bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two New 3,4‐seco‐Cycloartane Triterpenes from Gardenia sootepensis
Authors: Song Wei‐Wu , Wang Xue‐Qin , Li Bo 
Published: February 2016

AbstractTwo new 3,4‐seco‐cycloartane triterpenes, named sootepin F (1) and sootepin G (2), together with two known compounds, coronalolide methyl ester (3) and sootepin D (4), were isolated from the leaves and twigs of Gardenia sootepensis. Their structures were elucidated on the basis of 1D‐ and 2D‐NMR experiments, including HMBC, HSQC, 1H,1H‐COSY, and ROESY, as well as HR‐MS.
A Convenient Synthesis of 1‐Alkoxy‐2‐alkyl‐1,2‐dihydroisoquinoline‐3,4‐diones Utilizing the Reaction of 2‐(Dialkoxymethyl)phenyllithiums with Dimethyl Oxalate
Authors: Kobayashi Kazuhiro , Honda Yuuya , Kuroda Minami 
Published: February 2016

AbstractA new and convenient method for the preparation of 1,2‐dihydroisoquinoline‐3,4‐diones with alkoxy and alkyl groups at the 4‐ and 3‐positions, respectively, using an easily operated three‐step sequence starting from 2‐(dialkoxymethyl)phenyl bromides has been developed. Thus, the starting materials are treated with BuLi to generate 2‐(dialkoxymethyl)phenyllithiums, which are allowed to react with (COOMe)2 to give methyl 2‐(dialkoxymethyl)phenyl‐2‐oxoacetates. These are then transformed into the corresponding secondary amides by the reaction with primary amines. Treatment of these keto amides with a catalytic amount of TsOH⋅H2O affords the desired products. In order to demonstrate the synthetic utility of these products, transformation of one of them into the corresponding isoquinoline‐1,3,4(2H)‐trione derivative by the oxidation with PCC was achieved.
The Diffusible Signal Factor Family of Bacterial CellCell Signals
Authors: Dow J. Maxwell , Naughton Lynn M. , Hollmann Birte , An Shi‐Qi , Ryan Robert P. 
Published: February 2016

AbstractBacterial cell‐to‐cell signals of the diffusible signal factor (DSF) family are cis‐2‐unsaturated fatty acids that differ in their chain length and branching patterns. Signaling involving DSF family members occurs in diverse bacteria to include plant and human pathogens. In the majority of these organisms, the perception of DSF is linked to turnover of the second messenger cyclic di‐GMP by one of two “core” pathways. Additional “accessory” signal transduction pathways can also be found, but are not widely conserved. DSF signaling acts to regulate diverse functions to include biofilm formation and architecture, antibiotic resistance, and the production of virulence factors in pathogens. DSF family signals can also participate in interspecies signaling with other bacteria and interkingdom signaling with the yeast Candida albicans. Such interactions may have importance in modifying microbial behavior during polymicrobial infections.
3, 3′, 5‐triiodo‐L‐thyronine Increases In Vitro Chondrogenesis of Mesenchymal Stem Cells From Human Umbilical Cord Stroma Through SRC2
Authors: Fernández‐Pernas Pablo , Fafián‐Labora Juan , Lesende‐Rodriguez Iván , Mateos Jesús , De la Fuente Alexandre , Fuentes Isaac , De Toro Santos Javier , Blanco García Fco. , Arufe María C. 
Published: February 2016

