bluuebunny/crossref_metadata_2025 huggingface dataset:
Extensive Citrullination Promotes Immunogenicity of HSP90 through Protein Unfolding and Exposure of Cryptic Epitopes
Authors: Travers Timothy S. , Harlow Lisa , Rosas Ivan O. , Gochuico Bernadette R. , Mikuls Ted R. , Bhattacharya Sanjoy K. , Camacho Carlos J. , Ascherman Dana P.
Published: July 2016

Post-translational protein modifications such as citrullination have been linked to the breach of immune tolerance and clinical autoimmunity. Previous studies from our laboratory support this concept, demonstrating that autoantibodies targeting citrullinated isoforms of heat shock protein 90 (HSP90) are associated with rheumatoid arthritis complicated by interstitial lung disease. To further explore the relationship between citrullination and structural determinants of HSP90 immunogenicity, we employed a combination of ELISA-based epitope profiling, computational modeling, and mass-spectrometric sequencing of peptidylarginine deiminase (PAD)-modified protein. Remarkably, ELISAs involving selected citrullinated HSP90β/α peptides identified a key epitope corresponding to an internal Arg residue (R502 [HSP90β]/R510 [HSP90α]) that is normally buried within the crystal structure of native/unmodified HSP90. In vitro time/dose-response experiments reveal an ordered pattern of PAD-mediated deimination events culminating in citrullination of R502/R510. Conventional as well as scaled molecular dynamics simulations further demonstrate that citrullination of selected Arg residues leads to progressive disruption of HSP90 tertiary structure, promoting exposure of R502/R510 to PAD modification and subsequent autoantibody binding. Consistent with this process, ELISAs incorporating variably deiminated HSP90 as substrate Ag indicate a direct relationship between the degree of citrullination and the level of ex vivo Ab recognition. Overall, these data support a novel structural paradigm whereby citrullination-induced shifts in protein structure generate cryptic epitopes capable of bypassing B cell tolerance in the appropriate genetic context.
Immediate Dysfunction of Vaccine-Elicited CD8+ T Cells Primed in the Absence of CD4+ T Cells
Authors: Provine Nicholas M. , Larocca Rafael A. , Aid Malika , Penaloza-MacMaster Pablo , Badamchi-Zadeh Alexander , Borducchi Erica N. , Yates Kathleen B. , Abbink Peter , Kirilova Marinela , Ng’ang’a David , Bramson Jonathan , Haining W. Nicholas , Barouch Dan H.
Published: July 2016

CD4+ T cell help is critical for optimal CD8+ T cell memory differentiation and maintenance in many experimental systems. In addition, many reports have identified reduced primary CD8+ T cell responses in the absence of CD4+ T cell help, which often coincides with reduced Ag or pathogen clearance. In this study, we demonstrate that absence of CD4+ T cells at the time of adenovirus vector immunization of mice led to immediate impairments in early CD8+ T cell functionality and differentiation. Unhelped CD8+ T cells exhibited a reduced effector phenotype, decreased ex vivo cytotoxicity, and decreased capacity to produce cytokines. This dysfunctional state was imprinted within 3 d of immunization. Unhelped CD8+ T cells expressed elevated levels of inhibitory receptors and exhibited transcriptomic exhaustion and anergy profiles by gene set enrichment analysis. Dysfunctional, impaired effector differentiation also occurred following immunization of CD4+ T cell–deficient mice with a poxvirus vector. This study demonstrates that following priming with viral vectors, CD4+ T cell help is required to promote both the expansion and acquisition of effector functions by CD8+ T cells, which is accomplished by preventing immediate dysfunction.
Gut Microbial Membership Modulates CD4 T Cell Reconstitution and Function after Sepsis
Authors: Cabrera-Perez Javier , Babcock Jeffrey C. , Dileepan Thamotharampillai , Murphy Katherine A. , Kucaba Tamara A. , Badovinac Vladimir P. , Griffith Thomas S.
Published: July 2016

Transient lymphopenia is one hallmark of sepsis, and emergent data indicate the CD4 T cell compartment in sepsis survivors is numerically and functionally altered (when examined at the Ag-specific level) compared with nonseptic control subjects. Previous data from our laboratory demonstrated Ag-independent, lymphopenia-induced homeostatic proliferation to be a contributing mechanism by which CD4 T cells numerically recover in sepsis survivors. However, we reasoned it is also formally possible that some CD4 T cells respond directly to Ag expressed by gut-resident microbes released during polymicrobial sepsis. The effect of gut microbiome leakage on CD4 T cells is currently unknown. In this study, we explored the number and function of endogenous CD4 T cells specific for segmented filamentous bacterium (SFB) after cecal ligation and puncture (CLP)-induced sepsis using mice that either contained or lacked SFB as a normal gut-resident microbe. Interestingly, SFB-specific CD4 T cells underwent Ag-driven proliferation in CLP-treated SFB+, but not in SFB−, mice. Moreover, CLP-treated SFB+ mice showed resistance to secondary lethal infection with recombinant SFB Ag-expressing virulent Listeria (but not wild-type virulent Listeria), suggesting the CLP-induced polymicrobial sepsis primed for a protective response by the SFB-specific CD4 T cells. Thus, our data demonstrate that the numerical recovery and functional responsiveness of Ag-specific CD4 T cells in sepsis survivors is, in part, modulated by the intestinal barrier’s health discreetly defined by individual bacterial populations of the host’s microbiome.
Modelling ecological specificities of freshwater molluscs: the exemplary case of Bythinella austriaca (v. Frauenfeld 1857) (Gastropoda, Prosobranchia)
Authors: Sturm Robert
Published: July 2016

