bluuebunny/crossref_metadata_2025 huggingface dataset:
One‐Pot Synthesis of Multiple Protein‐Encapsulated DNA Flowers and Their Application in Intracellular Protein Delivery
Authors: Kim Eunjung , Zwi‐Dantsis Limor , Reznikov Natalie , Hansel Catherine S. , Agarwal Shweta , Stevens Molly M.
Published: May 2017

Inspired by biological systems, many biomimetic methods suggest fabrication of functional materials with unique physicochemical properties. Such methods frequently generate organic–inorganic composites that feature highly ordered hierarchical structures with intriguing properties, distinct from their individual components. A striking example is that of DNA–inorganic hybrid micro/nanostructures, fabricated by the rolling circle technique. Here, a novel concept for the encapsulation of bioactive proteins in DNA flowers (DNF) while maintaining the activity of protein payloads is reported. A wide range of proteins, including enzymes, can be simultaneously associated with the growing DNA strands and Mg2PPi crystals during the rolling circle process, ultimately leading to the direct immobilization of proteins into DNF. The unique porous structure of this construct, along with the abundance of Mg ions and DNA molecules present, provides many interaction sites for proteins, enabling high loading efficiency and enhanced stability. Further, as a proof of concept, it is demonstrated that the DNF can deliver payloads of cytotoxic protein (i.e., RNase A) to the cells without a loss in its biological function and structural integrity, resulting in highly increased cell death compared to the free protein.
Nomenclature and definition in asymmetric regional body overgrowth
Authors: Kalish Jennifer M. , Biesecker Leslie G. , Brioude Frederic , Deardorff Matthew A. , Di Cesare‐Merlone Alessandra , Druley Todd , Ferrero Giovanni B. , Lapunzina Pablo , Larizza Lidia , Maas Saskia , Macchiaiolo Marina , Maher Eamonn R. , Maitz Silvia , Martinez‐Agosto Julian A. , Mussa Alessandro , Robinson Peter , Russo Silvia , Selicorni Angelo , Hennekam Raoul C.
Published: May 2017

We designate a novel term “isolated lateralized overgrowth” (ILO) for the findings previously described as “isolated hemihypertrophy” and “isolated hemihyperplasia.” ILO is defined as lateralized overgrowth in the absence of a recognized pattern of malformations, dysplasia, or morphologic variants. ILO is likely genetically heterogeneous. Further study is required to determine more of the underlying genetic etiologies and potential associations with currently unrecognized patterns of malformation.
Metal‐Free Ionic‐Liquid‐Mediated Synthesis of Benzimidazoles and Quinazolin‐4(3H)‐ones from Benzylamines
Authors: Sharma Rohit , Abdullaha Mohd. , Bharate Sandip B.
Published: May 2017

An expedient metal‐free synthetic protocol for the construction of benzimidazoles has been developed from o‐phenylenediamine and benzylamine, using an imidazolium‐based ionic liquid as the reaction medium. The reactions proceed by oxidation of benzylamine derivatives to their corresponding imines, followed by intramolecular cyclization, to yield benzimidazoles. Advantages of this method include: an environmentally friendly metal‐free process, recyclable reaction media, high yields, short reaction times, and the applicability for the synthesis of quinazolin‐4(3H)‐ones. An NMR spectroscopy study provided further insight into the reaction.
Synthesis of 18‐Demethoxy Analogues of the Aglycon of Saundersiosides A and B, Based on a Cascade Process
Authors: Jiang Xiao‐Ling , Shi Yong , Tian Wei‐Sheng
Published: May 2017

A deprotection/retro‐vinylogous aldol/vinylogous aldol/intramolecular transesterification/O‐Michael cascade triggered by Bu4NF was found to lead to a hexacyclic lactone in high yield on gram scale. This intermediate was used to prepare several 18‐demethoxy analogues of the aglycon of saundersiosides A and B.
Utilizing Paper‐Based Devices for Antimicrobial‐Resistant Bacteria Detection
Authors: Boehle Katherine E. , Gilliand Jake , Wheeldon Christopher R. , Holder Amethyst , Adkins Jaclyn A. , Geiss Brian J. , Ryan Elizabeth P. , Henry Charles S.
Published: May 2017

Antimicrobial resistance (AMR), the ability of a bacterial species to resist the action of an antimicrobial drug, has been on the rise due to the widespread use of antimicrobial agents. Per the World Health Organization, AMR has an estimated annual cost of USD 34 billion in the US and is predicted to be the number one cause of death worldwide by 2050. One way AMR bacteria can spread, and by which individuals can contract AMR infections, is through contaminated water. Monitoring AMR bacteria in the environment currently requires that samples be transported to a central laboratory for slow and labor intensive tests. We have developed an inexpensive assay using paper‐based analytical devices (PADs) that can test for the presence of β‐lactamase‐mediated resistance. To demonstrate viability, the PAD was used to detect β‐lactam resistance in wastewater and sewage and identified resistance in individual bacterial species isolated from environmental water sources.
Additive‐Free, Robust H2 Production from H2O and DMF by Dehydrogenation Catalyzed by Cu/Cu2O Formed In Situ
Authors: Zhang Sai , Ma Yuanyuan , Zhang Huan , Zhou Xuemei , Chen Xiao , Qu Yongquan
Published: May 2017

