Dielectric response and transport properties of alkylammonium formate ionic liquids
NASA Astrophysics Data System (ADS)
Nazet, Andreas; Buchner, Richard
2018-05-01
Dielectric relaxation spectra of three members of the alkylammonium formate family of protic ionic liquids (PILs), namely, ethylammonium formate (EAF), n-butylammonium formate (BuAF), and n-pentylammonium formate (PeAF), as well as the pseudo-PIL triethylamine + formic acid (molar ratio 1:2; TEAF) have been studied over a wide frequency (50 MHz to 89 GHz) and temperature range (5-65 °C), complemented by measurements of their density, viscosity, and conductivity. It turned out that the dominating relaxation of EAF, BuAF, and PeAF arises from both cation and anion reorientations which are synchronized in their dynamics due to hydrogen bonding. Amplitudes and relaxation times of this mode reflect the—compared to nitrate—different nature of H bonding between the formate anion and ethylammonium cation, as well as increasing segregation of the PIL structure into polar and non-polar domains. The TEAF data suggest that its dominating relaxation is due to the rotation of the complex triethylamineṡ(formic acid)2 in which no significant proton transfer to an ion pair occurred. Weak dissociation of this complex into ions was postulated to account for the high conductivity of TEAF.
Administration and Stenographic Career Ladders, AFS 702x0/A/B/C and 702X1.
1980-04-01
MEN mIIIIIIIII hhhllllhlhhl UNITED STATES AIR FORCE _Si -j.- 0 ADMINISTRATION AND5$TENOGRAPHIC -CAREER LADDERS AIS 702XO/ A /B/C AND 702X1 -J AFPT- 9...7J2-389 ( ,/ " ’ _ LA. -IAPRI 180 This document has n a :’.-pro+ved1 + ,for pil s’ s ;i - , OqCUPATIONAL ANALYSIS PROGRAM USAF OCCUPATIONAL...79 APPENDIX A O--------------------------------------------- 80 Acc22~C~For 1 -* ii L PREFACE This report presents the results of a detailed Air
Kilmury, Sara L N; Burrows, Lori L
2016-05-24
Type IV pili are important virulence factors for many pathogens, including Pseudomonas aeruginosa Transcription of the major pilin gene-pilA-is controlled by the PilS-PilR two-component system in response to unknown signals. The absence of a periplasmic sensing domain suggested that PilS may sense an intramembrane signal, possibly PilA. We suggest that direct interactions between PilA and PilS in the inner membrane reduce pilA transcription when PilA levels are high. Overexpression in trans of PilA proteins with diverse and/or truncated C termini decreased native pilA transcription, suggesting that the highly conserved N terminus of PilA was the regulatory signal. Point mutations in PilA or PilS that disrupted their interaction prevented autoregulation of pilA transcription. A subset of PilA point mutants retained the ability to interact with PilS but could no longer decrease pilA transcription, suggesting that interaction between the pilin and sensor kinase is necessary but not sufficient for pilA autoregulation. Furthermore, PilS's phosphatase motif was required for the autoregulation of pilA transcription, suggesting that under conditions where PilA is abundant, the PilA-PilS interaction promotes PilR dephosphorylation and thus down-regulation of further pilA transcription. These data reveal a clever bacterial inventory control strategy in which the major subunit of an important P. aeruginosa virulence factor controls its own expression.
DOE Office of Scientific and Technical Information (OSTI.GOV)
McCallum, Matthew; Tammam, Stephanie; Little, Dustin J.
Pseudomonas aeruginosa is an opportunistic bacterial pathogen that expresses type IVa pili. The pilus assembly system, which promotes surface-associated twitching motility and virulence, is composed of inner and outer membrane subcomplexes, connected by an alignment subcomplex composed of PilMNOP. PilM binds to the N terminus of PilN, and we hypothesize that this interaction causes functionally significant structural changes in PilM. To characterize this interaction, we determined the crystal structures of PilM and a PilM chimera where PilM was fused to the first 12 residues of PilN (PilM·PilN(1–12)). Structural analysis, multiangle light scattering coupled with size exclusion chromatography, and bacterial two-hybridmore » data revealed that PilM forms dimers mediated by the binding of a novel conserved motif in the N terminus of PilM, and binding PilN abrogates this binding interface, resulting in PilM monomerization. Structural comparison of PilM with PilM·PilN(1–12) revealed that upon PilN binding, there is a large domain closure in PilM that alters its ATP binding site. Using biolayer interferometry, we found that the association rate of PilN with PilM is higher in the presence of ATP compared with ADP. Bacterial two-hybrid data suggested the connectivity of the cytoplasmic and inner membrane components of the type IVa pilus machinery in P. aeruginosa, with PilM binding to PilB, PilT, and PilC in addition to PilN. Pull-down experiments demonstrated direct interactions of PilM with PilB and PilT. As a result, we propose a working model in which dynamic binding of PilN facilitates functionally relevant structural changes in PilM.« less
McCallum, Matthew; Tammam, Stephanie; Little, Dustin J.; ...
