bluuebunny/crossref_metadata_2025_split huggingface dataset:
Zinc‐Catalyzed Synthesis of Conjugated Dienoates through Unusual Cross‐Couplings of Zinc Carbenes with Diazo Compounds
Authors: Mata Sergio , González María J. , González Jesús , López Luis A. , Vicente Rubén 
Published: November 2016

AbstractZinc‐catalyzed selective cross‐coupling of two carbene sources, such as vinyl diazo compounds and enynones, enabled the synthesis of conjugated dienoate derivatives. This reaction involved the unprecedented coupling of a zinc furyl carbene with vinyl diazo compounds through the γ‐carbon. Alternatively, dienoates were also prepared by a commutative cross‐coupling of zinc vinyl carbenes generated from cyclopropenes and simple diazo compounds.
Thioaldehydes from Aldehyde–Hydrogen Sulfide Interaction Under Organocatalysis
Authors: Kumar Manoj , Francisco Joseph S. 
Published: November 2016

AbstractThioaldehydes are an important class of sulfur compounds involved in atmospheric, synthetic organic, and biological chemistry. Traditionally, they are believed to be formed by the nucleophilic attack of bisulfide anion on the carbonyl compounds. Herein, we suggest a new mechanism that does not require the formation of bisulfide anion, but rather involves an interaction between hydrogen sulfide and an aldehyde. Though the uncatalyzed or the water‐catalyzed reactions involve high barriers, the formic acid‐catalyzed reactions involve moderate barriers that should be accessible in planetary atmospheres. Under acid catalysis, thioaldehydes are formed in a hydrogen‐bonded state, which is at least 6.8 kcal mol−1 more stable than separated product and catalyst. This may have implications for the solution‐phase synthesis of simpler thioaldehydes, which has been a challenge because of their tendency to oligomerize. Another important implication of these results is for the aspartate semialdehyde→aspartate semithioaldehyde conversion, which is a key biosynthetic reaction in methanogen archaea. The unique ability of the active site aspartate or glutamate residue to catalyze hydrosulfidation of semialdehyde may explain catalysis inside these enzymes.
Vicinal Difluoroalkylation and Aminosulfonylation of Alkynes under Photoinduced Conditions
Authors: Xiang Yuanchao , Li Yuewen , Kuang Yunyan , Wu Jie 
Published: November 2016

AbstractA photoinduced vicinal difluoroalkylation and aminosulfonylation of alkynes under photocatalysis was realized. The combination of ethyl 2‐bromo‐2,2‐difluoroacetate, alkynes, and DABCO⋅(SO2)2 with hydrazines, catalyzed by 9‐mes‐10‐methyl acridinium perchlorate in the presence of visible light, afforded (E)‐ethyl 2,2‐difluoro‐4‐aryl‐4‐sulfamoylbut‐3‐enoates in good yields with high stereoselectivity. This four‐component reaction proceeds through radical addition with the insertion of sulfur dioxide.
Molecules‐in‐molecules fragment‐based method for the calculation of chiroptical spectra of large molecules: Vibrational circular dichroism and Raman optical activity spectra of alanine polypeptides
Authors: Jose K. V. Jovan , Raghavachari Krishnan 
Published: November 2016