Hydrogen production from organic/inorganic hydrides is a promising strategy for the development of novel clean energy resources to replace fossil fuels and satisfy ever‐increasing energy demands. Most current processes involve small flammable chemicals and are catalyzed by noble metals in basic media with the release of the greenhouse gas CO2. Herein, we describe an alternative pathway for highly efficient and robust H2 production through a dehydrogenation reaction between water and N,N‐dimethylformamide catalyzed by Cu/Cu2O catalysts formed in situ. The catalysts exhibit high and robust activity for H2 production. Importantly, the formation of H2 as the sole gas and the valuable by‐product N,N‐dimethylaminoformic acid make this process clean and valuable with 100 % atom economy.
Preparation at the water–oil interface of Janus composite nanoparticles and their photoelectric properties
Authors: Qiao Yisha , Du Yixuan , Zhang Xiaowei , Li Yunbo
Published: May 2017

A series of Janus composite poly(3‐hexyl thiophene)‐b‐poly(3‐thiophenehexanethiol)–gold nanoparticles were synthesized by self‐assembly at the water–oil interface, and their photoelectric performance was investigated. The results show that the precise Janus composite nanostructure could be controlled by the adjustment of the reaction temperature and stirring time. The UV–visible measurement revealed that the absorption maximum had an appreciable redshift, and the photoluminescence (PL) spectra indicated that the PL intensity of poly(3‐hexyl thiophene)‐b‐poly[3‐(6‐thiolhexyl thiophene)] decreased upon the addition of gold nanoparticles. In addition, compared to a common composite of poly(3‐hexyl thiophene), the conductivity properties of the Janus composite nanostructure increased remarkably. Therefore, the Janus composite nanoparticles have the potential for applications in photovoltaic devices. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45107.
Coopetition as a Potential Strategy for Corporate Sustainability
Authors: Christ Katherine L. , Burritt Roger L. , Varsei Mohsen
Published: May 2017

The paper is among the first to consider coopetition strategy in the context of corporate level sustainability. Through examination of literature and an example of an actual coopetitive agreement in wine industry logistics, consideration is given to the potential benefits of and problems with sustainability‐based coopetition strategies. The research, based on publicly available information, leads to suggestions for future study into specific theoretical, methodological and pragmatic aspects of sustainability‐related coopetition strategies. At a theoretical level, research into the dynamics of coopetition strategies and relationships between win–win and trade‐offs within economic, environmental and social performance settings is suggested. As the field of study continues to emerge, a broader set of exploratory case studies involving collaborative engagement and participation of practitioners is needed. Attention is also drawn to a broad range of settings available for further research into the design and implementation of sustainability‐related coopetitive strategies exploring advantages for corporations and society. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
Directing virtual crowds based on dynamic adjustment of navigation fields
Authors: Tsai Tsung‐Yu , Wong Sai‐Keung , Chou Yi‐Hung , Lin Guan‐Wen
Published: May 2017

Navigation fields are a popular data structure for directing the movement of virtual crowds. However, the congestion problem may occur at the corners of objects in using a navigation field because the agents move quite closely to each other. The agents may congest at the corners even though there is room for the agents to move away from the congested regions. In this paper, we propose to place crowd monitors at the corners to collect the data such as the movement direction of crowds and crowd densities. Then the navigation field is adjusted dynamically so that the crowds are led to move away from the congested regions. We also propose a simple data structure for speeding up the collision detection process between agents and objects. Experimental results show that our approach successfully alleviates the congestion problem at the corners.
Supported Vanadium Oxide Clusters in Partial Oxidation Processes: Catalytic Consequences of Size and Electronic Structure
Authors: Yun Dongmin , Song Yang , Herrera José E.
Published: May 2017

The catalytic activity for ethanol partial oxidation of vanadium oxide (VOx) anchored on titanium oxide was correlated to their electronic structure. In situ Raman spectroscopy and temperature‐programmed desorption (TPD) experiments indicate that the presence of catalytically active VOx moieties is very sensitive to vanadia loading: highly dispersed VOx predominantly exists at low VOx contents whereas larger vanadia clusters coexist at higher VOx loadings. In situ UV/Vis spectroscopy revealed that a significant fraction of these larger clusters remain reduced during catalysis, and thus do not fully participate in catalytic turnovers. The electronic structures of model VOx nanoclusters of different sizes (monomer, dimer, trimer, and one‐dimensional polymers) were investigated by using periodic density functional theoretical calculations. Results indicate that their electronic structures are significantly affected by their size. Our analysis also revealed that the formation of reduced VOx species (V4+) during catalysis is concomitant to the reduction of adjacent Ti cations (Ti3+). Theoretically calculated optical absorption spectra matched the experimental spectroscopic results obtained under in situ reaction conditions. Furthermore, the determination of defect formation enthalpies reported previously as the main descriptor for catalytic activity of vanadia nanoclusters, predicted that isolated monomeric VOx clusters predominantly take part in catalytic turnovers.
Cuprous Ion Mass Transport Limitations During Copper Electrodeposition
Authors: Schmidt Ralf , Gaida Josef
Published: May 2017

Polarization experiments in sulfuric acid based copper plating electrolytes disclosed unique mass‐transport limitations at very small cathodic overpotentials. Determination of the bulk concentration of the species, which is correlated to the observed limiting current plateaus, by means of Levich plots indicated that these plateaus may be related to mass‐transport‐limited copper deposition from cuprous ions. This hypothesis was further supported by comparison of the equilibrium constant of the comproportionation of cupric ions and metallic copper to cuprous ions obtained from experiments with literature values. The results provide a simple technique to detect cuprous ions and support the view that cuprous ions are deposited at a diffusion‐limited rate, whereas cupric ions deposition is controlled by electrochemical kinetics. The method may be of relevance for superfilling, since the action of additives in industrial plating electrolytes involves interaction with cuprous ions.
Facile Preparation of Water‐Soluble and Cytocompatible Small‐Sized Chitosan‐Polydopamine Nanoparticles
Authors: Ni Yunzhou , Chen Feng , Shi Leilei , Tong Gangsheng , Wang Jie , Li Huimei , Yu Chunyang , Zhou Yongfeng
Published: May 2017

