bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural glance into a novel anti‐staphylococcal peptide
Authors: Iannucci N. B. , Curto L. M. , Albericio F. , Cascone O. , Delfino J. M. 
Published: August 2013

ABSTRACTNovel antimicrobial peptides are valuable molecules for developing anti‐infective drugs to counteract the contemporary spread of microbial drug‐resistance. Here we focus on a novel peptide (RKWVWWRNR‐NH2) derived from the fragment 107–115 of the human lysozyme that displays a 20‐fold increase in anti‐staphylococcal activity. The conformational analysis of this peptide and its interaction with model lipidic phases—as assayed by circular dichroism and fluorescence spectroscopy—show a noteworthy spectral change, which might be related to its anti‐staphylococcal activity. The secondary structure of peptide [K108W111] 107–115 hLz was dramatically affected through a single substitution at position 111 (Ala by Trp). Therefore, this conformational change might improve the interaction of the novel peptide with the bacterial plasma membrane. These results highlight the role of peptide secondary structure and the distribution of polar/nonpolar residues for the effective interaction of this peptide with the bacterial plasma membrane, a key step for triggering its lethal effect. This knowledge may contribute to the rational design of a new generation of antimicrobial peptides with increased efficacy developed from natural sources by simple screening tools. © 2013 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 102: 49–57, 2014.
Structural characterization of the regulatory domain of brain carnitine palmitoyltransferase 1
Authors: Samanta Soma , Situ Alan J. , Ulmer Tobias S. 
Published: August 2013

AbstractNeurons contain a mammalian‐specific isoform of the enzyme carnitine palmitoyltransferase 1 (CPT1C) that couples malonyl‐CoA to ceramide levels thereby contributing to systemic energy homeostasis and feeding behavior. In contrast to CPT1A, which controls the rate‐limiting step of long‐chain fatty acid β‐oxidation in all tissues, the biochemical context and regulatory mechanism of CPT1C are unknown. CPT1 enzymes are comprised of an N‐terminal regulatory domain and a C‐terminal catalytic domain (CD) that are separated by two transmembrane helices. In CPT1A, the regulatory domain, termed N, adopts an inhibitory and non‐inhibitory state, Nα and Nβ, respectively, which differ in their association with the CD. To provide insight into the regulatory mechanism of CPT1C, we have determined the structure of its regulatory domain (residues Met1‐Phe50) by NMR spectroscopy. In relation to CPT1A, the inhibitory Nα state was found to be structurally homologues whereas the non‐inhibitory Nβ state was severely destabilized, suggesting a change in overall regulation. The destabilization of Nβ may contribute to the low catalytic activity of CPT1C relative to CPT1A and makes its association with the CD unlikely. In analogy to the stabilization of Nβ by the CPT1A CD, non‐inhibitory interactions of N of CPT1C with another protein may exist. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 398–405, 2014.
Stabilization of duplex DNA and RNA by dangling ends studied by free energy simulations
Authors: Kara Mahmut , Zacharias Martin 
Published: August 2013

ABSTRACTSingle unpaired nucleotides at the end of double‐stranded nucleic acids, termed dangling ends, can contribute to duplex stability. Umbrella sampling free energy simulations of dangling cytosine and guanine nucleotides at the end of duplex and single stranded RNA and DNA molecules have been used to investigate the molecular origin of dangling end effects. In unrestraint simulations, the dangling end nucleotides stayed close to placements observed in experimental structures. Calculated free energy contributions associated with the presence of dangling nucleotides were in reasonable agreement with experiment predicting the general trend of a more stabilizing effect of purine vs. pyrimidine dangling ends. In addition, the calculations indicate a more significant stabilizing effect of dangling ends at the 5′‐end vs. 3′‐end in case of DNA and the opposite trend in case of RNA. Both electrostatic and van der Waals interactions contribute to the duplex stabilizing effect of dangling end nucleotides. The free energy simulation scheme could also be used to design dangling end nucleotides that result in enhanced duplex stabilization. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 418–427, 2014.
Effects of organic modifier and temperature on the enantiomeric separation of several azole drugs using supercritical fluid chromatography and the Chiralpak AD column
Authors: Toribio L. , Bernal J. L. , Martín M. T. , Bernal J. , del Nozal M. J. 
Published: August 2013

