bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nucleophile‐Directed Selective Transformation of cis‐1‐Tosyl‐2‐tosyloxymethyl‐3‐(trifluoromethyl)aziridine into Aziridines, Azetidines, and Benzo‐Fused Dithianes, Oxathianes, Dioxanes, and (Thio)morpholines
Authors: Kenis Sara , D'hooghe Matthias , Verniest Guido , Reybroeck Maaike , Dang Thi Tuyet Anh , Pham The Chinh , Thi Pham Tham , Törnroos Karl W. , Van Tuyen Nguyen , De Kimpe Norbert 
Published: March 2013

AbstractA five‐step procedure for the synthesis of cis‐1‐tosyl‐2‐tosyloxymethyl‐3‐(trifluoromethyl)aziridine was developed, starting from 1‐ethoxy‐2,2,2‐trifluoroethanol, involving imination, aziridination, ester reduction, hydrogenation, and N‐,O‐ditosylation steps. Further synthetic elaborations revealed a remarkable difference in the reactivity of cis‐1‐tosyl‐2‐tosyloxymethyl‐3‐(trifluoromethyl)aziridine with respect to aromatic sulfur and oxygen nucleophiles, thus enabling the selective deployment of this versatile substrate as a building block for the synthesis of functionalized aziridines, azetidines, and benzo‐fused dithianes, oxathianes, dioxanes, and (thio)morpholines.
An Array of Bengamide E Analogues Modified at the Terminal Olefinic Position: Synthesis and Antitumor Properties
Authors: Martín‐Gálvez Francisca , García‐Ruiz Cristina , Sánchez‐Ruiz Antonio , Valeriote Frederick A. , Sarabia Francisco 
Published: March 2013

AbstractBased on our previously described synthetic strategy for bengamide E, a natural product of marine origin with antitumor activity, a small library of analogues modified at the terminal olefinic position was generated with the objective of investigating the effect of structural modifications on antitumor properties. Biological evaluation of these analogues, consisting of IC50 determinations against various tumor cell lines, revealed important aspects with respect to the structural requirements of this olefinic position for activity. Interestingly, the analogue possessing a cyclopentyl group displayed greater potency than the parent bengamide E, representing a key finding upon which to base further investigations into the design of new analogues with promising biological activities.
NMR quadrupole liouvillians for arbitrary spin: Exact symbolic expressions and perturbation solutions
Authors: Bain Alex D. 
Published: March 2013

AbstractThe NMR of quadrupolar nuclei with half‐integer spins is almost always described by treating the quadrupole interaction with second‐order perturbation theory. The standard practice is to perturb the wave functions, then calculate the transitions. In this article, we elaborate on the so‐called direct method in which the transitions are calculated directly without the requirement of knowing the operators and the wavefunctions. The method is set up using a set of formulae giving fully symbolic expressions. First of all, this provides a convenient way for a full and exact numerical solution that goes beyond perturbation theory. The other possibility is that it allows us to see the effect of the quadrupole perturbation on the unperturbed transitions. The results are the same, as they must be, but this approach reveals a number of important symmetries. Perturbations will mix the unperturbed transitions, but despite the use of high‐order perturbation theory, the mixing is very simple, specific, and controlled by selection rules. This gives a clear physical picture of the physical basis of the effects of perturbation theory. The approach is systematic and general and is easily extended to an arbitrary half‐integral spin. © 2013 Wiley Periodicals, Inc. Concepts Magn Reson Part 42A: 45–358, 2013.
Increase of suicide and accidental death after hematopoietic stem cell transplantation
Authors: Tichelli André , Labopin Myriam , Rovó Alicia , Badoglio Manuela , Arat Mutlu , van Lint Maria Teresa , Lawitschka Anita , Schwarze Carl Philipp , Passweg Jakob , Socié Gérard 
Published: March 2013