2016-03-28
Pseudomonas aeruginosa is an opportunistic bacterial pathogen that expresses type IVa pili. The pilus assembly system, which promotes surface-associated twitching motility and virulence, is composed of inner and outer membrane subcomplexes, connected by an alignment subcomplex composed of PilMNOP. PilM binds to the N terminus of PilN, and we hypothesize that this interaction causes functionally significant structural changes in PilM. To characterize this interaction, we determined the crystal structures of PilM and a PilM chimera where PilM was fused to the first 12 residues of PilN (PilM·PilN(1–12)). Structural analysis, multiangle light scattering coupled with size exclusion chromatography, and bacterial two-hybridmore » data revealed that PilM forms dimers mediated by the binding of a novel conserved motif in the N terminus of PilM, and binding PilN abrogates this binding interface, resulting in PilM monomerization. Structural comparison of PilM with PilM·PilN(1–12) revealed that upon PilN binding, there is a large domain closure in PilM that alters its ATP binding site. Using biolayer interferometry, we found that the association rate of PilN with PilM is higher in the presence of ATP compared with ADP. Bacterial two-hybrid data suggested the connectivity of the cytoplasmic and inner membrane components of the type IVa pilus machinery in P. aeruginosa, with PilM binding to PilB, PilT, and PilC in addition to PilN. Pull-down experiments demonstrated direct interactions of PilM with PilB and PilT. As a result, we propose a working model in which dynamic binding of PilN facilitates functionally relevant structural changes in PilM.« less
Li, Yongquan; Huang, Shuangsheng; Zhang, Xiaosu; Huang, Tao; Li, Hongyu
2013-02-01
PilT is a hexameric ATPase required for type IV pili (Tfp) retraction in gram-negative bacterium. Retraction of Tfp mediates intimate attachment and motility on inorganic solid surfaces. We investigated the cloning and expression of pilT and pilU genes of Acidithiobacillus ferrooxidans strains ATCC 23270, and the results indicate that PilT and PilU contain the canonical conserved AIRNLIRE and GMQTXXXXLXXL motifs that are the characteristic motifs of the PilT protein family; PilT and PilU also contain the canonical nucleotide-binding motifs, named with Walker A box (GxxGxGKT/S) and Walker B box (hhhhDE), respectively. The pilT and pilU genes were expressed to produce 37.1- and 42.0-kDa proteins, respectively, and co-transcribed induced by 10 % mineral powder. However, ATPase activity of PilT was distinctly higher than those of PilU. These results indicated that the PilT protein was the real molecular motor of Tfp, while PilU could play a key role in the assembly, modification, and twitching motility of Tfp in A. ferrooxidans. However, PilT and PilU were nonetheless interrelated in the forming and function of the molecular motor of Tfp.