ABSTRACTThe effects of organic modifier and temperature on the enantioseparation of 10 triazoles and eight imidazoles, using supercritical fluid chromatography with the Chiralpak AD column, have been investigated in this work. For this purpose four different organic modifiers (methanol, ethanol, 2‐propanol and acetonitrile) were evaluated. Only in the case of two compounds could the enantiomeric separation not be achieved with any of the modifiers tested; the rest of compounds were baseline or partially resolved with at least one of the modifiers. The alcohol‐type modifiers provided the best results in terms of retention time and resolution. In general, retention increased in the order methanol < ethanol < 2‐propanol; moreover it was possible to establish a relationship between the retention and the number of aromatic rings and dioxolane groups in the molecule, that is, the higher the number is, the higher the retention time. From the study of the temperature effect, the enthalpy–entropy compensation was demonstrated for all the compounds, except for bifonazole using methanol and miconazole using acetonitrile. This suggested that both analytes are enantiomerically resolved through different mechanisms. Copyright © 2013 John Wiley & Sons, Ltd.
Angiographic fate of side branch dissections in bifurcation lesions treated with a provisional single stenting strategy: A post‐hoc analysis of the international multicenter randomized DEBIUT study
Authors: Belkacemi Anouar , Stella Pieter R. , Chunlai Shao , Uiterwijk Marcelle , Ali Danish , Agostoni Pierfrancesco 
Published: August 2013

BackgroundThe provisional single stenting strategy is currently the preferred treatment strategy in bifurcation lesions. However, in case of nonflow limiting side branch (SB) dissections, it is not clear whether outcomes may be inferior to coronaries without a SB dissection, whether it can be safe to leave a SB dissection untreated, and whether bail‐out SB stenting provides benefits over conservative treatment.MethodsBifurcation lesions treated with a provisional single stenting in the randomized DEBIUT were screened according to the presence or absence of SB dissections. Additional treatment (with possible stent implantation) or conservative management was left to the discretion of the operator.ResultsOut of the 117 lesions included, 18 (15.4%) angiographic SB dissections were seen following intervention (type A = 3, B = 7, C = 6, D/E = 2), 9 (50%) were treated with additional stenting, while 9 (50%) were left untreated. At 6‐month follow up, all dissections that were left untreated were healed. The late‐luminal loss was similar (P = 0.33) between patients without dissection (0.11 mm [−0.22 to 0.43 mm]) and with dissection (0.29 mm [−0.28 to 0.88 mm]). The late‐luminal loss was nonsignificantly lower (P = 0.40) in the nonstented dissection group (−0.01 mm [−0.33 to 0.87 mm]), than in the stented dissection group (0.41 mm [−0.20 to 0.97 mm]), while binary restenosis was 1 (13%) and 2 (25%), respectively.ConclusionCoronary SB dissections have similar 6‐month angiographic late‐luminal loss as lesions without SB dissection, with complete angiographic healing of the dissections. Moreover, this study suggests that in case of a dissection, if operators consider it safe not to stent the dissection, this can lead to a satisfactory result at mid‐term follow‐up. © 2013 Wiley Periodicals, Inc.
Copper(II) Triflate Catalyzed Allylic Arylation of Allylic Alcohols: Direct and Selective Access to C‐Allylanilines
Authors: Chen Ke , Chen Houguang Jeremy , Wong Jonathan , Yang Jinglei , Pullarkat Sumod A. 
Published: August 2013

AbstractCopper(II) triflate was used as a simple and commercially available catalyst in the direct amination of allylic alcohols with anilines to provide C‐allylanilines. A wide range of functional groups were tolerated under the reaction conditions, and the products were obtained regioselectivity without the need of an activator. A detailed mechanistic investigation was undertaken. The efficacy of this protocol was demonstrated in the conversion of the 2‐allylanilines into substituted quinolines through an oxidative cycloaddition reaction.
The Genetics of Dilated Cardiomyopathy: A Prioritized Candidate Gene Study of LMNA, TNNT2, TCAP, and PLN
Authors: Hirtle‐Lewis Marika , Desbiens Katia , Ruel Isabelle , Rudzicz Nicholas , Genest Jacques , Engert James C. , Giannetti Nadia 
Published: August 2013