In this paper, a kind of novel water‐soluble chitosan‐polydopamine (CHT‐PDA) nanoparticles with a hydrodynamic diameter (Dh) around 10 nm were reported by the combination of self‐polymerization of PDA and electrostatic complexation between PDA and CHT in water/DMSO (W/D) mixture at the molar fraction of DMSO (xDMSO = 0.37). The preparation method was efficient with a yield of 98% around. The as‐prepared water‐soluble CHT‐PDA nanoparticles exhibited effective UV‐screen ability, enhanced visible‐light transmittance and good cytocompatibility via MTT assay, which might be used in transparent formulation for UV protection usage, especially in biological field including sun care application.
Diameter‐Sensitive Breakdown of Single‐Walled Carbon Nanotubes upon KOH Activation
Authors: Ye Jianglin , Wu Shuilin , Ni Kun , Tan Ziqi , Xu Jin , Tao Zhuchen , Zhu Yanwu
Published: May 2017

While potassium hydroxide (KOH) activation has been used to create pores in carbon nanotubes (CNTs) for improved energy‐storage performance, the KOH activation mechanism of CNTs has been rarely investigated. In this work, the reaction between single‐walled CNTs (SWCNTs) and KOH is studied in situ by thermogravimetric analysis coupled to infrared (IR) spectroscopy and gas chromatography/mass spectrometry (MS). The IR and MS results clearly demonstrate the sequential evolution of CO, hydrocarbons, CO2, and H2O in the activation process. By using the radial breathing mode of Raman spectroscopy, a diameter‐sensitive selectivity is observed in the reaction between SWCNTs and KOH, leading to a preferential distribution of SWCNTs with diameters larger than 1 nm after activation at 900 °C and a preferential removal of SWCNTs with diameters below 1 nm upon activation.
Evaluation of Therapeutics for Advanced‐Stage Heart Failure and Other Severely‐Debilitating or Life‐Threatening Diseases
Authors: Prescott JS , Andrews PA , Baker RW , Bogdanffy MS , Fields FO , Keller DA , Lapadula DM , Mahoney NM , Paul DE , Platz SJ , Reese DM , Stoch SA , DeGeorge JJ
Published: May 2017

Severely‐debilitating or life‐threatening (SDLT) diseases include conditions in which life expectancy is short or quality of life is greatly diminished despite available therapies. As such, the medical context for SDLT diseases is comparable to advanced cancer and the benefit vs. risk assessment and development of SDLT disease therapeutics should be similar to that of advanced cancer therapeutics. A streamlined development approach would allow patients with SDLT conditions earlier access to therapeutics and increase the speed of progression through development. In addition, this will likely increase the SDLT disease therapeutic pipeline, directly benefiting patients and reducing the economic and societal burden of SDLT conditions. Using advanced‐stage heart failure (HF) as an example that illustrates the concepts applicable to other SDLT indications, this article proposes a streamlined development paradigm for SDLT disease therapeutics and recommends development of aligned global regulatory guidance.
Corporate stakeholder responsiveness? Exploring the state and quality of GRI‐based stakeholder engagement disclosures of European firms
Authors: Moratis Lars , Brandt Satu
Published: May 2017

Stakeholder engagement (SE) is recognized as a key process to align firm and stakeholder interests and to identify material content for sustainability reporting (SR). Research on SE quality in an SR context has, however, been largely neglected. This paper investigates the current state and quality of SE within SR within a sample of 55 sustainability reports issued by European firms that used the new Global Reporting Initiative's G4 Guidelines. It will focus on why, how, and with whom firms are involved in SE based on an SE disclosures analysis framework and investigate the extent to which reporting maturity influences the state of SE disclosures and SE quality. While SE seems common practice, many firms are failing to provide full disclosure on how stakeholders have been engaged in defining report content. Less than half of the studied reports contained clear disclosures on how firms had responded to stakeholder concerns. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
Using Formal Concept Analysis to Examine Water Disclosure in Corporate Social Responsibility Reports
Authors: Kleinman Gary , Kuei Chu‐hua , Lee Picheng
Published: May 2017

Corporate social responsibility (CSR) water disclosures vary in content, leading to concern about the quality and extent of such disclosures. This paper employs formal concept analysis (FCA) to examine water reporting of selected companies in the US food and beverage industry that have followed the water guidelines set forth by the Global Reporting Initiative (GRI) and in the disclosure guidelines of the CEO Water Mandate. Assessments of water consumption and water withdrawal were cited more often in our sample firms' CSR reports. FCA results also identify the major focus of our sample firms as setting sustainable water management goals and water quality strategy. Other important issues included leadership, partnership, and employee involvement. While the FCA text mining tool is demonstrated using water‐related behaviors here, it can be used to identify continuous improvement opportunities and examine many other issues of interest to corporate stakeholders in other industries and communities worldwide. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
Modeling and analysis of simultaneous information and energy transfer in Internet of Things
Authors: Liu Chang , Natarajan Balasubramaniam
Published: May 2017