A Dynamic Retention Model for Air Force Officers: Theory and Estimates
1984-12-01
9YOS STAY 2 2 2 1 1973 PIL ACAD 9YOS STAY 2 2 2 2 1 1973 PIL ACAD 9YOS STAY 2 2 2 2 2 4 1973 PIL ACAD 9YOS STAY 2 2 2...2 16 .37 1973 PIL ACAD 9YOS STAY 2 2 2 15 15 1973 PIL ACAD 9YOS STAY 2 2 14 14 14 1973 PIL ACAD 9YOS STAY 2 13 13 13 13 1973 PIL ACAD 9YOS STAY 2...13 13 13 31 1973 PIL ACAD 9YOS LEAVE 2 2 2 2 2 1 1973 PIL ACAD 9YOS LEAVE 2 7 1973 PIL ACAD 9YOS LEAVE 2 2 1 1973 PIL ACAD 9YOS LEAVE 2 2 2
Georgiadou, Michaella; Castagnini, Marta; Karimova, Gouzel; Ladant, Daniel; Pelicic, Vladimir
2012-06-01
The functionally versatile type IV pili (Tfp) are one of the most widespread virulence factors in bacteria. However, despite generating much research interest for decades, the molecular mechanisms underpinning the various aspects of Tfp biology remain poorly understood, mainly because of the complexity of the system. In the human pathogen Neisseria meningitidis for example, 23 proteins are dedicated to Tfp biology, 15 of which are essential for pilus biogenesis. One of the important gaps in our knowledge concerns the topology of this multiprotein machinery. Here we have used a bacterial two-hybrid system to identify and quantify the interactions between 11 Pil proteins from N. meningitidis. We identified 20 different binary interactions, many of which are novel. This represents the most complex interaction network between Pil proteins reported to date and indicates, among other things, that PilE, PilM, PilN and PilO, which are involved in pilus assembly, indeed interact. We focused our efforts on this subset of proteins and used a battery of assays to determine the membrane topology of PilN and PilO, map the interaction domains between PilE, PilM, PilN and PilO, and show that a widely conserved N-terminal motif in PilN is essential for both PilM-PilN interactions and pilus assembly. Finally, we show that PilP (another protein involved in pilus assembly) forms a complex with PilM, PilN and PilO. Taken together, these findings have numerous implications for understanding Tfp biology and provide a useful blueprint for future studies. © 2012 Blackwell Publishing Ltd.
Andrews, T Daniel; Gojobori, Takashi
2004-01-01
The PilE protein is the major component of the Neisseria meningitidis pilus, which is encoded by the pilE/pilS locus that includes an expressed gene and eight homologous silent fragments. The silent gene fragments have been shown to recombine through gene conversion with the expressed gene and thereby provide a means by which novel antigenic variants of the PilE protein can be generated. We have analyzed the evolutionary rate of the pilE gene using the nucleotide sequence of two complete pilE/pilS loci. The very high rate of evolution displayed by the PilE protein appears driven by both recombination and positive selection. Within the semivariable region of the pilE and pilS genes, recombination appears to occur within multiple small sequence blocks that lie between conserved sequence elements. Within the hypervariable region, positive selection was identified from comparison of the silent and expressed genes. The unusual gene conversion mechanism that operates at the pilE/pilS locus is a strategy employed by N. meningitidis to enhance mutation of certain regions of the PilE protein. The silent copies of the gene effectively allow "parallelized" evolution of pilE, thus enabling the encoded protein to rapidly explore a large area of sequence space in an effort to find novel antigenic variants.
Outside-in assembly pathway of the type IV pilus system in Myxococcus xanthus.
Friedrich, Carmen; Bulyha, Iryna; Søgaard-Andersen, Lotte
2014-01-01
Type IV pili (T4P) are ubiquitous bacterial cell surface structures that undergo cycles of extension, adhesion, and retraction. T4P function depends on a highly conserved envelope-spanning macromolecular machinery consisting of 10 proteins that localizes polarly in Myxococcus xanthus. Using this localization, we investigated the entire T4P machinery assembly pathway by systematically profiling the stability of all and the localization of eight of these proteins in the absence of other T4P machinery proteins as well as by mapping direct protein-protein interactions. Our experiments uncovered a sequential, outside-in pathway starting with the outer membrane (OM) PilQ secretin ring. PilQ recruits a subcomplex consisting of the inner membrane (IM) lipoprotein PilP and the integral IM proteins PilN and PilO by direct interaction with the periplasmic domain of PilP. The PilP/PilN/PilO subcomplex recruits the cytoplasmic PilM protein, by direct interaction between PilN and PilM, and the integral IM protein PilC. The PilB/PilT ATPases that power extension/retraction localize independently of other T4P machinery proteins. Thus, assembly of the T4P machinery initiates with formation of the OM secretin ring and continues inwards over the periplasm and IM to the cytoplasm.
Cheng, Yuan; Johnson, Michael D. L.; Burillo-Kirch, Christine; Mocny, Jeffrey C.; Anderson, James E.; Garrett, Christopher K.; Redinbo, Matthew R.