ABSTRACTOur group focuses on the study of mesenchymal stem cells (MSCs) from human umbilical cord stroma or Warthońs jelly and their directed differentiation toward chondrocyte‐like cells capable of regenerating damaged cartilage when transplanted into an injured joint. This study aimed to determine whether lactogenic hormone prolactin (PRL) or 3, 3′, 5‐triiodo‐L‐thyronine (T3), the active thyroid hormone, modulates chondrogenesis in our in vitro model of directed chondrogenic differentiation, and whether Wnt signalling is involved in this modulation. MSCs from human umbilical cord stroma underwent directed differentiation toward chondrocyte‐like cells by spheroid formation. The addition of T3 to the chondrogenic medium increased the expression of genes linked to chondrogenesis like collagen type 2, integrin alpha 10 beta 1, and Sox9 measured by quantitative real time polymerase chain reaction (qRT‐PCR) analysis. Levels of collagen type 2 and aggrecane analyzed by immunohistochemistry, and staining by Safranin O were increased after 14 days in spheroid culture with T3 compared to those without T3 or only with PRL. B‐catenin, Frizzled, and GSK‐3β gene expressions were significantly higher in spheroids cultured with chondrogenic medium (CM) plus T3 compared to CM alone after 14 days in culture. The increase of chondrogenic differentiation was inhibited when the cells were treated with T3 plus ML151, an inhibitor of the T3 steroid receptor. This work demonstrates, for first time, that T3 promotes differentiation towards chondrocytes‐like cells in our in vitro model, that this differentiation is mediated by steroid receptor co‐activator 2 (SRC2) and does not induce hypertrophy. J. Cell. Biochem. 117: 2097–2108, 2016. © 2016 Wiley Periodicals, Inc.
Diffusion tensor imaging of the human kidney: Does image registration permit scanning without respiratory triggering?
Authors: Seif Maryam , Mani Laila Yasmin , Lu Huanxiang , Boesch Chris , Reyes Mauricio , Vogt Bruno , Vermathen Peter 
Published: February 2016

PurposeTo investigate if image registration of diffusion tensor imaging (DTI) allows omitting respiratory triggering for both transplanted and native kidneysMaterials and MethodsNine kidney transplant recipients and eight healthy volunteers underwent renal DTI on a 3T scanner with and without respiratory triggering. DTI images were registered using a multimodal nonrigid registration algorithm. Apparent diffusion coefficient (ADC), the contribution of perfusion (FP), and the fractional anisotropy (FA) were determined. Relative root mean square errors (RMSE) of the fitting and the standard deviations of the derived parameters within the regions of interest (SDROI) were evaluated as quality criteria.ResultsRegistration significantly reduced RMSE in all DTI‐derived parameters of triggered and nontriggered measurements in cortex and medulla of both transplanted and native kidneys (P < 0.05 for all). In addition, SDROI values were lower with registration for all 16 parameters in transplanted kidneys (14 of 16 SDROI values were significantly reduced, P < 0.04) and for 15 of 16 parameters in native kidneys (9 of 16 SDROI values were significantly reduced, P < 0.05). Comparing triggered versus nontriggered DTI in transplanted kidneys revealed no significant difference for RMSE (P > 0.14) and for SDROI (P > 0.13) of all parameters. In contrast, in native kidneys relative RMSE from triggered scans were significantly lower than those from nontriggered scans (P < 0.02), while SDROI was slightly higher in triggered compared to nontriggered measurements in 15 out of 16 comparisons (significantly for two, P < 0.05).ConclusionRegistration improves the quality of DTI in native and transplanted kidneys. Diffusion parameters in renal allografts can be measured without respiratory triggering. In native kidneys, respiratory triggering appears advantageous. J. Magn. Reson. Imaging 2016;44:327–334.
Amylose Stereoselectively Includes Poly(d‐alanine) to Form Inclusion Complex in Vine‐Twining Polymerization: A Novel Saccharide–Peptide Supramolecular Conjugate
Authors: Gotanda Ryuya , Yamamoto Kazuya , Kadokawa Jun‐ichi 
Published: February 2016

In this study, it is found that amylose stereoselectively includes poly(d‐alanine) in the polyalanine stereoisomers in vine‐twining polymerization to form the corresponding inclusion complex, a novel saccharide–peptide supramolecular conjugate. The vine‐twining polymerization is performed by thermostable phosphorylase‐catalyzed enzymatic polymerization, which produces amylose, in the presence of poly(d‐alanine), poly(l‐alanine), or poly(dl‐alanine) dispersed in aqueous buffer solvent. The X‐ray diffraction and 1H NMR measurements of the products indicate that the inclusion complex is formed from poly(d‐alanine), whereas the systems using the other stereoisomers do not induce the inclusion complexation. The analytical results and the guest exchange experiment suggest the that average molecular ratio of amylose to poly(d‐alanine) is 1:1, and the host cavity is partially occupied by the guest.
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Mitochondrial Respiratory Function in Peripheral Blood Cells from Huntington's Disease Patients
Authors: Ehinger Johannes K. , Morota Saori , Hansson Magnus J. , Paul Gesine , Elmér Eskil 
Published: February 2016

