bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solid‐phase extraction of phenoxyacetic acid herbicides in complex samples with a zirconium(IV)‐based metal–organic framework
Authors: Si Tiantian , Liu Lei , Liang Xiaojing , Duo Huixiao , Wang Licheng , Wang Shuai 
Published: April 2019

AbstractA zirconium(IV)‐based metal–organic framework material (MOF‐808) has been synthesized in a simple way and used for the extraction of phenoxyacetic acids in complex samples. The material has good thermal and chemical stability, large specific surface area (905.36 m²/g), and high pore size (22.18 Å). Besides, it contains a large amount of Zr‐O groups, easy‐to‐form Zr‐O‐H bond with carboxyl groups of phenoxyacetic acids, and possesses biphenyl skeleton structure, easy to interact with compounds through π‐π and hydrophobic interactions. These characteristics make the material very suitable for the extraction of certain compounds with a high extraction efficiency and excellent selectivity. The extraction conditions were optimized, and then an analytical method was successfully established and applied for analysis of actual samples. The solid‐phase extraction method based on prepared material had a wide linear range of 0.2–250 μg/L and a low detection limit of 0.1–0.5 μg/L for four phenoxyacetic acid compounds including 2,4‐dichlorophenoxyacetic acid, 2‐(2,4‐dichlorophenoxy) propionic acid, 4‐chlorophenoxyacetic acid, and dicamba. The relative standard deviations of intra‐ and interday precision were 1.8–3.8 and 4.3–6.9%, and the recoveries after spiking were between 77.1 and 109.3%. The results showed that the material is a desired substituent for the extraction of compounds with benzene ring structure containing carboxyl groups.
A Phenyl Thioether‐Based Probe: Zn2+ Ion Sensor, Structure Determination and Live Cell Imaging†
Authors: Dey Sunanda , Maity Suvendu , Dasmahapatra Ananya , Chattopadhyay Debprasad , Sinha Chittaranjan 
Published: April 2019

Abstract3,3′‐((1Z,1′Z)‐(((Propane‐1,3‐diylbis(sulfanediyl))bis(2,1‐phenylene))bis(azanyyldiene))bis(methanylylidene))bis(2‐hydroxy‐5‐methylbenzaldehyde) (H2‐SAP), characterized by different spectroscopic data, exhibits yellow emission (λem, 560 nm) when binds with Zn2+ in H2O‐MeOH (1:9 v/v, HEPES buffer, pH 7.4) in a mixture of seventeen biologically important other metal ions. The limit of detection (LOD) is 9.0 nM which is far below the World Health Organization (WHO) recommended data. The composition of the complex, 1:1 Zn2+:SAP2−, is supported by Job's plot, ESI‐MS and single crystal X‐Ray crystallographic structure. Intracellular Zn2+ ion is detected in Vero Cells (African Green Monkey Kidney) by using the probe, H2‐SAP, in the cell lines under fluorescence microscope. The probe has successfully been applied to recover Zn2+ in surface water.
Preparation and Thermophysical Properties of High Thermal Conductive Solar Salt/MWCNTs Composite Materials
Authors: Wu Yanze , Li Jinli , Wang Min , Wang Huaiyou , Zhao Youjing 
Published: April 2019

AbstractTo improve the heat transfer performance of the photothermal molten salt (Solar salt), a composite material of Solar salt doped with MWCNTs (Multi‐walled carbon nanotubes) which has excellent thermal conductivity, was prepared and analyzed. XRD was used to analyze the composition of the composite, which remained as NaNO3 and KNO3 without change. XPS was used to analyze the C1s energy spectrum, the carbon nanotubes were purified and the impurity groups were greatly reduced after high temperature melting. Melting point, phase change enthalpy and specific heat of composite materials were measured by DSC; the decomposition temperature of composite material were measured by TGA; the density was measured by the Archimedes method; the thermal diffusivity was measured by the laser flash method. The thermal conductivity was calculated according to the thermal conductivity formula: k=Cp⋅ρ⋅α. When the Solar salt was doped with 0.4% MWCNTs, the thermal conductivity was greatly improved, increasing by 87% to 0.77 W/(m⋅k). And the influence of carbon nanotubes on the spatial structure of nitrate was analyzed by Raman spectroscopy. This composite material had superior thermal properties than Solar salt and was expected to be applied in solar thermal power generation to improve solar energy utilization efficiency.
Synthesis, Biological Activity and QSAR Studies of Organotin(IV) and Organosilicon(IV) Complexes
Authors: Devi Jai , Devi Suman , Yadav Jyoti , Kumar Ashwani 
Published: April 2019