AbstractBackgroundDilated cardiomyopathy (DCM), which is characterized by left ventricular enlargement and systolic dysfunction, is divided into cases with a clear predisposing condition (eg, hypothyroidism, chemotherapeutic agents, alcoholism, ischemia) and those of unknown cause (idiopathic DCM). Many cases (20%–35%) of DCM are familial, implicating a genetic contribution to the etiology. More than 30 genes have been identified, many involving “private” mutations not shared among families. Evidence suggests that nonfamilial cases also have a genetic predisposition, again involving many genes. The goal of this study was to identify mutations in genes associated with DCM in a Québec study sample including familial and nonfamilial DCM cases.HypothesisA prioritized gene study conducted within a framework for the classification of identified genetic variants could yield etiological information even in the absence of family data.MethodsWe sequenced 4 previously identified genes: lamin A/C (LMNA), cardiac troponin T type 2 (TNNT2), titin‐cap (TCAP), and phospholamban (PLN).ResultsWe discovered a nonsense mutation in the LMNA gene and a frameshift mutation in the TNNT2 gene, as well as other clinically significant variants that were not observed in publicly available databases or in Québec‐based controls. PLN was sequenced to investigate a previously published promoter variant. However, our data confirm that this variant does not have a causal role in DCM.ConclusionsDespite high locus and allele heterogeneity, we demonstrate that a prioritized gene study, combined with next‐generation exome‐sequencing data, can be fruitful for the identification of DCM mutations.
Differences in Coronary Blood Flow in Aortic Regurgitation and Systemic Arterial Hypertension Have Implications for Diastolic Blood Pressure Targets: A Systematic Review and Meta‐Analysis
Authors: Rabkin Simon W. 
Published: August 2013

AbstractThe objective was to evaluate coronary blood flow (CBF) in patients with systemic arterial hypertension (HTN) and to compare it with CBF in patients with aortic regurgitation (AR). A systematic literature search was conducted using the reference terms “coronary blood flow” and either “aortic regurgitation” or “hypertension.” The selection criteria included CBF measurement in a concomitant control group, except studies evaluating CBF with aortic‐valve replacement surgery. Twenty‐two studies met the inclusion criteria. There were 318 persons with HTN, with 185 controls; and 102 persons with AR, with 144 controls. Despite an overall increase in CBF in HTN, CBF per gram of left ventricular mass was significantly (P < 0.0001) reduced. In contrast, CBF per gram of left ventricular mass was significantly (P = 0.004) increased in AR. Aortic regurgitation was associated with a significant (P < 0.0001) increase in CBF during systole and away from diastole, in contrast to persons with HTN. Aortic‐valve replacement reversed the increase in systolic CBF. These data suggest that patients with HTN are more vulnerable than patients with AR to lower diastolic blood pressure (DBP), because resting CBF is compromised in HTN. Furthermore, patients with HTN may not compensate for DBP reductions by shifting CBF to systole, such as can occur with the low DBP in AR. Lower DBP in patients with AR cannot be used to justify treating patients with HTN to similar DBP because of the dramatic differences in CBF between the 2 conditions.
Methamphetamine‐Associated Cardiomyopathy
Authors: Won Sekon , Hong Robert A. , Shohet Ralph V. , Seto Todd B. , Parikh Nisha I. 
Published: August 2013

AbstractMethamphetamine and related compounds are now the second most commonly used illicit substance worldwide, after cannabis. Reports of methamphetamine‐associated cardiomyopathy (MAC) are increasing, but MAC has not been well reviewed. This analysis of MAC will provide an overview of the pharmacology of methamphetamine, historical perspective and epidemiology, a review of case and clinical studies, and a summary of the proposed mechanisms for MAC. Clinically, many questions remain, including the appropriate therapeutic interventions for MAC, the incidence and prevalence of cardiac pathology in methamphetamine users, risk factors for developing MAC, and prognosis of these patients. In conclusion, recognition of the significance of MAC among physicians and other medical caregivers is important given the growing use of methamphetamine and related stimulants worldwide.
Neoadjuvant chemotherapy followed by concurrent chemoradiation for locoregionally advanced nasopharyngeal carcinoma
Authors: Kong Lin , Hu Chaosu , Niu Xiaoshuang , Zhang Youwang , Guo Ye , Tham Ivan W. K. , Lu Jiade Jay 
Published: August 2013

