bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proteasome Inhibitors with Photocontrolled Activity
Authors: Hansen Mickel J. , Velema Willem A. , de Bruin Gerjan , Overkleeft Herman S. , Szymanski Wiktor , Feringa Ben L. 
Published: August 2014

AbstractProteasome inhibitors are widely used in cancer treatment as chemotherapeutic agents. However, their employment often results in severe side effects, due to their non‐specific cytotoxicity towards healthy tissue. This problem might be overcome by using a photopharmacological approach, that is, by attaining external, dynamic, spatiotemporal photocontrol over the activity of a cytotoxic agent, achieved by the introduction of a photoswitchable moiety into its molecular structure. Here we describe the design, synthesis, and activity of photoswitchable proteasome inhibitors. Substantial differences in proteasome inhibitory activity in cell extracts were observed before and after irradiation with light. The presented results show potential for the development of chemotherapeutic agents that can be switched on and off with light, constituting a new strategy for spatiotemporally modulating proteasomal activity.
Intriguing Manipulation of Metal‐Enhanced Fluorescence for the Detection of CuII and Cysteine
Authors: Ganguly Mainak , Pal Jaya , Mondal Chanchal , Pal Anjali , Pal Tarasankar 
Published: August 2014

AbstractCommercially available salicylaldehyde, in alkaline medium, exhibits strong fluorescence after one hour of UV exposure in the presence of AgI. The phenolic group of salicylaldehyde is converted into the quinone form under alkaline conditions in the presence of AgNO3, resulting in aggregated Ag(0), which causes approximately 250 times fluorescence enhancement of the in situ produced quinone. Such high silver‐enhanced‐fluorescence (SEF) is selectively quenched by cysteine, arginine, histidine, methionine, and tryptophan. In contrast to the other amino acids, ageing brings selectivity of the cysteine‐induced quenching effect. Interestingly, CuII is found to be the only metal ion that exclusively regenerates the lost fluorescence. Thus, quenching and recovery of fluorescence (Turn Off/On) can be used for the selective and sensitive detection of cysteine as well as CuII ions in one pot. Alteration of the electric field density around the fluorophore (lightening rod effect) and scattering/absorption cross‐section have been proposed to account for the Off/On fluorescence.
Preparation of Dithienylphospholes by 1,1‐Carboboration
Authors: Möbus Juri , Galstyan Anzhela , Feldmann Andreas , Daniliuc Constantin G. , Fröhlich Roland , Strassert Cristian A. , Kehr Gerald , Erker Gerhard 
Published: August 2014

AbstractIn this study the scope of the 1,1‐carboboration reaction was extended to the preparation of mixed heterole‐based conjugated π‐systems. Two arylbis(alkynyl)phosphane starting materials 2 were synthesized bearing two thiophene isomers at the alkyne units and the bulky tipp‐substituent (tipp=2,4,6‐triisopropylphenyl) at the phosphorous atom. The bis(thienylethynyl)phosphanes 2 were converted into the corresponding 2,5‐thienyl‐substituted 3‐borylphospholes 4 in a double 1,1‐carboboration reaction sequence employing the strongly electrophilic B(C6F5)3 reagent under mild reaction conditions. Subsequent Suzuki–Miyaura type cross‐coupling yielded the corresponding 3‐phenylphospholes 7 in a one‐pot procedure from phosphanes 2 in high yields. Phospholes 7 were converted into the respective phosphole oxides 8. A photophysical characterization of derivatives 7 and 8 was carried out. The results presented here demonstrate the suitability of the 1,1‐carboboration reaction for the preparation of phosphole‐/thiophene‐based, light‐emitting systems.
Manganese‐Mediated Intermolecular Arylation of H‐Phosphinates and Related Compounds
Authors: Berger Olivier , Montchamp Jean‐Luc 
Published: August 2014