Main objective of the study was the description of Weighted Average Analysis (WAA) as appropriate mathematical method for modelling the demands of freshwater molluscs on their habitats. With this approach site-specific environmental factors defining a certain biotope are weighted by the related population density of a selected organism. This allows the determination of optimum ranges of physical and chemical factors, within which highest probabilities of occurrence of the investigated organism may be expected. As an exemplary case ecological demands of the Austrian spring snail, Bythinella austriaca, were modelled by using WAA. In addition, a global marginality coefficient, which reflects the ability of the gastropod to occupy ecological niches, and a global tolerance coefficient, describing the width of the niche colonized by the organism, were computed for 10 selected environmental factors. As suggested by the modelling results, B. austriaca exhibits specialist behaviour with regard to water temperature, electric conductivity, dissolved oxygen, and dissolved nitrate. Furthermore, the gastropod only tolerates small fluctuations of these environmental factors, which remarkably reduces its ability to act as a pioneer species. 
No Postoperative Adrenal Insufficiency in a Patient with Unilateral Cortisol-Secreting Adenomas Treated with Mifepristone before Surgery
Authors: Saroka Rachel M. , Kane Michael P. , Robinson Lawrence , Busch Robert S.
Published: July 2016

Background

Glucocorticoid replacement is commonly required to treat secondary adrenal insufficiency after surgical resection of unilateral cortisol-secreting adrenocortical adenomas. Here, we describe a patient with unilateral cortisol-secreting adenomas in which the preoperative use of mifepristone therapy was associated with recovery of the hypothalamic–pituitary–adrenal (HPA) axis, eliminating the need for postoperative glucocorticoid replacement.

Case Presentation

A 66-year-old Caucasian man with type 2 diabetes mellitus, hyperlipidemia, hypertension, and obesity was hospitalized for Fournier's gangrene and methicillin-resistant Staphylococcus aureus sepsis. Abdominal computed tomography scan revealed three left adrenal adenomas measuring 1.4, 2.1, and 1.2 cm and an atrophic right adrenal gland. Twenty-four-hour urinary free cortisol level was elevated (237 µg/24 hours, reference range 0–50 µg/24 hours). Hormonal evaluation after resolution of the infection showed an abnormal 8 mg overnight dexamethasone suppression test (cortisol postdexamethasone 14.5 µg/dL), suppressed adrenocorticotropic hormone (ACTH; <5 pg/mL, reference range 7.2–63.3 pg/mL), and low-normal dehydroepiandrosterone sulfate (50.5 µg/dL, male reference range 30.9–295.6 µg/dL). Because of his poor medical condition and uncontrolled diabetes, his Cushing's syndrome was treated with medical therapy before surgery. Mifepristone therapy was started and, within five months, his diabetes was controlled and insulin discontinued. The previously suppressed ACTH increased to above normal range accompanied by an increase in dehydroepiandrosterone sulfate levels, indicating recovery of the HPA axis and atrophic contralateral adrenal gland. The patient received one precautionary intraoperative dose of hydrocortisone and none thereafter. Two days postoperatively, ACTH (843 pg/mL) and cortisol levels (44.8 µg/dL) were significantly elevated, reflecting an appropriate HPA axis response to the stress of surgery, and two weeks postoperatively, ACTH was within normal range and a repeat dexamethasone suppression test was normal. Six months postoperatively, ACTH was within normal limits and cortisol was approaching normal. The patient has exhibited no postoperative signs or symptoms of adrenal insufficiency in 12 months.

Conclusion

Preoperative mifepristone therapy was associated with apparent recovery of the HPA axis prior to unilateral adrenalectomy in a patient with unilateral adrenal adenomas. Postoperatively, the patient experienced no signs or symptoms of adrenal insufficiency and no glucocorticoid replacement was required.
Cryptococcosis in Acquired Immunodeficiency Syndrome Patients Clinically Confirmed and/or Diagnosed at Necropsy in a Teaching Hospital in Brazil
Authors: Torres Rafael Garcia , Etchebehere Renata Margarida , Adad Sheila Jorge , Micheletti Adilha Rua , Ribeiro Barbara de Melo , Silva Leonardo Eurípedes Andrade , Mora Delio Jose , Paim Kennio Ferreira , Silva-Vergara Mario León
Published: July 2016

Cryptococcosis occurs in acquired immunodeficiency syndrome (AIDS) patients with poor compliance to antiretroviral therapy or unaware of their human immunodeficiency virus status who present severe immunosuppression at admission. Consequently, high mortality rates are observed due to disseminated fungal infection. This report presents clinical and postmortem data of AIDS patients with cryptococcosis in a teaching hospital in Brazil. Retrospectively, medical and necropsy records of AIDS patients with cryptococcosis clinically confirmed and/or postmortem verified were reviewed. Clinical data were compared with those of patients presenting a good outcome to evaluate disseminated fungal infection and the agreement between clinical and postmortem diagnosis. At admission, most of the 45 patients with cryptococcal meningitis who died, presented more altered consciousness (P = 0.0047), intracranial increased pressure (P = 0.047), and severe malnutrition (P = 0.0006) than the survivors. Of 29 (64.4%) patients with cryptococcal meningitis, 23 died before week 2 on antifungal therapy, and the other six during the next 3 months. The remaining 16 (35.6%) cases had other diagnoses and died soon after. At necropsy, 31 (68.9%) presented disseminated infection involving two or more organs, whereas 14 (31.1%) cases had meningeal or pulmonary localized infection. The agreement of 64.4% between clinical and postmortem diagnosis was similar to some studies. However, other reports have shown figures ranging from 34% to 95%. Currently, a progressive worldwide decrease of autopsies is worrying because the role of postmortem examination is pivotal to verify or identify the death causes, which contributes to improve the quality of clinical diagnosis and medical training.
Big Data Matching Using the Identity Correlation Approach
Authors: Smyth Mary , McCormack Kevin
Published: July 2016