BACKGROUNDThe authors studied the efficacy of neoadjuvant chemotherapy, consisting of a taxane, cisplatin, and 5‐fluorouracil (5‐FU) (the TPF regimen) followed by concurrent chemoradiation, in 2 separately designed and synchronously executed phase 2 trials for stage III and IVA/IVB nasopharyngeal cancer (NPC).METHODSPatients with newly diagnosed NPC were accrued to 2 trials, 1 for patients with stage III disease and the other for patients with IVA/IVB disease. All patients received TPF (docetaxel 75 mg/m2, cisplatin 75 mg/m2, and 5‐FU 2500 mg/m2 every 3 weeks for 3 cycles) followed by cisplatin 40 mg/m2 per week concurrently with either 3‐dimentional conformal radiation therapy or intensity‐modulated radiation therapy.RESULTSFrom January 2007 to July 2011, 52 eligible patients with stage III NPC and 64 eligible patients with nonmetastatic stage IV NPC were accrued. With a median follow‐up of 32.9 months, the 3‐year overall survival rates were 94.8% (95% confidence interval [CI], 87.6%‐100%) and 90.2% (95% CI, 81.8%‐98.6%) for the stage III NPC group and the IVA/IVB NPC group, respectively. The 3‐year progression‐free survival, distant metastasis‐free survival, and local progression‐free survival rates were 78.2% (95% CI, 64.6%‐91.8%), 90.5% (95% CI, 79.7%‐100%), and 93.9%(87.1%‐100%), respectively, for patients with stage III NPC and 85.1% (95% CI, 75.1%‐95.1%), 88% (95% CI, 78.6%‐97.4%), and 100%, respectively, for patients with stage IVA/IVB NPC. The most common severe (grade 3/4) hematologic and nonhematologic adverse events were neutropenia (64 patients; 55.2%) and nausea/vomiting (23 patients; 19.8%).CONCLUSIONSNeoadjuvant TPF followed by concurrent chemoradiation was well tolerated and produced encouraging outcomes in patients with locally advanced NPC in this hypothesis‐generating study. The authors concluded that randomized controlled trials are warranted to definitively confirm this aggressive and potentially efficacious strategy. Cancer 2013;119:4111–4118. © 2013 American Cancer Society.
Interior Least Tern (Sternula antillarum) breeding distribution and ecology: implications for population‐level studies and the evaluation of alternative management strategies on large, regulated rivers
Authors: Lott Casey A. , Wiley Robert L. , Fischer Richard A. , Hartfield Paul D. , Scott J. Michael 
Published: August 2013

AbstractInterior Least Terns (Sternula antillarum) (ILT) are colonial, fish‐eating birds that breed within active channels of large sand bed rivers of the Great Plains and in the Lower Mississippi Valley. Multipurpose dams, irrigation structures, and engineered navigation systems have been present on these rivers for many decades. Despite severe alteration of channels and flow regimes, regulation era floods have remained effective at maintaining bare sandbar nesting habitat on many river segments andILTpopulations have been stable or expanding since they were listed as endangered in 1985. We usedILTbreeding colony locations from 2002 to 2012 and dispersal information to identify 16 populations and 48 subpopulations. More than 90% ofILTand >83% of river km with suitable nesting habitat occur within the two largest populations. However, replicate populations remain throughout the entire historical, geophysical, and ecological range ofILT. Rapid colonization of anthropogenic habitats in areas that were not historically occupied suggests metapopulation dynamics. The highest likelihood of demographic connectivity amongILTpopulations occurs across the Southern Plains and the Lower Mississippi River, which may be demographically connected with Least Tern populations on the Gulf Coast. Paired ecological and bird population models are needed to test whether previously articulated threats limitILTpopulation growth and to determine if management intervention is necessary and where. Given current knowledge, the largest sources of model uncertainty will be: (1) uncertainty in relationships between high flow events and subsequent sandbar characteristics and (2) uncertainty regarding the frequency of dispersal among population subunits. We recommend research strategies to reduce these uncertainties.
Metathesis Reactions: Recent Trends and Challenges
Authors: Deraedt Christophe , d'Halluin Martin , Astruc Didier 
Published: August 2013

AbstractMetathesis reactions are now essential for the synthesis of complex organic molecules; a large variety of useful materials are available, and progress in this field is growing rapidly. Emphasis in this review on metathesis is placed on the recent developments of stereoselectivity aspects by using new families of molybdenum (Schrock type) and ruthenium (Grubbs type) catalysts for olefin metathesis. Recent progress in alkyne metathesis catalysts (Fürstner type) and their properties and impressive synthetic applications are highlighted as well as new terminal alkyne metathesis catalysts (Tamm type). The various strategies involved in recovering the catalyst and removing metal impurities from products towards “green chemistry” are briefly reviewed. The relationship of olefin metathesis is shown with the alkyne metathesis reaction that was exploited by Fürstner, with alkane metathesis that was achieved by using surface organometallic chemistry and highlighted by Basset, and with the use of classic organometallic catalysts by the Goldman and Brookhart groups. Finally, recent developments in polymer chemistry that involve stereochemical control, low polydispersities, and applications are summarized.
Sensitive Stripping Determination of Cadmium(II) and Lead(II) on Disposable Graphene Modified Screen‐Printed Electrode
Authors: Huangfu Chao , Fu Liang , Li Yuzhi , Li Xueling , Du Haijun , Ye Jianshan 
Published: August 2013

