bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intralaboratory Validation of a Fast and Sensitive UHPLC/MS/MS Method with Fast Polarity Switching for the Analysis of Lipophilic Shellfish Toxins
Authors: Braña-Magdalena Ana , Leão-Martins José Manuel , Glauner Thomas , Gago-Martínez Ana 
Published: April 2014

Abstract
This paper shows the results of an intralaboratory validation of a fast method for the determination of lipophilic shellfish toxins working under acidic conditions using ultra-high performance LC (UHPLC) with MS/MS. Fourteen lipophilic marine toxins and domoic acid were acquired with fast polarity switching.Whereas azaspiracids (AZAs), pecenotoxins, 13-desmethyl spirolide C (SPX1), and gymnodimine were analyzed in the positive mode, yessotoxins (YTXs) were measured in negative mode. The okadaic acid (OA) group compounds were analyzed in both positive and negativeionization modes, and the accuracy of the results for both were compared. When using dynamic multiple reaction monitoring (MRM) in fast polarity switching, LODs were lower and reproducibility and linearity were better compared to static MRM. The UHPLC separation allowed for higher sample throughput in routineuse. Compared to the previously used HPLC/MS/MS method, LODs were improved up to a factor of 10 in mussel extract. Matrix effects were evaluated by comparing standards prepared in solvent with matrix-matchedcalibrations in blank mussel extract. For accurate quantification matrix-matched calibrations were used when analyzing reference mussel materials, providingrecoveries for OA, Dynophysis toxins (DTX)1, DTX2, YTX,AZA1, and SPX1 between 80 and 120% with RSDs below 8% over a 3-day validation procedure.
Flow Cytometric-Membrane Potential Detection of Sodium Channel Active Marine Toxins: Application to Ciguatoxins in Fish Muscle and Feasibility of Automating Saxitoxin Detection
Authors: Manger Ronald , Woodle Doug , Berger Andrew , Dickey Robert W , Jester Edward , Yasumoto Takeshi , Lewis Richard , Hawryluk Timothy , Hungerford James 
Published: April 2014

Abstract
Ciguatoxins are potent neurotoxins with a significant public health impact. Cytotoxicity assays have allowed the most sensitive means of detection of ciguatoxin-like activity without reliance on mouse bioassays and have been invaluable in studying outbreaks. An improvement of these cell-based assays is presented here in which rapid flow cytometric detection of ciguatoxins and saxitoxins is demonstrated using fluorescent voltage sensitive dyes. A depolarization response can be detected directly due to ciguatoxin alone; however, an approximate 1000-fold increase insensitivity is observed in the presence of veratridine. These results demonstrate that flow cytometric assessment of ciguatoxins is possible at levels approaching the trace detection limits of our earlier cytotoxicity assays, however, with a significant reduction in analysis time. Preliminary results are also presented for detection of brevetoxins and for automation and throughput improvements to a previously described method for detecting saxitoxins in shellfish extracts.
Liquid Chromatography/Mass Spectrometry of Domoic Acid and Lipophilic Shellfish Toxins with Selected Reaction Monitoring and Optional Confirmation by Library Searching of Product Ion Spectra
Authors: McCarron Pearse , Wright Elliott , Quilliam Michael A 
Published: April 2014

Abstract
LC/MS methodology for the analysis of domoic acidand lipophilic toxins in shellfish was developed using a hybrid triple quadrupole linear ion trap mass spectrometer. For routine quantitation a scheduled selected reaction monitoring (SRM) method for the analysis of domoic acid, okadaic acid, dinophysistoxins,azaspiracids, pectenotoxins, yessotoxins, gymnodimines, spirolides, and pinnatoxins was developed and validated. The method performed well in terms of LOD, linearity, precision, and trueness. Taking advantageof the high instrument sensitivity, matrix effects were mitigated by reducing the amount of sample introduced to the mass spectrometer. Optionally, samples can be analyzed using information dependent acquisition (IDA) methods, either in positive or negative mode, which can provide an extra level of confirmationby matching the full product ion spectra acquired for a sample with those from a specially constructedspectral library. Methods were applied to the analysisof a new certified reference material and Canadian mussels (Mytilus edulis) implicated in a 2011 diarrhetic shellfish poisoning (DSP) incident. The scheduled SRM method enabled the screening and quantitation of multiple phycotoxins. As DSPhad not previously been observed in this area of Canada,positive identification of putative toxins was accomplished using the IDA and spectral search method. Analysis of the 2011 toxic mussel samples revealed thepresence of high levels of dinophysistoxin-1, which explained the DSP symptoms, as well as pectenotoxins, yessotoxins, and variety of cyclic imines.
Short Laminin Peptide for Improved Neural Stem Cell Growth
Authors: Li Xiaowei , Liu Xiaoyan , Josey Benjamin , Chou C. James , Tan Yu , Zhang Ning , Wen Xuejun 
Published: April 2014