The Internet of Things (IoT) will allow unprecedented connectivity among devices and is predicted to make our worldsmarter. However, due to battery constraints, energy efficiency of IoT with numerous smart devices is a key challenge. Simultaneous information and energy transfer (SIET) is a promising method to provide green energy for energy‐constrained wireless networks. This paper, for the first time, investigates the modeling and analysis of SIET in a network where IoT nodes are powered via IoT gateways. Specifically, a Ginibre point process that captures the repulsion between spatially distributed nodes is used to model the IoT gateway network. The goal of our work is to uncover a strategy to balance the trade‐off between power outage probability and transmission outage probability by a careful design of the power split ratio of SIET. To achieve that, we derive closed‐form expressions for these 2 probabilities in IoT for a practical case. The simulation results verify our theoretical results and illustrate the effects of different network parameters (eg, transmit power and density of gateways and signal‐to‐interference‐plus‐noise ratio threshold) on SIET.
Reporting Degradation from Different Fuel Contaminants in Ni‐anode SOFCs
Authors: Lanzini A. , Ferrero D. , Papurello D. , Santarelli M.
Published: May 2017

The real‐life operation of solid oxide fuel cell (SOFC) system has to deal with fuel contaminants which might reduce even significantly the lifetime of reformer and stack depending on the type and amount of contaminant present in the feed stream. From a system perspective, detecting and correlating observed stack and reformer performance degradation with fuel contamination is fundamental to implement correctional procedures (e.g., change of clean‐up vessels catalysts) and/or trigger alarms to prevent a further contamination of the fuel cell. In this work, based on own experiments with several fuel contaminants (H2S, HCl, tars, siloxanes), we have developed empirical degradation models which are able to quantitatively correlate the range of degradation rate resulting from known amounts of a certain contaminant type in the fuel stream. Degradation induced by carbon deposition is also assessed using a simulation model. The techno‐economic trade‐off of having ultra‐stringent purification requirements on the fuel clean‐up unit due to additional operating costs (e.g., for frequent catalysts change) or capital costs (e.g., for vessel over‐sizing to accommodate a larger amount of catalysts and possibly of different types) versus the lifetime of the fuel cell stacks is eventually analyzed.
Therapeutic application of multipotent stem cells
Authors: Mirzaei Hamed , Sahebkar Amirhossein , Sichani Laleh Shiri , Moridikia Abdullah , Nazari Sara , Sadri Nahand Javid , salehi Hossein , Stenvang Jan , Masoudifar Aria , Mirzaei Hamid R. , Jaafari Mahmoud R.
Published: May 2017

Cell therapy is an emerging fields in the treatment of various diseases such as cardiovascular, pulmonary, hepatic, and neoplastic diseases. Stem cells are an integral tool for cell therapy. Multipotent stem cells are an important class of stem cells which have the ability to self‐renew through dividing and developing into multiple specific cell types in a specific tissue or organ. These cells are capable to activate or inhibit a sequence of cellular and molecular pathways leading to anti‐inflammatory and anti‐apoptotic effects which might contribute to the treatment of various diseases. It has been showed that multipotent stem cells exert their therapeutic effects via inhibition/activation of a sequence of cellular and molecular pathways. Although the advantages of multipotent stem cells are numerous, further investigation is still necessary to clarify the biology and safety of these cells before they could be considered as a potential treatment for different types of diseases. This review summarizes different features of multipotent stem cells including isolation, differentiation, and therapeutic applications.
Tailoring the luminescence and photocatalytic activity of KMn4(PO4)3by Anions (N3‐and S2‐) doping
Authors: Chandiri Sudhakar Reddy , Gundeboina Ravi , Perala Venkataswamy , Kurra Sreenu , Baig Uzma , Muga Vithal
Published: May 2017

BACKGROUND

Phosphates of bivalent, trivalent, or quadrivalent transition metal cations with alkali or alkaline earth ions are promising materials in the field of materials science and technology. Anions‐doped phosphate materials have attracted considerable attention due to their potential applications in environmental remediation by degrading organic pollutants to less harmful byproducts. Thus, in the present work nitrogen/sulphur was doped into KMn4(PO4)3(KMnPO) to improve its visible light photocatalytic activity.

RESULT

S or N‐doped KMn4(PO4)3(KMnPOS or KMnPON) were prepared by a solid state method. The photocatalytic activities of these materials were evaluated by photodegradation of methylene blue, methyl violet and 4‐chlorophenol. Quenching studies were carried out to identify the reactive species during the photodegradation of dyes. The photoluminescence properties of phosphate materials were investigated, and the color coordinates were also calculated using CIE 1931 chromaticity.

CONCLUSION

The color coordinates obtained give the information that KMnPO, KMnPON and KMnPOS phosphors were suitable for blue light LEDs. KMnPOS is a novel highly visible light responsive photocatalyst and can be reused at least four times efficiently. The higher photocatalytic activity of KMnPOS can be attributed to its lower electron–hole recombination rate and generation of more•OH radicals during photoreaction. © 2017 Society of Chemical Industry
Biosynthesis of 4‐isopropylbenzoic acid from α‐pinene by using a mutant strain originated from the α‐pinene degrader Pseudomonas veronii ZW
Authors: Cheng Zhuowei , Tao Jinguo , Ye Jiexu , Li Chao , Zhang Xiaomin , Chen Jianmeng
Published: May 2017

BACKGROUND

Anthropogenic activities, in particular industrial processes, increase the emissions of volatile organic compounds to the atmosphere. Using special microorganisms to achieve resource recovery is a challenge for pollutant purification.

