bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catalytic, Asymmetric Synthesis of Phosphonic γ‐(Hydroxyalkyl)butenolides with Contiguous Quaternary and Tertiary Stereogenic Centers
Authors: Frings Marcus , Thomé Isabelle , Schiffers Ingo , Pan Fangfang , Bolm Carsten 
Published: January 2014

AbstractA procedure that enables high yielding access to phosphonic γ‐(hydroxyalkyl)butenolides with excellent regio‐, diastereo‐ and enantiocontrol is reported. The simultaneous construction of up to two adjacent quaternary stereogenic centers by a catalytic asymmetric vinylogous Mukaiyama aldol reaction unites biologically and medicinally relevant entities, namely α‐hydroxy phosphonates and γ‐(hydroxyalkyl)butenolides. This is achieved by utilizing a readily available chiral copper‐sulfoximine catalyst showing a broad functional group tolerance for both the electrophilic and nucleophilic reactants. A discussion about potential factors affecting the observed level of enantioselectivity, which stems from the enantiopure sulfoximine ligand, is also included.
Process Simulation of an Adsorption Chiller: True Moving Bed Approximation
Authors: Günther Philipp , Kunz Philip , Stierle Rolf , Eigenberger Gerhart , Nieken Ulrich 
Published: January 2014

AbstractMithilfe von Adsorptionswärmepumpen kann thermische Energie unmittelbar zur Heizung oder Klimatisierung eingesetzt werden. Um Wärmeverluste zu vermeiden wird bei Mehrbett‐Prozessen die für die Desorption benötigte Wärme zwischen den Betten übertragen und so mehrfach genutzt. Da die Auslegung derartiger Prozesse sehr aufwendig ist, ist es sinnvoll, zunächst den theoretischen Grenzfall eines stationären Gegenstromprozesses zu betrachten. Diese True‐Moving‐Bed‐Approximation erlaubt es, sowohl Methoden der Parameterverfolgung zu nutzen als auch Ausgangsgrößen zu spezifizieren.
Design and Synthesis of Tricyclic JAK3 Inhibitors with Picomolar Affinities as Novel Molecular Probes
Authors: Gehringer Matthias , Pfaffenrot Ellen , Bauer Silke , Laufer Stefan A. 
Published: January 2014

AbstractThe Janus kinase (JAK) signaling pathway is of particular importance in the pathology of inflammatory diseases and oncological disorders, and the inhibition of Janus kinase 3 (JAK3) with small molecules has proven to provide therapeutic immunosuppression. A novel class of tricyclic JAK inhibitors derived from the 3‐methyl‐1,6‐dihydrodipyrrolo[2,3‐b:2′,3′‐d]pyridine scaffold was designed based on the tofacitinib–JAK3 crystal structure by applying a rigidization approach. A convenient synthetic strategy to access the scaffold via an intramolecular Heck reaction was developed, and a small library of inhibitors was prepared and characterized using in vitro biochemical as well as cellular assays. IC50 values as low as 220 pM could be achieved with selectivity for JAK3 over other JAK family members. Both activity and selectivity were confirmed in a cellular STAT phosphorylation assay, providing also first‐time data for tofacitinib. Our novel inhibitors may serve as tool compounds and useful probes to explore the role of JAK3 inhibition in pharmacodynamics studies.
Spectroscopy and Redox Chemistry of Copper in Mordenite
Authors: Vanelderen Pieter , Vancauwenbergh Julie , Tsai Ming‐Li , Hadt Ryan G. , Solomon Edward I. , Schoonheydt Robert A. , Sels Bert F. 
Published: January 2014

AbstractCopper‐containing zeolites, such as mordenite (MOR), have recently gained increased attention as a consequence of their catalytic potential. While the preferred copper loadings in these catalytic studies are generally high, the literature lacks appropriate spectroscopic and structural information on such Cu‐rich zeolite samples. Higher copper loadings increase the complexity of the copper identity and their location in the zeolite host, but they also provide the opportunity to create novel Cu sites, which are perhaps energetically less favorable, but possibly more reactive and more suitable for catalysis. In order to address the different role of each Cu site in catalysis, we here report a combined electron paramagnetic resonance (EPR), UV/Vis‐NIR and temperature‐programmed reduction (TPR) study on highly copper‐loaded MOR. Highly resolved diffuse reflectance (DR) spectra of the CuMOR samples were obtained due to the increased copper loading, allowing the differentiation of two isolated mononuclear Cu2+ sites and the unambiguous correlation with extensively reported features in the EPR spectrum. Ligand field theory is applied together with earlier suggested theoretical calculations to determine their coordination chemistry and location within the zeolite matrix, and the theoretical analysis further allowed us to define factors governing their redox behavior. In addition to monomeric species, an EPR‐silent, possibly dimeric, copper site is present in accordance with its charge transfer absorption feature at 22200 cm−1, and quantified with TPR. Its full description and true location in MOR is currently being investigated.
[Sb7Se8Br2]3+and [Sb13Se16Br2]5+– Double and Quadruple Spiro Cubanes from Ionic Liquids
Authors: Ahmed Ejaz , Breternitz Joachim , Groh Matthias F. , Isaeva Anna , Ruck Michael 
Published: January 2014