AbstractHuman neural stem/progenitor cells (hNSCs) are very difficult to culture and require human or animal source extracellular matrix molecules, such as laminin or collagen type IV, to support attachment and to regulate their survival and proliferation. These extracellular matrix molecules are difficult to purify from human or animal tissues, have high batch-to-batch variability, and may cause an immune response if used in clinical applications. Although several laminin- and collagen IV-derived peptides are commercially available, they do not support long-term hNSC attachment and growth. To solve this problem, we developed a novel peptide sequence with only 12 amino acids based on the Ile-Lys-Val-Ala-Val, or IKVAV, sequence: Ac-Cys-Cys-Arg-Arg-Ile-Lys-Val-Ala-Val-Trp-Leu-Cys. This short peptide sequence, similar to tissue-derived full laminin molecules, supported hNSCs to attach and proliferate to confluence for continuous passage and subculture. This short peptide also directed hNSCs to differentiate into neurons. When conjugated to poly(ethylene glycol) hydrogels, this short peptide benefited hNSC attachment and proliferation on the surface of hydrogels and promoted cell migration inside the hydrogels with maximum enhancement at a peptide density of 10 μM. This novel short peptide shows great promise in artificial niche development for supporting hNSC culture in vitro and in vivo and for promoting hNSC transplantation in future clinical therapy.
Human Papillomavirus Types 2, 27, and 57 Identified in Plantar Verrucae from HIV-Positive and HIV-Negative Individuals
Authors: King Christy M. , Johnston James S. , Ofili Kene , Tam Maylynn , Palefsky Joel , Da Costa Maria , Mathur Yasha , Barbosa Peter 
Published: April 2014

BackgroundAlthough an increased prevalence of plantar verrucae has been associated with human immunodeficiency virus (HIV) infection, human papillomavirus (HPV) typing studies have not been published about this patient population. We sought to determine the prevalence of HPV types in plantar verrucae of HIV-positive (HIV+) and HIV-negative (HIV–) individuals.MethodsThirty-nine plantar verruca lesions in 17 individuals were examined. Nine participants were HIV+ and eight were HIV–. Detection of HPV was performed by polymerase chain reaction using two sets of primers: MY09/MY11. The type of HPV was determined by hybridization to 38 different HPV types. Clinical types of verrucae were correlated to the HPV strain identified in each lesion.ResultsOf the 39 plantar verruca samples, 38 typed to HPV-2, HPV-27, and HPV-57 strains in HIV+ and HIV– individuals. Specifically, a large proportion of the samples from HIV– individuals typed as HPV-27 (87.5%), and HPV-2 was the predominant type identified in HIV+ individuals (50%). No rare or atypical HPV types were found in either group. We identified HPV-2 and HPV-27 in 96% of verruca plantaris clinical type. Mosaic warts typed to HPV-27 and HPV-57, and 80% of punctate verrucae typed to HPV-57.ConclusionsThis study presents an increased prevalence of HPV-2, HPV-27, and HPV-57 in plantar verrucae in this study population and provides insight into the occurrence of these types in HIV+ and HIV– individuals.
Pitted Keratolysis
Authors: Bristow Ivan R. , Lee Yong Leng H. 
Published: April 2014

Background
Pitted keratolysis is a bacterial infection that affects the plantar epidermis. Despite the condition being reported in many countries affecting both shod and unshod populations, there is little guidance for clinicians providing evidence or best practice guidelines on the management of this often stubborn infection.

Methods
Using a structured search of a range of databases, papers were identified that reported treatments tested on patients with the condition.

Results
Most of the literature uncovered was generally of a low level, such as case-based reporting or small case series. Studies were focused mainly on the use of topical antibiotic agents, such as clindamycin, erythromycin, fusidic acid, and mupirocin, often in combination with other measures, such as hygiene advice and the use of antiperspirants. From the limited evidence available, the use of topical antibiotic agents shows some efficacy in the treatment of pitted keratolysis. However, there is currently no suggestion that oral antibiotic drug therapy alone is effective in managing the condition.