Abstract The Identity Correlation Approach (ICA) is a statistical technique developed for matching big data where a unique identifier does not exist. This technique was developed to match the Irish Census 2011 dataset to Central Government Administrative Datasets in order to attach a unique identifier to each individual person in the Census dataset (McCormack & Smyth, 20151). The unique identifier attached is the PPS No. (Personal Public Service No.2). By attaching the PPS No. to the Census dataset, each individual can be linked to datasets held centrally by Public Sector Organisations. This expands the range of variables for statistical analysis at individual level. Statistical techniques developed here were undertaken for a major European Structure of Earnings Survey (SES) compiled by the CSO using administrative data only,  and thus eliminating the need for an expensive business survey to be conducted (NES, 20073,4,5). A description of how the Identity Correlation Approach was developed is given in this paper. Data matching results and conclusions are presented here in relation to the Structure of Earnings Survey (SES)6 results for 2011.
Validation of a web mining technique to measure innovation in the Canadian nanotechnology-related community
Authors: Rietsch Constant , Beaudry Catherine , Héroux-Vaillancourt Mikaël
Published: July 2016

In this exploratory study, we explore a methodology using a web mining technique to source data in order to analyse innovation and commercialisation processes in Canadian nanotechnology firms. 79 websites have been extracted and analysed based on keywords related to 4 core concepts (R&D, intellectual property, collaboration and external financing) especially important for the commercialisation of nanotechnology. To validate our methodology, we compare our web mining results with those from a classic questionnaire-based survey. Our results show a correlation between the indicators from the two methods of r=0.306 (p-value=0.007) for R&D, of r=0.368 (p-value=0.002) for IP, of r=0.222 (p-value of 0.071) for Collaboration and of r=0.222 (p-value=0.067) for external financing. We conclude that some of the data extracted by our web mining technique can be used as proxy for specific variables obtained from more classical methods.
Total Antioxidant Capacity and Characterization of Nitraria tangutorum Fruit Extract by Rapid Bioassay-Directed Fractionation
Authors: Rana Jat , Missler Stephen R , Persons Kathryn , Han Johnson , Li Teric
Published: July 2016

In recent years, the role of reactive nitrogen and oxygen species (RNOS) in human disease has been the subject of considerable study. This has led to research on the potential benefit of natural products as dietary antioxidants to mitigate oxidative stress caused by increased RNOS associated with tissue damage. Five physiologically relevant reactive species include peroxyl radical, hydroxyl radical, peroxynitrite anion, superoxide radical anion, and singlet oxygen. Excessive amounts of these species can lead to the degradation of important biomolecules in vivo, and dietary antioxidants have been shown to inhibit damage both in vitro and in vivo. In this investigation, we have discovered that an extract of the fruit from Nitraria tangutorum Bobr. (Tangut white thorn) demonstrates significant antioxidant capacity against all five reactive species. Rapid bioassay-directed fractionation was used to identify antioxidant phytochemicals by collecting fractions from HPLC effluent into 96 well microplates and testing for antioxidant activity against the 2,2-diphenyl-1-picrylhydrazyl radical. Two different classes of phytochemicals, anthocyanins and flavonoids, were associated with antioxidant activity. Active components were further characterized by UV-Vis spectroscopy and high-resolution MS.
Visual landmarks sharpen grid cell metric and confer context specificity to neurons of the medial entorhinal cortex
Authors: Pérez-Escobar José Antonio , Kornienko Olga , Latuske Patrick , Kohler Laura , Allen Kevin
Published: July 2016

Neurons of the medial entorhinal cortex (MEC) provide spatial representations critical for navigation. In this network, the periodic firing fields of grid cells act as a metric element for position. The location of the grid firing fields depends on interactions between self-motion information, geometrical properties of the environment and nonmetric contextual cues. Here, we test whether visual information, including nonmetric contextual cues, also regulates the firing rate of MEC neurons. Removal of visual landmarks caused a profound impairment in grid cell periodicity. Moreover, the speed code of MEC neurons changed in darkness and the activity of border cells became less confined to environmental boundaries. Half of the MEC neurons changed their firing rate in darkness. Manipulations of nonmetric visual cues that left the boundaries of a 1D environment in place caused rate changes in grid cells. These findings reveal context specificity in the rate code of MEC neurons.
Definition of two agonist types at the mammalian cold-activated channel TRPM8
Authors: Janssens Annelies , Gees Maarten , Toth Balazs Istvan , Ghosh Debapriya , Mulier Marie , Vennekens Rudi , Vriens Joris , Talavera Karel , Voets Thomas
Published: July 2016

Various TRP channels act as polymodal sensors of thermal and chemical stimuli, but the mechanisms whereby chemical ligands impact on TRP channel gating are poorly understood. Here we show that AITC (allyl isothiocyanate; mustard oil) and menthol represent two distinct types of ligands at the mammalian cold sensor TRPM8. Kinetic analysis of channel gating revealed that AITC acts by destabilizing the closed channel, whereas menthol stabilizes the open channel, relative to the transition state. Based on these differences, we classify agonists as either type I (menthol-like) or type II (AITC-like), and provide a kinetic model that faithfully reproduces their differential effects. We further demonstrate that type I and type II agonists have a distinct impact on TRPM8 currents and TRPM8-mediated calcium signals in excitable cells. These findings provide a theoretical framework for understanding the differential actions of TRP channel ligands, with important ramifications for TRP channel structure-function analysis and pharmacology.
Mechanistic signs of double-barreled structure in a fluoride ion channel
Authors: Last Nicholas B , Kolmakova-Partensky Ludmila , Shane Tania , Miller Christopher
Published: July 2016

