bluuebunny/crossref_metadata_2025 huggingface dataset:
Attachment of Iron Oxide Nanoparticles to Carbon Nanotubes and the Consequences for Catalysis
Authors: Krans Nynke A. , van der Feltz Ewout C. , Xie Jingxiu , Dugulan Iulian A. , Zečević Jovana , de Jong Krijn P.
Published: April 2018

The attachment of colloidal iron‐oxide nanoparticles (designated Fe‐NPs) to pristine and surface‐oxidized carbon nanotubes (CNTs and CNT‐Ox, respectively) was investigated. The loadings of Fe‐NPs (size 7 nm) on the CNT and CNT‐Ox supports amounted to 3.4 and 2.3 wt. %, respectively; the difference was attributed to weaker van der Waals interactions between the colloidal Fe‐NPs and the surface of CNT‐Ox. Fischer–Tropsch to olefins (FTO) synthesis was performed to investigate the impact of support functionalization on catalyst performance. Weak interactions between the Fe‐NPs and the CNT‐Ox support facilitated particle growth and led to substantial deactivation of the Fe/CNT‐Ox catalysts. The addition of promoters (Na+S) to Fe/CNT resulted in remarkable activity, selectivity to lower olefins, and stability, making colloidal iron nanoparticles on pristine CNTs a suitable catalyst for FTO synthesis.
Use of Rotating Ring‐Disk Electrodes to Investigate Graphene Nanoribbon Loadings for the Oxygen Reduction Reaction in Alkaline Medium
Authors: Cardoso Eduardo S. F. , Fortunato Guilherme V. , Maia Gilberto
Published: April 2018

The oxygen reduction reaction (ORR) is typically slow. Its kinetics, however, are influenced not only by the structure, nature, and doping of electrocatalysts, but also by the loadings of these materials, where all of these factors influence ORR selectivity to produce H2O and/or H2O2. The loadings employed for graphene nanoribbon (GNR)‐modified glassy carbon (GC) electrodes and GC disk modified with commercial Pt (20 wt.%) on carbon (PtC) at 150 μg cm−2 (also resulting in electrode roughness) produced turbulence in the electrolyte flow, significantly changing the geometry of the rotating ring‐disk electrode (RRDE) and collection efficiency (N), as well as causing N to change with the rotation rate of the electrode. This effect toward the ORR was investigated with two analytical methods derived by Wu et al. and Zhou et al. A current deconvolution method for a better‐resolved Tafel analysis separating
formation and reduction reactions resulted in more insightful understanding of the ORR responses provided by the RRDE for different GNR and PtC loadings.
Metal‐Organic Frameworks as Catalyst Supports: Influence of Lattice Disorder on Metal Nanoparticle Formation
Authors: Rivera‐Torrente Miguel , Filez Matthias , Hardian Rifan , Reynolds Emily , Seoane Beatriz , Coulet Marie‐Vanessa , Oropeza Palacio Freddy E. , Hofmann Jan P. , Fischer Roland A. , Goodwin Andrew L. , Llewellyn Philip L. , Weckhuysen Bert M.
Published: April 2018

Because of their high tunability and surface area, metal‐organic frameworks (MOFs) show great promise as supports for metal nanoparticles. Depending on the synthesis route, MOFs may contain defects. Here, we show that highly crystalline MIL‐100(Fe) and disordered Basolite® F300, with identical iron 1,3,5‐benzenetricarboxylate composition, exhibit very divergent properties when used as a support for Pd nanoparticle deposition. While MIL‐100(Fe) shows a regular MTN‐zeotype crystal structure with two types of cages, Basolite® F300 lacks long‐range order beyond 8 Å and has a single‐pore system. The medium‐range configurational linker‐node disorder in Basolite® F300 results in a reduced number of Lewis acid sites, yielding more hydrophobic surface properties compared to hydrophilic MIL‐100(Fe). The hydrophilic/hydrophobic nature of MIL‐100(Fe) and Basolite® F300 impacts the amount of Pd and particle size distribution of Pd nanoparticles deposited during colloidal synthesis and dry impregnation methods, respectively. It is suggested that polar (apolar) solvents/precursors attractively interact with hydrophilic (hydrophobic) MOF surfaces, allowing tools at hand to increase the level of control over, for example, the nanoparticle size distribution.
Mikrobieller Abbau organischer Fremdstoffe im Boden
Authors: Scheunert Irene
Published: April 2018

Im Prinzip kann fast jede organische Industriechemikalie durch die Mikroorganismen des Bodens abgebaut werden.
Large Crystals Synthesis of Siliceous Layered Zeolitic PLS‐1 and CDS‐1 Zeolite by Dry Gel Conversion Method
Authors: Banno Shohei , Komura Kenichi
Published: April 2018

The large crystal of siliceous zeolitic layered PLS‐1, which is a precursor of CDS‐1 zeolite with CDO‐type topology, can be successfully prepared by dry‐gel conversion (DGC) method from a dry‐gel containing layered silicate H‐kanemite and tetramethylammonium hydroxide (TMAOH) as an organic structure‐directing agent (OSDA), and it allows transform to CDS‐1 zeolite by calcination with retaining its large crystal particle. Characterizations of the obtained CDS‐1 zeolite reveal the different morphology compared by conventional methods. Its particle is found to be aggregated by an enlarged thickness of layered crystals reflecting a zeolitic precursor of PLS‐1. Gradual increases of nitrogen adsorption at around middle pressure and FE‐SEM measurements strongly indicate that the obtained particles have many steps and aperture like card‐house assembly of layered PLS‐1 large crystals.
Scalable Membraneless Direct Liquid Fuel Cells Based on a Catalyst‐Selective Strategy
Authors: Yu Xingwen , Manthiram Arumugam
Published: April 2018