BACKGROUNDRelapse and transplant‐related complications are leading causes of mortality after hematopoietic stem cell transplantation (HSCT). Suicides and accidents have not been studied in these patients. This study sought to determine whether there is an excess of suicide and accidental deaths after HSCT, and to determine risk factors.METHODSThe incidence of suicidal and accidental death in patients after undergoing HSCT, standardized mortality ratio (SMR), and absolute excess risk (AER) of suicide and accidental deaths was determined, compared with the general European population. A case‐control analysis was done to define factors associated with suicide and accidental deaths. Data were derived from the European Group for Blood and Marrow Transplantation Registry, including 294,922 patients who underwent autologous or allogeneic HSCT from 1980 to 2009.RESULTSThe 10‐year cumulative incidence of suicide and accidental deaths was 101.8 and 55.6 per 100,000 patients, respectively. SMR and AER of suicide after HSCT were 2.12 (P < .001) and 10.91, higher than in the European general population for 100,000 deaths, respectively. SMR and AER of accidental death were 1.23 (P < .05) and 2.54, respectively. In the case‐control study, relapses were more frequent among patients who committed suicide after autologous HSCT (37% versus 18%; P < .0001). Chronic graft‐versus‐host disease was higher among patients who committed suicide after allogeneic HSCT (64% versus 37%; P = .001).CONCLUSIONSThere is an excess of deaths due to suicide and accidents in patients after undergoing HSCT as compared with the European general population. Relapse was associated with more suicide and accidental deaths after autologous HSCT, and chronic graft‐versus‐host disease was associated with more deaths by suicide after allogeneic HSCT. Cancer 2013;119:2012–2021. © 2013 American Cancer Society.
Health care‐associated infections after major cancer surgery
Authors: Sammon Jesse , Trinh Vincent Q. , Ravi Praful , Sukumar Shyam , Gervais Mai‐Kim , Shariat Shahrokh F. , Larouche Alexandre , Tian Zhe , Kim Simon P. , Kowalczyk Keith J. , Hu Jim C. , Menon Mani , Karakiewicz Pierre I. , Trinh Quoc‐Dien , Sun Maxine 
Published: March 2013

BACKGROUNDApproximately 1.7 million individuals per year are affected with health care‐associated infections (HAIs) in the United States. The authors examined trends in the incidence of HAI after major cancer surgery (MCS) and risk factors for HAI to describe the effects of HAI on mortality after MCS.METHODSPatients undergoing 1 of 8 MCS procedures within the Nationwide Inpatient Sample between 1999 and 2009 were identified (n = 2,502,686). Generalized linear regression models were used to estimate the impact of the primary predictors (procedure type, age, sex, race, insurance status, Charlson comorbidity index, hospital volume, and hospital bed size) on the odds of HAI and in‐hospital mortality. Trends in incidence were evaluated with linear regression.RESULTSOverall, MCS‐associated HAI incidence increased 2.7% per year (P < .001), whereas mortality decreased 1.3% per year (P < .001). Male gender (odds ratio [OR], 1.12, 95% confidence interval [CI], 1.10‐1.14), advancing age (OR, 1.02; 95% CI, 1.02‐1.02), black race (OR, 1.26; 95% CI, 1.21‐1.31), ≥1 comorbidities (OR, from 1.08 [95% CI, 1.04‐1.13] to 1.31 [95% CI, 1.27‐1.35]), and nonprivate insurance (OR, from 1.18 [95% CI, 1.15‐1.22] to 1.67 [95% CI, 1.59‐1.76]) were associated with an increased odds of HAI on multivariable analysis. Conversely, increasing hospital volume was associated with lower odds of HAI (OR, 0.999; 95% CI, 0.99‐0.99). Patients with MCS‐associated HAI had increased odds of mortality (OR, 8.66; 95% CI, 8.51‐8.82).CONCLUSIONSBetween 1999 and 2009, the incidence of MCS‐associated HAI events increased; however, HAI‐associated mortality decreased. That said, significant disparities exist in the hospital and demographic attributes associated with MCS‐associated HAI, with attendant health policy implications. Moreover, HAI remains detrimentally linked to mortality during hospitalization. Cancer 2013;119:2317–2324. © 2013 American Cancer Society.
Improvement of Solar Energy Conversion with Nb‐Incorporated TiO2 Hierarchical Microspheres
Authors: Hoang Son , Ngo Thong Q. , Berglund Sean P. , Fullon Raymond R. , Ekerdt John G. , Mullins C. Buddie 
Published: March 2013