The Fluc family of F− ion channels protects prokaryotes and lower eukaryotes from the toxicity of environmental F−. In bacteria, these channels are built as dual-topology dimers whereby the two subunits assemble in antiparallel transmembrane orientation. Recent crystal structures suggested that Fluc channels contain two separate ion-conduction pathways, each with two F− binding sites, but no functional correlates of this unusual architecture have been reported. Experiments here fill this gap by examining the consequences of mutating two conserved F−-coordinating phenylalanine residues. Substitution of each phenylalanine specifically extinguishes its associated F− binding site in crystal structures and concomitantly inhibits F− permeation. Functional analysis of concatemeric channels, which permit mutagenic manipulation of individual pores, show that each pore can be separately inactivated without blocking F− conduction through its symmetry-related twin. The results strongly support dual-pathway architecture of Fluc channels.
Saúde do homem e doença cardiovascular: gerenciamento do cuidado de enfermagem em nível ambulatorial Men’s health and cardiovascular disease: the nursing care management in ambulatory
Authors: Bessa Amanda Trindade Teixeira de , Mesquita Maria Gefé da Rosa , Stipp Marluci Andrade Conceição
Published: July 2016

Objetivos: caracterizar as condições sóciodemográficas e de hábitos de vida de uma clientela masculina e discutir sobre gerenciamento do cuidado de enfermagem cardiovascular em nível ambulatorial. Metodologia: é um estudo transversal, descritivo, exploratório com abordagem quantitativa, amostra do tipo de não probabilidade. Resultados: caracterizaram-se homens com mais de 40 anos, aposentados, pensionistas ou desempregados, com baixa renda e escolaridade, padrão de sono insatisfatório e 52% hipertensos. Discussão: observou-se que os fatores de risco são modificáveis, podendo-se corrigi-los através da educação em saúde e mudanças no estilo de vida. Conclusão: são grandes os desafios para o gerenciamento do cuidado de enfermagem na perspectiva de gênero oferecendo importantes discussões sobre promoção e prevenção de agravos à saúde.
Characterizing cometary electrons with kappa distributions
Authors: Broiles T. W. , Livadiotis G. , Burch J. L. , Chae K. , Clark G. , Cravens T. E. , Davidson R. , Eriksson A. , Frahm R. A. , Fuselier S. A. , Goldstein J. , Goldstein R. , Henri P. , Madanian H. , Mandt K. , Mokashi P. , Pollock C. , Rahmati A. , Samara M. , Schwartz S. J.
Published: July 2016

The Rosetta spacecraft has escorted comet 67P/Churyumov‐Gerasimenko since 6 August 2014 and has offered an unprecedented opportunity to study plasma physics in the coma. We have used this opportunity to make the first characterization of cometary electrons with kappa distributions. Two three‐dimensional kappa functions were fit to the observations, which we interpret as two populations of dense and warm (density = 10 cm−3, temperature = 2 × 105 K, invariant kappa index = 10−>1000), and rarefied and hot (density = 0.005 cm−3, temperature = 5 × 105 K, invariant kappa index = 1–10) electrons. We fit the observations on 30 October 2014 when Rosetta was 20 km from 67P, and 3 AU from the Sun. We repeated the analysis on 15 August 2015 when Rosetta was 300 km from the comet and 1.3 AU from the Sun. Comparing the measurements on both days gives the first comparison of the cometary electron environment between a nearly inactive comet far from the Sun and an active comet near perihelion. We find that the warm population density increased by a factor of 3, while the temperature cooled by a factor of 2, and the invariant kappa index was unaffected. We find that the hot population density increased by a factor of 10, while the temperature and invariant kappa index were unchanged. We conclude that the hot population is likely the solar wind halo electrons in the coma. The warm population is likely of cometary origin, but its mechanism for production is not known.
Superfluidity of a dipolar Fermi gas in 2D optical lattices bilayer
Authors: Camacho‐Guardian A. , Paredes R.
Published: July 2016

Ultracold Fermi molecules lying in 2D square optical lattices bilayers with its dipole moment perpendicularly aligned to the layers, having interlayer finite range s‐wave interactions, are shown to form superfluid phases, both, in the Bardeen, Cooper and Schrieffer (BCS) regime of Cooper pairs, and in the condensate regime of bound dimeric molecules. We demonstrate this result using a functional integral scheme within the Ginzburg‐Landau theory. For the deep Berezinskii‐Kosterlitz‐Thouless (BKT) phase transition, we predict critical temperatures around 5nK and 20nK for 23Na40K and OH molecules, which are within reach of current experiments [J. W. Park, S. Will and M. Zwierlein, Phys. Rev. Lett. 114, 205302 (2015)].

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Label‐Free Analysis of Single Viruses with a Resolution Comparable to That of Electron Microscopy and the Throughput of Flow Cytometry
Authors: Ma Ling , Zhu Shaobin , Tian Ye , Zhang Wenqiang , Wang Shuo , Chen Chaoxiang , Wu Lina , Yan Xiaomei
Published: July 2016

Viruses are by far the most abundant biological entities on our planet, yet existing characterization methods are limited by either their speed or lack of resolution. By applying a laboratory‐built high‐sensitivity flow cytometer (HSFCM) to precisely quantify the extremely weak elastically scattered light from single viral particles, we herein report the label‐free analysis of viruses with a resolution comparable to that of electron microscopy and the throughput of flow cytometry. The detection of single viruses with diameters down to 27 nm is described. T7 and lambda bacteriophages, which differ in size by as little as 4 nm, could be baseline‐resolved. Moreover, subtle structural differences of the same viral particles can be discriminated. Using monodisperse silica nanoparticles as the size reference standards, the virus sizes measured by the HSFCM are in agreement with the equivalent particle diameters derived from their structural dimensions. The HSFCM opens a new avenue for virus characterization.
Highly Enantioselective Iron‐Catalyzed cis‐Dihydroxylation of Alkenes with Hydrogen Peroxide Oxidant via an FeIII‐OOH Reactive Intermediate
Authors: Zang Chao , Liu Yungen , Xu Zhen‐Jiang , Tse Chun‐Wai , Guan Xiangguo , Wei Jinhu , Huang Jie‐Sheng , Che Chi‐Ming
Published: July 2016