AbstractBackgroundPatients with Huntington's disease display symptoms from both the central nervous system and peripheral tissues. Mitochondrial dysfunction has been implicated as part of the pathogenesis of the disease and has been reported in brain tissue and extracerebral tissues, such as muscle and blood cells, but the results are inconsistent. Therefore, the authors performed a refined evaluation of mitochondrial function in 2 types of peripheral blood cells from 14 patients with Huntington's disease and 21 control subjects. Several hypotheses were predefined, including impaired mitochondrial complex II function (primary), complex I function (secondary), and maximum oxidative phosphorylation capacity (secondary) in patient cells.MethodsHigh‐resolution respirometry was applied to viable platelets and mononuclear cells. Data were normalized to cell counts, citrate synthase activity, and mitochondrial DNA copy numbers.ResultsNormalized to citrate synthase activity, platelets from patients with Huntington's disease displayed respiratory dysfunction linked to complex I, complex II, and lower maximum oxidative phosphorylation capacity. No difference was seen in mononuclear cells or when platelet data were normalized to cell counts or mitochondrial DNA. The ratio of complex I respiration through maximum oxidative phosphorylation was significantly decreased in patients compared with controls. The corresponding ratio for complex II was unaffected.ConclusionsThe data indicate decreased function of mitochondrial complex I in peripheral blood cells from patients with Huntington's disease, although this could not be uniformly confirmed. The results do not confirm a systemic complex II dysfunction and do not currently support the use of mitochondrial function in blood cells as a biomarker for the disease.
Birth Prevalence of Sickle Cell Trait and Sickle Cell Disease in Shelby County, TN
Authors: Smeltzer Matthew P. , Nolan Vikki G. , Yu Xinhua , Nottage Kerri A. , Davis Bertha A. , Yang Yong , Wang Winfred C. , Gurney James G. , Hankins Jane S. 
Published: February 2016

BackgroundAccurate quantification of the regional burden of sickle cell disease (SCD) is vital to allocating health‐related resources. Shelby County, TN, which includes the city of Memphis and the regional pediatric SCD treatment center at St. Jude Children's Research Hospital, is home to a large population of African Americans.ProcedureWe postulated that the regional birth prevalence of SCD in Shelby County, TN, would differ from national rates. Using data from 2002 to 2012, we estimated the birth prevalence of SCD and sickle cell trait (SCT) in Shelby County and evaluated the distribution of SCD cases by ZIP code of residence with geographic information systems (GIS).ResultsThe prevalence of SCD in African Americans was 1/287 (95% confidence interval [CI]: 1/323, 1/256) live births, significantly higher than the nationally reported 1/350 –1/500. The prevalence of SCT in African Americans was 1/14.7 (95% CI: 1/15.0, 1/14.3) live births, significantly lower than the nationally reported 1/12. We found that 48% of the SCD cases resided in only six of the 37 residential ZIP codes, and using GIS mapping there were two clusters composed of two and four adjacent urban ZIP codes. SCT cases were also centered predominantly in the same two clusters, but slightly more dispersed.ConclusionsRecent Shelby County birth prevalence estimates differ substantially from national estimates with higher SCD and lower SCT than expected. Preliminary evidence suggests substantial clustering in two small geographic urban areas within Shelby County that may provide target areas for educational and outreach services.
Guidewire Catheter Exchange in Pediatric Oncology: Indications, Postoperative Complications, and Outcomes
Authors: Fernandez‐Pineda I. , Ortega‐Laureano L. , Wu H. , Wu J. , Sandoval J. A. , Rao B. N. , Shochat S. J. , Davidoff A. M. 
Published: February 2016