AbstractThe intermolecular radical functionalization of arenes with aryl and alkyl H‐phosphinate esters, as well as diphenylphosphine oxide and H‐phosphonate diesters, is described. The novel catalytic MnII/excess MnIV system is a convenient and inexpensive solution to directly convert Csp2H into CP bonds. The reaction can be employed to functionalize P‐stereogenic H‐phosphinates since it is stereospecific. With monosubstituted aromatics, the selectivity for para‐substitution increases in the order (RO)2P(O)H<R1P(O)(OR)H<Ph2P(O)H, a trend that may be explained by steric effects.
Comparison of different kinetic models for NOX storage on a lean NOX trap
Authors: Watling Timothy C. , Bolton Paul D. , Swallow Daniel 
Published: August 2014

The kinetics of NOX storage on a lean NOX trap (LNT) were studied using NOX breakthrough curves measured with a laboratory reactor. A much wider range of temperatures (125–450°C) was used than in most studies to facilitate discrimination between potential models. The breakthrough curves were run until the LNT was saturated to (i) enable NO oxidation to NO2 to be studied in the absence of NOX storage, (ii) to enable the effective NOX capacity as a function of temperature to be determined, and (iii) to provide a more demanding test for potential models.Breakthrough curves for 125 and 450°C were very similar, while curves at intermediate temperatures initially followed that for 125°C before breaking away from this curve at a point that became earlier with increasing temperature. Thus, the breakthrough curves have a temperature independent initial portion, followed by a temperature dependant portion. This was explained by there being two types of site: fast sites and slow sites. Fast sites are responsible for the initial part of the curve; both the rate of storage on these sites and the available capacity are independent of temperature. The rate of storage on slow sites, on the other hand, is temperature dependant, as is the available storage capacity. Slow sites are more abundant than fast sites. The performance of three NOX storage models for these sites was compared.The amount of NOX stored as a function of temperature was bell‐shaped. The models naturally predicted that storage was limited by kinetics at lower temperatures and nitrate stability at higher temperatures.
The theory of parallel channels manifolds (Ladder networks) revisited part 1: Discrete mesoscopic modelling
Authors: Midoux Noel , Tondeur Daniel 
Published: August 2014

AbstractThis article proposes a theoretical overview of the distribution of fluid flow through manifolds composed of parallel channels connected through T‐junctions to a distributor and to a collector channel, thus composing a ladder‐like network. Such networks are used in solar heaters, fuel cells, heat exchanger plates, and other engineering devices, one issue being to achieve a nearly uniform distribution. This first part focuses on the discrete mesoscopic momentum and energy balances governing the T‐junctions, with particular attention to the empirical, flow‐rate and geometry dependent, pressure change coefficients. By “mesoscopic”, it is meant that the control volume for the balance equations includes the junction zone and that the local flow‐field in that zone is not described. The existing results and correlations for these coefficients are reviewed, compared, and synthesized.In keeping with the discrete character of the channel network, the overall network relations are compacted as a single non‐linear finite‐difference equation relating the flow‐rates in the different segments of the distributor. This formulation is suitable for convenient numerical resolution even when all the coefficients are allowed to vary with local conditions. The conditions for simplifications, such as assuming constancy of certain coefficients, are carefully investigated. A number of approximate analytical, semi‐explicit or explicit solutions are constructed. In particular, an original view of the structure of these solutions is proposed, relying on an invariance property which is demonstrated, and on the analogy with the classical McCabe‐Thiele construction in chemical engineering. These approximations are compared to exact numerical solutions.
The Relationship Between Revascularization Extent and the Long‐term Prognosis of Patients With Stable Angina Pectoris and Three‐Vessel Disease Treated by Percutaneous Coronary Intervention in the Era of Drug‐Eluting Stents
Authors: Li Quan , Yu Xianpeng , He Jiqiang , Gao Yuechun , Zhang Xiaoling , Wu Changyan , Luo Yawei , Zhang Yuchen , Ren Xuejun , Lv Shuzheng , Chen Fang 
Published: August 2014