AbstractThe molecules‐in‐molecules (MIM) fragment‐based method has recently been adapted to evaluate the chiroptical (vibrational circular dichroism [VCD] and Raman optical activity [ROA]) spectra of large molecules such as peptides. In the MIM‐VCD and MIM‐ROA methods, the relevant higher energy derivatives of the parent molecule are assembled from the corresponding derivatives of smaller fragment subsystems. In addition, the missing long‐range interfragment interactions are accounted at a computationally less expensive level of theory (MIM2). In this work we employed the MIM‐VCD and MIM‐ROA fragment‐based methods to explore the evolution of the chiroptical spectroscopic characteristics of 310‐helix, α‐helix, β‐hairpin, γ‐turn, and β‐extended conformers of gas phase polyalanine (chain length n = 6–14). The different conformers of polyalanine show distinctive features in the MIM chiroptical spectra and the associated spectral intensities increase with evolution of system size. For a better understanding the site‐specific effects on the vibrational spectra, isotopic substitutions were also performed employing the MIM method. An increasing redshift with the number of isotopically labeled 13C=O functional groups in the peptide molecule was seen. For larger polypeptides, we implemented the two‐step‐MIM model to circumvent the high computational expense associated with the evaluation of chiroptical spectra at a high level of theory using large basis sets. The chiroptical spectra of α‐(alanine)20 polypeptide obtained using the two‐step‐MIM model, including continuum solvation effects, show good agreement with the full calculations and experiment. This benchmark study suggests that the MIM‐fragment approach can assist in predicting and interpreting chiroptical spectra of large polypeptides.
Synthese von Calciumsilicathydraten für eine Rückgewinnung von Phosphor in der Abwasserbehandlung
Authors: Zeggel Lars , Fritzsche Moritz , Gellermann Carsten , Stauber Rudolf 
Published: November 2016

AbstractMit der in Deutschland geplanten Verpflichtung zur Phosphorrückgewinnung im Rahmen der Abwasserbehandlung erlangt das Thema Phosphor‐Recycling für Kommunen und Industrie zunehmend Relevanz. Bedingt durch ihre große Oberfläche und Oberflächenladung besitzen Calciumsilicathydrate (CSH) ein bedeutendes Potenzial als Reaktionsmaterial. CSH‐Phasen werden aus Quarz, Kalk und Wasser unter erhöhten Druck‐ und Temperaturbedingungen hergestellt. Dieser Beitrag widmet sich der CSH‐Synthese im Hinblick auf eine Optimierung der Phosphor‐Rückgewinnung unter Verwendung leicht verfügbarer und günstiger Rohstoffe.
Glycated 99mTc‐Tricarbonyl‐Labeled Peptide Conjugates for Tumor Targeting by “Click‐to‐Chelate”
Authors: Römhild Karolin , Fischer Christiane A. , Mindt Thomas L. 
Published: November 2016

AbstractAttaching polar pharmacological modifiers to molecular imaging probes is a common strategy to modulate their pharmacokinetic profiles to improve such parameters as the clearance rate of radiotracers and/or metabolites, and to enhance signal‐to‐background ratios. We combined the tumor‐targeting peptide sequence of bombesin (BBN) with glucuronic acid and the single‐photon emission computed tomography (SPECT) radionuclide 99mTc by the “click‐to‐chelate” methodology. The 99mTc‐tricarbonyl‐labeled glucuronated BBN conjugate was compared with a reference compound lacking the carbohydrate. The radiolabeled conjugates displayed similar characteristics in vitro (cell internalization, receptor affinity), but the hydrophilicity of the glycated version was significantly increased. While the tumor uptake of the two radioconjugates in xenografted mice was similar, the glycated peptide exhibited unexpected higher uptake in organs of the hepatobiliary excretion pathway than the more lipophilic reference compound. Control experiments suggest that this may be the result of unspecific accumulation of metabolites in which the glucuronic acid moiety does not act as an innocent pharmacological modifier.
Synthesis and Biological Evaluation of New Triazolo‐ and Imidazolopyridine RORγt Inverse Agonists
Authors: Hintermann Samuel , Guntermann Christine , Mattes Henri , Carcache David A. , Wagner Juergen , Vulpetti Anna , Billich Andreas , Dawson Janet , Kaupmann Klemens , Kallen Joerg , Stringer Rowan , Orain David 
Published: November 2016