This perspective presents a membraneless direct liquid fuel cell (DLFC) concept based on a catalyst‐selective strategy. The membraneless DLFCs are operated at low temperatures by employing a non‐precious cathode catalyst with a high catalytic selectivity. The uniqueness is that the inexpensive cathode catalyst only catalyzes the oxygen reduction reaction but does not catalyze the oxidation reaction of a specific fuel. Therefore, during the operation of DLFCs, the liquid fuel can enter the cathode freely without any concern of fuel crossover. This catalyst‐selective approach tactfully avoids the use of high‐cost or technically unviable ion‐exchange polymer membranes in DLFCs. The catalyst‐selective operating principle also overcomes the scalability issue of the traditional laminar‐flow membraneless DLFCs. Through a proper management of the anode and cathode catalysts in the cell, a variety of inexpensive, renewable alcohols, and small‐molecule organics can be employed as anode fuels. This innovative approach of membraneless alkaline DLFCs offers a great opportunity for the development of inexpensive energy‐generation systems for both mobile and stationary applications. In addition to summarizing the principle and the research progress of the unique membraneless DLFC platform, the challenges and future research directions are presented.
Distance between Metal Centres Affects Catalytic Efficiency of Dinuclear CoIII Complexes in the Hydrolysis of a Phosphate Diester
Authors: Bencze Eva Szusanna , Zonta Cristiano , Mancin Fabrizio , Prins Leonard J. , Scrimin Paolo
Published: April 2018

Dinuclear CoIII complex catalysed hydrolysis of bis‐p‐nitrophenylphosphate, a DNA model substrate, is reported. The catalysts were designed in such a way that the two CoIII ions cannot be contemporaneously involved in the complexation of the substrate or transition state. Experimental evidence of the involvement of such a remote metal centre in the catalysis of the hydrolysis of a phosphate diester is provided. This contribution amounts to a ca. 64‐fold rate acceleration for the second‐order rate constants of the best dinuclear complex over the mononuclear one, which is apparently due to general acid or H‐bonding catalysis. Furthermore, there is significant distance dependence for this catalytic contribution and, in this case, it appears that the best distance (as estimated by DFT calculations) is ca. 7.7 Å. This may indicate that the presence of metal centres in close proximity, as required for mechanism proposals in which all metals are directly involved in transition‐state coordination, is not the only option for rate acceleration in natural phosphate hydrolysis.
Light‐Promoted Allylation of Iododifluoromethylated Alcohols
Authors: Panferova Liubov I. , Struchkova Marina I. , Dilman Alexander D.
Published: April 2018

A method for the synthesis of β,β‐difluorinated alcohols by the formal substitution of iodine in the iododifluoromethyl fragment by the allyl group is described. The reaction involves silylation of the starting alcohols with allyl(chloro)dimethylsilane followed by an light‐promoted atom transfer process. The C,C‐bond‐forming event proceeds through 7‐endo‐trig radical cyclization.
The effect of the implementation of low price medicine policy on medicine price in China: A retrospective study
Authors: Guan Xiaodong , Yang Mingchun , Man Chunxia , Tian Ye , Shi Luwen
Published: April 2018

In an effort to relieve the pressure of drug shortages, the Chinese government implemented Low‐price Medicines (LPM) policy to raise the price cap in July 2014. The purpose of this study is to examine the effect of the implementation of this policy on drug price in China. Price data of 491 LPM, including 218 low‐price chemical medicines (LPCM) and 273 low‐price traditional Chinese medicines (LPTCM), were collected from 699 hospitals. We used interrupted time series design to identify the variation of monthly Laspeyres Indexes (LI) and Paasche Indexes (PI) for LPM, LPCM, and LPTCM. The result demonstrated that although LPM expenditures increased, the proportion of LPM expenditures accounting for all medicine expenditures fell from 3.6% to 3.2%. After the implementation of LPM policy, there was a significant increasing trend in LPM‐PI, LPCM‐PI, and LPTCM‐PI. The trend in LPM‐LI and LPCM‐LI was found from descending to rising. However, for LPTCM, the trend in the LI remained to decrease after the policy implementation. Despite the LPM policy had an increasing impact on the LPM drug price, the proportion of LPM expenditures accounting for all medicine expenditures did not increase. More efforts are needed in the future to promote the rational drug use in China.
Analysis of human chromosome images: Application towards an automated chromosome classification
Authors: Madian Nirmala , Jayanthi K. B. , Suresh S.
Published: April 2018

Karyotyping is the process of arranging the chromosomes to examine the chromosomal abnormalities, a solution for birth defects. Karyotype is achieved from analyzing the metaspread chromosome images. Metaspread chromosome images generally have problem related with overlapping and touching of chromosomes with each other. Segmentation and separation of overlapping and touching chromosomes are still an open issue. The paper proposes an automated algorithm to separate the touching chromosomes and overlapping chromosomes from G‐Band metaspread images. Segmentation is performed by obtaining the interesting (concave and convex) points on the image contour. A proper hypothesis is performed for separating overlapped and touching chromosome images. The isolation of overlapping and touching metaspread chromosome image helps in accurate automated chromosome classification to obtain a karyotype. The overall accuracy of the proposed method works well for separation of touching chromosome with 97.09% and overlapped chromosome with 95%.
Testing the rationality of expectations of qualitative outcomes
Authors: Madeira Carlos
Published: April 2018

This article provides an adequate statistic for testing the rationality of point predictions of categorical outcomes under a subjective median or mode assumption. The test improves upon previous approaches by accounting for all the required moment inequalities and their respective covariance matrix in a single statistic. Monte Carlo simulations show that the test has an improved Type I error, especially in cases with multiple modes. Applying these tests to a dataset with parents' and students' predictions of school scores, I find that respondents are biased towards expecting higher grades and that students' expectations are correlated with the time of study.
Calculating particle pair potentials from fluid‐state pair correlations: Iterative ornstein–zernike inversion
Authors: Heinen Marco
Published: April 2018

