivity and high optical transparency. But the device performance and stability are greatly inhibited due to the corrosion of Ag electrode by perovskite. The PH1000 (highly conductive PEDOT:PSS)‐involved electrochemical corrosion of the Ag electrode is found to be a major reason of the low device performance for flexible Ag grid electrode‐based perovskite solar cells. This redox reaction occurred via the reduction of PH1000 (a kind of highly conductive PEDOT:PSS) layer and the oxidation of Ag electrode, and finally caused a rapid reaction between the Ag electrode and perovskite precursor solution. Such corrosion is suppressed by introduction of an ammonia: polyethylenimine modified PH1000 (PH1000:ammonia:PEI) layer, possibly because PH1000 is reduced by PEI in the composite layer prior to Ag. High‐performance flexible perovskite solar cells with power conversion efficiencies (PCEs) of 14.52% are fabricated on PET/Ag‐grid/modified highly conductive PEDOT:PSS (PH1000) flexible composite transparent electrodes via a facile one‐step anti‐solvent‐assisted fast crystallization route. Flexible perovskite solar cells using this composite electrode exhibited excellent robustness and durability, maintaining more than 86% of the initial performance after 5000 full bending cycles.
Optimizing data stream processing for large‐scale applications
Authors: Cappellari Paolo , Roantree Mark , Chun Soon Ae
Published: June 2018

Stream processing systems are designed to analyze data arriving in real time and using continuous queries and respond when a specific event or sequence of events are detected. An important aspect of these systems is Streaming Analytics, which facilitates statistical calculations on continuous data within the stream. These systems must be designed to handle high volumes of data, be scalable, and accommodate a multitude of long‐lived concurrently running analytics. The challenges involved in the development of stream processing include on‐the‐fly transformation of data streams to match the query needs of users and the ability to model stream transformations to detect overlaps and possibilities for optimizations and to specify a methodology to deliver optimizations. In particular, this work focuses on exposing data stream application internals in order to detect reusable parts and then consolidate applications to optimize computational resource usage. The Streaming Data Analytics Model presented in this paper adopts a declarative approach that enables processing and manipulation of data streams in a simple manner while facilitating powerful optimizations necessary for managing high volumes of streaming data in real time. An evaluation is provided to demonstrate in both theoretical and quantitative aspects the high performance offered by our approach.
Simultaneous qualitative and quantitative determination of compounds in Aloe arborescens Mill using liquid chromatography with ion trap time‐of‐flight mass spectrometry and diode array detectors
Authors: Li Tiantian , Liao Ziqiong , Chen Mingyi , Liu Deliang , Zhang Shaobao , Lin Lei , Zheng Haihui , Liao Qiongfeng , Xie Zhiyong , Song Fenyun
Published: June 2018

An effective and comprehensive method was developed for the simultaneous analysis of compounds in the powder of Aloe arborescens Mill by liquid chromatography with ion trap time‐of‐flight mass spectrometry and high‐performance liquid chromatography with diode array detection. Qualitative analysis of all the compounds presented in Aloe arborescens Mill was performed by liquid chromatography with ion trap time‐of‐flight mass spectrometry. A total of 28 components from Aloe arborescens Mill were identified, including chromones, phenyl pyrones, anthrones and anthraquinones. The quantitative analysis of multi‐components by a single‐marker method was developed and validated for the simultaneous determination of aloenin, 2′‐α‐rhamnopyranosylisovitexin, aloinA, and aloinB in Aloe arborescens Mill leaves using high‐performance liquid chromatography. We can than calculate the contents of the other constituents with the relative correction factors correspondingly. In comparison with the results obtained using the external standard method, the quantitative analysis of multi‐components by the single‐marker method demonstrates no significant difference. This is the first simultaneous characterization and quantitative determination of multiple compounds in Aloe arborescens Mill. It can be applied to standardize the quality of Aloe arborescens Mill as well as the future design of nutraceutical and cosmetic preparations.