AbstractA panel of penta‐coordinated, neutral organotin(IV) and organosilicon(IV) complexes of newly designed Schiff bases: 4‐(2‐hydroxymethyl‐phenylimino)‐2‐methyl‐4H‐pyran‐3‐ol (H2L1) and 4‐(benzothiazol‐2‐ylimino)‐2‐methyl‐4H‐pyran‐3‐ol (HL2) were synthesized and characterized using elemental analysis, spectral studies (UV/Vis, IR, 1H, 13C, 29Si, 119Sn NMR and Fluorescence) and thermal technique. Spectral studies conferred that the Schiff base act as bi/tridentate and form the penta coordinated geometry with oxygen and nitrogen donor atom (NO/NOO). The compounds were screened for in vitro antimicrobial activity using twofold serial dilution method against Gram‐positive bacteria (Staphylococcus aureus, Bacillus cereus), Gram‐negative bacteria (Escherichia coli, Klebsiella pneumoniae) and fungi (Aspergillus niger, Candida albicans). The antimicrobial study exposed good activity with tri‐ and di‐phenyl derivatives exhibiting excellent biological activity. Compounds 5, 6, 10, 13, 14, 17 and 18 displayed better activity than the standard drugs. Quantitative structure activity relationship involves correlation of biological activity with the structural properties of the compounds using statistical means.
The First Vinylogous, Decarboxylative Michael Reaction with 3‐Cyano‐4‐methylcoumarins as Pronucleophiles
Authors: Bojanowski Jan , Albrecht Anna 
Published: April 2019

AbstractIn the manuscript the first vinylogous, decarboxylative Michael reaction is described. It utilizes 3‐cyano‐4‐methylcoumarins as pronucleophiles undergoing Michael reaction with Michael acceptors activated by the presence of carboxylic acid moiety. Subsequent decarboxylative protonation affords interesting heterocycles in high yields with the reaction realized in the presence of Brønsted base catalyst. Attempts to develop an enantioselective variant of the decarboxylative reaction cascade are also described.
Sequentially Formations of Csp3‐Csp2 and Csp2‐Csp2 Bonds by a One‐pot Reaction Involving N‐Tosylhydrazone and p‐Bromobenzeneboronic Acid
Authors: He Jing , Zhang Jie , Dai Bin , Liu Ping 
Published: April 2019

AbstractA one‐pot multi‐step reaction of two N‐tosylhydrazones with p‐bromobenzeneboronic acid was established. With the aid of sequentially formations of Csp3‐Csp2 bond and Csp2‐Csp2 bond, a series of 1‐benzyl‐4‐(1‐phenylvinyl)benzene derivatives can be synthesized from readily available starting materials in good yields. The transformation features a broad substrate scope and good functional group tolerance.
Effect of Ligand Concentration, Dilution, and Excitation Wavelength on the Emission Properties of CdSe/CdS Core Shell Quantum Dots and Their Implication on Detection of Uranium
Authors: Singhal Pallavi , Pulhani Vandana 
Published: April 2019

AbstractMany applications of quantum dots (QDs); such as solar energy harvesting and toxic ion detection advice to understand the photoluminescence properties of QDs in water. However, this property can vary with concentration, purification and excitation wavelength which is seldom understood and can affect the above mentioned applications. The work carried out in this article demonstrates the effect and importance of these parameters on the photoluminescence properties of water dispersible CdSe/CdS core shell QDs. Three core shell QDs having the same core and shell thickness, but different number of ligands were synthesized. It was observed that the ligand concentration, excitation wavelength and concentration has a profound effect on the emission properties of QDs. The effect of above mentioned parameters on the detection of uranium by QDs was also discussed and it was shown that tuning these parameters can impact the detection limit drastically. A detection limit of 10 ppb was achieved by varying the experimental conditions which is much below than the limit prescribed by World Health Organization for uranium in drinking water suggesting the potential of these dots in sensing application and importance to tune different experimental conditions to achieve at a better detection limit.
Smart Microcapsules with Molecular Polarity‐ and Temperature‐Dependent Permeability
Authors: Kim Ji‐Won , Lee Sang Seok , Park Jinho , Ku Minhee , Yang Jaemoon , Kim Shin‐Hyun 
Published: April 2019