Conclusions
Currently, there is no consensus on the most effective approach to managing pitted keratolysis, but a combination of antimicrobial agents and adjunctive measures, such as antiperspirants, seems to demonstrate the most effective approach from the current literature available.
Immunologic Applications of Conditional Gene Modification Technology in the Mouse
Authors: Sharma Suveena , Zhu Jinfang 
Published: April 2014

AbstractSince the success of homologous recombination in altering mouse genome and the discovery of Cre‐loxP system, the combination of these two breakthroughs has created important applications for studying the immune system in the mouse. Here, we briefly summarize the general principles of this technology and its applications in studying immune cell development and responses; such implications include conditional gene knockout and inducible and/or tissue‐specific gene over‐expression, as well as lineage fate mapping. We then discuss the pros and cons of a few commonly used Cre‐expressing mouse lines for studying lymphocyte development and functions. We also raise several general issues, such as efficiency of gene deletion, leaky activity of Cre, and Cre toxicity, all of which may have profound impacts on data interpretation. Finally, we selectively list some useful links to the Web sites as valuable mouse resources. Curr. Protoc. Immunol. 105:10.34.1‐10.34.13. © 2014 by John Wiley & Sons, Inc.
Retrieving aerosol microphysical properties by Lidar‐Radiometer Inversion Code (LIRIC) for different aerosol types
Authors: Granados‐Muñoz M. J. , Guerrero‐Rascado J. L. , Bravo‐Aranda J. A. , Navas‐Guzmán F. , Valenzuela A. , Lyamani H. , Chaikovsky A. , Wandinger U. , Ansmann A. , Dubovik O. , Grudo J. O. , Alados‐Arboledas L. 
Published: April 2014

AbstractLIRIC (Lidar‐Radiometer Inversion Code) is applied to combined lidar and Sun photometer data from Granada station corresponding to different case studies. The main aim of this analysis is to evaluate the stability of LIRIC output volume concentration profiles for different aerosol types, loadings, and vertical distributions of the atmospheric aerosols. For this purpose, in a first part, three case studies corresponding to different atmospheric situations are analyzed to study the influence of the user‐defined input parameters in LIRIC when varied in a reasonable range. Results evidence the capabilities of LIRIC to retrieve vertical profiles of microphysical properties during daytime by the combination of the lidar and the Sun photometer systems in an automatic and self‐consistent way. However, spurious values may be obtained in the lidar incomplete overlap region depending on the structure of the aerosol layers. In a second part, the use of a second Sun photometer located in Cerro Poyos, in the same atmospheric column as Granada but at higher altitude, allowed us to obtain LIRIC retrievals from two different altitudes with independent Sun photometer measurements in order to check the self‐consistency and robustness of the method. Retrievals at both levels are compared, providing a very good agreement (differences below 5 µm3/cm3) in those cases with the same aerosol type in the whole atmospheric column. However, some assumptions such as the height independency of parameters (sphericity, size distribution, or refractive index, among others) need to be carefully reviewed for those cases with the presence of aerosol layers corresponding to different types of atmospheric aerosols.
Skilled Observation and Change Blindness: A Comparison of Law Enforcement and Student Samples
Authors: Smart Shannon M. , Berry Melissa A. , Rodriguez Dario N. 
Published: April 2014

SummarySome evidence suggests that expertise and observational skills training can reduce attentional errors, such as change blindness. Laypeople typically assume that law enforcement officers possess acute observational skills, but no research to date has compared law enforcement and lay samples on their susceptibility to change blindness. In the present study, student and law enforcement samples completed a change blindness task and attempted to identify the target(s) from four line‐ups. Law enforcement officers and students were equally susceptible to change blindness regarding the switch in the target's identity, but students were more likely than officers to detect changes in the target's clothing. Students also performed better on the line‐up task, overall, than officers. Additionally, whereas students' confidence was positively correlated with identification accuracy under some circumstances, officers' confidence was either uncorrelated or negatively correlated with accuracy. We discuss the implications of these findings and suggest some factors accounting for law enforcement officers' relatively poor performance on these tasks. Copyright © 2014 John Wiley & Sons, Ltd.
Synthesis of 6‐Phenanthridinephosphonates via a Radical Phosphonation and Cyclization Process Mediated by Manganese(III) Acetate
Authors: Gao Yuzhen , Wu Ju , Xu Jian , Wang Xuerui , Tang Guo , Zhao Yufen 
Published: April 2014