2013-01-01
Neisseria gonorrhoeae PilC1 is a member of the PilC family of type IV pilus-associated adhesins found in Neisseria species and other type IV pilus-producing genera. Previously, a calcium-binding domain was described in the C-terminal domains of PilY1 of Pseudomonas aeruginosa and in PilC1 and PilC2 of Kingella kingae. Genetic analysis of N. gonorrhoeae revealed a similar calcium-binding motif in PilC1. To evaluate the potential significance of this calcium-binding region in N. gonorrhoeae, we produced recombinant full-length PilC1 and a PilC1 C-terminal domain fragment. We show that, while alterations of the calcium-binding motif disrupted the ability of PilC1 to bind calcium, they did not grossly affect the secondary structure of the protein. Furthermore, we demonstrate that both full-length wild-type PilC1 and full-length calcium-binding-deficient PilC1 inhibited gonococcal adherence to cultured human cervical epithelial cells, unlike the truncated PilC1 C-terminal domain. Similar to PilC1 in K. kingae, but in contrast to the calcium-binding mutant of P. aeruginosa PilY1, an equivalent mutation in N. gonorrhoeae PilC1 produced normal amounts of pili. However, the N. gonorrhoeae PilC1 calcium-binding mutant still had partial defects in gonococcal adhesion to ME180 cells and genetic transformation, which are both essential virulence factors in this human pathogen. Thus, we conclude that calcium binding to PilC1 plays a critical role in pilus function in N. gonorrhoeae. PMID:24002068
Maurer, L; Orndorff, P E
1987-01-01
We describe the identification and characterization of two genes and their gene products responsible for determining receptor binding and pilus length in type 1-piliated Escherichia coli. One gene, pilE, conferred the ability of piliated cells to agglutinate guinea pig erythrocytes. The other gene, pilF, determined pilus length, in that mutants having lesions in pilF had very long pili. The two genes were detected after Tn5 mutagenesis of a cloned segment of DNA that normally complemented a pilE lesion in the chromosome. Thus, lesions in pilE or pilF on the cloned segment resulted in mutants having the PilE- phenotype (piliated but unable to agglutinate erythrocytes). Introduction of the plasmid-encoded mutant alleles of pilE and pilF into the chromosome followed by electron microscopic examination of the mutants showed that only lesions in pilF conferred the striking increase in pilus length. Mutations in pilF could be complemented in trans by the original cloned segment to produce cells with parental-length pili. Minicell transcription and translation of the cloned pilE and pilF genes having representative Tn5 insertion mutations showed that the pilE gene product was a protein of ca. 31 kilodaltons and that the pilF gene product was a protein of ca. 18 kilodaltons. We believe that the pilF gene product may act as a competitive inhibitor of pilus polymerization. Thus, pilus length may be controlled by the ratio of pilin to pilF gene product present within the cell. Images PMID:2879830
Liu, Fang; Abdul-Hussain, Sarah; Mahboob, Shams; Rai, Vijay; Kostrzewski, Andrzej
2014-08-01
Patient information leaflets (PILs) are the most important information source for older patients to effectively manage their drug therapy. The objective of this study is to evaluate the appropriateness of current available PILs for use by older adults. The content of the PILs were assessed by checking the availability of information relevant to older patients including pharmacokinetics, safety and dose instructions. The layout of the PILs was evaluated using criteria derived from the relevant regulatory guidelines on the design of PILs. The Gunning Fog Index was used to determine the readability of the PILs to older adults. Total of 48 PILs were analysed involving 25 drug substances for the treatment of cardiovascular disease and type 2 diabetes. One out of the 48 PILs contained information on pharmacokinetic changes in older patients and only 15 % of the PILs specified the age of the older person. Thirty-one percent of the PILs provided nonspecific warnings to the older population, while only 15 % included specific side effects that could occur in the older generation. Text font sizes of the PILs were generally too small for older adults to read, with only 9 % of the PILs used type size 12 or over. The readability of 63 % of the PILs had a score above 12, which is considered difficult for older people to understand. Currently available medication PILs are inappropriate for use by older adults to manage their medications effectively, which could adversely affect patient safety and adherence to drug therapy.