AbstractIn the present work, a sensitive, facile and disposable sensing platform for trace analysis of heavy metal ions was developed at the Bi modified graphene‐poly(sodium 4‐styrenesulfonate) composite film screen printed electrode (GR/PSS/Bi/SPE). The GR/PSS/Bi/SPE improved sensitivity and linearity due to the functionalization of graphene with negatively charged PSS providing more absorbing sites. The detection limit of the GR/PSS/Bi/SPE is found to be 0.042 µg L−1 for Cd2+ and 0.089 µg L−1 for Pb2+ with linear responses of Cd2+ and Pb2+ in the range of 0.5–120 µg L−1. Finally, the practical application was confirmed in real water with satisfactory results.
Electrochemical Determination of the Anticancer Herbal Drug Shikonin at a Nanostructured Poly(hydroxymethylated‐3,4‐ethylenedioxythiophene) Modified Electrode
Authors: Wu Liping , Lu Limin , Zhang Long , Xu Jingkun , Zhang Kaixin , Wen Yangping , Duan Xuemin , Yang Fan 
Published: August 2013

AbstractA simple and sensitive method is described for the electrochemical determination of shikonin, a widely used anti‐tumoral agent, based on its electrochemical oxidation at a nanostructured poly(hydroxymethylated‐3,4‐ethylenedioxy‐thiophene) (PEDOT‐MeOH) electrode, which was fabricated by a facile electropolymerization method. Compared with bare and poly(3,4‐ethylenedioxythiophene) (PEDOT) electrodes, the PEDOT‐MeOH film exhibited a distinctly higher activity for the electrooxidation of shikonin. The PEDOT‐MeOH electrode showed a wide linear response for shikonin in the concentration range from 1.0 nM to 10.0 µM with detection limit of 0.3 nM. Furthermore, the PEDOT‐MeOH electrode displayed high stability, good reproducibility and high sensitivity for the detection of shikonin.
Antibiotic Detection in Urine Using Electrochemical Sensors Based on Vertically Aligned Carbon Nanotubes
Authors: Moraes Fernando C. , Silva Tiago A. , Cesarino Ivana , Lanza Marcos R. V. , Machado Sergio A. S. 
Published: August 2013

AbstractA sensitive way to determine levofloxacin using a sensor based on vertical aligned carbon nanotubes is described. The morphology and the electrochemical performance of the electrodes were characterised by atomic force microscopy, cyclic voltammetry and square wave voltammetry. A scan‐rate study and electrochemical impedance spectroscopy showed that the levofloxacin oxidation product is adsorbed on the electrode surface. Differential pulse voltammetry in phosphate‐buffer solution allowed the development of a method to determine levofloxacin levels in the range of 1.0–10.0 µmol L−1, with a detection limit of 75.2 nmol L−1. The proposed sensor was successfully applied in the determination of levofloxacin in urine, and the obtained results were in full agreement with those from the HPLC procedure.
Fullerene‐β‐Cyclodextrin Conjugate Based Electrochemical Sensing Device for Ultrasensitive Detection of p‐Nitrophenol
Authors: Rather Jahangir Ahmad , Debnath Pradip , De Wael Karolien 
Published: August 2013

AbstractThe article describes the use of a fullerene (C60)‐β‐cyclodextrin conjugate, synthesized via 1,3‐dipolar cycloaddition, for the ultrasensitive electrochemical detection of p‐nitrophenol. This conjugate was successfully immobilized on the surface of a glassy carbon electrode and the developed device showed high activity towards p‐nitrophenol due to the synergetic effect of C60, the latter becoming highly conductive upon reduction. The determination of p‐nitrophenol was performed by using square wave voltammetry over a concentration range from 2.8×10−9 mol L−1 to 4.2×10−7 mol L−1 and the detection limit was calculated to be 1.2×10−9 mol L−1.
Bi‐Directional Electrocatalytic Detection of Dopamine at an Electrode Modified with Ferrocene‐Filled Carbon Nanotube Peapods
Authors: Cheng Huiming , Guan Lunhui , Shi Zujin , Zhu Zhiwei , Gu Zhennan , Li Meixian 
Published: August 2013

AbstractA glassy carbon electrode (GCE) was modified with nanopeapods formed by ferrocene filled single‐walled carbon nanotubes (Fc@SWNTs). The modified electrode showed bi‐directional electrocatalysis toward dopamine (DA), which suggested a synergistic effect of ferrocene and carbon nanotubes. Bi‐directional detection of DA was realized based on the modified electrode.