Abstract6‐Phenanthridinephosphonates have interesting biological activities and potential pharmaceutical applications. However, methods for preparing these compounds are very limited. In this report, dialkyl 6‐phenanthridinephosphonates were synthesized through Mn(OAc)3‐mediated radical phosphonation of 2‐isocyanobiaryls in good to excellent yields under relatively mild reaction conditions. As one of its notable features, the radical process allows the direct formation of a PC bond and the construction of a phenanthridine ring in one reaction.
High Yielding Synthesis of Carboranes Under Mild Reaction Conditions Using a Homogeneous Silver(I) Catalyst: Direct Evidence of a Bimetallic Intermediate
Authors: El‐Zaria Mohamed E. , Keskar Kunal , Genady Afaf R. , Ioppolo Joseph A. , McNulty James , Valliant John F. 
Published: April 2014

AbstractMethods used to prepare functionalized carboranes generally require heating to high temperatures, and thus limits the range of derivatives which can be prepared directly from alkynes. We show here that by using a homogeneous silver(I) catalyst it is now possible to prepare carboranes in good to excellent yield at temperatures below 40 °C, including at room temperature. The process is general and provides an important new synthetic strategy for the preparation of functionalized boron clusters.
Antimicrobial activity of water resistant surface coating from catechol conjugated polyquaternary amine on versatile substrates
Authors: Kim Sungmin , Nam Jeong A. , Lee Sangkug , In Insik , Park Sung Young 
Published: April 2014

ABSTRACTWater resistant polymer with adhesive behavior is reported to exhibit long‐term antimicrobial activities under diverse conditions. To obtain highly adhesive polymer with prolonged antimicrobial activities and catechol moiety, 2‐chloro‐3′,4′‐dihydroxyacetophenone (CCDP) has been quaternized to poly(dimethylaminoethyl methacrylate) (PDMA). Later, for gaining the antimicrobial effects, the polymer (CCDP‐q‐PDMA) was quaternized with 1‐bromododecane (C12) [CCDP/C12‐q‐PDMA]. X‐ray photoelectron spectroscopy rectified the quaternization and adhesion of the polymer onto different substrates. The CCDP/C12‐q‐PDMA coated substrates exhibited remarkable bacterial killing efficiency against both Gram‐positive Staphylococcus aureus and Gram‐negative Escherichia coli, after incubation for 24 h. The remarkable antimicrobial activities exhibited in aqueous medium at 60°C for up to 60 days indicate the strong adhesiveness of CCDP/C12‐q‐PDMA on the substrate. Therefore, the synthesized polymer offers merit as a potential coating material, to protect a broad range of material from microbial contamination, for a prolonged period of time, under a highly stressed water environment. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40708.
N‐Arylated‐Lactam‐Type Iminosugars as New Immunosuppressive Agents: Discovery, Optimization, and Biological Evaluation
Authors: Wu Xiaowei , Zhang Fu‐Yu , Zhu Jingjing , Song Chengcheng , Xiong De‐Cai , Zhou Yifa , Cui Yuxin , Ye Xin‐Shan 
Published: April 2014

AbstractWe have previously described the discovery of N‐alkylated iminosugars that showed immunosuppressive activity both in vitro and in vivo. Herein, we report the synthesis and biological evaluation of N‐arylated lactam‐type iminosugar derivatives. The synthesis started from simple monosaccharides and featured a Buchwald–Hartwig coupling reaction to construct the key N‐aryl connection, thereby providing a highly diverse compound library. Structure–activity relationship studies, guided by a mouse‐spleen‐proliferation assay, led to the identification of ′hit′ compound 12 f. Subsequently, the systematic modification of compound 12 f afforded compounds 21 h, 21 k, 21 n, 21 t, and 21 x with improved activities (IC50=12–30 μM) and low Jurkat cytotoxicities (IC50>100 μM). These new compounds also inhibited the secretion of IFN‐γ and IL‐4, which are hallmark cytokines of Th1 and Th2 cells, respectively. This work demonstrated that the N‐arylated iminosugar structure represents a new scaffold with immunosuppressive activity.
Two‐dimensional LC‐MS/MS to enhance ceramide and phosphatidylcholine species profiling in mouse liver
Authors: Ling Yee Soon , Liang Hao‐Jan , Lin Ming‐Huan , Tang Chuan‐Ho , Wu Kuen‐Yuh , Kuo Min‐Liang , Lin Ching Yu 
Published: April 2014