An iterative Monte Carlo inversion method for the calculation of particle pair potentials from given particle pair correlations is proposed in this article. The new method, which is best referred to as Iterative Ornstein–Zernike Inversion, represents a generalization and an improvement of the established Iterative Boltzmann Inversion technique (Reith, Pütz and Müller‐Plathe, J. Comput. Chem. 2003, 24, 1624). Our modification of Iterative Boltzmann Inversion consists of replacing the potential of mean force as an approximant for the pair potential with another, generally more accurate approximant that is based on a trial bridge function in the Ornstein–Zernike integral equation formalism. As an input, the new method requires the particle pair correlations both in real space and in the Fourier conjugate wavenumber space. An accelerated iteration method is included in the discussion, by which the required number of iterations can be greatly reduced below that of the simple Picard iteration that underlies most common implementations of Iterative Boltzmann Inversion. Comprehensive tests with various pair potentials show that the new method generally surpasses the Iterative Boltzmann Inversion method in terms of reliability of the numerical solution for the particle pair potential. © 2018 Wiley Periodicals, Inc.
Utility of the immature granulocyte percentage for diagnosing acute appendicitis among clinically suspected appendicitis in adult
Authors: Park Jae‐Sang , Kim June‐Sung , Kim Youn‐Jung , Kim Won Young
Published: April 2018

Background

Acute appendicitis is the most common cause of abdominal surgical emergencies that present at the emergency department (ED). Although early phase of acute appendicitis cannot induce systemic inflammatory responses, it may induce proliferation immature granulocyte before leukocytosis is occurred. Based on this, we hypothesized that IG% may be beneficial for detecting appendicitis, in addition to classic inflammatory markers including the WBC count, a left shift in neutrophils, and CRP, at no additional cost.

Methods

A retrospective observational study was conducted in a tertiary‐care, university‐affiliated hospital emergency department in adults (>18 years old) with suspected appendicitis from January 1, 2015 to December 31, 2016. The diagnostic performance of IG% and other inflammatory markers, namely white blood cell (WBC) count, proportion of neutrophils, and C‐reactive protein (CRP), for acute appendicitis was evaluated.

Results

Of 403 patients, 204 (50.6%) were diagnosed with acute appendicitis and 45 (22.0%) had complicated appendicitis. All inflammatory markers, including WBC count, proportion of neutrophils, IG%, and CRP, were statistically different between the appendicitis and nonappendicitis group (P < .01). However, IG% was not clinically useful because the median IG% was the same (0.3 vs 0.3) between the appendicitis and nonappendicitis group. Moreover, the area under the curve for IG% was smaller than for other inflammatory markers (0.57, 0.51‐0.63, P < .02).

Conclusion

The diagnostic ability of IG% for appendicitis is insufficient, and it brings no additional benefit over other inflammatory markers.
Psychological need frustration as a transdiagnostic process in associations of self‐critical perfectionism with depressive symptoms and eating pathology
Authors: Campbell Rachel , Boone Liesbet , Vansteenkiste Maarten , Soenens Bart
Published: April 2018

Objective

The identification of transdiagnostic risk factors and processes that explain the comorbidity between depressive symptoms and eating disorder symptoms is critical. We examined the mediating role of the frustration of adolescents’ psychological needs for autonomy, competence, and relatedness in the association between self‐critical perfectionism, depressive symptoms and eating disorder symptoms.

Method

A cross‐sectional study (N = 248; 58% female, mean age = 14 years) and a two‐wave longitudinal study (N = 608; 59% female; mean age = 16 years) were conducted.

Results

At the level of inter‐individual differences and intra‐individual change, self‐critical perfectionism was a robust predictor of both symptoms. After introducing need frustration as an underlying mechanism, the relation between self‐critical perfectionism and the two types of symptoms, as well as the relation between the symptoms themselves, decreased.

Conclusions

Need frustration represents a transdiagnostic vulnerability process that helps to explain why self‐critical perfectionism relates to depressive symptoms and eating disorder symptoms.
Dentinal tubule occluding capability of nano‐hydroxyapatite; The in‐vitro evaluation
Authors: Baglar Serdar , Erdem Umit , Dogan Mustafa , Turkoz Mustafa
Published: April 2018

In this in‐vitro study, the effectiveness of experimental pure nano‐hydroxyapatite (nHAP) and 1%, 2%, and 3% F¯ doped nano‐HAp on dentine tubule occlusion was investigated. And also, the cytotoxicity of materials used in the experiment was evaluated. Nano‐HAp types were synthesized by the precipitation method. Forty dentin specimens were randomly divided into five groups of; 1—no treatment (control), 2—specimens treated with 10% pure nano‐HAp and 3, 4, 5 specimens treated with 1%, 2%, and 3% F−doped 10% nano‐HAp, respectively. To evaluate the effectiveness of the materials used; pH, FTIR, and scanning electron microscopy evaluations were performed before and after degredation in simulated body fluid. To determine cytotoxicity of the materials, MTT assay was performed. Statistical evaluations were performed with F and t tests. All of the nano‐HAp materials used in this study built up an effective covering layer on the dentin surfaces even with plugs in tubules. It was found that this layer had also a resistance to degradation. None of the evaluated nano‐HAp types were have toxicity. Fluoride doping showed a positive effect on physical and chemical stability until a critical value of 1% F−. The all evaluated nano‐HAp types may be effectively used in dentin hypersensitivity treatment. The formed nano‐HAp layers were seem to resistant to hydrolic deletion. The pure and 1% F−doped nano‐HAp showed the highest biocompatibility thus it was assessed that pure and 1% F−doped materials may be used as an active ingredient in dentin hypersensitivity agents.
Ultra‐high‐b radial diffusion‐weighted imaging (UHb‐rDWI) of human cervical spinal cord
Authors: Thapa Bijaya , Sapkota Nabraj , Lee YouJung , Jeong Kyle , Rose John , Shah Lubdha M. , Bisson Erica , Jeong Eun‐Kee
Published: April 2018