AbstractNiobium‐modified TiO2 hierarchical spherical micrometer‐size particles, which consist of many nanowires, are synthesized by solvothermal synthesis and studied as photoelectrodes for water photo‐oxidation and dye‐sensitized solar cell (DSSC) applications. Incorporation of Nb leads to a rutile‐to‐anatase TiO2 phase transition in the TiO2 hierarchical spheres (HSs), with the anatase percentage increasing from 0 % for the pristine TiO2 HSs to 47.6 % for the 1.82 at. % Nb‐incorporated TiO2 sample. Incorporation of Nb leads to significant improvements in water photo‐oxidation with the photocurrents reaching 70.5 μA cm−2 at 1.23 V versus the reversible hydrogen electrode, compared with 28.3 μA cm−2 for the pristine TiO2 sample. The photoconversion efficiency of Nb:TiO2 HS‐based DSSCs reaches 6.09±0.15 % at 0.25 at. % Nb, significantly higher than that for the pristine TiO2 HS cells (3.99±0.02 %). In addition, the incident‐photon‐to‐current efficiency spectra for DSSCs show that employing TiO2 and Nb:TiO2 HSs provides better light harvesting, especially of long‐wavelength photons, than anatase TiO2 nanoparticle‐based DSSCs.
Intensive Protein Digestion Using Cross‐Linked Trypsin Aggregates in Proteomics Analysis
Authors: Wang Meng‐Fan , Mu Yang‐Yang , Qi Wei , Su Rong‐Xin , He Zhi‐Min 
Published: March 2013

AbstractIn this study, cross‐linked enzyme aggregates of tissue‐culture‐grade trypsin (CLEAs‐T) were prepared and introduced to the proteomics analysis instead of the expensive proteomics‐grade trypsin, which benefits from the protein purification during the preparation of the CLEAs. Bovine serum albumin, lysozyme, bovine hemoglobin, and α‐casein were used as model proteins, and three intensive strategies (high‐enzyme‐concentration, high‐temperature, and ultrasound‐assisted digestion) were applied to the rapid and efficient digestion of model proteins by CLEAs‐T. The peptide fragments were then identified by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, which revealed the higher sequence coverage and sharply reduced digestion time of these strategies compared with the conventional in‐solution 12 h digestion method. Morphology studies demonstrated that the excellent performance of CLEAs‐T in proteomics analysis came from the “scaffoldlike” supermolecular structure, which provided a high resistance to the autolysis and denaturation of trypsin under high‐enzyme‐concentration, high‐temperature, and ultrasound‐assisted digestion.
Direct Fluorination of Cyclic Carbonates and closo‐K2[B12H12] in a Slug‐Flow Ministructured Reactor
Authors: Hill Mathias , Baron Patrick , Cobry Keith , Goll Sascha K. , Lang Philipp , Knapp Carsten , Scherer Harald , Woias Peter , Zhang Pengcheng , Krossing Ingo 
Published: March 2013

AbstractInvited for this month’s cover are the groups of Prof. Ingo Krossing and Prof. Peter Woias based at Albert‐Ludwigs‐Universität Freiburg as well as Prof. Carsten Knapp who is now at Bergische Universität Wuppertal. The background of the cover picture shows the Rhine Falls (Schaffhausen, Switzerland), which is the largest waterfall in Europe and only one hour away from the laboratories in Freiburg. The waterfall symbolizes flow chemistry and the wild nature of direct fluorination reactions.
Normalization of mass cytometry data with bead standards
Authors: Finck Rachel , Simonds Erin F. , Jager Astraea , Krishnaswamy Smita , Sachs Karen , Fantl Wendy , Pe'er Dana , Nolan Garry P. , Bendall Sean C. 
Published: March 2013

AbstractMass cytometry uses atomic mass spectrometry combined with isotopically pure reporter elements to currently measure as many as 40 parameters per single cell. As with any quantitative technology, there is a fundamental need for quality assurance and normalization protocols. In the case of mass cytometry, the signal variation over time due to changes in instrument performance combined with intervals between scheduled maintenance must be accounted for and then normalized. Here, samples were mixed with polystyrene beads embedded with metal lanthanides, allowing monitoring of mass cytometry instrument performance over multiple days of data acquisition. The protocol described here includes simultaneous measurements of beads and cells on the mass cytometer, subsequent extraction of the bead‐based signature, and the application of an algorithm enabling correction of both short‐ and long‐term signal fluctuations. The variation in the intensity of the beads that remains after normalization may also be used to determine data quality. Application of the algorithm to a one‐month longitudinal analysis of a human peripheral blood sample reduced the range of median signal fluctuation from 4.9‐fold to 1.3‐fold. © 2013 International Society for Advancement of Cytometry
Facing the crowd: intruder pressure, within‐group competition, and the resolution of conflicts over group‐membership
Authors: Port Markus , Johnstone Rufus A. 
Published: March 2013