RESULTS

The α‐pinene‐degrading bacterium, Pseudomonas veronii ZW completely mineralized α‐pinene to CO2 and H2O. One important intermediate metabolite, 4‐isopropylbenzoic acid, was chosen as the target accumulated compound. Through mutagenesis technology, the mutant, P. veronii ZW‐A (CCTCC M2015788), was obtained from the wild strain, and its metabolic pathway for α‐pinene was verified to block in the step of 4‐isopropylbenzoic acid. A 663‐bp DNA fragment flanking the transposon insertion site was obtained through self‐formed adaptor PCR, and was designated as gene orfA, displaying 96% deduced amino acid sequence – similar to rulAB‐like protein. Since this protein contained the mono‐aromatic and polyaromatic compounds homologue degradation gene, the mutant ZW‐A might be an orfA‐disrupted strain, incapable of degrading 4‐isopropylbenzoic acid. Through the optimization of cultural medium, the accumulation rate increased from 19% to 30.4%.

CONCLUSION

This research identified the gene which was related to the degradation of 4‐isopropylbenzoic acid. Such results provided a further understanding of microbial metabolism of α‐pinene by Pseudomonas species and a new method for microbial biosynthesis of 4‐isopropylbenzoic acid. © 2017 Society of Chemical Industry
Restoration of Open‐Cut Mining in Semi‐Arid Systems: A Synthesis of Long‐Term Monitoring Data and Implications for Management
Authors: Shackelford Nancy , Miller Ben P. , Erickson Todd E.
Published: May 2017

Restoration is becoming an increasing global priority. Particularly in high impact developments like open cut mining, restoring ecosystems to pre‐disturbance states is difficult but essential. Successful restoration of vegetation communities requires complex achievements of cover, density, community composition, species richness, and structural elements. This study synthesises 10 years of monitoring surveys to measure restoration success in six mining operations in the semi‐arid Pilbara of Western Australia, with the goal of quantifying current and past restoration performance. We assessed composition, structure, cover, density, and richness. We found that each metric resulted in slightly different performance measures within mining operations. For example, native perennial grasses in restored sites fell short of reference density and cover, while woody species density and cover were regularly within the reference range. Richness was often much higher in restored than in reference sites. Finally, to explore the potential drivers of performance, we analysed the influence of restoration characteristics on each of the vegetation metrics. We found that older restoration had increased cover and density of all vegetation types compared to more recent restoration, while other variables had impacts on restoration results that shifted between metrics and monitoring periods. Compositional similarity with reference sites was higher when restoration occurred on low impact mining activities, when first year rainfall was higher, and when seeding treatments were not applied. Overall, this assessment of long‐term monitoring data highlighted where each performance measure was important to understanding overall restoration patterns in semi‐arid systems and paves the way for improving future restoration practice. Copyright © 2017 John Wiley & Sons, Ltd.
Toward a standard for the evaluation of PET‐Auto‐Segmentation methods following the recommendations of AAPM task group No. 211: Requirements and implementation
Authors: Berthon Beatrice , Spezi Emiliano , Galavis Paulina , Shepherd Tony , Apte Aditya , Hatt Mathieu , Fayad Hadi , De Bernardi Elisabetta , Soffientini Chiara D. , Ross Schmidtlein C. , El Naqa Issam , Jeraj Robert , Lu Wei , Das Shiva , Zaidi Habib , Mawlawi Osama R. , Visvikis Dimitris , Lee John A. , Kirov Assen S.
Published: May 2017

Purpose

The aim of this paper is to define the requirements and describe the design and implementation of a standard benchmark tool for evaluation and validation of PET‐auto‐segmentation (PET‐AS) algorithms. This work follows the recommendations of Task Group 211 (TG211) appointed by the American Association of Physicists in Medicine (AAPM).

Methods

The recommendations published in the AAPM TG211 report were used to derive a set of required features and to guide the design and structure of a benchmarking software tool. These items included the selection of appropriate representative data and reference contours obtained from established approaches and the description of available metrics. The benchmark was designed in a way that it could be extendable by inclusion of bespoke segmentation methods, while maintaining its main purpose of being a standard testing platform for newly developed PET‐AS methods. An example of implementation of the proposed framework, named PETASset, was built. In this work, a selection of PET‐AS methods representing common approaches to PET image segmentation was evaluated within PETASset for the purpose of testing and demonstrating the capabilities of the software as a benchmark platform.

Results

A selection of clinical, physical, and simulated phantom data, including “best estimates” reference contours from macroscopic specimens, simulation template, and CT scans was built into the PETASset application database. Specific metrics such as Dice Similarity Coefficient (DSC), Positive Predictive Value (PPV), and Sensitivity (S), were included to allow the user to compare the results of any given PET‐AS algorithm to the reference contours. In addition, a tool to generate structured reports on the evaluation of the performance of PET‐AS algorithms against the reference contours was built. The variation of the metric agreement values with the reference contours across the PET‐AS methods evaluated for demonstration were between 0.51 and 0.83, 0.44 and 0.86, and 0.61 and 1.00 for DSC, PPV, and the S metric, respectively. Examples of agreement limits were provided to show how the software could be used to evaluate a new algorithm against the existing state‐of‐the art.