Background

Injury in the cervical spinal cord (CSC) can lead to varying degrees of neurologic deficit and persistent disability. Diffusion tensor imaging (DTI) is a promising method to evaluate white matter integrity and pathology. However, the conventional DTI results are limited with respect to the specific details of neuropathology and microstructural architecture. In this study we used ultrahigh‐b radial‐DWI (UHb‐rDWI) with b‐values ranging from 0 to ∼7500 s/mm2 and calculated decay constant (DH) at the high b‐values, which gives much deeper insight about the microscopic environment of CSC white matter.

Purpose

To evaluate a novel diffusion MRI, UHb‐rDWI technique for imaging of the CSC.

Study Type

Longitudinal.

Subjects

Four healthy controls, each scanned twice.

Field Strength/Sequence

3T/2D single shot diffusion‐weighted stimulated echo planar imaging with reduced field of view.

Assessment

The signal from each pixel of b0 (b = 0) and b‐value (b ≠ 0) images were fitted to a biexponential function and normalized. The signal‐b curve is obtained by dividing the latter curve by the former. DH was obtained from the curve at b >4000 s/mm2. A Monte‐Carlo Simulation (MCS) was performed to investigate how DH changes upon the increased water‐exchange at the CSC.

Results

The signal‐b curves plotted at multiple levels of healthy CSC are almost identical on two successive scans and show a biexponential decay behavior: fast exponential decay at lower b‐values and much slower decay at UHb‐values. The mean values of DH were measured as (0.0607 ± 0.02531) ×10‐3 and (0.0357 ± 0.02072) ×10‐3 s/mm2 at the lateral funiculus and posterior column, respectively. MCS of diffusion MRI shows that the DH is elevated by increased water exchange between the intra‐ and extraaxonal spaces.

Data Conclusion

UHb‐rDWI signal‐b plots of the normal CSC were highly reproducible on successive scans and their biexponential decay behavior can be used to characterize normal spinal white matter.

Level of Evidence: 2

Technical Efficacy: Stage 1

J. Magn. Reson. Imaging 2019;49:204–211.
Association Between Shear Wave Elastography of Virtual Touch Tissue Imaging Quantification Parameters and the Ki‐67 Proliferation Status in Luminal‐Type Breast Cancer
Authors: Liu Yubo , Huang Yini , Han Jing , Wang Jianwei , Li Fei , Zhou Jianhua
Published: April 2018

Objectives

To evaluate the association between shear wave elastography parameters using virtual touch tissue imaging quantification (VTIQ) and the Ki‐67 index in luminal‐type breast cancer.

Methods

Eighty‐one patients with 82 lesions of pathologic confirmed luminal‐type breast cancer underwent virtual touch tissue imaging quantification examination before surgery between December 2015 and June 2016. Patients were divided into 2 groups according to the Ki‐67 index (≥14% versus < 14%), which is used to define luminal type B and luminal type A, respectively. The mean shear wave velocity (SWVmean) and lesion‐to‐adjacent tissues ratio (SWV ratio) were calculated for each lesion.

Results

The SWVmean, SWV ratio, histologic grade, axillary lymph node involvement, and lymphovascular invasion showed a significant positive association with a high Ki‐67 index (all P < .05). Receiver operating characteristic curve analysis for the differential diagnosis between high (≥14%) and low (<14%) Ki‐67 groups displayed that the optimal cutoff value for SWVmean and SWV ratio were 3.99 meters per second and 2.861, with sensitivity 94% and 72%, specificity 40.6% and 56.2%, and area under the receiver operating characteristic curve of 0.689 and 0.651, respectively. Univariate analysis showed that SWVmean (P = .005), SWV ratio (P = .029), histologic grade (P = .011), presence of axillary node involvement (P = .004), and lymphovascular invasion (P = .008) were significantly associated with high Ki‐67 status. Multivariable analysis displayed that SWVmean (hazard ratio [HR], 1.459, 95% confidence interval [CI], 1.028–2.072; P = .035), histologic grade (HR, 4.105; 95% CI, 1.142–14.763; P = .031), and presence of axillary node involvement (HR, 3.75; 95% CI, 1.228–11.453; P = .020) maintained significance for predicting high Ki‐67 status.

Conclusions

The SWVmean using the virtual touch tissue imaging quantification method showed significant correlation with the Ki‐67 index, suggesting the potential to assess tumor proliferation status in luminal‐type breast cancer with a noninvasive manner.
Lipidomic Study of Precursors of Endocannabinoids in Freshwater Bryozoan Pectinatella magnifica
Authors: Řezanka Tomáš , Vítová Milada , Lukavský Jaromír , Sigler Karel
Published: April 2018