AbstractThe reaction of antimony and selenium in the bromine‐rich Lewis acidic ionic liquid [BMIm]Br·4.7AlBr3(BMIm: 1‐butyl‐3‐methylimidazolium) in the presence of a small amount of NbCl5at 160 °C yielded dark‐red crystals of [Sb7Se8Br2][AlX4]3. For X = Cl0.15(1)Br0.85(1), the compound is isostructural to [Sb7S8Br2][AlCl4]3[P212121,a= 12.5132(5) Å,b= 17.7394(6) Å,c= 18.3013(6) Å]. For a higher chlorine content, X = Cl0.58(1)Br0.42(1), a slightly disordered variant with a bisected unit cell is found [P21212,a= 12.3757(3) Å,b= 17.4116(5) Å,c= 9.0420(2) Å]. The [Sb7Se8Br2]3+heteropolycation (C2symmetry) is a spiro double‐cubane with an antimony atom on the shared corner. From this distorted octahedrally coordinated central atom, tricoordinate selenium and antimony atoms alternate in the bonding sequence. The terminal antimony atoms each bind to a bromine atom. Quantum chemical calculations confirm polar covalent Sb–Se bonding within the cubes and indicate three‐center, four‐electron bonds for the six‐coordinate spiro atoms. The calculated charge distribution reflects the electron‐donor role of the antimony atoms. The use of a chlorine‐rich ionic liquid resulted in the formation of triclinic [Sb13Se16Br2][AlX4]5with X = Cl0.80(1)Br0.20(1)[P$\bar {1}$,a= 9.0842(5) Å,b= 19.607(1) Å,c= 21.511(1) Å,α= 64.116(6)°,β= 79.768(7)°,γ= 88.499(7)°]. The cationic cluster [Sb13Se16Br2]5+is a bromine‐terminated spiro quadruple‐cubane. This 31 atom concatenation of four cubes is assumed to be the largest known discrete main group polycation. A similar reaction in a chloride‐free system yielded [Sb7Se8Br2][Sb13Se16Br2][AlBr4]8. In its monoclinic structure [P2/c,a= 27.214(5) Å,b= 9.383(2) Å,c= 22.917(4) Å,β= 101.68(1)°], the two types of polycations alternate in layers along theaaxis. In the series [Sb4+3nSe4+4nBr2](2+n)+, these cations are the members withn= 1 and 3.
Solvolytic Behavior of Aliphatic Carboxylates
Authors: Matić Mirela , Denegri Bernard , Kronja Olga 
Published: January 2014

AbstractThe leaving group abilities (nucleofugalities) of a series of aliphatic carboxylates have been obtained by determining the nucleofuge‐specific parameters (Nf and sf) from solvolysis rate constants of X,Y‐substituted benzhydryl carboxylates in a series of aqueous ethanol mixtures by applyication of the linear free energy relationship (LFER) equation: log k = sf (Ef + Nf). These values can be employed to compare reactivities of carboxylates with those of other leaving groups previously included in the nucleofugality scale, and also to estimate the solvolysis rates of various carboxylates. It is confirmed that the inductive effect is the most important variable governing the reactivities of halogenated carboxylates in solution. Moreover, both the Hammett correlation and the solvolytic activation parameters have revealed a strong influence of the inductive effect on the nucleofugality of alkyl‐substituted carboxylates. The reaction constants (sf) indicate that carboxylate substrates with weaker leaving groups solvolyze via later, more carbocation‐like, transition states, which is in accord with the Hammond postulate. In addition, due to the weaker demand for solvation of transition states that produce more strongly stabilized benzhydrylium ions, in which more efficient charge delocalization occurs, the reaction constants (sf) obtained with most of the leaving groups investigated here increase as the polarity of the solvent decreases.
Recycling and recovery of PE‐PP‐PET‐based fiber polymeric wastes as aggregate replacement in lightweight mortar: Evaluation of environmental friendly application
Authors: Verdolotti Letizia , Iucolano Fabio , Capasso Ilaria , Lavorgna Marino , Iannace Salvatore , Liguori Barbara 
Published: January 2014