ABSTRACTBackgroundThe effects of revascularization extent (RE) on the long‐term prognosis of patients with stable angina pectoris and 3‐vessel disease who underwent percutaneous coronary intervention were unknown.HypothesisThe study was aimed at evaluating whether there was an effect of RE on patients presenting with stable angina pectoris and 3‐vessel disease.MethodsRE, which was calculated by baseline SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score minus residue SYNTAX score divided by baseline SYNTAX score, was initially used in our study. Five hundred fifty‐eight patients presenting with stable angina pectoris and 3‐vessel disease were assigned to and compared among tertiles according to RE and clinical outcomes. The primary end point was the major adverse cardiovascular event (MACE), a composite of cardiac death, nonfatal myocardial infarction (MI), and any repeat revascularization.ResultsThe median follow‐up period was 56.9 months (interquartile range, 52.1–63.6). The incidence of MACE increased significantly as RE increased (13.3%, 31.4%, and 44.1%, log‐rank P < 0.001). The same tendency was observed in occurrences of target‐vessel failure (TVF) (a composite of cardiac death, MI, or target‐vessel revascularization) (8.8%, 20.3%, and 28.4%, log‐rank P < 0.001), repeat revascularization (11.8%, 26.2%, and 35.6%, log‐rank P < 0.001), and MI (1.1%, 2.9%, and 12.6%, log‐rank P < 0.001). Multivariate analysis confirmed the tendencies mentioned above.ConclusionsFor patients presenting with stable angina pectoris and 3‐vessel disease, the increasing extent of revascularization resulted in a less favorable prognosis.
Transport Phenomena in Nanoporous Materials
Authors: Kärger Jörg 
Published: August 2014

AbstractDiffusion, that is, the irregular movement of atoms and molecules, is a universal phenomenon of mass transfer occurring in all states of matter. It is of equal importance for fundamental research and technological applications. The present review deals with the challenges of the reliable observation of these phenomena in nanoporous materials. Starting with a survey of the different variants of diffusion measurement, it highlights the potentials of “microscopic” techniques, notably the pulsed field gradient (PFG) technique of NMR and the techniques of microimaging by interference microscopy (IFM) and IR microscopy (IRM). Considering ensembles of guest molecules, these techniques are able to directly record mass transfer phenomena over distances of typically micrometers. Their concerted application has given rise to the clarification of long‐standing discrepancies, notably between microscopic equilibrium and macroscopic non‐equilibrium measurements, and to a wealth of new information about molecular transport under confinement, hitherto often inaccessible and sometimes even unimaginable.
Methanol Steam Reforming Promoted by Molten Salt‐Modified Platinum on Alumina Catalysts
Authors: Kusche Matthias , Agel Friederike , Ní Bhriain Nollaig , Kaftan Andre , Laurin Mathias , Libuda Jörg , Wasserscheid Peter 
Published: August 2014

AbstractWe herein describe a straight forward procedure to increase the performance of platinum‐on‐alumina catalysts in methanol steam reforming by applying an alkali hydroxide coating according to the “solid catalyst with ionic liquid layer” (SCILL) approach. We demonstrate by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature‐programmed desorption (TPD) studies that potassium doping plays an important role in the catalyst activation. Moreover, the hygroscopic nature and the basicity of the salt modification contribute to the considerable enhancement in catalytic performance. During reaction, a partly liquid film of alkali hydroxides/carbonates forms on the catalyst/alumina surface, thus significantly enhancing the availability of water at the catalytically active sites. Too high catalyst pore fillings with salt introduce a considerable mass transfer barrier into the system as indicated by kinetic studies. Thus, the optimum interplay between beneficial catalyst modification and detrimental mass transfer effects had to be identified and was found on the applied platinum‐on‐alumina catalyst at KOH loadings around 7.5 mass %.
Negative intergroup contact is more influential, but positive intergroup contact is more common: Assessing contact prominence and contact prevalence in five Central European countries
Authors: Graf Sylvie , Paolini Stefania , Rubin Mark 
Published: August 2014