Freshwater bryozoan Pectinatella magnifica was collected from a sand pit (South Bohemia). The total lipids after extraction from lyophilized bryozoans were analyzed using high‐performance liquid chromatography/high‐resolution negative tandem electrospray mass spectrometry. A total of 19 lipid classes were identified, including N‐acyl‐substituted phospholipids, that is, N‐acylphosphatidylethanolamine and N‐acylphosphatidylserine in their plasmenyl forms. Based on gas chromatography/mass spectrometry of 3‐pyridylcarbonyl (picolinyl) esters, a very unusual fatty acid was identified, namely 24:7n‐3 (all‐cis‐3,6,9,12,15,18,21‐tetracosaheptaenoic acid). The presence of polyunsaturated fatty acids in individual classes is very specific: arachidonic and eicosapentaenoic acids being predominantly bound as amides in N‐acyl phospholipids, that is, diacyl‐N‐acylphosphatidylethanolamines (NAPtdEtn), plasmenyl‐N‐acylphosphatidyl ethanolamines (PlsNAPtdEtn), diacyl‐N‐acylphosphatidylserines (NAPtdSer), and plasmenyl‐N‐acylphosphatidylserines (PlsNAPtdSer). While 24:6n‐3 was identified in the sn‐2 position of several phospholipids, 24:7n‐3 was identified in only two plasmalogens, that is, PlsNAPtdEtn and PlsNAPtdSer. Thanks to the tandem mass spectrometry, we managed to identify the position of all acyl groups in both diacyl‐ and also in alkenyl‐acyl‐(plasmenyl) molecular species of N‐acylphospholipids. The identification of the molecular species of N‐acyl‐substituted phosphatidylethanolamine and phosphatidylserine, including their plasmalogen forms, in the freshwater bryozoan P. magnifica has enabled the identification of endogenous cannabinoid precursors.
Preparation of PEGylated Iodine‐Loaded Nanoparticles via Polymer‐Directed Self‐Assembly
Authors: Tang Christina , York Adam W. , Mikitsh John L. , Wright Alexander C. , Chacko Ann‐Marie , Elias Drew R. , Xu Yaodong , Lim Heng‐Keang , Prud'homme Robert K.
Published: April 2018

The preparation of size‐tunable PEGylated, iodine‐loaded nanoparticles is investigated for biomedical applications. Di‐iodination of polyvinyl phenol and encapsulation of the iodinated polymer via directed self‐assembly with an amphiphilic polyethylene glycol‐based diblock copolymer are reported. Nanoparticles with iodine loadings up to 45 wt% are achieved using a rapid, scalable process. The size of the nanoparticles can be readily tuned between 35 and 130 nm by increasing the ionic strength of the antisolvent used during nanoparticle self‐assembly. The resulting PEGylated iodine‐loaded nanoparticles have potential applications in nanomedicine for 1) quantitative biodistribution analysis via inductively coupled plasma mass spectrometry (ICP‐MS) or 2) X‐ray contrast in biomedical imaging. For quantitative biodistribution studies using ICP‐MS, a limit of detection of 2 µg mL−1 in mouse serum is achieved. For biomedical imaging, the X‐ray attenuation rates are comparable to currently commercially available iodine‐based contrast agents. Therefore, encapsulation of the iodinated polymer enables formulation of trackable, size tunable nanoparticles as a versatile platform for developing nanomedicines.
Controlling CO2‐Responsive Behaviors of Polymersomes Self‐Assembled by Coumarin‐Containing Star Polymer via Regulating Its Crosslinking Pattern
Authors: Yang Qi , Li Guo , Xia Hesheng , Liu Zhaotie , Liu Zhongwen , Jiang Jinqiang
Published: April 2018

An oligo(ethylene glycol)‐based star polymer of N2‐(OEG‐C)3 with fluorescent coumarin as hydrophobic end groups and dual tertiary amines as the star center is designed and synthesized. Owing to its amphiphilic nature of N2‐(OEG‐C)3, it will self‐assemble into hollow vesicles with coumarin groups dispersed in the hydrophobic membrane and exhibits CO2‐responsive behavior due to the protonation of amine centers with CO2. More importantly, coumarin moieties can either form non‐crosslinking with γ‐cyclodextrin via the 2/1 host–guest inclusion, or covalently photodimerized by 365 nm light, offering a tunable crosslinking pattern in the hydrophobic membrane and thus adjusting its CO2‐stimulated reorganization and disassembly behaviors of these vesicles in aqueous solution.
Cationic Polymer‐Mediated CRISPR/Cas9 Plasmid Delivery for Genome Editing
Authors: Zhang Zhen , Wan Tao , Chen Yuxuan , Chen Yu , Sun Hongwei , Cao Tianqi , Songyang Zhou , Tang Guping , Wu Chuanbin , Ping Yuan , Xu Fu‐Jian , Huang Junjiu
Published: April 2018

Delivery of CRISPR (clustered regularly interspaced short palindromic repeats)/CRISPR‐associated protein‐9 (Cas9) represents a major hurdle for successful clinical translation of genome editing tools. Owing to the large size of plasmids that encode Cas9 and single‐guide RNA (sgRNA), genome editing efficiency mediated by current delivery carriers is still unsatisfactory to meet the requirement for its real applications. Herein, cationic polymer polyethyleneimine‐β‐cyclodextrin (PC), known to be efficient for small plasmid transfection, is reported to likewise mediate efficient delivery of plasmid encoding Cas9 and sgRNA. Whereas PC can condense and encapsulate large plasmids at high N/P ratio, the delivery of plasmid results in efficient editing at two genome loci, namely, hemoglobin subunit beta (19.1%) and rhomboid 5 homolog 1 (RHBDF1) (7.0%). Sanger sequencing further confirms the successful genome editing at these loci. This study defines a new strategy for the delivery of the large plasmid encoding Cas9/sgRNA for efficient genome editing.
General Syntheses of Nanotubes Induced by Block Copolymer Self‐Assembly
Authors: Zhao Jianming , Huang Wei , Si Pengchao , Ulstrup Jens , Diao Fangyuan , Zhang Jingdong
Published: April 2018