The development of environmentally benign catalysts for highly enantioselective asymmetric cis‐dihydroxylation (AD) of alkenes with broad substrate scope remains a challenge. By employing [FeII(L)(OTf)2] (L=N,N′‐dimethyl‐N,N′‐bis(2‐methyl‐8‐quinolyl)‐cyclohexane‐1,2‐diamine) as a catalyst, cis‐diols in up to 99.8 % ee with 85 % isolated yield have been achieved in AD of alkenes with H2O2 as an oxidant and alkenes in a limiting amount. This “[FeII(L)(OTf)2]+H2O2” method is applicable to both (E)‐alkenes and terminal alkenes (24 examples >80 % ee, up to 1 g scale). Mechanistic studies, including 18O‐labeling, UV/Vis, EPR, ESI‐MS analyses, and DFT calculations lend evidence for the involvement of chiral FeIII‐OOH active species in enantioselective formation of the two C−O bonds.
[5+2] Cycloaddition of 2‐(2‐Aminoethyl)oxiranes with Alkynes via Epoxide Ring‐Opening: A Facile Access to Azepines
Authors: Hu Chao , Song Ren‐Jie , Hu Ming , Yang Yuan , Li Jin‐Heng , Luo Shenglian
Published: July 2016

A new FeCl3 and BF3⋅OEt2 co‐catalyzed tandem hetero‐[5+2] cycloaddition of 2‐(2‐aminoethyl)oxiranes with a wide range of alkynes, including terminal alkynes and alkyl‐substituted internal alkynes is presented. This is the first example of rapid and facile production of diverse 2,3‐dihydro‐1H‐azepines through a sequence of epoxide ring‐opening, annulation, and dehydroxylation with broad substrate scope and exquisite selectivity control.
Cation Intercalation in Manganese Oxide Nanosheets: Effects on Lithium and Sodium Storage
Authors: Lu Ke , Hu Ziyu , Xiang Zhonghua , Ma Jizhen , Song Bin , Zhang Jintao , Ma Houyi
Published: July 2016

The rapid development of advanced energy‐storage devices requires significant improvements of the electrode performance and a detailed understanding of the fundamental energy‐storage processes. In this work, the self‐assembly of two‐dimensional manganese oxide nanosheets with various metal cations is introduced as a general and effective method for the incorporation of different guest cations and the formation of sandwich structures with tunable interlayer distances, leading to the formation of 3D MxMnO2 (M=Li, Na, K, Co, and Mg) cathodes. For sodium and lithium storage, these electrode materials exhibited different capacities and cycling stabilities. The efficiency of the storage process is influenced not only by the interlayer spacing but also by the interaction between the host cations and shutter ions, confirming the crucial role of the cations. These results provide promising ideas for the rational design of advanced electrodes for Li and Na storage.
Organosulfate Formation through the Heterogeneous Reaction of Sulfur Dioxide with Unsaturated Fatty Acids and Long‐Chain Alkenes
Authors: Passananti Monica , Kong Lingdong , Shang Jing , Dupart Yoan , Perrier Sébastien , Chen Jianmin , Donaldson D. James , George Christian
Published: July 2016

The heterogeneous reaction between SO2 and unsaturated compounds results in the efficient production of organosulfates for several fatty acids and long‐chain alkenes. The presence of an acid group, the physical state of the reactants (solid or liquid), the nature of the double bond (cis, trans, terminal), and the use of light irradiation all have an impact on the reaction rate. The reaction was investigated using different set‐ups (coated flow tube, aerosol flow tube, and diffuse reflectance infrared Fourier transform cell). The reaction products were identified by high‐resolution mass spectrometry and the impact of this reaction on organosulfate formation in the atmosphere is discussed.
Co(salen) supported on graphene oxide for oxidation of lignin
Authors: Zhou Xue‐Fei , Lu Xu‐Jie
Published: July 2016

Co(salen) was supported on graphene oxide (GO) (Co‐GO) by covalently grafting. Spectroscopy analyses confirmed its successful synthesis. Co‐GO demonstrated a high activity in the cleavage of βO4 linkage in lignin model compounds. The catalyst was also effective in depolymerizing an organosolv lignin polymer. The polymer residues were separated, and extensively analyzed by FTIR and NMR in order to understand the various structural changes of the polymer occurring versus catalyst. In catalytic oxidation, the βO4 ether linkages were cleaved and the side‐chains were oxidized occurring in the polymer. The polymer was thus converted into smaller monomers called degradation products which were detected by GC‐MS. The evolution of the polymer found that Co‐GO exhibited a significant catalytic effect as compared with Co‐NaY, Co‐MCM‐48, Co‐SSZ‐13. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44133.
Updated mortality study of a cohort of asbestos textile workers
Authors: Pira Enrico , Romano Canzio , Violante Francesco S. , Farioli Andrea , Spatari Giovanna , La Vecchia Carlo , Boffetta Paolo
Published: July 2016