ABSTRACTA two‐dimensional (2D) hydrophilic interaction liquid chromatography (HILIC) and reverse‐phase (RP) liquid chromatography (LC) system coupled with triple‐quadrupole mass spectrometry (MS) was developed to comprehensively profile ceramides and phosphatidylcholine in extracted biological samples. Briefly, the 2D HILIC‐RPLC system used a silica HILIC column operated in the first dimension to distinguish the lipid classes and a BEH C18 column operated in the second dimension to separate the lipid species of the same class. The regression linearity of each lipid was satisfactory in both systems; however, the absolute matrix effect factor was reduced in 2D LC‐MS/MS system. Limits of detection of 2D LC‐MS/MS system were 2‐ to 3‐fold lower compared with one‐dimensional RPLC‐MS/MS. The recovery from the sample ranged from 84.5 to 110%. To summarize, the developed method was proven to be accurate and producible, as relative standard deviations remained <20% at three spiked levels. The efficiency of this newly developed system was applied to measure changes of lipids in the liver of mice after naphthalene treatment. Orthogonal projection to latent structures‐discriminant analysis discriminated the lipids from control and the treatment group. We concluded that 2D LC‐MS/MS is a promising method to assist lipidomic studies of complex biological samples. Copyright © 2014 John Wiley & Sons, Ltd.
Hydrogen Release from Dialkylamine–Boranes Promoted by Mg and Ca Complexes: A DFT Analysis of the Reaction Mechanism
Authors: Butera Valeria , Russo Nino , Sicilia Emilia 
Published: April 2014

AbstractMg and Ca β‐diketiminato silylamides [HC{(Me)CN(2,6‐iPr2C6H3)}2M(THF)n{N(SiMe3)2}] (M=Mg, n=0; M=Ca, n=1) were studied as precatalysts for the dehydrogenation/dehydrocoupling of secondary amine–boranes R2HNBH3. By reaction with equimolar quantities of amine–boranes, the corresponding amidoborane derivatives are formed, which further react to yield dehydrogenation products such as the cyclic dimer [BH2NMe2]2. DFT was used here to explore the mechanistic alternatives proposed on the basis of the experimental findings for both Mg and Ca amidoboranes. The influence of the steric demand of amine–boranes on the course of the reaction was examined by performing calculations on the dehydrogenation of dimethylamine–borane (DMAB), pyrrolidine–borane (PB), and diisopropylamine–borane. In spite of the analogies in the catalytic activity of Mg‐ and Ca‐based complexes in the dehydrocoupling of amine–boranes, our theoretical analysis confirmed the experimentally observed lower reactivity of Ca complexes. Differences in catalytic activity of Mg‐ and Ca‐based complexes were examined and rationalized. As a consequence of the increase in ionic radius on going from Mg2+ to Ca2+, the dehydrogenation mechanism changes and formation of a key metal hydride intermediate becomes inaccessible. Dimerization is likely to occur off‐metal in solution for DMAB and PB, whereas steric hindrance of iPr2NHBH3 hampers formation of the cyclic dimer. The reported results are of particular interest because, although amine–borane dehydrogenation is now well established, mechanistic insight is still lacking for many systems.
A New Strategy for Realizing the Conversion of “Homo–Hetero–Homo” Heteroepitaxial Growth in Bi2Te3 and the Thermoelectric Performance
Authors: Guo Wei , Ma Jianmin , Yang Jiaqin , Li Di , Qin Qing , Wei Caiying , Zheng Wenjun 
Published: April 2014

AbstractUncovering the reason for structure‐dependent thermoelectric performance still remains a big challenge. A low‐temperature and easily scalable strategy for synthesizing Bi2Te3 nanostring hierarchical structures through solution‐phase reactions, during which there is the conversion of “homo–hetero–homo” in Bi2Te3 heteroepitaxial growth, is reported. Bi2Te3 nanostrings are obtained through the transformation from pure Bi2Te3 hexagonal nanosheets followed by TeBi2Te3 “nanotop” heterostructures to Bi2Te3 nanostrings. The growth of Bi2Te3 nanostrings appears to be a self‐assembly process through a wavy competition process generated from Te and Bi3+. The conversion of homo–hetero–homo opens up new platforms to investigate the wet chemistry of Bi2Te3 nanomaterials. Furthermore, to study the effect of morphologies and hetero/homo structures, especially with the same origin and uniform conditions on their thermoelectric properties, the thermoelectric properties of Bi2Te3 nanostrings and TeBi2Te3 heterostructured pellets fabricated by spark plasma sintering have been investigated separately.