Amphiphilic block copolymer templating strategies are extensively used for syntheses of mesoporous materials. However, monodisperse tubular nanostructures are limited. Here, a general method is developed to synthesize monodisperse nanotubes with narrow diameter distribution induced by self‐assembly of block copolymer. 3‐Aminophenol (AP) and formaldehyde (F) polymerize and self‐assemble with cylindrical PS‐b‐PEO micelles into worm‐like PS‐b‐PEO@APF composites with uniform diameter (49 ± 3 nm). After template extraction, worm‐like APF polymer nanotubes are formed. The structure and morphology of the polymer nanotubes can be tuned by regulating the synthesis conditions. Furthermore, PS‐b‐PEO@APF composites are uniformly converted to isomorphic carbon nanotubes with large surface area of 662 m2 g−1, abundant hierarchical porous frameworks and nitrogen doping. The synthesis can be extended to silica nanotubes. These findings open an avenue to the design of porous materials with controlled structural framework, composition, and properties for a wide range of applications.
Transition matrices for quantum waveguides with impurities
Authors: Rabinovich Vladimir , Urbano‐Altamirano Francisco
Published: April 2018

We consider the electron propagation in a cylindrical quantum waveguide
where D is a bounded domain in
described by the Dirichlet problem for the Schrödinger operator

urn:x-wiley:mma:media:mma4920:mma4920-math-0006
where x=(x1, x2),
,
is the transversal confinement potential, and
is the impurity potential.  We construct the left and right transition matrices and give an numerical algorithm for their calculations based on the spectral parameter power series method.
Analysis of dual tree M‐band wavelet transform based features for brain image classification
Authors: Ayalapogu Ratna Raju , Pabboju Suresh , Ramisetty Rajeswara Rao
Published: April 2018

Purpose

The most complex organ in the human body is the brain. The unrestrained growth of cells in the brain is called a brain tumor. The cause of a brain tumor is still unknown and the survival rate is lower than other types of cancers. Hence, early detection is very important for proper treatment.

Methods

In this study, an efficient computer‐aided diagnosis (CAD) system is presented for brain image classification by analyzing MRI of the brain. At first, the MRI brain images of normal and abnormal categories are modeled by using the statistical features of dual tree m‐band wavelet transform (DTMBWT). A maximum margin classifier, support vector machine (SVM) is then used for the classification and validated with k‐fold approach.

Results

Results show that the system provides promising results on a repository of molecular brain neoplasia data (REMBRANDT) with 97.5% accuracy using 4th level statistical features of DTMBWT.

Conclusion

Viewing the experimental results, we conclude that the system gives a satisfactory performance for the brain image classification.
Comprehensive Peptide Analysis of Mouse Brain Striatum Identifies Novel sORF‐Encoded Polypeptides
Authors: Budamgunta Harshavardhan , Olexiouk Volodimir , Luyten Walter , Schildermans Karin , Maes Evelyne , Boonen Kurt , Menschaert Gerben , Baggerman Geert
Published: April 2018

Bio‐active peptides are involved in the regulation of most physiological processes in the body. Classical bio‐active peptides (CBAPs) are cleaved from a larger precursor protein and stored in secretion vesicles from which they are released in the extracellular space. Recently, another non‐classical type of bio‐active peptides (NCBAPs) has gained interest. These typically are not secreted but instead appear to be translated from short open reading frames (sORF) and released directly into the cytoplasm. In contrast to CBAPs, these peptides are involved in the regulation of intra‐cellular processes such as transcriptional control, calcium handling and DNA repair. However, bio‐chemical evidence for the translation of sORFs remains elusive. Comprehensive analysis of sORF‐encoded polypeptides (SEPs) is hampered by a number of methodological and biological challenges: the low molecular mass (many 4–10 kDa), the low abundance, transient expression and complications in data analysis. We developed a strategy to address a number of these issues. Our strategy is to exclude false positive identifications. In total sample, we identified 926 peptides originated from 37 known (neuro)peptide precursors in mouse striatum. In addition, four SEPs were identified including NoBody, a SEP that was previously discovered in humans and three novel SEPS from 5′ untranslated transcript regions (UTRs).
Time of metastatic disease presentation and volume of disease are prognostic for metastatic hormone sensitive prostate cancer (mHSPC)
Authors: Francini Edoardo , Gray Kathryn P. , Xie Wanling , Shaw Grace K. , Valença Loana , Bernard Brandon , Albiges Laurence , Harshman Lauren C. , Kantoff Philip W. , Taplin Mary‐Ellen , Sweeney Cristopher J.
Published: April 2018

Background

Currently, there is no universally accepted prognostic classification for patients (pts) with metastatic hormone sensitive prostate cancer (mHSPC) treated with androgen deprivation therapy (ADT). Subgroup analyses demonstrated that pts with low volume (LV), per CHAARTED trial definition, mHSPC, and those who relapse after prior local therapy (PLT) have longer overall survival (OS) compared to high volume (HV) and de‐novo (DN), respectively. Using a hospital‐based registry, we aimed to assess whether a classification based on time of metastatic disease (PLT vs DN) and disease volume (LV vs HV) are prognostic for mHSPC pts treated with ADT.

Methods

A retrospective cohort of consecutive patients with mHSPC treated with ADT between 1990 and 2013 was selected from the prospectively collected Dana‐Farber Cancer Institute database and categorized as DN or PLT and HV or LV, at time of ADT start. Primary and secondary endpoints were OS and time to castration‐resistant prostate cancer (CRPC), respectively, which were measured from date of ADT start using Kaplan‐Meier method. Multivariable Cox proportional hazards models using known prognostic factors was used.

Results

The analytical cohort consisted of 436 patients. The median OS and time to CRPC for PLT/LV were 92.4 (95%CI: 80.4‐127.2) and 25.6 (95%CI: 21‐35.7) months and 43.2 (95%CI: 37.2‐56.4) and 12.2 (95%CI: 9.8‐14.8) months for DN/HV, respectively, whereas intermediate values were observed for PLT/HV and DN/LV. A robust gradient for both outcomes was observed (Trend test P < 0.0001) in the four groups. In a multivariable analysis, DN presentation, HV, and cancer‐related pain were independent prognostic factors.