AbstractRecent theory in social evolution has been mainly concerned with competition and cooperation within social groups of animals and their impact on the stability of those groups. Much less attention has been paid to conflicts arising as a result of solitary floaters (outsiders) attempting to join groups of established residents (insiders). We model such conflicts over group‐membership using a demographically explicit approach in which the rates of births and deaths in a population determine the availability of group‐vacancies and the number of floaters competing over these vacancies. We find that the outcome of within‐group competition, reflected in the partitioning of reproduction among group members, exerts surprisingly little influence on the resolution of insider‐outsider conflict. The outcome of such conflict is also largely unaffected by differences in resource holding potential between insiders and outsiders. By contrast, whether or not groups form is mainly determined by demographic factors (variation in vital rates such as fecundity and mortality) and the resulting population dynamics. In particular, at high floater densities territory defense becomes too costly, and groups form because insiders give in to the intruder pressure imposed on them by outsiders. We emphasize the importance of insider‐outsider conflicts in social evolution theory and highlight avenues for future research.
Estimating the water balance of a thermokarst lake in the middle of the Lena River basin, eastern Siberia
Authors: Fedorov A. N. , Gavriliev P. P. , Konstantinov P. Y. , Hiyama T. , Iijima Y. , Iwahana G. 
Published: March 2013

ABSTRACTPermafrost degradation and changes in water balance in a thermokarst lake in the middle part of the Lena River basin in eastern Siberia were investigated. We analysed the role of permafrost thawing in the water balance of a growing thermokarst lake. Long‐term observations during the last two decades (1992–2008) at our thermokarst monitoring site, Yukechi, showed significant modifications of the landforms. Observations included ground temperature, thawing depth, soil moisture content in the active layer, surface subsidence rate, and ecological changes in the surrounding environment. We also used data obtained at the Yakutsk weather station to estimate the potential evaporation. During the observation period, the water surface area increased steadily from 195 m2 in 1993 to 3135 m2 in 2008, and the lake water increased from 33·7 m3 in 1993 to 3503 m3 in 2008. Water balance estimations showed that ground ice melt made up to one third of the total water input into the lake. The rapid development of growing thermokarst lakes indicates an ecological risk on the edges of cryogenic landscapes. Finally, we found that climate change and anthropogenic impacts have led to enhanced activity of cryogenic processes in the region. In particular, cultivated fields underlying ice‐rich permafrost face enhanced degradation by cryogenic and hydrological processes because of recent climate change in the region. Copyright © 2013 John Wiley & Sons, Ltd.
Oligo(naphthylene–ethynylene) Molecular Rods
Authors: Cramer Jacob R. , Ning Yanxiao , Shen Cai , Nuermaimaiti Ajiguli , Besenbacher Flemming , Linderoth Trolle R. , Gothelf Kurt V. 
Published: March 2013

AbstractMolecular rods designed for surface chirality studies have been synthesized in high yields. The molecules are composed of oligo(naphthylene–ethynylene) skeletons and functionalized at their two termini with carboxylic acids and hydrophobic groups. The molecular skeletons were constructed by means of palladium‐catalyzed Sonogashira reactions between naphthyl halides and acetylenes. The triazene functionality was used as a protected iodine precursor to allow linear extension of the molecular rods during the syntheses. The carboxylic acid groups in the target molecules were protected as esters during the synthesis to keep the large aromatic molecules soluble during their syntheses. These rigid oligomers were designed to form lamella‐like structures when adsorbed on a surface, through which multiple distinguishable surface conformations should be obtainable. Preliminary scanning tunneling microscopy imaging confirmed these properties.
An Efficient Formal Total Synthesis of Cladosporin
Authors: Mohapatra Debendra K. , Maity Saurabh , Rao T. Srinivasa , Yadav J. S. , Sridhar B. 
Published: March 2013

AbstractA highly diasteroselective and efficient approach for the formal total synthesis of cladosporin is described. Cross‐metathesis, iodocyclization to construct the trans‐2,6‐disubstituted dihydropyran ring system, and an Alder–Rickert reaction to form the aromatic ring were used as the key steps.
Controversy Over LNG Exports Heats Up as Production Expands
Authors: Dotten Michael , Till Dustin 
Published: March 2013