Waste polymeric material, classified as secondary raw material, mainly consisting of selected polyolefins, PE and PP, and PET has brought great pressure on the environment, due to the large quantities produced by the urban lifestyles and economic activity. This research evaluated the possibility to reuse the plastic waste as aggregates in hydraulic lime based composite mortars.The composite mortars were prepared by replacing the conventional aggregate, silica sand, with 10, 15, and 20 % of fiber polymeric waste in a mixture of lime and water. The chemico‐physical interaction between the recycled plastic aggregates and the lime matrix was examined through FTIR, X‐Ray diffraction and morphological analyses. The effect of fiber polymeric waste on the degree of hydration and mechanical performances of the produced composites was also evaluated. Experimental results show that the good chemical interaction between the fiber plastic aggregates and the mortar induced an improvement of ductility of mortar composites. However, the plastic waste limited the degree of hydration of the hydraulic lime, due to the organic characterof the plastic as opposed to the inorganic character of lime. © 2014 American Institute of Chemical Engineers Environ Prog, 33: 1445–1451, 2014
Expression of DGCR8‐Dependent MicroRNAs Is Indispensable for Osteoclastic Development and Bone‐Resorbing Activity
Authors: Sugatani Toshifumi , Hildreth Blake E. , Toribio Ramiro E. , Malluche Hartmut H. , Hruska Keith A. 
Published: January 2014

AbstractRecently, microRNAs (miRs) have been implicated in bone formation and homeostasis. We previously reported that Dicer generated miRs have pivotal roles in differentiation and activity of osteoclasts. However, recent studies have demonstrated that Dicer is implicated in production of endogenous small interfering RNAs, non‐canonical miRs, and other small RNAs in mammals. Hence, a challenging question is the extent to which expression of canonical miRs is obligatory for osteoclastic control of bone metabolism. DiGeorge syndrome critical region gene 8 (DGCR8) is exclusively related to expression of miRs by a canonical processing pathway together with the nuclear RNase III enzyme Drosha. Osteoclast‐specific deletion of DGCR8 led to impaired osteoclastic development and bone resorption so that bone development was significantly retarded. In culture, the expression levels of osteoclastic phenotype‐related genes and proteins were remarkably inhibited during osteoclastogenesis in DGCR8‐deficiency. Thus, we have identified that DGCR8‐dependent miRs are indispensable for osteoclastic control of bone metabolism. J. Cell. Biochem. 115: 1043–1047, 2014. © 2013 Wiley Periodicals, Inc.
Assessment of rat sciatic nerve function following acute implantation of high density utah slanted electrode array (25 electrodes/mm2) based on neural recordings and evoked muscle activity
Authors: Mathews Kiran S. , Wark Heather A.C. , Normann Richard A. 
Published: January 2014

ABSTRACTIntroduction: High density Utah slanted electrode arrays (HD‐USEAs) have been developed recently for intrafascicular access to submillimeter neural structures. Insertion of such high electrode density devices may cause nerve crush injury, counteracting the intended improved selective nerve fiber access. Methods: HD‐USEAs were implanted into sciatic nerves of anesthetized rats. Nerve function was assessed before and after HD‐USEA implantation by measuring changes in evoked muscle and nerve compound action potentials and single unit neuronal recordings. Results: Neural activity was recorded with over half of all implanted electrodes. Average decreases of 38%, 36%, and 13% in nerve, medial gastrocnemius, and tibialis anterior compound action potential amplitudes, respectively, were observed following array implantation. Only 1 of 8 implantations resulted in loss of all signals. Conclusions: These studies demonstrate that HD‐USEAs provide a useful neural interface without causing a nerve crush injury that would otherwise negate their use in acute preparations (<12 h). Muscle Nerve 50: 417–424, 2014
Do Hydropeaking Flows Alter Juvenile Fish Growth Rates? A Test with Juvenile Humpback Chub in the Colorado River
Authors: Finch C. , Pine W. E. , Limburg K. E. 
Published: January 2014