Limited information is available on risk of peritoneal mesothelioma after asbestos exposure, and in general on the risk of cancer after cessation of asbestos exposure. We updated to 2013 the follow‐up of a cohort of 1083 female and 894 male textile workers with heavy asbestos exposure (up to 100 fb/mL), often for short periods. A total of 1019 deaths were observed, corresponding to a standardized mortality ratio (SMR) of 1.68 (95% confidence interval [CI]: 1.57–1.78). SMRs were 29.1 (95% CI: 21.5–38.6) for peritoneal cancer, 2.96 (95% CI: 2.50–3.49) for lung cancer, 33.7 (95% CI: 25.7–43.4) for pleural cancer, and 3.03 (95% CI: 1.69–4.99) for ovarian cancer. For pleural and peritoneal cancer, there was no consistent pattern of risk in relation to time since last exposure, whereas for lung cancer there was an indication of a decline in risk after 25 years since last exposure. The findings of this unique cohort provide novel data for peritoneal cancer, indicating that – as for pleural cancer – the excess risk does not decline up to several decades after cessation of exposure.
Multiscale Approach to the Study of the Electronic Properties of Two Thiophene Curcuminoid Molecules
Authors: Etcheverry‐Berríos Alvaro , Olavarría Ignacio , Perrin Mickael L. , Díaz‐Torres Raúl , Jullian Domingo , Ponce Ingrid , Zagal José H. , Pavez Jorge , Vásquez Sergio O. , van der Zant Herre S. J. , Dulić Diana , Aliaga‐Alcalde Núria , Soler Monica
Published: July 2016

We studied the electronic and conductance properties of two thiophene–curcuminoid molecules, 2‐thphCCM (1) and 3‐thphCCM (2), in which the only structural difference is the position of the sulfur atoms in the thiophene terminal groups. We used electrochemical techniques as well as UV/Vis absorption studies to obtain the values of the HOMO–LUMO band gap energies, showing that molecule 1 has lower values than 2. Theoretical calculations show the same trend. Self‐assembled monolayers (SAMs) of these molecules were studied by using electrochemistry, showing that the interaction with gold reduces drastically the HOMO–LUMO gap in both molecules to almost the same value. Single‐molecule conductance measurements show that molecule 2 has two different conductance values, whereas molecule 1 exhibits only one. Based on theoretical calculations, we conclude that the lowest conductance value, similar in both molecules, corresponds to a van der Waals interaction between the thiophene ring and the electrodes. The one order of magnitude higher conductance value for molecule 2 corresponds to a coordinate (dative covalent) interaction between the sulfur atoms and the gold electrodes.
Aspartate‐Based CXCR4 Chemokine Receptor Binding of Cross‐Bridged Tetraazamacrocyclic Copper(II) and Zinc(II) Complexes
Authors: Maples Randall D. , Cain Amy N. , Burke Benjamin P. , Silversides Jon D. , Mewis Ryan E. , D'huys Thomas , Schols Dominique , Linder Douglas P. , Archibald Stephen J. , Hubin Timothy J.
Published: July 2016

The CXCR4 chemokine receptor is implicated in a number of diseases including HIV infection and cancer development and metastasis. Previous studies have demonstrated that configurationally restricted bis‐tetraazamacrocyclic metal complexes are high‐affinity CXCR4 antagonists. Here, we present the synthesis of Cu2+ and Zn2+ acetate complexes of six cross‐bridged tetraazamacrocycles to mimic their coordination interaction with the aspartate side chains known to bind them to CXCR4. X‐ray crystal structures for three new Cu2+ acetate complexes and two new Zn2+ acetate complexes demonstrate metal‐ion‐dependent differences in the mode of binding the acetate ligand concomitantly with the requisite cis‐V‐configured cross‐bridged tetraazamacrocyle. Concurrent density functional theory molecular modelling studies produced an energetic rationale for the unexpected [Zn(OAc)(H2O)]+ coordination motif present in all of the Zn2+ cross‐bridged tetraazamacrocycle crystal structures, which differs from the chelating acetate [Zn(OAc)]+ structures of known unbridged and side‐bridged tetraazamacrocyclic Zn2+‐containing CXCR4 antagonists.
Judicious Ligand Design in Ruthenium Polypyridyl CO2 Reduction Catalysts to Enhance Reactivity by Steric and Electronic Effects
Authors: Johnson Ben A. , Agarwala Hemlata , White Travis A. , Mijangos Edgar , Maji Somnath , Ott Sascha
Published: July 2016

A series of RuII polypyridyl complexes of the structural design [RuII(R−tpy)(NN)(CH3CN)]2+ (R−tpy=2,2′:6′,2′′‐terpyridine (R=H) or 4,4′,4′′‐tri‐tert‐butyl‐2,2′:6′,2′′‐terpyridine (R=tBu); NN=2,2′‐bipyridine with methyl substituents in various positions) have been synthesized and analyzed for their ability to function as electrocatalysts for the reduction of CO2 to CO. Detailed electrochemical analyses establish how substitutions at different ring positions of the bipyridine and terpyridine ligands can have profound electronic and, even more importantly, steric effects that determine the complexes’ reactivities. Whereas electron‐donating groups para to the heteroatoms exhibit the expected electronic effect, with an increase in turnover frequencies at increased overpotential, the introduction of a methyl group at the ortho position of NN imposes drastic steric effects. Two complexes, [RuII(tpy)(6‐mbpy)(CH3CN)]2+ (trans‐[3]2+; 6‐mbpy=6‐methyl‐2,2′‐bipyridine) and [RuII(tBu−tpy)(6‐mbpy)(CH3CN)]2+ (trans‐[4]2+), in which the methyl group of the 6‐mbpy ligand is trans to the CH3CN ligand, show electrocatalytic CO2 reduction at a previously unreactive oxidation state of the complex. This low overpotential pathway follows an ECE mechanism (electron transfer–chemical reaction–electron transfer), and is a direct result of steric interactions that facilitate CH3CN ligand dissociation, CO2 coordination, and ultimately catalytic turnover at the first reduction potential of the complexes. All experimental observations are rigorously corroborated by DFT calculations.
Synthesis and Isolation of the Titanium–Scandium Endohedral Fullerenes—Sc2TiC@Ih‐C80, Sc2TiC@D5h‐C80and Sc2TiC2@Ih‐C80: Metal Size Tuning of the TiIV/TiIIIRedox Potentials
Authors: Junghans Katrin , Ghiassi Kamran B. , Samoylova Nataliya A. , Deng Qingming , Rosenkranz Marco , Olmstead Marilyn M. , Balch Alan L. , Popov Alexey A.
Published: July 2016