AbstractThe present research tested the idea that the ecological impact of intergroup contact on outgroup attitudes can be fully understood only when relative frequency and relative influence of positive and negative contact are considered simultaneously. Participants from five European countries (Austria, the Czech Republic, Germany, Poland and Slovakia; N = 1276) freely described their contact experiences with people of neighboring nationalities and then reported on their outgroup attitudes. Contact descriptions were coded for positive versus negative valence and for person versus situation framing. Consistently across the five participant groups, positive intergroup contact was reported to occur three times more frequently than negative intergroup contact; however, positive contact was found to be only weakly related to outgroup attitudes. On the contrary, the less frequent negative (vs. positive) contact was comparatively more influential in shaping outgroup attitudes, especially when negativity was reported around the contact person, rather than the contact situation. This research's findings reconcile contrasting lines of past research on intergroup contact and suggest that the greater prevalence of positive contact may compensate for the greater prominence of negative contact, thus leading to modest net improvements in outgroup attitudes after intergroup contact. Copyright © 2014 John Wiley & Sons, Ltd.
Dynamic contrast enhanced MR imaging for rectal cancer response assessment after neo‐adjuvant chemoradiation
Authors: Intven Martijn , Reerink Onne , Philippens Marielle E.P. 
Published: August 2014

BackgroundPatient selection for organ sparing treatment after good response to neo‐adjuvant chemoradiation (CRT) for locally advanced rectal cancer is challenging as no optimal restaging modality is available after CRT. In this study, we assessed the value of dynamic contrast enhanced magnetic resonance imaging (DCE‐MRI) for rectal cancer pathological response prediction.MethodsIn 51 patients with locally advanced rectal cancer, the tumor volume and volume transfer constant (Ktrans) were obtained at 3 Tesla before CRT and surgery. The predictive potential for pathological complete response (pCR) and good response (GR) was assessed. GR was defined as pCR and near‐pCR based on the tumor regression grade.ResultsThe GR group consisted of 10 patients (19.6%) with six pCR (11.8%). Both the post‐CRT tumor volume and post‐CRT Ktrans values and the relative change in volume (ΔVolume) and Ktrans (ΔKtrans) were predictive for pathological response. ΔKtrans showed the best predictive potential with a positive predictive value (PPV) of 100% for GR using a cutoff value of 32% reduction in Ktrans. For pCR the best PPV was 80% with a multiparameter model containing ΔVolume and ΔKtrans.ConclusionDCE‐MRI has predictive potential for pathological response after CRT in rectal cancer with the relative ΔKtrans being the most predictive parameter.J. Magn. Reson. Imaging 2015;41:1646–1653. © 2014 Wiley Periodicals, Inc.
Impact of blood transfusions on patients with head and neck cancer undergoing free tissue transfer
Authors: Danan Deepa , Smolkin Mark E. , Varhegyi Nikole E. , Bakos Stephen R. , Jameson Mark J. , Shonka David C. 
Published: August 2014

Objectives/HypothesisTo determine whether blood transfusions are associated with adverse outcomes in patients with head and neck cancer (HNC) undergoing microvascular free tissue transfer.Study DesignRetrospective cohort study.MethodsThe records of all patients who underwent free flaps for reconstruction after HNC resection from July 2007 through February 2013 at a single institution were reviewed. Rates of overall survival (OS), recurrence free survival (RFS), and postoperative wound infection were determined. Statistical analyses included Cox proportional hazards models and chi‐square tests.ResultsOf 167 patients, 90 received 0 to 2 units of blood and 77 received ≥ 3. After controlling for age, preoperative hemoglobin, preoperative albumin, cancer stage, and adverse pathologic features, transfusion of ≥ 3 (versus 0 to 2) units was associated with poorer OS (P = 0.0006; hazard ratio [HR] = 2.96) and RFS (P = 0.003; HR = 2.35). The rates of wound infection in patients who received 0, 1, 2, or ≥ 3 units were 13.3%, 21.2%, 33.3%, and 31.2%, respectively. There was a statistically significant difference in wound infection rates between those patients receiving 0 to 1 versus ≥ 2 units (P = 0.04).ConclusionsPatients who receive ≥ 3 units of blood after free tissue transfer for HNC had a significantly increased risk of death after controlling for age, preoperative hemoglobin and albumin, cancer stage, and adverse pathologic features. Increased transfusions are also associated with higher wound infection rates. The increased tendency to transfuse free flap patients in order to maintain a threshold hematocrit may have a detrimental impact on survival and wound infections and should be revisited.Level of Evidence2b. Laryngoscope, 125:86–91, 2015
From yeast to patient neurons and back again: Powerful new discovery platforms
Authors: Tardiff Daniel F. , Khurana Vikram , Chung Chee Yeun , Lindquist Susan 
Published: August 2014