BackgroundMaintaining long‐term central venous catheters (CVCs) in children undergoing chemotherapy can be challenging. Guidewire catheter exchange (GCE) replaces a CVC without repeat venipuncture. This study evaluated the indications, success rate, and complications of GCE in a large cohort of pediatric cancer patients.ProcedureMedical records of pediatric cancer patients who underwent GCE at our institution between 2003 and 2013 were retrospectively reviewed. Variables analyzed included gender, age at GCE, primary cancer diagnosis, indication for GCE, absolute neutrophil count (ANC) at GCE, vein used, success rate, and postoperative complications (<30 days after exchange).ResultsA total of 435 GCEs performed in 407 patients (230 males and 177 females) were reviewed. Median age at GCE was 8 years (range, 0.2–24). Acute lymphoblastic leukemia was the most common diagnosis (50.6%). The primary indication for GCE was the desire to have an alternative type of CVC (71%). Other indications included catheter displacement (17%), catheter malfunction (11%), and catheter infection (1%). Median ANC at GCE was 2,581/mm3 (range, 0–43,400). Left subclavian vein was more commonly used (57.7%). The success rate of GCE was 93.4% (406 of 435 procedures, 95% confidence interval: 91.0–97.5%). A total of 33 (7.5%) postoperative complications occurred including central line associated bloodstream infection (CLABSI) (n = 20, 4.5%), catheter dislodgement (n = 6, 1.4%), and catheter malfunction (n = 7, 1.6%).ConclusionsWe conclude that GCE in pediatric cancer patients is associated with a high success rate and a low risk of complications. The most common postoperative complication, CLABSI, occurred at a rate significantly lower than following de novo CVC placement.
Poly(N‐vinyl pyrrolidone)‐block‐Poly(N‐vinyl carbazole)‐block‐poly(N‐vinyl pyrrolidone) triblock copolymers: Synthesis via RAFT/MADIX process, self‐assembly behavior, and photophysical properties
Authors: Xiang Yixin , Cong Houluo , Li Lei , Zheng Sixun 
Published: February 2016

ABSTRACTPoly(N‐vinyl pyrrolidone)‐block‐poly(N‐vinyl carbazole)‐block‐poly(N‐vinyl pyrrolidone) (PVP‐b‐PVK‐b‐PVP) triblock copolymers were synthesized via sequential reversible addition‐fragmentation chain transfer/macromolecular design via the interchange of xanthate (RAFT/MADIX) process. First, 1,4‐phenylenebis(methylene)bis(ethyl xanthate) was used as a chain transfer agent to mediate the radical polymerization of N‐vinyl carbazole (NVK). It was found that the polymerization was in a controlled and living manner. Second, one of α,ω‐dixanthate‐terminated PVKs was used as the macromolecular chain transfer agent to mediate the radical polymerization of N‐vinyl pyrrolidone (NVP) to obtain the triblock copolymers with various lengths of PVP blocks. Transmission electron microscopy (TEM) showed that the triblock copolymers in bulks were microphase‐separated and that PVK blocks were self‐organized into cylindrical microdomains, depending on the lengths of PVP blocks. In aqueous solutions, all these triblock copolymers can self‐assemble into the spherical micelles. The critical micelle concentrations of the triblock copolymers were determined without external adding fluorescence probe. By analyzing the change in fluorescence intensity as functions of the concentration, it was judged that the onset of micellization occurred at the concentration while the FL intensity began negatively to deviate from the initial linear increase with the concentration. Fluorescence spectroscopy indicates that the self‐assembled nanoobjects of the PVP‐b‐PVK‐b‐PVP triblock copolymers in water were capable of emitting blue/or purple fluorescence under the irradiation of ultraviolet light. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1852–1863
Unraveling the mechanism of proton translocation in the extracellular half‐channel of bacteriorhodopsin
Authors: Ge Xiaoxia , Gunner M. R. 
Published: February 2016

ABSTRACTBacteriorhodopsin, a light activated protein that creates a proton gradient in halobacteria, has long served as a simple model of proton pumps. Within bacteriorhodopsin, several key sites undergo protonation changes during the photocycle, moving protons from the higher pH cytoplasm to the lower pH extracellular side. The mechanism underlying the long‐range proton translocation between the central (the retinal Schiff base SB216, D85, and D212) and exit clusters (E194 and E204) remains elusive. To obtain a dynamic view of the key factors controlling proton translocation, a systematic study using molecular dynamics simulation was performed for eight bacteriorhodopsin models varying in retinal isomer and protonation states of the SB216, D85, D212, and E204. The side‐chain orientation of R82 is determined primarily by the protonation states of the residues in the EC. The side‐chain reorientation of R82 modulates the hydrogen‐bond network and consequently possible pathways of proton transfer. Quantum mechanical intrinsic reaction coordinate calculations of proton‐transfer in the methyl guanidinium‐hydronium‐hydroxide model system show that proton transfer via a guanidinium group requires an initial geometry permitting proton donation and acceptance by the same amine. In all the bacteriorhodopsin models, R82 can form proton wires with both the CC and the EC connected by the same amine. Alternatively, rare proton wires for proton transfer from the CC to the EC without involving R82 were found in an O′ state where the proton on D85 is transferred to D212. Proteins 2016; 84:639–654. © 2016 Wiley Periodicals, Inc.
Differentiating samples and experimental protocols by direct comparison of tandem mass spectra
Authors: Plas‐Duivesteijn Suzanne J. van der , Wulff Tune , Klychnikov Oleg , Ohana Dana , Dalebout Hans , van Veelen Peter A. , de Keijzer Jeroen , Nessen Merel A. , van der Burgt Yuri E. M. , Deelder André M. , Palmblad Magnus 
Published: February 2016