The formation of endohedral metallofullerenes (EMFs) in an electric arc is reported for the mixed‐metal Sc–Ti system utilizing methane as a reactive gas. Comparison of these results with those from the Sc/CH4and Ti/CH4systems as well as syntheses without methane revealed a strong mutual influence of all key components on the product distribution. Whereas a methane atmosphere alone suppresses the formation of empty cage fullerenes, the Ti/CH4system forms mainly empty cage fullerenes. In contrast, the main fullerene products in the Sc/CH4system are Sc4C2@C80(the most abundant EMF from this synthesis), Sc3C2@C80, isomers of Sc2C2@C82, and the family Sc2C2 n(2 n=74, 76, 82, 86, 90, etc.), as well as Sc3CH@C80. The Sc–Ti/CH4system produces the mixed‐metal Sc2TiC@C2 n(2 n=68, 78, 80) and Sc2TiC2@C2 n(2 n=80) clusterfullerene families. The molecular structures of the new, transition‐metal‐containing endohedral fullerenes, Sc2TiC@Ih‐C80, Sc2TiC@D5h‐C80, and Sc2TiC2@Ih‐C80, were characterized by NMR spectroscopy. The structure of Sc2TiC@Ih‐C80was also determined by single‐crystal X‐ray diffraction, which demonstrated the presence of a short Ti=C double bond. Both Sc2TiC‐ and Sc2TiC2‐containing clusterfullerenes have Ti‐localized LUMOs. Encapsulation of the redox‐active Ti ion inside the fullerene cage enables analysis of the cluster–cage strain in the endohedral fullerenes through electrochemical measurements.
Towards an Observation of Active Conformations in Asymmetric Catalysis: Interaction‐Induced Conformational Preferences of a Chiral Thiourea Model Compound
Authors: Kreienborg Nora M. , Pollok Corina H. , Merten Christian
Published: July 2016

The observation of the active species is the goal of most spectroscopic investigations on enantioselective organocatalysts in solution. Although NMR spectroscopy is widely applied, it has low sensitivity for conformational changes or the chiral nature of the interactions. In the present work, we exemplify the use of vibrational circular dichroism (VCD) spectroscopy for the characterization of a chiral thiourea model compound in nonpolar and polar solvents, as well as for a detailed analysis of its interaction with a model reactant. We discuss solvent‐induced conformational changes of the thiourea, and provide evidence for an unexpected binding topology between the thiourea and an acetate anion. The results clearly showcase the possibilities offered by using VCD spectroscopy in the characterization of chiral organocatalysts.
In Situ Generation of CoIII–Salen Complexes for Copolymerization of Propylene Oxide and CO2
Authors: Hatazawa Masahiro , Nakabayashi Koji , Ohkoshi Shin‐ichi , Nozaki Kyoko
Published: July 2016

A simple admixture of CoII–salcy complexes with [Cp2FeIII]PF6 resulted in reproduction of the results with isolated CoIII–salcy complexes in the copolymerization of epoxide and carbon dioxide. By using this in situ‐generated active species with bis(triphenylphosphoranilydene)ammonium 2,4‐dinitrophenolate, a para‐methoxy‐substituted Co–salcy complex was proven to be more active than the parent tert‐butyl‐substituted system. In contrast, the CoII–salcy complex substituted with the more strongly electron‐donating NMe2 group did not show any activity for this copolymerization.
Oxidative Annulation of Arenecarboxylic and Acrylic Acids with Alkynes under Ambient Conditions Catalyzed by an Electron‐Deficient Rhodium(III) Complex
Authors: Kudo Eiji , Shibata Yu , Yamazaki Mutsumi , Masutomi Koji , Miyauchi Yuta , Fukui Miho , Sugiyama Haruki , Uekusa Hidehiro , Satoh Tetsuya , Miura Masahiro , Tanaka Ken
Published: July 2016

It has been established that an electron‐deficient CpE rhodium(III) complex catalyzes the oxidative [4+2] annulation of substituted arenecarboxylic and acrylic acids with alkynes under ambient conditions (at RT–40 °C, under air) without using excess amounts of substrates to produce the corresponding substituted isocoumarins and α‐pyrones in high yields. Minor modification of reaction conditions depending on the coordination ability of alkynes realized the high efficiency.
Randomized phase 2 trial of a coordinated breast cancer follow‐up care program
Authors: Ruddy Kathryn J. , Guo Hao , Baker Emily L. , Goldstein Matthew J. , Mullaney Erin E. , Shulman Lawrence N. , Partridge Ann H.
Published: July 2016

BACKGROUND

Previous research has demonstrated that cancer survivors often fail to receive recommended care and also undergo unnecessary care; this reduces care quality and increases costs.

METHODS

This phase 2 trial randomized 100 stage 0 to IIIa breast cancer patients who had primary care providers within a large Massachusetts‐based hospital network (with accessible online records) to either coordinated follow‐up care (CC), which entailed a tailored survivorship care plan (SCP) and patient navigator calls every 3 months, or standard care (SC), which did not include an SCP or patient navigation, for 1 year after the completion of their last chemotherapy, surgery, or radiation treatment. The primary endpoint was the frequency of redundant examinations (>1 breast/chest wall examination per patient within any 30‐day period in the absence of a new breast or chest wall complaint) over the year of follow‐up. The total number of non–plastic surgery visits in the year of follow‐up was a secondary endpoint.