AbstractNo disease‐modifying therapies are available for synucleinopathies, including Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple systems atrophy (MSA). The lack of therapies has been impeded by a paucity of validated drug targets and problematic cell‐based model systems. New approaches are therefore needed to identify genes and compounds that directly target the underlying cellular pathologies elicited by the pathological protein, α−synuclein (α−syn). This small, lipid‐binding protein impinges on evolutionarily conserved processes such as vesicle trafficking and mitochondrial function. For decades, the genetically tractable, single‐cell eukaryote, budding yeast, has been used to study nearly all aspects of cell biology. More recently, yeast has revealed key insights into the underlying cellular pathologies caused by α−syn. The robust cellular toxicity caused by α−syn expression facilitates unbiased high‐throughput small‐molecule screening. Critically, one must validate the discoveries made in yeast in disease‐relevant neuronal models. Here, we describe two recent reports that together establish yeast‐to‐human discovery platforms for synucleinopathies. In this exemplar, genes and small molecules identified in yeast were validated in patient‐derived neurons that present the same cellular phenotypes initially discovered in yeast. On validation, we returned to yeast, where unparalleled genetic approaches facilitated the elucidation of a small molecule's mode of action. This approach enabled the identification and neuronal validation of a previously unknown “druggable” node that interfaces with the underlying, precipitating pathologies caused by α−syn. Such platforms can provide sorely needed leads and fresh ideas for disease‐modifying therapy for these devastating diseases. © 2014 International Parkinson and Movement Disorder Society
Well‐controlled ring‐opening polymerization of cyclic esters catalyzed by aluminum amido complexes: Kinetics and mechanism
Authors: Liu Junpeng , Ma Haiyan 
Published: August 2014

ABSTRACTA series of aluminum dimethyl complexes 1–6 bearing N‐[2‐(pyrrolidinyl)benzyl]anilido ligands were synthesized and well characterized. The molecular structure of complex 1 determined by an X‐ray diffraction study indicates the bidentate chelating mode of the pyrrolidinyl‐anilido ligand. In the absence of a coinitiator, these complexes exhibited excellent control toward the polymerizations of ε‐caprolactone and rac‐lactide, affording polyesters with quite narrow molecular weight distributions (Mw/Mn = 1.04–1.26). The end group analysis of ε−CL oligomer via 1H NMR and ESI‐TOF MS methods gave strong support to the hypothesis that the polymerization catalyzed by these aluminum complexes proceeds via a coordination‐insertion mechanism involving a unique AlN (amido) bond initiation. Via 1H NMR scale oligomerization studies, it is suggested that the insertion of the first lactide monomer into AlN bond of the complex is much easier than the insertion of lactide monomer into the newly formed AlO (lactate) bond and might also be easier than the insertion of the first ε−CL monomer into AlN bond. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 3096–3106
Resmethrin, the first modern pyrethroid insecticide
Authors: Soderlund David M 
Published: August 2014

AbstractThe discovery of resmethrin almost five decades ago was the seminal event in the development of pyrethroid insecticides as important pest management tools, the value of which endures to this day. This brief review considers the development of pyrethroids from the perspective of the discovery of resmethrin. I describe the pathway to the discovery of resmethrin and the unique properties that differentiated it from the pyrethrins and earlier synthetic pyrethroids is described. I also summarize information on metabolic fate and mechanisms of selective toxicity, first elucidated with resmethrin, that have shaped our understanding of pyrethroid toxicology since that time. Finally, I review the discovery pathway that led from resmethrin to the development of the first photostable, agriculturally useful pyrethroids that established the importance of this insecticide class. © 2014 Society of Chemical Industry