AbstractRetinoic‐acid‐related orphan receptor γt (RORγt) is a key transcription factor implicated in the production of pro‐inflammatory Th17 cytokines, which drive a number of autoimmune diseases. Despite diverse chemical series having been reported, combining high potency with a good physicochemical profile has been a very challenging task in the RORγt inhibitor field. Based on available chemical structures and incorporating in‐house knowledge, a new series of triazolo‐ and imidazopyridine RORγt inverse agonists was designed. In addition, replacement of the terminal cyclopentylamide metabolic soft spot by five‐membered heterocycles was investigated. From our efforts, we identified an optimal 6,7,8‐substituted imidazo[1,2‐a]pyridine core system and a 5‐tert‐butyl‐1,2,4‐oxadiazole as cyclopentylamide replacement leading to compounds 10 ((S)‐N‐(8‐((4‐(cyclopentanecarbonyl)‐3‐methylpiperazin‐1‐yl)methyl)‐7‐methylimidazo[1,2‐a]pyridin‐6‐yl)‐2‐methylpyrimidine‐5‐carboxamide) and 33 ((S)‐N‐(8‐((4‐(5‐(tert‐butyl)‐1,2,4‐oxadiazol‐3‐yl)‐3‐methylpiperazin‐1‐yl)methyl)‐7‐methylimidazo[1,2‐a]pyridin‐6‐yl)‐2‐methylpyrimidine‐5‐carboxamide). Both derivatives showed good pharmacological potencies in biochemical and cell‐based assays combined with excellent physicochemical properties, including low to medium plasma protein binding across species. Finally, 10 and 33 were shown to be active in a rodent pharmacokinetic/pharmacodynamic (PK/PD) model after oral gavage at 15 mg kg−1, lowering IL‐17 cytokine production in ex vivo antigen recall assays.
Multicolor Tuning in Room‐Temperature Self‐Activated Ca2Nb2O7 Submicroplates by Lanthanide Doping
Authors: Zhang Jun‐Cheng , Liu Yan‐Jie , Yan Xu , Zhang Hong‐Di , Zhang Jun , Wang Xiaoxiong , Han Wen‐Peng , Long Yun‐Ze , Sun Xin‐Yuan 
Published: November 2016

AbstractSelf‐activated phosphors are capable of generating optical emissions from the internal ion groups of host lattice before externally introducing luminescent ions. However, numerous self‐activated phosphors only show luminescence at low temperature due to the thermally activated energy migration among ion groups at room temperature, severely confining their application conditions. In this letter, we propose a strategy to converting the low‐temperature luminescence to a room‐temperature one through changing the synthesis conditions to induce structural distortions and thus to limit energy migration. Room‐temperature self‐activated luminescence of Ca2Nb2O7 was accordingly achieved in submicroplates synthesized using the sol–gel method. By further coupling the blue broadband emission from Ca2Nb2O7 submicroplates with the characteristic luminescence of Ln3+ (Pr3+, Sm3+, and Dy3+) dopants, multicolor emissions were successively tuned through adjusting the concentration of Ln3+. Our results are expected to expand the scope of designing room‐temperature self‐activated phosphors and tuning multicolor emission.
Assessment of oral appliance for obstructive sleep apnea patients
Authors: Makihara Eri , Kawano Toshihiro , Miyajima Ryuichiro , Masumi Shin‐ichi , Enciso Reyes , Clark Glenn T. 
Published: November 2016