Hunt, William T N; McGrath, Emily J
2016-06-01
Postoperative patient information leaflets (PILs) provide important guidance to patients after skin surgery. Readability is a method of evaluating information for text comprehension. The recommended level for PIL readability is US grade ≤6. To evaluate the readability of public English dermatological postoperative PILs. All dermatology departments in England were requested to provide their postoperative PILs. Patient information leaflets were evaluated using Readability Studio (Oleander Software, Vandalia, OH). Two preselected parameters were also noted: whether the PIL was doctor or nurse-written, and whether the PIL was Information Standard hallmarked. Eighty-five of one hundred thirty (65.4%) of PILs were evaluated. Only 29.4% of the PILs were grade level ≤6 with Flesch-Kincaid. The mean readability levels were 7.8 for Flesch-Kincaid, 67 for Flesch reading ease, 10.5 for Simple Measure of Gobbledygook (SMOG), 9.4 for Gunning-Fog, 8 for Fry, and 9.8 for FORCAST. No instruments demonstrated a significant difference between doctor (6) and nurse-written (7) PILs. Two instruments found that the 3 Information Standard hallmarked PILs had a higher (harder) readability than ordinary PILs (n = 82) (Gunning-Fog, p = .029*; SMOG p = .049*). Most English postoperative dermatological PILs' readability levels exceed recommendations (US grade ≤6). Departmental PILs should be reviewed to ensure that they are comprehensible to their patients.
Counteranion-Mediated Intrinsic Healing of Poly(ionic liquid) Copolymers.
Guo, Panlong; Zhang, Houyu; Liu, Xiaokong; Sun, Junqi
2018-01-17
Fabrication of self-healing/healable materials using reversible interactions that are governed by their inherent chemical features is highly desirable because it avoids the introduction of extra groups that may present negative effects on their functions. The present study exploits the inherently featured electrostatic interactions of the ion pairs in polymeric ionic liquids (PILs) as the driving force to fabricate healable PIL copolymers. The healable PIL copolymers are fabricated through the copolymerization of the IL monomers with ethyl acrylate followed by the replacement of Br - counteranions with bulkier ones such as bis(trifluoromethanesulfonyl)imide (TFSI - ). Without modifying the chemical structures of the PIL moieties, the healing performance of the as-prepared PIL copolymers can be effectively mediated by their counteranions. The PIL copolymers that do not possess healability when paired with Br - counteranions become healable after exchanging the Br - counteranions with larger-sized ones (e.g., TFSI - ). The PIL copolymers paired with bulky counteranions exhibit enhanced chain mobility and highly reversible ion-pair interactions, which facilitate the healing process. The PIL copolymers paired with TFSI - anions can completely heal the damage/cut upon heating at 55 °C for 7.5 h. Meanwhile, the counteranions with larger sizes not only benefit the healing performance of the PIL copolymers but also enhance their ion conductivity. The ion conductivity of the PIL copolymers paired with TFSI - is an order of magnitude higher than that of the PIL copolymers paired with Br - . Therefore, the as-prepared healable PIL copolymers are potentially useful as solid electrolytes in PIL-based energy devices to improve their safety and reliability.
Shi, Xiangyang; Lin, Hong
2016-04-08
Xylella fastidiosa is a Gram-negative non-flagellated bacterium that causes a number of economically important diseases of plants. The twitching motility provides X. fastidiosa a means for long-distance intra-plant movement and colonization, contributing toward pathogenicity in X. fastidiosa. The twitching motility of X. fastidiosa is operated by type IV pili. Type IV pili of Xylella fastidiosa are regulated by pilG, a chemotaxis regulator in Pil-Chp operon encoding proteins that are involved with signal transduction pathways. To elucidate the roles of pilG in the twitching motility of X. fastidiosa, a pilG-deficient mutant XfΔpilG and its complementary strain XfΔpilG-C containing native pilG were developed. A microfluidic chambers integrated with a time-lapse image recording system was used to observe twitching motility in XfΔpilG, XfΔpilG-C and its wild type strain. Using this recording system, it permits long-term spatial and temporal observations of aggregation, migration of individual cells and populations of bacteria via twitching motility. X. fastidiosa wild type and complementary XfΔpilG-C strain showed typical twitching motility characteristics directly observed in the microfluidic flow chambers, whereas mutant XfΔpliG exhibited the twitching deficient phenotype. This study demonstrates that pilG contributes to the twitching motility of X. fastidiosa. The microfluidic flow chamber is used as a means for observing twitching motility.