Conclusions

PETASset provides a platform that allows standardizing the evaluation and comparison of different PET‐AS methods on a wide range of PET datasets. The developed platform will be available to users willing to evaluate their PET‐AS methods and contribute with more evaluation datasets.
In vivo measurement of T1 and T2 relaxation times in awake pigeon and rat brains at 7T
Authors: Behroozi Mehdi , Chwiesko Caroline , Ströckens Felix , Sauvage Magdalena , Helluy Xavier , Peterburs Jutta , Güntürkün Onur
Published: May 2017

Purpose

Establishment of regional longitudinal (T1) and transverse (T2) relaxation times in awake pigeons and rats at 7T field strength. Regional differences in relaxation times between species and between two different pigeon breeds (homing pigeons and Figurita pigeons) were investigated.

Methods

T1 and T2 relaxation times were determined for nine functionally equivalent brain regions in awake pigeons and rats using a multiple spin‐echo saturation recovery method with variable repetition time and a multi‐slice/multi‐echo sequence, respectively. Optimized head fixation and habituation protocols were applied to accustom animals to the scanning conditions and to minimize movement.

Results

The habituation protocol successfully limited movement of the awake animals to a negligible minimum, allowing reliable measurement of T1 and T2 values within all regions of interest. Significant differences in relaxation times were found between rats and pigeons but not between different pigeon breeds.

Conclusion

The obtained T1 and T2 values for awake pigeons and rats and the optimized habituation protocol will augment future MRI studies with awake animals. The differences in relaxation times observed between species underline the importance of the acquisition of T1/T2 values as reference points for specific experiments. Magn Reson Med 79:1090–1100, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Measurement of lipid composition in human skeletal muscle and adipose tissue with 1H‐MRS homonuclear spectral editing
Authors: Lindeboom Lucas , de Graaf Robin A.
Published: May 2017

Purpose

Accumulation of triglycerides in nonadipose tissue (e.g. ectopic lipids) is characteristic of metabolic derangements and is linked to insulin resistance and cardiovascular disease. Although the detrimental effects of the total amount of ectopic fat has been established, the role of composition of the ectopic lipid stores is unknown. In this study we used proton magnetic resonance spectroscopy (1H‐MRS) homonuclear spectral editing to characterize lipid stores in adipose tissue and skeletal muscle at 4 T.

Methods

A MEGA‐sLASER sequence was used to selectively detect lipid resonances that are scalar coupled to the methine resonance at 5.31 ppm and that can be used to estimate saturated fatty acid and mono‐ and polyunsaturated fatty acids. Phantom experiments were performed to empirically determine correction factors for editing efficiency of the different lipid groups.

Results

The spectral editing approach enabled the estimation of saturated, mono‐unsaturated, and polyunsaturated fatty acid contributions in phantoms and in vivo. These estimations are in the same order as reported in studies using invasive biopsies.

Conclusions

In this study, we have shown the feasibility of spectral editing techniques for ectopic lipid store characterization with 1H‐MRS, regardless of spectral resolution (e.g., B0‐field strength). This new approach offers the opportunity to study ectopic lipid composition in relation to metabolic diseases. Magn Reson Med 79:619–627, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
The INTERGROWTH‐21st gestational weight gain standard and interpregnancy weight increase: A population‐based study of successive pregnancies
Authors: Hutcheon Jennifer A. , Chapinal Nuria , Bodnar Lisa M. , Lee Lily
Published: May 2017

Objective

To link the INTERGROWTH‐21st gestational weight gain standard with the risks of excess maternal postpartum weight retention, approximated by women's weight change between successive pregnancies.

Methods

A population‐based retrospective cohort study of 58,534 women delivering successive pregnancies in British Columbia, Canada (2000‐2015) was conducted. Pregnancy weight gain (kg) in the index pregnancy was converted into a gestational age‐standardized z‐score using the INTERGROWTH‐21st standard. Excess interpregnancy weight gain was defined as weight increases of 5 kg, 10 kg, or obesity (≥30 kg/m2) at the next pregnancy. Weight gain z‐scores and excess interpregnancy weight change were associated using logistic regression.

Results

For all definitions of excess interpregnancy weight gain, risks remained low and stable below a weight gain z‐score of 0 (50th percentile) but rose sharply with increasing z‐scores above zero. Compared with women gaining −1 to 0 SD (16th to 50th percentiles), women gaining > 0 to +1 SD (51st to 84th percentiles) were 55% to 84% more likely to retain excess weight between pregnancies. Risks were three‐ to sixfold higher in women gaining >+1 SD.

Conclusions

A large range of the INTERGROWTH‐21st percentiles were associated with increased risks of excess interpregnancy weight gain. The standard may normalize high weight gains of women at increased risk of excess weight retention.
Prospective evaluation of quality of life in children treated in UKALL 2003 for acute lymphoblastic leukaemia: A cohort study
Authors: Eiser C. , Stride C.B. , Vora A. , Goulden N. , Mitchell C. , Buck G. , Adams M. , Jenney M.E.M. ,   the National Cancer Research Institute Childhood Leukaemia Sub‐Group and UK Childhood Leukaemia Clinicians Network
Published: May 2017

Background

Health‐related quality of life (HRQoL) from diagnosis until end of treatment for children with acute lymphoblastic leukaemia was investigated, examining effects of age, gender, risk‐stratified treatment regimen, and therapy intensity (one vs. two ‘delayed intensifications’ [DIs]).

Method

In a multi‐centre prospective study, parents reported their child's generic and disease‐specific HRQoL and their own care‐giving burden at five time points. From 1,428 eligible patients, 874 parents completed questionnaires at least once during treatment.