AbstractAlthough oral appliances (OAs) have become widely used for the management of obstructive sleep apnea (OSA), side effects of OAs are generally related to poor utilization. The purpose of the present study was to evaluate relationship between utilization and treatment efficacy of a boil‐and‐bite appliance for OSA patients. A total of 135 patients with OSA who had used an OAs were mailed a questionnaire to determine whether they were currently using the OA. If so, they were asked about OA use, improvement of signs and subjective symptoms, and utilization. Otherwise, they were asked to indicate why and when they quit using the OA. Results of overnight polysomnography (PSG) before and after treatment were reviewed. Of the 48 responding patients, 33 patients were currently using the OA. The most common complication was excessive salivation (n = 11). All indices from PSG excluding arousal index were significantly improved after treatment (p < 0.05). Thirty patients showed improved signs and subjective symptoms. Eight out of 12 subjects (66.7%) were successfully treated, achieving an apnea‐hypopnea index (AHI) < 10/h and >50% reduction in apnea‐hypopnea index. Of the 15 patients no longer using the OA, the primary reason for quitting was “no treatment effect” (n = 5). No indices from PSG recording differed between before and after treatment in the not‐using group. These results suggest that both subjective and objective signs and symptoms improved with use of the OA in the using group. However, no signs and subjective symptoms or indices of sleep quality differed between before and after treatment in the not‐using group. Device improvements are needed to achieve better treatment efficacy, and thus improve compliance. The present study evaluated relationship between utilization and treatment efficacy of a boil ‐and bite appliance for OSA patients. Device improvements are needed to achieve better treatment efficacy, thus improve compliance.
Cunningham's skinks show low genetic connectivity and signatures of divergent selection across its distribution
Authors: Ofori Benjamin Y. , Beaumont Linda J. , Stow Adam J. 
Published: November 2016

AbstractEstablishing corridors of connecting habitat has become a mainstay conservation strategy to maintain gene flow and facilitate climate‐driven range shifts. Yet, little attention has been given to ascertaining the extent to which corridors will benefit philopatric species, which might exhibit localized adaptation. Measures of genetic connectivity and adaptive genetic variation across species’ ranges can help fill this knowledge gap. Here, we characterized the spatial genetic structure of Cunningham's skink (Egernia cunninghami), a philopatric species distributed along Australia's Great Dividing Range, and assessed evidence of localized adaptation. Analysis of 4,274 SNPs from 94 individuals sampled at four localities spanning 500 km and 4° of latitude revealed strong genetic structuring at neutral loci (mean FST ± SD = 0.603 ± 0.237) among the localities. Putatively neutral SNPs and those under divergent selection yielded contrasting spatial patterns, with the latter identifying two genetically distinct clusters. Given low genetic connectivity of the four localities, we suggest that the natural movement rate of this species is insufficient to keep pace with spatial shifts to its climate envelope, irrespective of habitat availability. In addition, our finding of localized adaptation highlights the risk of outbreeding depression should the translocation of individuals be adopted as a conservation management strategy.
Reliable estimation of microvascular flow patterns in patients with disrupted blood–brain barrier using dynamic susceptibility contrast MRI
Authors: Hansen Mikkel Bo , Tietze Anna , Kalpathy‐Cramer Jayashree , Gerstner Elizabeth R. , Batchelor Tracy T. , Østergaard Leif , Mouridsen Kim 
Published: November 2016

PurposeTo present and quantify the performance of a method to compute tissue hemodynamic parameters from dynamic susceptibility contrast (DSC) MRI data in brain tissue with possible nonintact blood–brain barrier.Theory and Materials and MethodsWe propose a Bayesian scheme to obtain perfusion metrics, including capillary transit‐time heterogeneity (CTH), from DSC‐MRI data in the presence of contrast agent extravasation. Initial performance assessment is performed through simulations. Next, we assessed possible over‐ or under correction for tracer extravasation in two patients receiving contrast agent preloading and two patients not receiving preloading. Perfusion metrics for N = 60 patients diagnosed with either grade III (N = 14) or grade IV gliomas (N = 46) were analyzed across tissue types to evaluate the ability to distinguish regions with different hemodynamic patterns. Finally, N = 4 patient cases undergoing anti‐angiogenic treatment are evaluated qualitatively for treatment effects. All patient data were acquired at 3.0 Tesla.ResultsThe simulation studies showed good robustness against low signal‐to‐noise ratios, exemplified with Pearson correlations of R = 0.833 (mean transit time) and R = 0.738 (CTH) at signal‐to‐noise ratio = 20. Region‐of‐interest analysis of the N = 60 glioma patients showed that cerebral blood volume (CBV) significantly separated enhancing core from edema (grade IV: P < 10−8, grade III: P < 0.05) and enhancing core from normal appearing ipsilateral white matter (NAWM) (grade IV: P < 10−8, grade III: P < 0.05). The microvascular parameters were particularly good in separating edematous tissue from NAWM tissue in grade IV gliomas (P < 0.001). Finally, CTH separated grade III and grade IV core tissue (P < 0.05).ConclusionWe have demonstrated robustness of the proposed Bayesian algorithm against experimental noise and demonstrated complementary value in microvascular parameters to the CBV parameter in separating tissue types in gliomas.Level of Evidence: 3Technical Efficacy: Stage 2J. MAGN. RESON. IMAGING 2017;46:537–549
Evaluation of recurrent high‐grade gliomas treated with bevacizumab: A preliminary report of 3D pseudocontinuous artery spin labeling
Authors: Lyu Yuelei , Liu Shuai , You Hui , Hou Bo , Wang Yu , Ma Wenbin , Feng Feng 
Published: November 2016