Speers, Allison M.; Schindler, Bryan D.; Hwang, Jihwan; Genc, Aycin; Reguera, Gemma
2016-01-01
The metal-reducing bacterium Geobacter sulfurreducens requires the expression of conductive pili to reduce iron oxides and to wire electroactive biofilms, but the role of pilus retraction in these functions has remained elusive. Here we show that of the four PilT proteins encoded in the genome of G. sulfurreducens, PilT3 powered pilus retraction in planktonic cells of a PilT-deficient strain of P. aeruginosa and restored the dense mutant biofilms to wild-type levels. Furthermore, PilT3 and PilT4 rescued the twitching motility defect of the PilT-deficient mutant. However, PilT4 was the only paralog whose inactivation in G. sulfurreducens lead to phenotypes associated with the hyperpiliation of non-retractile mutants such as enhanced adhesion and biofilm-forming abilities. In addition, PilT4 was required to reduce iron oxides. Taken together, the results indicate that PilT4 is the motor ATPase of G. sulfurreducens pili and reveal a previously unrecognized role for pilus retraction in extracellular electron transfer, a strategy that confers on Geobacter spp. an adaptive advantage for metal reduction in the natural environment. PMID:27799920
Richter, Lubna V.; Sandler, Steven J.
2012-01-01
Type IV pili of Geobacter sulfurreducens are composed of PilA monomers and are essential for long-range extracellular electron transfer to insoluble Fe(III) oxides and graphite anodes. A previous analysis of pilA expression indicated that transcription was initiated at two positions, with two predicted ribosome-binding sites and translation start codons, potentially producing two PilA preprotein isoforms. The present study supports the existence of two functional translation start codons for pilA and identifies two isoforms (short and long) of the PilA preprotein. The short PilA isoform is found predominantly in an intracellular fraction. It seems to stabilize the long isoform and to influence the secretion of several outer-surface c-type cytochromes. The long PilA isoform is required for secretion of PilA to the outer cell surface, a process that requires coexpression of pilA with nine downstream genes. The long isoform was determined to be essential for biofilm formation on certain surfaces, for optimum current production in microbial fuel cells, and for growth on insoluble Fe(III) oxides. PMID:22408162
Chakraborty, Subhra; Monfett, Michael; Maier, Tamara M.; Benach, Jorge L.; Frank, Dara W.; Thanassi, David G.
2008-01-01
Francisella tularensis, a highly virulent facultative intracellular bacterium, is the causative agent of tularemia. Genome sequencing of all F. tularensis subspecies revealed the presence of genes that could encode type IV pili (Tfp). The live vaccine strain (LVS) expresses surface fibers resembling Tfp, but it was not established whether these fibers were indeed Tfp encoded by the pil genes. We show here that deletion of the pilF putative Tfp assembly ATPase in the LVS resulted in a complete loss of surface fibers. Disruption of the pilT putative disassembly ATPase also caused a complete loss of pili, indicating that pilT functions differently in F. tularensis than in model Tfp systems such as those found in Pseudomonas aeruginosa and Neisseria spp. The LVS pilF and pilT mutants were attenuated for virulence in a mouse model of tularemia by the intradermal route. Furthermore, although absence of pili had no effect on the ability of the LVS to replicate intracellularly, the pilF and pilT mutants were defective for adherence to macrophages, pneumocytes, and hepatocytes. This work confirms that the surface fibers expressed by the LVS are encoded by the pil genes and provides evidence that the Francisella pili contribute to host cell adhesion and virulence. PMID:18426883
Hoppe, Julia; Ünal, Can M; Thiem, Stefanie; Grimpe, Louisa; Goldmann, Torsten; Gaßler, Nikolaus; Richter, Matthias; Shevchuk, Olga; Steinert, Michael
2017-01-01
Legionnaires' disease is an acute fibrinopurulent pneumonia. During infection Legionella pneumophila adheres to the alveolar lining and replicates intracellularly within recruited macrophages. Here we provide a sequence and domain composition analysis of the L. pneumophila PilY1 protein, which has a high homology to PilY1 of Pseudomonas aeruginosa . PilY1 proteins of both pathogens contain a von Willebrand factor A (vWFa) and a C-terminal PilY domain. Using cellular fractionation, we assigned the L. pneumophila PilY1 as an outer membrane protein that is only expressed during the transmissive stationary growth phase. PilY1 contributes to infection of human lung tissue explants (HLTEs). A detailed analysis using THP-1 macrophages and A549 lung epithelial cells revealed that this contribution is due to multiple effects depending on host cell type. Deletion of PilY1 resulted in a lower replication rate in THP-1 macrophages but not in A549 cells. Further on, adhesion to THP-1 macrophages and A549 epithelial cells was decreased. Additionally, the invasion into non-phagocytic A549 epithelial cells was drastically reduced when PilY1 was absent. Complementation variants of a PilY1-negative mutant revealed that the C-terminal PilY domain is essential for restoring the wild type phenotype in adhesion, while the putatively mechanosensitive vWFa domain facilitates invasion into non-phagocytic cells. Since PilY1 also promotes twitching motility of L. pneumophila , we discuss the putative contribution of this newly described virulence factor for bacterial dissemination within infected lung tissue.