AbstractPresident Obama is expected to address a broad array of energy and energy‐related policies during his second term—particularly those that relate to the dramatic surge in domestic natural gas and oil production. Not since the first OPEC oil embargo in 1973–74 has the United States been presented with the opportunity to dramatically reduce its dependence on foreign energy suppliers. The United States is projected to become a net exporter of natural gas by 2020.1 America is similarly projected to become the largest global oil producer around 2020, and a net oil exporter by 2030.2
Electric Regulation: Renewable Incentives Have Led to Job Creation
Authors: Bowden Nicholas S. 
Published: March 2013

AbstractJob creation appears to be priority number one for the Obama administration in its second term, and investments in renewable electricity infrastructure are seen as a means to achieve this goal while also meeting social concerns about the environment. In order to continue federal government support for these investments, the American Taxpayer Relief Act of 2012 extended the production tax credit (PTC) for utility‐scale wind farms.
Energy and the Environment: A Fractured Europe Debates Fracking
Authors: Lesser Jonathan A. 
Published: March 2013

AbstractThe United States is not the only country with shale gas reserves. According to a 2011 report prepared by the US Energy Information Administration (EIA),1 Europe, most of which is beholden to Russia for its natural gas supplies, has perhaps 600 trillion cubic feet of technically recoverable shale gas reserves. In comparison, that same report estimated US shale gas reserves at 862 trillion cubic feet. Of the 14 countries the EIA report evaluated, Poland and France have the largest estimated reserves by far, at 187 trillion cubic feet and 180 trillion cubic feet, respectively.
Characteristics of magma‐driven hydrothermal systems at oceanic spreading centers
Authors: Lowell Robert P. , Farough Aida , Hoover Joshua , Cummings Kylin 
Published: March 2013

AbstractWe use one‐ and two‐limb single‐pass models to de termine vent field characteristics such as mass flow rate Q, bulk permeability in the discharge zone kd, thickness of the conductive boundary layer at the base of the system δ, magma replenishment rate, and residence time in the discharge zone. Data on vent temperature, vent field area, heat output, and the surface area and depth of the subaxial magma chamber (AMC) constrain the models. The results give Q ~ 100 kg/s, kd ~ 10−13 m2, and δ ~ 10 m, essentially independent of spreading rate, and detailed characteristics of the AMC. In addition, we find no correlation between heat output at individual vent fields and spreading rate or depth to the AMC. We conclude that high‐temperature hydrothermal systems are driven by local magma supply rates in excess of that needed for steady state crustal production and that crustal permeability enables hydrothermal circulation to tap magmatic heat regardless of AMC depth. Using data on partitioning of heat flow between focused and diffuse flow, we find that 80–90% of the hydrothermal heat output is derived from high‐temperature fluid, even though much of the heat output discharges as low‐temperature fluid. In some cases, diffuse flow fluids may exhibit considerable conductive cooling or heating. By assuming conservative mixing of diffuse flow fluids at East Pacific Rise 9°50′N, we find that most transport of metals such as Fe and Mn occurs in diffuse flow and that CO2, H2, and CH4 are taken up by microbial activity.
Core Self‐Evaluation and Goal Orientation: Understanding Work Stress
Authors: Morris Michael Lane , Messal Carrie B. , Meriac John P. 
Published: March 2013

AbstractThis study investigates the dispositional factors related to work stress. Specifically, previous research has demonstrated a relationship between core self‐evaluation (CSE) and general life stress. This article extends past research by examining the relationship between CSE and work stress, and includes goal orientation as a potential mediator of this relationship. Learning goal orientation and performance goal orientation are two variables that are salient to HRD scholarship interests. The study results supported the hypothesis that CSE is negatively related to work stress, and that performance‐prove goal orientation partially mediates this relationship. Given Russ‐Eft's (2001) call for additional research exploring work stress and learning, and a recent meta‐analysis exploring the relationship between another core personality trait (psychological capital) and work stress (Avey, Reichard, Luthans, & Mhatre, 2011), the results of this study make an important contribution to our understanding of the relationship between core personality traits and work stress research. Furthermore, managers and executive coaches can use the results of this study to develop interventions designed to address the stress‐related problems of individuals and organizations.