AbstractMicrocapsules with molecule‐selective permeation are appealing as microreactors, capsule‐type sensors, drug and cell carriers, and artificial cells. To accomplish molecular size‐ and charge‐selective permeation, regular size of pores and surface charges have been formed in the membranes. However, it remains an important challenge to provide advanced regulation of transmembrane transport. Here, smart microcapsules are designed that provide molecular polarity‐ and temperature‐dependent permeability. With capillary microfluidic devices, water‐in‐oil‐in‐water (W/O/W) double‐emulsion drops are prepared, which serve as templates to produce microcapsules. The oil shell is composed of two monomers and dodecanol, which turns to a polymeric framework whose continuous voids are filled with dodecanol upon photopolymerization. One of the monomers provides mechanical stability of the framework, whereas the other serves as a compatibilizer between growing polymer and dodecanol, preventing macrophase separation. Above melting point of dodecanol, molecules that are soluble in the molten dodecanol are selectively allowed to diffuse across the shell, where the rate of transmembrane transport is strongly influenced by partition coefficient. The rate is drastically lowered for temperatures below the melting point. This molecular polarity‐ and temperature‐dependent permeability renders the microcapsules potentially useful as drug carriers for triggered release and contamination‐free microreactors and microsensors.
Screening Therapeutic Agents Specific to Breast Cancer Stem Cells Using a Microfluidic Single‐Cell Clone‐Forming Inhibition Assay
Authors: Lin Dongguo , Li Peiwen , Feng Jin , Lin Zhun , Chen Xiao , Yang Na , Wang Lihui , Liu Dayu 
Published: April 2019

AbstractScreens of cancer stem cells (CSCs)‐specific agents present significant challenges to conventional cell assays due to the difficulty in preparing CSCs ready for drug testing. To overcome this limitation, developed is a microfluidic single‐cell assay for screening breast cancer stem cell–specific agents. This assay takes advantage of the single‐cell clone‐forming capability of CSCs, which can be specifically inhibited by CSC‐targeting agents. The single‐cell assay is performed on a microfluidic chip with an array of 3840 cell‐capturing units; the single‐cell arrays are easily formed by flowing a cell suspension into the microchip. Achieved is a single cell‐capture rate of ≈60% thus allowing more than 2000 single cells to be analyzed in a single test. Over long‐term suspension culture, only a minority of cells survive and form tumorspheres. The clone‐formation rate of MCF‐7, MDA‐MB‐231, and T47D cells is 1.67%, 5.78%, and 5.24%, respectively. The clone‐forming inhibition assay is conducted by exposing the single‐cell arrays to a set of anticancer agents. The CSC‐targeting agents show complete inhibition of single‐cell clone formation while the nontargeting ones show incomplete inhibition effects. The resulting microfluidic single‐cell assay with the potential to screen CSC‐specific agents with high efficiency provides new tools for individualized tumor therapy.
Xylitol production on sugarcane biomass hydrolysate by newly identified Candida tropicalis JA2 strain
Authors: Morais Junior Wilson G. , Pacheco Thályta F. , Trichez Débora , Almeida João R.M. , Gonçalves Sílvia B. 
Published: April 2019

AbstractXylitol is a building block for a variety of chemical commodities, besides being widely used as a sugar substitute in the food and pharmaceutical industries. The aim of this work was to develop a microbial process for xylitol production using sugarcane bagasse hydrolysate as substrate. In this context, 218 non‐Saccharomyces yeast strains were screened by growth on steam‐exploded sugarcane bagasse hydrolysate containing a high concentration of acetic acid (8.0 g/L). Seven new Candida tropicalis strains were selected and identified, and their ability to produce xylitol on hydrolysate at low pH (4.6) under aerobic conditions was evaluated. The most efficient strain, designated C. tropicalis JA2, was capable of producing xylitol with a yield of 0.47 g/g of consumed xylose. To improve xylitol production by C. tropicalis JA2, a series of experimental procedures were employed to optimize pH and temperature conditions, as well as nutrient source, and initial xylose and inoculum concentrations. C. tropicalis JA2 was able to produce 109.5 g/L of xylitol with a yield of 0.86 g/g of consumed xylose, and with a productivity of 2.81 g·L·h, on sugarcane bagasse hydrolysate containing 8.0 g/L acetic acid and177 g/L xylose, supplemented with 2.0 g/L yeast nitrogen base and 4.0 g/L urea. Thus, it was possible to identify a new C. tropicalis strain and to optimize the xylitol production process using sugarcane bagasse hydrolysate as a substrate. The xylitol yield on biomass hydrolysate containing a high concentration of acetic acidobtained in here is among the best reported in the literature.
Digitaler OP: bessere Planung und Kommunikation
Authors: Meppelink A. 
Published: April 2019