RESULTS

Two patients (both on CC) were ineligible, and 2 patients (1 per arm) had a recurrence or died during follow‐up; this left 96 for analysis (47 in the CC arm and 49 in the SC arm). Twenty‐two of the 47 CC patients (47%; 95% confidence interval, 32%‐62%) and 19 of the 49 SC patients (39%; 95% confidence interval, 25%‐54%) had 1 or more redundant breast/chest wall examinations during the year. The median number of non–plastic surgery visits was 12 for CC patients and 8 for SC patients.

CONCLUSIONS

Early‐stage breast cancer patients visit health care providers very frequently during their first year of follow‐up and often receive unnecessary breast/chest wall examinations. An SCP and patient navigator calls did not reduce this surrogate for redundant care. Cancer 2016;122:3546–3554. © 2016 American Cancer Society
Is Regioselectivity in the Enzyme‐Catalyzed Hydroperoxidation of Arachidonic Acid Necessarily Determined by Hydrogen Abstraction? The Case of Rabbit Leu597Ala/Ile663Ala ALOX15 Mutant
Authors: Saura Patricia , Masgrau Laura , Heydeck Dagmar , Kühn Hartmut , Lluch José M. , González‐Lafont Àngels
Published: July 2016

Molecular dynamics simulations and quantum mechanics/molecular mechanics calculations were performed on the in silico Leu597Ala/Ile663Ala double mutant of rabbit ALOX15 (12/15 lipoxygenase). The computational results suggested that subtle steric hindrance by the conserved Leu597 and C‐terminal Ile663 residues disturbed H10 abstractions in wildtype ALOX15 (which abstracts H13), but if these two bulky residues were mutated to smaller ones, H10 abstraction was no longer impeded and the regioselectivity of the initial H‐abstraction step was changed. However, site‐directed mutagenesis with HPLC analysis of the products of the whole oxidation process showed that the regioselectivity of the hydroperoxidation was not altered. This disagreement may be explained by the conformational reorganization of the system needed to rotate the −OO. group from an antarafacial to a suprafacial arrangement prior to back‐hydrogen transfer. After H10 abstraction and O2 insertion, the evolution of the peroxy radical at C12 was sterically impeded, whereas peroxyl group rotation at C15 (after H13 abstraction) could easily evolve to a suprafacial arrangement, which thus led to the final product. For this reason, the global regiospecificity was not affected in the mutant. These findings exemplify that the regioselectivity of initial hydrogen abstraction and the regioselectivity of the final product do not necessarily coincide (in fact, they can be opposite) for the hydroperoxidation of arachidonic acid catalyzed by a lipoxygenase.
Efficient Batch‐Mode Parahydrogen‐Induced Polarization of Propane
Authors: Salnikov Oleg G. , Barskiy Danila A. , Coffey Aaron M. , Kovtunov Kirill V. , Koptyug Igor V. , Chekmenev Eduard Y.
Published: July 2016

We report on a simple approach for efficient NMR proton hyperpolarization of propane using the parahydrogen‐induced polarization (PHIP) technique, which yielded ≈6.2 % proton polarization using ≈80 % parahydrogen, a record level achieved with any hyperpolarization technique for propane. Unlike in previously developed approaches designed for continuous‐flow operation, where reactants (propene and parahydrogen) are simultaneously loaded for homogeneous or heterogeneous pairwise addition of parahydrogen, here a batch‐mode method is applied: propene is first loaded into the catalyst‐containing solution, which is followed by homogeneous hydrogenation via parahydrogen bubbling delivered at ≈7.1 atm. The achieved nuclear spin polarization of this contrast agent potentially useful for pulmonary imaging is approximately two orders of magnitude greater than that achieved in the continuous‐flow homogeneous catalytic hydrogenation, and a factor of 3–10 more efficient compared to the typical results of heterogeneous continuous‐flow hydrogenations.
Vibronic Spectroscopy of Sympathetically Cooled CaH+
Authors: Rugango René , Calvin Aaron T. , Janardan Smitha , Shu Gang , Brown Kenneth R.
Published: July 2016

We report the measurement of the 11Σ→21Σ transition of CaH+ by resonance‐enhanced photodissociation of CaH+ that is co‐trapped with laser‐cooled Ca+. We observe four resonances that we assign to transitions from the vibrational v=0 ground state to the v′=1–4 excited states based on theoretical predictions. A simple theoretical model that assumes instantaneous dissociation after resonant excitation yields results in good agreement with the observed spectral features except for the unobserved v′=0 peak. This discrepancy is attributed to an insufficient understanding of the dissociation process, and further experimental and theoretical studies are required to confirm the assignment. The resolution of our experiment is limited by the mode‐locked excitation laser, but this survey spectroscopy enables future rotationally resolved studies with applications in astrochemistry and precision measurement.
Ionic Liquid Ordering at an Oxide Surface
Authors: Wagstaffe Michael , Jackman Mark J. , Syres Karen L. , Generalov Alexander , Thomas Andrew G.
Published: July 2016

The interaction of the ionic liquid [C4C1Im][BF4] with anatase TiO2, a model photoanode material, has been studied using a combination of synchrotron radiation photoelectron spectroscopy and near‐edge X‐ray absorption fine structure spectroscopy. The system is of interest as a model for fundamental electrolyte–electrode and dye‐sensitized solar cells. The initial interaction involves degradation of the [BF4]− anion, resulting in incorporation of F into O vacancies in the anatase surface. At low coverages, [C4C1Im][BF4] is found to order at the anatase(101) surface via electrostatic attraction, with the imidazolium ring oriented 32±4° from the anatase TiO2 surface. As the coverage of ionic liquid increases, the influence of the oxide surface on the topmost layers is reduced and the ordering is lost.