Results

At each time point, generic HRQoL was significantly lower than equivalent norm scores for healthy children. HRQoL decreased significantly at the start of treatment, before recovering gradually (but remained below pre‐treatment levels). Parents reported that older children worried more about side effects and their appearance, but showed less procedural anxiety than younger children. Concern for appearance was greater among girls than boys. Compared to Regimen B (i.e. additional doxorubicin during induction and additional cyclophosphamide and cytarabine during consolidation chemotherapy), patients receiving Regimen A had fewer problems with pain and nausea. There were no statistically significant differences in HRQoL by number of DI blocks received.

Interpretation

HRQoL is compromised at all stages of treatment, and is partly dependent on age. The findings increase understanding of the impact of therapy on children's HRQoL and parental care‐giving burden, and will contribute to the design of future trials.
Long‐term follow‐up of endocrine function among young children with newly diagnosed malignant central nervous system tumors treated with irradiation‐avoiding regimens
Authors: Cochrane Anne M. , Cheung Clement , Rangan Kasey , Freyer David , Nahata Leena , Dhall Girish , Finlay Jonathan L.
Published: May 2017

Background

The adverse effects of irradiation on endocrine function among patients with pediatric brain tumor are well documented. Intensive induction chemotherapy followed by marrow‐ablative chemotherapy with autologous hematopoietic cell rescue (AuHCR) without central nervous system (CNS) irradiation has demonstrated efficacy in a proportion of very young children with some malignant CNS tumors. This study assessed the long‐term endocrine function of young children following chemotherapy‐only treatment regimens.

Procedures

A retrospective chart review was performed on 99 patients under 6 years of age with malignant brain tumors newly diagnosed between May 1991 and October 2010 treated with irradiation‐avoiding strategies. Thirty patients survived post‐AuHCR without cranial irradiation for a mean of 8.1 years (range 3.0–22.25 years). The patient cohort included 18 males and 12 females (mean age at AuHCR of 2.5 years, range 0.8–5.1 years).

Results

All 30 surviving patients had documented normal age‐related thyroid function, insulin‐like growth factor binding protein 3 (IGF‐BP3), prolactin, testosterone, and estradiol levels. Insulin‐like growth factor 1 age‐related levels were abnormal in one child with normal height. Ninety‐seven percent of patients had normal cortisol levels, while follicle‐stimulating hormone and LH levels among females were normal in 83% and 92%, respectively, and in 100% of males. Growth charts demonstrated age‐associated growth within 2 standard deviations of the mean in 67% of patients. Of 10 patients (33%) with short stature, 6 had proportional diminutions in both height and weight.

Conclusions

These findings demonstrate that the use of relatively brief, intensive chemotherapy regimens including marrow‐ablative chemotherapy with AuHCR results in fewer endocrine sequelae than treatment schemes utilizing CNS irradiation.
A Click‐Generated Triethoxysilane Tethered Ferrocene‐Chalcone‐Triazole Triad for Selective and Colorimetric Detection of Cu2+ Ions
Authors: Singh Gurjaspreet , Arora Aanchal , Rani Sunita , Kalra Pooja , Kumar Manoj
Published: May 2017

This article describes an efficient synthetic approach to design ferrocene tailed chalcone appended triazole encapped organosilanes (7‐12) from acetylinic ferrocene precursors (1‐6). The synthesized compounds were well characterized by general spectroscopic techniques. The framed ligands were then evaluated for their ion sensing properties and were found to display significant perturbation in their absorption and emission behaviour upon addition of Cu2+ ions. Their sensing ability is highly reversible on addition of ethylenediaminetetraacetic acid (EDTA) and hence can be employed as potential Cu(II) sensing materials. In addition, the presence of ferrocene functionality overtures an electro active unit generating a multiple signalling sensor that also offers naked eye detection of Cu(II) ions with analytical detection limit of as low as 10 μM. Above all, the designed chemosensor exhibits tolerance against other metal ions which enables the Cu2+ ion detection even in a complex matrix. Complexation behaviour of one of the silanes, FCTS 12 was also deliberated by computational analysis following DFT approach.
Graphene Oxide Nanosheets as An Efficient and Reusable Sorbents for Eosin Yellow Dye Removal from Aqueous Solutions
Authors: Veerakumar Pitchaimani , Tharini Jeyapragasam , Ramakrishnan Muneeswaran , Panneer Muthuselvam I. , Lin King‐Chuen
Published: May 2017

In this study, 2D graphene oxide nanosheets (GONS) were synthesized and characterized by XRD, Raman, SEM, FE‐SEM, TEM, XPS, TGA, UV‐vis and FTIR spectral techniques. The efficiency of eosin yellow (EY) dye adsorption on the GONS under various experimental parameters such as contact time, pH and temperature was investigated. Adsorption kinetic data were characterized appropriately using pseudo second‐order‐kinetics and intraparticle diffusion methods. Free energy of adsorption (ΔG0), enthalpy (ΔH0), entropy (ΔS0) changes, activation energy and Arrhenius factors were also calculated. The endothermic and spontaneous nature of the adsorption process was confirmed by the positive value of the enthalpy change (ΔH0) and the negative value of free energy change (ΔG0). The adsorption mechanism was investigated by FTIR spectra of GONS before and after adsorption of EY dye molecules. The remarkable adsorption capacity of EY onto the GONS can be attributed to the various adsorption interaction mechanisms such as hydrogen bonding, π‐π electron, and electrostatic interactions. The maximum adsorption capacity for EY was calculated to be 217.33 mg g‐1.
Mechanistic Study on Electrocatalytic Hydrogen Evolution by High Efficiency Graphene/MoS2 Heterostructure
Authors: Behera Sushant Kumar , Deb Pritam , Ghosh Arghya
Published: May 2017