Zusammenfassung
Im Mittelpunkt der digitalen HNO-Chirurgie stehen v. a. 4 technologische Fortschritte: Neben dem Potenzial eines digitalisierten Operationssaals (OP) sind dies moderne Navigationsverfahren, Planungssoftware sowie roboterbasierte Assistenzsysteme. Im OP der Zukunft spielen nicht nur Datenanreicherung und Informationsintegration eine Rolle, sondern auch die Integration medizinischer Hightech-Geräte. Deren Nutzung und die von ihnen gelieferten Informationen werden vereinfacht; gleichzeitig jedoch werden weitere klinische Daten vor, während und nach dem chirurgischen Eingriff optimiert. Mit speziell entwickelten intuitiven Benutzeroberflächen, automatisierten Arbeitsabläufen und erweiterten Bildgebungsverfahren lässt sich das Potenzial diagnostischer, chirurgischer und postoperativer Patientendaten voll ausschöpfen. Chirurgische Planungstechnologie hilft HNO-Operateuren, komplexe anatomische Strukturen leichter zu evaluieren und Krankheitsbilder genauer und schneller zu bestimmen. Auf Basis eines anpassungsfähigen anatomischen Software-Modells lässt sich eine Vielzahl anatomischer Strukturen erkennen und als Objekte erstellen. Die hohe Genauigkeit und Konsistenz der Objekte machen die Segmentierung zu einem elementaren Bestandteil präziser Behandlungsplanung. Mit Planungssoftware lassen sich Tumoren und Risikostrukturen in 3‑D-Patientenbildern genau einzeichnen, Trajektorien planen sowie CT- und MRT-Bilder fusionieren und anschließend im OP darauf für die weitere Nutzung einfach zurückgreifen. Dies dient während des Eingriffs als Anleitung und letztlich höherer Patientensicherheit sowie effizienteren Prozessen im klinischen Alltag.
Time course of neuropsychiatric symptoms and cognitive diagnosis in National Alzheimer's Coordinating Centers volunteers
Authors: Wise Elizabeth A. , Rosenberg Paul B. , Lyketsos Constantine G. , Leoutsakos Jeannie‐Marie 
Published: April 2019

AbstractIntroductionNeuropsychiatric symptoms (NPSs) are nearly universal in cognitive disorders. The mild behavioral impairment construct postulates that NPS may be the first symptom of impending dementia.MethodsParticipants were cognitively normal volunteers followed up approximately annually at Alzheimer's Disease Centers, who were assessed on the Neuropsychiatric Inventory and had at least one follow‐up visit during which they were diagnosed with mild cognitive impairment (MCI) or dementia. Descriptive statistics were used to determine sequencing of NPS presence with cognitive diagnoses.ResultsData were available for 1998 participants who progressed to MCI or dementia. Over 59% developed NPS before the diagnosis of any cognitive disorder. Depression and irritability were the most common NPSs to precede cognitive diagnoses (24 and 21%, respectively).DiscussionNPSs precede a cognitive diagnosis in most people who develop cognitive decline, both MCI and dementia. These individuals are an important group to focus clinical and research efforts.
Tracing sub-surface swept profiles of tapered toroidal end mills between level cuts
Authors: Aras Eyyup 
Published: April 2019