AbstractRiverine ecosystems have been altered in many large catchments by dam development to provide water, power, flood control and navigational benefits to humans. Conservation actions in these river ecosystems are commonly focused on minimum releases of water to downstream ecosystems. Increasingly minimum release approaches are being replaced with ‘experimental’ flows that mimic natural conditions in order to benefit riverine ecosystems. While these new policies are intuitive in their design, there is limited data of how riverine ecosystems actually respond to more natural flows. A test of more natural steady‐flow water release was compared with typical fluctuating hydropower flows in the adaptive management programme at Glen Canyon Dam, Arizona, during 2008–2011 to assess growth improvements of endangered juvenile humpback chub Gila cypha. Our results are counterintuitive and show that more natural steady flows reduced growth rates of juvenile humpback chub compared with fluctuating flows when both treatments occurred within the same year. Daily growth rates during steady flows of 2009 and 2010 were 0.05 and 0.07 mm day−1 slower, respectively, than fluctuating flows those same years, despite similar water temperatures. Juvenile humpback chub also grew more slowly during steady flows that occurred in the same season. During the summer, juvenile humpback chub grew 0.12 and 0.16 mm day−1 in fluctuating flow regimes in 2009 and 2010, respectively, and only 0.07 mm day−1 in the experimental steady flow regime in 2011, despite higher water temperatures. Our results suggest that optimal conservation management policies for endangered species in regulated rivers may not always be achieved with more natural flows. Copyright © 2014 John Wiley & Sons, Ltd.
The automorphism group of the -orbifold of the Barnes–Wall lattice vertex operator algebra of central charge 32
Authors: SHIMAKURA HIROKI 
Published: January 2014

AbstractIn this paper, we prove that the full automorphism group of the${\mathbb Z}_2$-orbifold of the Barnes–Wall lattice vertex operator algebra of central charge 32 has the shape 227.E6(2). In order to identify the group structure, we introduce a graph structure on the Griess algebra and show that it is a rank 3 graph associated toE6(2).
Magnetic resonance imaging-guided surgical design: can we optimise the Fontan operation?
Authors: Haggerty Christopher M. , Yoganathan Ajit P. , Fogel Mark A. 
Published: January 2014

AbstractThe Fontan procedure, although an imperfect solution for children born with a single functional ventricle, is the only reconstruction at present short of transplantation. The haemodynamics associated with the total cavopulmonary connection, the modern approach to Fontan, are severely altered from the normal biventricular circulation and may contribute to the long-term complications that are frequently noted. Through recent technological advances, spear-headed by advances in medical imaging, it is now possible to virtually model these surgical procedures and evaluate the patient-specific haemodynamics as part of the pre-operative planning process. This is a novel paradigm with the potential to revolutionise the approach to Fontan surgery, help to optimise the haemodynamic results, and improve patient outcomes. This review provides a brief overview of these methods, presents preliminary results of their clinical usage, and offers insights into its potential future directions.
Atomic-scale decoration for improving the pitting corrosion resistance of austenitic stainless steels
Authors: Zhou Y. T. , Zhang B. , Zheng S. J. , Wang J. , San X. Y. , Ma X. L. 
Published: January 2014

AbstractStainless steels are susceptible to the localized pitting corrosion that leads to a huge loss to our society. Studies in the past decades confirmed that the pitting events generally originate from the local dissolution in MnS inclusions which are more or less ubiquitous in stainless steels. Although a recent study indicated that endogenous MnCr2O4nano-octahedra within the MnS medium give rise to local nano-galvanic cells which are responsible for the preferential dissolution of MnS, effective solutions of restraining the cells from viewpoint of electrochemistry are being tantalizingly searched. Here we report such a galvanic corrosion can be greatly resisted via bathing the steels in Cu2+-containing solutions. This chemical bath generates Cu2−δS layers on the surfaces of MnS inclusions, invalidating the nano-galvanic cells. Our study provides a low-cost approach via an atomic scale decoration to improve the pitting corrosion resistance of stainless steels in a volume-treated manner.
500-year climate cycles stacking of recent centennial warming documented in an East Asian pollen record
Authors: Xu Deke , Lu Houyuan , Chu Guoqiang , Wu Naiqin , Shen Caiming , Wang Can , Mao Limi 
Published: January 2014