PurposeTo investigate the role of cerebral blood flow (CBF) derived from a 3D fast spin echo (FSE) pseudocontinuous artery spin labeling (pcASL) sequence in evaluating the survival rate of recurrent high‐grade gliomas (rHGGs) that were treated with bevacizumab (BEV).Materials and MethodsSixteen patients with rHGGs who underwent 3T 3D FSE pcASL imaging 1–2 days before (baseline or pre‐BEV) and within 1 month after BEV treatment initiation (post‐BEV) were included in the study. Average (aCBF) and maximum (mCBF) cerebral blood flow of the enhancing tumor, their respective normalized values to contralateral normal‐appearing white matter (rCBF_wm and mCBF_wm) and cerebellum (rCBF_cb and mCBF_cb), and the related changes between baseline and post‐BEV were evaluated. Receiver operating characteristic (ROC) curve analysis was utilized to define the optimal cutoff perfusion values for overall survival (OS) and progression‐free survival (PFS) stratification. Kaplan–Meier analysis with log‐rank test was applied to assess and compare PFS and OS rates.ResultsAll the CBF measurements pre‐BEV and post‐BEV treatment were significantly different except mCBF. The CBF measurements (aCBF, rCBF_wm, rCBF_cb, mCBF_wm and mCBF_cb) pre‐BEV all decreased post‐BEV treatment. Cutoffs of aCBF (43.72 ml/100g/min) pre‐BEV for OS, rCBF_cb (1.09) pre‐BEV for PFS and OS, and ΔaCBF (–0.37) for PFS were found to be statistically significant in survival stratification (404 days vs. 140 days, P = 0.026; 251 days vs. 112 days, P = 0.044; 404 days vs. 194 days, P = 0.046; 267 days vs. 116 days, P = 0.048, respectively).ConclusionThree dimensional FSE pcASL can detect the decrease of perfusion in rHGGs treated with BEV and is a potential promising technique in stratifying survival rate of rHGGs under BEV treatment.Level of Evidence: 3Technical Efficacy: Stage 2J. MAGN. RESON. IMAGING 2017;46:565–573
Pilot testing of a novel surgical simulator for endoscopic zenker's diverticulotomy
Authors: Wiebracht Nathan D. , Giliberto John P. , Myer Charles , Casper Keith , Johnson Kaalan E. 
Published: November 2016