Abstract
Development of closed-form solutions and algorithms for constructing sub-surface swept profiles (SWP) of toroidal and conical bodies is presented in this paper. While the problem of identifying the entire SWP of such surfaces has been extensively investigated in extant studies, construction of subsurface SWPs has rarely been addressed despite the subject being of great significance to machining process employing nonstandard-shaped NC tools. Torus shapes considered in extant literature are restricted to the fourth quadrant of a tube cross section. In industrial applications, however, profile cutters contain different regions of a toroidal surface. To identify SWP elements in the proposed study, a single analytical expression in one variable has been deduced using two moving frames. The basic idea behind such a formulation is to employ the one-to-many strategy, which greatly reduces the computational cost and effort. Algorithms to identify feasible domains of SWP parameters at each level cut, where toroidal and conical surfaces meet, have also been proposed in this study. This is important, since cutting a tool surfaces along the rotation axis divides SWP-parameter domains into non overlapping sets of intervals that must be addressed for each tool posture. In addition, this study demonstrates that for certain tool postures, while C1 continuity between sub-surfaces is satisfied, the SWP connectivity is lost at some points. To locate these so called singular-characteristic points, some precomputation steps have been performed. Lastly, several factors affecting the smoothness of SWPs have been identified and discussed.
Highlights Closed form solutions have been derived for constructing the sub-swept profiles of toroidal tools. Three algorithms have been presented to identify the feasible domains of swept profile parameters. In order to locate the singular-characteristic points some precomputation steps have been carried out. Finally, several factors, affecting the smoothness of the swept profiles, have been identified.
Critical Issues in Ionospheric Data Quality and Implications for Scientific Studies
Authors: Araujo‐Pradere E. , Weatherhead E. C. , Dandenault P. B. , Bilitza D. , Wilkinson P. , Coker C. , Akmaev R. , Beig G. , Burešová D. , Paxton L. J. , Hernández‐Pajares M. , Liu J.‐Y. , Lin C. H. , Habarulema J. B. , Paznukhov V. 
Published: April 2019

AbstractIonospheric data are valuable records of the behavior of the ionosphere, solar activity, and the entire Sun‐Earth system. The data are critical for both societally important services and scientific investigations of upper atmospheric variability. This work investigates some of the difficulties and pitfalls in maintaining long‐term records of geophysical measurements. This investigation focuses on the ionospheric parameters contained in the historical data sets within the National Oceanic and Atmospheric Administration National Geophysical Data Center and Space Physics Interactive Data Resource databases. These archives include data from approximately 100 ionosonde stations worldwide, beginning in the early 1940s. Our study focuses on the quality and consistency of ionosonde data accessible via the primary Space Physics Interactive Data Resource node located within the National Oceanic and Atmospheric Administration National Geophysical Data Center and the World Data Center for Solar‐Terrestrial Physics located in Boulder, Colorado. We find that, although the Space Physics Interactive Data Resource archives contained an impressive amount of high‐quality data, specific problems existed involving missing and noncontiguous data sets, long‐term variations or changes in methodologies and analysis procedures used, and incomplete documentation. The important lessons learned from this investigation are that the data incorporated into an archive must have clear traceability back to the primary source, including scientific validation by the contributors, and that the historical records must have associated metadata that describe relevant nuances in the observations. Although this report only focuses on historical ionosonde data in National Oceanic and Atmospheric Administration databases, we feel that these findings have general applicability to environmental scientists interested in using long‐term geophysical data sets for climate and global change research.
Incorporating Multidimensional Probabilistic Information Into Robustness‐Based Water Systems Planning
Authors: Taner Mehmet Ümit , Ray Patrick , Brown Casey 
Published: April 2019

AbstractThe widespread uncertainty regarding future changes in climate, socioeconomic conditions, and demographics have increased interest in vulnerability‐based frameworks for long‐term planning of water resources. These frameworks shift the focus from projections of future conditions to the weaknesses of the baseline plans and then to options for reductions in those weaknesses across a wide range of futures. A consistent challenge for vulnerability‐based planning is how to assess the relative likelihood of the occurrence of the multidimensional and codependent uncertainties to which the system or plan is vulnerable. This work proposes a methodological solution to the problem, demonstrated in this case as an extension to Decision Scaling framework. The proposed approach first generates a wide range of futures using stochastic simulators, and then stress tests the system across those futures to identify vulnerabilities relative to stakeholder‐defined performance thresholds. The relative likelihood of the vulnerabilities is then explored using a Bayesian belief network of the knowledge domain of the water resources system. The Bayesian network provides a formal representation of the joint probabilistic behavior of the system conditioned on the uncertain but potentially useful sources of information about the future, including historical trends, expert judgments, and model‐based projections. The proposed approach is applied to compare four design options for a dam project in the Coastal Province of Kenya with respect to the reliability and net present value metrics. Results show that incorporation of belief information helps better distinguishing of the available options, principally by magnifying the differences between the computed net present values.