Improved efficiency of N‐doped graphene in van der Waals heterostructure (vdW) for hydrogen evolution reaction (HER) can complement future hydrogen economy. The local electronic environment of layered graphene/MoS2 interface is significantly influenced by doping with foreign atoms. Moreover, electrochemical robust hydrogen evolution at basal planes of vdW heterostructure and the underneath atomic‐scale reaction mechanism is yet to be realised. We have investigated the mechanism of substitutional N‐doping and its catalytic efficiency towards HER process on the basis of density functional theory. By analysing the electronic structure, free‐energy diagrams, Volmer reaction paths and volcano plot analysis, it is inferred that nitrogen doping on graphene layer significantly modulate the hydrogen binding energies resulting in numerous orders of magnitude enhancement in HER activity. This study shows an optimal way to tune hydrogen binding on graphene/MoS2 heterostructure, an efficient electrocatalyst tending towards the value gained by platinum.
Conformation‐Independent QSAR Study on Human Epidermal Growth Factor Receptor‐2 (HER2) Inhibitors
Authors: Duchowicz Pablo R. , Fioressi Silvina E. , Castro Eduardo , Wróbel Karolina , Ibezim Nnenna E. , Bacelo Daniel E.
Published: May 2017

Inhibition of HER2 (human epidermal growth factor receptor 2) expression and function is required in several cancer treatments. Numerous compounds with very different molecular structures have been suggested as HER2 inhibitors. Here we perform quantitative structure‐activity relationship (QSAR) analysis on 444 of such compounds to investigate the molecular properties that may influence its efficiency. Models based on 1D and 2D flexible molecular descriptors are proposed to develop simple models based solely on constitutional and topological molecular features. A large number of non‐conformational descriptors (17974) was used to thoroughly explore the structural characteristics that influence the HER2 inhibitory activity. Three different approaches were explored using: 1) Molecular Descriptors, 2) Flexible Molecular Descriptors, and 3) Hybrid Descriptors. A QSAR model for HER2 inhibitors was successfully developed. Some properties such as electronegativity, aromatic character, and the presence of amino groups appear as molecular characteristics that may have influence in the HER2 inhibitory activity.
Preparation and Characterization of Functional Alkoxysilanes via Catalyst‐Free Aza‐Michael Reaction
Authors: Feng Linglong , Zhu Siyu , Zhang Wenyu , Mei Kai , Wang Hua , Feng Shengyu
Published: May 2017

It is challenging to functionalize alkoxysilanes since they are moisture sensitive. The aza‐Michael reaction is reported as a simple and efficient way to prepare functional alkoxysilanes. The alkoxysilanes were synthesized by reacting amino‐alkoxysilanes with electron‐deficient alkenes under mild reaction conditions without any catalyst. The yield was very high, and a wide range of functional groups could be tolerated in this methodology to form monofunctional or multifunctional alkoxysilanes.
Magnetic HMS silica as a Support to Immobilization of Catalysts Based on Cationic Manganese Porphyrins
Authors: Ucoski Geani Maria , Pinto Victor Hugo Araújo , DeFreitas‐Silva Gilson , Rebouças Júlio Santos , Mazzaro Irineu , Nunes Fábio Souza , Nakagaki Shirley
Published: May 2017

The immobilization of cationic manganese porphyrins (MnP) over the surface of a magnetic hexagonal HMS silica (HMS‐Mag) produced a solid with high surface area and relatively homogeneous pores. Given the presence of the magnetite, the catalysts are easily recovered and reused without loss of mass. The MnP immobilization explored the strong interaction between the positive charges of the cationic MnP and the deprotonated Si‐OH groups on the surface of HMS‐Mag. Soret bands on the UV‐Vis spectra of the MnP‐loaded HMS‐Mag confirmed the presence of MnP on the prepared solids. The catalytic efficiency, robustness, and reusability of the prepared solids were investigated on cis‐cyclooctene and cyclohexane oxidations. The solids showed similar or higher catalytic efficiency than the corresponding MnP under homogeneous catalysis, with selectivity for cyclohexanol in cyclohexane oxidation. Additionally, the solid catalysts showed high resistance against deactivation, confirming the reusability capacity in at least five cycles of cyclooctene oxidation.
Solvent‐Controlled Friedel–Crafts Reaction for the Synthesis of 3‐Indolyl‐3‐hydroxy Oxindoles and 3, 3‐Diindolyl Oxindoles Catalyzed by Dabco‐Base Ionic Liquids
Authors: Tong Jun , Li Yu‐Wei , Xu Da‐Zhen
Published: May 2017

Solvent‐controlled Friedel–Crafts reaction of indoles with various isatins catalyzed by 1,4‐diazobicyclo[2.2.2]octane(DABCO)‐base ionic liquids for a general route toward synthesis of 3‐indolyl‐3‐hydroxy oxindoles and 3, 3‐diindolyl oxindoles has been successful developed. When the reaction was performed in THF, only the monoindolylation products of 3‐indolyl‐3‐hydroxy oxindoles were obtained in good to excellent yields (70–96%). While water was employed as solvent, 3, 3‐diindolyl oxindoles were obtained as the sole products in excellent yields (85–98%). Plausible reaction mechanisms were proposed according to the experimental results.