Conclusions

In our hospital‐based registry, time of metastatic presentation and disease volume were prognostic for mHSPC pts treated with ADT. This simple prognostic classification system can aid patient counseling and future trial design.
Effects of magnesium chloride on in vitro cholinesterase and ATPase poisoning by organophosphate (chlorpyrifos)
Authors: Ajilore Bamidele S. , Alli Adetayo A. , Oluwadairo Tolulope O.
Published: April 2018

The present study investigated possible benefits of magnesium ion (as MgCl2) in organophosphorus poisoning targeting its ability to interact with substrates and membrane enzymes. Blood samples collected from volunteered healthy adult by venepuncture into anticoagulant test tubes containing EDTA were separated into plasma and red blood cell and divided into three groups namely: normal, pesticide only (0.25‐2.0 mmol/L chlorpyrifos) and pesticide (0.25‐2.0 mmol/L chlorpyrifos) + 0.1 mol/L MgCl2. Acetylcholinesterase, Na+/K+ ATPase and Ca2+ATPase activities were evaluated. Results showed that Chlorpyrifos significantly (P < .05) reduced the levels of cholinesterase both in plasma and on red blood cells. Red blood cells Na+/K+ ATPase and Ca2+ ATPase were also significantly (P < .05) reduced by chlorpyrifos while MgCl2 counteracted effects of chlorpyrifos with significant (P < .05) increase in the levels of cholinesterase, Na+/K+ ATPase and Ca2+ ATPase. We concluded that MgCl2 neutralized effects of chlorpyrifos by promoting normal ATPase activities and inhibiting release of acetylcholine from cell.
Accounting for spatially heterogeneous conditions in local‐scale surveillance strategies: case study of the biosecurity insect pest, grape phylloxera (Daktulosphaira vitifoliae (Fitch))
Authors: Triska Maggie D , Powell Kevin S , Collins Cassandra , Pearce Inca , Renton Michael
Published: April 2018

BACKGROUND

Surveillance strategies are often standardized and completed on grid patterns to detect pest incursions quickly; however, it may be possible to improve surveillance through more targeted observation that accounts for landscape heterogeneity, dispersal and the habitat requirements of the invading organism. We simulated pest spread at a local scale, using grape phylloxera (Daktulosphaira vitifoliae (Fitch)) as a case study, and assessed the influence of incorporating spatial heterogeneity into surveillance compared with current, standard surveillance strategies.

RESULTS

Time to detection and spread within and beyond the vineyard were reduced by conducting surveys that target sampling effort in soil that is highly suitable for the invading pest in comparison with standard surveillance strategies. However, these outcomes were dependent on the virulence level of phylloxera because phylloxera is a complex pest with multiple genotypes that influence spread and detectability.

CONCLUSION

Targeting surveillance strategies based on local‐scale spatial heterogeneity can decrease the time to detection without increasing the survey cost, and surveillance that targets highly suitable soil is the most efficient strategy for detecting new incursions. In addition, combining targeted surveillance strategies with buffer zones and hygiene procedures, and updating surveillance strategies as additional species information becomes available, will further decrease the risk of pest spread. © 2018 Society of Chemical Industry
Localization Properties of Zig‐Zag Edge States in Disordered Phosphorene
Authors: Niţă Marian , Ostahie Bogdan , Ţolea Mugurel , Aldea Alexandru
Published: April 2018

Herein, the spectral and transport properties in the finite phosphorene lattice are investigated using the tight‐binding model in the presence of Anderson disorder potential. The focus is on the zig‐zag edge states localization, provided by the numerically calculated inverse participation number. At low disorder, the zig‐zag states undergo a localization process, keeping their 1D character, while further increasing the disorder leads to delocalization due to hybridization with the extended 2D states. The disorder‐induced changes in the electronic conductance, from one zig‐zag edge to the other, are also discussed.
SSRIs and linezolid interaction
Authors: Lam Y. W. Francis
Published: April 2018

Serotonin syndrome, caused by excessive serotonergic stimulation, can be a serious condition that can result in fatality. The most common pharmacological scenarios that can result in serotonin syndrome involve the concurrent use of monoamine oxidase inhibitors with selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants, or tryptophan.
A Five-Year Study of the Efficacy of Purified CD34+ Cell Therapy for Angiitis-Induced No-Option Critical Limb Ischemia
Authors: Fang Yuan , Wei Zheng , Chen Bin , Pan Tianyue , Gu Shiyang , Liu Peng , Guo Daqiao , Xu Xin , Jiang Junhao , Yang Jue , Shi Zhenyu , Zhu Ting , Shi Yun , Liu Yifan , Dong Zhihui , Fu Weiguo
Published: April 2018