Objectives/HypothesisRestrictions on resident work hours and the increasing purview of otolaryngology reduce the efficacy of the traditional surgical training model. With limited case volumes at many institutions and the unique instrumentation of endoscopic Zenker's diverticulotomy (EZD), simulation may be useful to improve training. In this study, a novel surgical simulator for EZD is developed and validated.Study DesignSimulation model development.MethodsAn EZD model was designed using an intubation trainer and disposable diverticulum inserts. A novel objective structured assessment of technical skill (OSATS) for EZD was developed. Performance of otolaryngology residents on simulations using the OSATS and time to completion were evaluated during an instructional course. Pre‐ and postencounter surveys were completed. Inter‐rater and intrarater reliability were evaluated via blinded video review of resident performance.ResultsSeventeen residents participated (n = 17). Surveys showed confidence improved two points on a five‐point scale (P < .001), and 94% agreed that the model would improve resident performance with in vivo EZD. More experienced trainees (postgraduate year [PGY] 3–5, n = 11 vs. PGY 1–2, n = 6) had shorter times to completion (P < .001) and higher assessment scores on initial attempts (P = .006). Both groups showed significant improvements from initial to final attempts on 30‐point scales for global rating by 6.2 ± 4.2 (mean ± standard deviation, P < .001). The novel OSATS demonstrated fair live/video reliability (к = 0.40) and inter‐rater reliability (к = 0.44), and moderate intrarater reliability (к = 0.60).ConclusionsPilot testing of an EZD simulator demonstrated acceptability, content validity, and construct validity. A novel OSATS was developed and evaluated. Further investigation of the impact on operative performance and validation of the OSATS in vivo is needed.Level of EvidenceNA Laryngoscope, 127:592–596, 2017
Contemporary management of carotid blowout syndrome utilizing endovascular techniques
Authors: Manzoor Nauman F. , Rezaee Rod P. , Ray Abhishek , Wick Cameron C. , Blackham Kristine , Stepnick David , Lavertu Pierre , Zender Chad A. 
Published: November 2016

Objectives/HypothesisTo illustrate complex interdisciplinary decision making and the utility of modern endovascular techniques in the management of patients with carotid blowout syndrome (CBS).Study DesignsRetrospective chart review.MethodsPatients treated with endovascular strategies and/or surgical modalities were included. Control of hemorrhage, neurological, and survival outcomes were studied.ResultsBetween 2004 and 2014, 33 patients had 38 hemorrhagic events related to head and neck cancer that were managed with endovascular means. Of these, 23 were localized to the external carotid artery (ECA) branches and five localized to the ECA main trunk; nine were related to the common carotid artery (CCA) or internal carotid artery (ICA), and one event was related to the innominate artery. Seven events related to the CCA/ICA or innominate artery were managed with endovascular sacrifice, whereas three cases were managed with a flow‐preserving approach (covered stent). Only one patient developed permanent hemiparesis. In two of the three cases where the flow‐preserving approach was used, the covered stent eventually became exposed via the overlying soft tissue defect, and definitive management using carotid revascularization or resection was employed to prevent further hemorrhage. In cases of soft tissue necrosis, vascularized tissues were used to cover the great vessels as applicable.ConclusionsThe use of modern endovascular approaches for management of acute CBS yields optimal results and should be employed in a coordinated manner by the head and neck surgeon and the neurointerventionalist.Level of Evidence4. Laryngoscope, 2016 127:383–390, 2017
Polymer Material Design by Microfluidics Inspired by Cell Biology and Cell‐Free Biotechnology
Authors: Thiele Julian 
Published: November 2016

Microfluidic flow cells provide excellent control over the formation of microemulsions, which are widely applied as templates for the fabrication of hydrogel microparticles and vesicles with defined physicochemical properties. In recent years, bio‐orthogonal synthesis schemes of macromolecular building blocks as well as their microfluidic processing under mild reaction conditions have greatly extended microfluidics‐based vesicle and hydrogel design beyond material sciences. In particular, in synthetic and cell biology, tissue engineering as well as cell‐free biotechnology, microgels and vesicles as experimental platforms with known parameter space allow for mimicking, studying and manipulating key aspects of cellular life in vitro in a tailored fashion. This article provides insights in recent advances to fabricate vesicles and microgels by microfluidic jets and droplets with tailored volume, shape and internal structure, and presents developments in applying these materials as artificial extracellular matrices as well as simple cell mimics designed by microfluidics.
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