RationalePeptide tandem mass spectra can be analyzed by a number of means. They can be compared against predicted spectra of peptides derived from genome sequences, compared against previously acquired and identified spectra, or – sometimes – sequenced de novo. We recently introduced another method which compares spectra between liquid chromatography/tandem mass spectrometry (LC/MS/MS) datasets to determine the shared spectral content, and demonstrated how this can be applied in a molecular phylogenetic study using sera from human and non‐human primates. We will here explore if such a method have other, serendipitous uses.MethodsWe used the existing compareMS2 algorithm without modification on a diverse set of experiments.ResultsFirst we conducted a small phylogenetic study, using (mammalian) bone samples to study old material, and human pathogens aiming to distinguish clinically important strains. Although not as straightforward as primate sera analysis, the method shows significant promise for all these applications. We also used the algorithm to compare 24 different protocols for extraction of proteins from muscle tissue. The results provided useful information in comparing protocols. Finally, we applied compareMS2 aiming for quality control of two traceable protein reference standards (troponin) used in clinical chemistry assays, by analysing the effect of storage conditions.ConclusionsThe results illustrate a broad applicability of the metric based on shared tandem mass spectra between LC/MS/MS datasets for analysing protein digests in different types of experiments. There is no reason to assume that our instance of this method is optimal in any of these situations, as it makes limited or no use of accurate mass and chromatographic retention time. We propose that with further improvement and refinement, this type of analysis can be applied as a simple but informative first step in many pipelines for bottom‐up tandem mass spectrometry data analysis in proteomics and other fields, comparing or analysing large numbers of samples or datasets. Copyright © 2016 John Wiley & Sons, Ltd.
Visualizing statistical models: Removing the blindfold
Authors: Wickham Hadley , Cook Dianne , Hofmann Heike 
Published: February 2016

AbstractVisualization can help in model building, diagnosis, and in developing an understanding about how a model summarizes data. This paper proposes three strategies for visualizing statistical models: (i) display the model in the data space, (ii) look at all members of a collection, and (iii) explore the process of model fitting, not just the end result. Each strategy is accompanied by examples, includingmanova, classification algorithms, hierarchical clustering, ensembles of linear models, projection pursuit, self‐organizing maps, and neural networks.
On the estimability of the PV single‐diode model parameters
Authors: Zaharatos Brian R. , Campanelli Mark , Tenorio Luis 
Published: February 2016

AbstractThe single‐diode model is a widely used representation of the electrical performance of a photovoltaic (PV) device. This model relates the PV device's terminal current and voltage at a given irradiance and temperature. In order to obtain reasonable estimates of single‐diode model parameters given noisy data, one ought to be able to characterize the estimability of the model parameters. Here, we look to an established method called data cloning to check for evidence of inestimability.
The potential of learning from erroneous models: comparing three types of model instruction
Authors: Wijnen Frances M. , Mulder Yvonne G. , Alessi Stephen M. , Bollen Lars 
Published: February 2016

AbstractLearning from computer models is a promising approach to learning. This study investigated how three types of learning from computer models can be applied to teach high‐school students (aged 14–17) about the process of glucose–insulin regulation. Two traditional forms of learning from models (i.e. simulating a predefined model and constructing a model) were compared to learning from an erroneous model. In this innovative form of learning from computer models, students are provided with a model that contained errors to be corrected. As such, students do not have to engage in the difficult task of constructing a model. Rather, they are challenged to work with and correct the model in order for the simulation to generate correct output. As predicted, learning from erroneous models enhances learning of domain‐specific knowledge better than running a simulation or constructing a model. Copyright © 2016 System Dynamics Society