AbstractHere we presented a high-resolution 5350-year pollen record from a maar annually laminated lake in East Asia (EA). Pollen record reflected the dynamics of vertical vegetation zones and temperature change. Spectral analysis on pollen percentages/concentrations of Pinus and Quercus and a temperature proxy, revealed ~500-year quasi-periodic cold-warm fluctuations during the past 5350 years. This ~500-year cyclic climate change occurred in EA during the mid-late Holocene and even the last 150 years dominated by anthropogenic forcing. It was almost in phase with a ~500-year periodic change in solar activity and Greenland temperature change, suggesting that ~500-year small variations in solar output played a prominent role in the mid-late Holocene climate dynamics in EA, linked to high latitude climate system. Its last warm phase might terminate in the next several decades to enter another ~250-year cool phase and thus this future centennial cyclic temperature minimum could partially slow down man-made global warming.
Improved Short-Term Outcomes with Off-Pump Reoperative Coronary Artery Bypass Grafting
Authors: Ramlawi Basel , Bedeir Kareem , Garcia-Morales Luis , Rodriguez Limael , Reardon Michael , Ramchandani Mahesh 
Published: January 2014

Objective Reoperative coronary surgery patients are usually sicker and older, and the procedure is more technically demanding. Comparisons between coronary surgery with (coronary artery bypass [CAB] surgery on cardiopulmonary bypass [CPB]) and without (off-pump CAB [OPCAB]) the pump have been conducted; however, few studies showed results in reoperative cases. We investigate the potential superiority of one technique over the other in redo coronary surgeries. Methods Our institutional Society of Thoracic Surgery database was used to gather the data for 266 isolated reoperative coronary artery surgeries from January 2004 to July 2011. These were divided into the CAB surgery in CPB group (n = 204) and the OPCAB group (n = 62). Results Baseline characteristics of the two groups were similar, except for a significantly higher prevalence of cerebrovascular disease among the off-pump group ( P = 0.01). There was also a trend toward fewer vessels bypassed among the same group ( P = 0.07). Risk adjustment was done using multivariable analyses for detection of independent effects. The use of CPB was an independent predictor of increased rates of postoperative events (odds ratio, 3.9; P = 0.004) and atrial fibrillation (odds ratio, 5.9; P < 0.005) and longer intensive care unit (0.006) and hospital stay (0.004). Conclusions Redo OPCAB seems to offer favorable short-term outcomes compared with redo CAB. Our results suggest a reduced rate of overall postoperative events, decreased new postoperative atrial fibrillation, reduced hours stayed in the intensive care unit, and fewer days stayed from surgery to discharge. This was not associated with an increase in morbidity and mortality. A randomized study with a larger number of patients and with a longer follow-up is needed.
Usefulness of P‐Wave Signal Averaging to Predict Atrial Fibrillation Recurrences after Electrical Cardioversion
Authors: Blanche Coralie , Tran Nam , Carballo David , Rigamonti Fabio , Burri Haran , Zimmermann Marc 
Published: January 2014

BackgroundAccurate markers of atrial fibrillation (AF) recurrences after electrical cardioversion (ECV) are lacking. This study was conducted to assess the value of P‐wave signal averaging (SAPW) for predicting AF recurrences in a nonselected patients population submitted to ECV.MethodsA total of 133 patients (107 males, 26 females, mean age 66 ± 9 years) were included after successful ECV for persistent AF (mean duration of AF 3.6 ± 2.2 months). The mean ejection fraction (EF) was 60 ± 9%, and left atrial (LA) diameter was 44 ± 6 mm. SAPW ECG was obtained immediately after ECV and patients were prospectively followed.ResultsDuring a mean follow‐up of 8.9 ± 5.2 months, AF recurrences occurred in 40.6% (54/133). No SAPW parameters was statistically different between the group of patients with and the group without recurrences. Recurrences were less often observed in patients with a total P‐wave duration <150 ms (16/52 or 31% vs 38/81 or 47% in patients with total P‐wave duration ≥150 ms) but the difference was not statistically different (P = 0.07). P‐wave duration was correlated with age (r = 0.32; P < 0.001) and left atrial diameter (r = 0.19; P = 0.02). Age, sex, structural heart disease, amiodarone therapy, or hypertension were not associated with AF recurrences but patients without recurrences had a shorter AF duration (P = 0.001) and more often had a history of previous ablation (P = 0.027).ConclusionIn this unselected “real‐life” group of patients submitted to ECV for persistent AF, none of the SAPW parameters, including total filtered P‐wave duration, was able to predict AF recurrences.