Angiitis-induced critical limb ischemia (AICLI) patients constitute a remarkable proportion of no-option critical limb ischemia (CLI) patients. Stem cell therapy has become an innovative and promising option for no-option CLI patients. As one of these promising stem cell therapies, purified CD34+ cell transplantation (PuCeT) has shown favorable short-term results. However, the long-term efficacy of PuCeT has yet to be reported. This study evaluates the long-term efficacy of PuCeT in AICLI patients. Twenty-seven AICLI patients were enrolled from May 2009 to December 2011. Granulocyte colony-stimulating factor (G-CSF) and enoxaparin sodium were administered for 5 days. On day 5, CD34+ cell isolation was performed, and cells were transplanted by intramuscular injection. The primary endpoint, major-amputation-free survival rate (MAFS), as well as secondary endpoints, such as peak pain-free walking time (PPFWT) and the Wong-Baker FACES pain rating scale score (WFPRSS), were routinely evaluated during the 5-year follow-up period. The endpoints were as follows: the MAFS was 88.89%; PPFWT increased from 3 ± 3 to 17 ± 6 minutes; WFPRSS decreased from 7 ± 2 to 0.3 ± 1.7; the ulcer healing rate was 85.71%; the recurrence rate was 11.11%; and SF-36v2 scores were significantly improved at 5 years after PuCeT. The rate of labor recovery 5 years after PuCeT was 65.38%, and no severe adverse effect was observed during the treatment. PuCeT demonstrated long-term efficacy and durability as a treatment of AICLI not only in achieving limb salvage but also in recovering the labor competence and improving the quality of life of patients.
Fluorescent Nanomaterials for Color‐Multiplexing Test Papers toward Qualitative/Quantitative Assays
Authors: Jiang Changlong , Liu Bianhua , Han Ming‐Yong , Zhang Zhongping
Published: April 2018

Paper‐based sensors (e.g., pH and pregnancy test papers) are the most promising sensors because analysts prefer on‐site and real‐time/visual detection without the aid of analytical instruments. Herein, advances in the new generation of nanofluorophore‐integrated test papers toward visual qualitative/quantitative assays of universal target species are described. The main aspects of the advances gained from a decade of work are summarized here: i) novel strategies for colorimetric assays on test papers are described by exploiting the paramount advantages of fluorescent nanomaterials, such as wide excitation wavelength, narrow/tunable emission, and surface‐modification flexibility; ii) motivated and driven by the challenges to upgrade the classical test papers, an established library of fluorescent nanoprobes with supersensitive visualizing capability through the molecular engineering of nanomaterial surfaces and the rational design of spectral responses is described, which is aimed at implementing the on‐site and real‐time/visual detection of universal analytes such as explosives, pesticides, food additives, metal ions, and biological molecules; iii) molecularly engineered fluorescent nanoprobes are then formulated into inks for inkjet‐printing test papers, greatly overcoming the technical challenges of test papers in reliability and reproducibility. Finally, a conceptually innovative framework of nanofluorophore‐integrated test papers that enable color‐multiplexing quantitative assays of universal analytes is established.
Dynamic Rheological and Textural Properties of Acorn (Quercus brantii Lindle.) Starch: Effect of Single and Dual Hydrothermal Modifications
Authors: Molavi Hooman , Razavi Seyed M. A.
Published: April 2018

In this paper, the small deformation (small amplitude oscillatory shear rheology) of native and hydrothermally modified acorn starch pastes as well as large deformation (texture profile analysis) of starch gels are investigated. Native starch presents the greatest values obtained by amplitude sweep test followed by annealed starch while heat‐moisture treated starch showed the minimum values. The values for dually modified starches are between those of single modifications. The loss tangent values at the linear viscoelastic region are in the range of 0.03–0.06, demonstrating the dominance of elastic behavior of native and modified starch dispersions. The magnitudes of storage modulus (G′) are greater than those of loss modulus (G″) over the frequency range (0.63–62.8 rad s−1). Native starch presents the most loss tangent values (tan δ) at 6.28 rad s−1, while HMT‐treated starches shows the smallest. The ability of gel formation reduces slightly in hydrothermal treatments. The hardness, adhesiveness, cohesiveness, springiness index, gumminess, and chewiness index of acorn starch were 261.3 g, 0.64 mJ, 0.96, 0.98, 252.1 g, and 248.0 g, respectively. Among different hydrothermal treatments, annealing did not alter the textural parameters of native starch significantly (p > 0.05).
Managing system obsolescence via multicriteria decision making
Authors: Adetunji Oluwatomi , Bischoff John , Willy Christopher J.
Published: April 2018

Obsolescence occurs when system elements become outdated, and it leads to operational, logistical, reliability, and cost implications. In the U.S. military, this problem is a result of the U.S. Department of Defense's (DoD) departure from Military Specification (MILSPEC) standards in 1994 and transition to the use of Commercial Off the Shelf products. Obsolescence costs the DoD more than $750 million annually. The current risk management tools for obsolescence are based on a quantitative approach that uses cost optimization, and expert judgment is not used as a critical criterion. A review of the literature has revealed that during the design phase of technological systems, there is limited knowledge and a lack of training associated with mitigating obsolescence, and multicriteria decision‐making (MCDM) methods are not currently used to mitigate the risk of obsolescence. Thus, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS, which is a MCDM method) and Monte Carlo simulations are proposed as the foundation for this work. This paper adds to the methodology by introducing an expert judgment criterion. A case study was conducted using military and civilian experts. Expert validation showed that the TOPSIS model successfully identified the best system for mitigating obsolescence. This model can be used by system designers and other decision makers to conduct trade studies in obsolescence management.
Flood frequency analysis: The Bayesian choice
Authors: Gaume Eric
Published: April 2018

After an introduction to the traditional flood frequency analysis methods, this article discusses their limits and the risks associated with their thoughtless use: overconfidence in the estimated values of flood quantiles or return periods and systematic underestimation of risks. The article then presents and illustrates the added value of modern Bayesian flood frequency inference procedures that are statistically consistent, numerically accurate, and now computationally affordable. The implementation of such methods shows that estimated flood frequencies, based on observed samples of limited size, are generally affected by large uncertainties. This acknowledgement should be an incentive for increasing the size of the analyzed samples through a more systematic use of historic information as well as regional approaches in flood frequency analyses. It also clearly points out that the margin of errors should be considered when using inference results for design or risk assessment purposes. Several pieces of software are now available to conduct Bayesian flood frequency analyses relatively straightforwardly. There is no remaining obstacle to the implementation of these modern approaches in operational hydrological studies.

This article is categorized under:

Science of Water > Methods

Science of Water > Water Extremes