Wang, Po-Hsin; Wang, Tzong-Liu; Lin, Wen-Churng; Lin, Hung-Yin; Lee, Mei-Hwa; Yang, Chien-Hsin
2018-04-07
A photopolymerization method is used to prepare a mixture of polymer ionic liquid (PIL) and ionic liquid (IL). This mixture is used as a solid-state electrolyte in carbon nanoparticle (CNP)-based symmetric supercapacitors. The solid electrolyte is a binary mixture of a PIL and its corresponding IL. The PIL matrix is a cross-linked polyelectrolyte with an imidazole salt cation coupled with two anions of Br - in PIL-M-(Br) and TFSI - in PIL-M-(TFSI), respectively. The corresponding ionic liquids have imidazolium salt cation coupled with two anions of Br - and TFSI - , respectively. This study investigates the electrochemical characteristics of PILs and their corresponding IL mixtures used as a solid electrolyte in supercapacitors. Results show that a specific capacitance, maximum power density and energy density of 87 and 58 F·g - ¹, 40 and 48 kW·kg - ¹, and 107 and 59.9 Wh·kg - ¹ were achieved in supercapacitors based on (PIL-M-(Br)) and (PIL-M-(TFSI)) solid electrolytes, respectively.
2014-01-01
Background Neisseria meningitidis expresses type four pili (Tfp) which are important for colonisation and virulence. Tfp have been considered as one of the most variable structures on the bacterial surface due to high frequency gene conversion, resulting in amino acid sequence variation of the major pilin subunit (PilE). Meningococci express either a class I or a class II pilE gene and recent work has indicated that class II pilins do not undergo antigenic variation, as class II pilE genes encode conserved pilin subunits. The purpose of this work was to use whole genome sequences to further investigate the frequency and variability of the class II pilE genes in meningococcal isolate collections. Results We analysed over 600 publically available whole genome sequences of N. meningitidis isolates to determine the sequence and genomic organization of pilE. We confirmed that meningococcal strains belonging to a limited number of clonal complexes (ccs, namely cc1, cc5, cc8, cc11 and cc174) harbour a class II pilE gene which is conserved in terms of sequence and chromosomal context. We also identified pilS cassettes in all isolates with class II pilE, however, our analysis indicates that these do not serve as donor sequences for pilE/pilS recombination. Furthermore, our work reveals that the class II pilE locus lacks the DNA sequence motifs that enable (G4) or enhance (Sma/Cla repeat) pilin antigenic variation. Finally, through analysis of pilin genes in commensal Neisseria species we found that meningococcal class II pilE genes are closely related to pilE from Neisseria lactamica and Neisseria polysaccharea, suggesting horizontal transfer among these species. Conclusions Class II pilins can be defined by their amino acid sequence and genomic context and are present in meningococcal isolates which have persisted and spread globally. The absence of G4 and Sma/Cla sequences adjacent to the class II pilE genes is consistent with the lack of pilin subunit variation in these isolates, although horizontal transfer may generate class II pilin diversity. This study supports the suggestion that high frequency antigenic variation of pilin is not universal in pathogenic Neisseria. PMID:24690385
USDA-ARS?s Scientific Manuscript database
Type IV pili of X. fastidiosa are regulated by pilG, a response regulator protein putatively involved in chemotaxis-like operon sensing stimuli through signal transduction pathways. To elucidate roles of pilG in pathogenicity of X. fastidiosa, the pilG-deletion mutant and complementary strain contai...
Wang, Po-Hsin; Wang, Tzong-Liu; Lin, Wen-Churng; Lin, Hung-Yin; Lee, Mei-Hwa; Yang, Chien-Hsin
2018-01-01
A photopolymerization method is used to prepare a mixture of polymer ionic liquid (PIL) and ionic liquid (IL). This mixture is used as a solid-state electrolyte in carbon nanoparticle (CNP)-based symmetric supercapacitors. The solid electrolyte is a binary mixture of a PIL and its corresponding IL. The PIL matrix is a cross-linked polyelectrolyte with an imidazole salt cation coupled with two anions of Br− in PIL-M-(Br) and TFSI− in PIL-M-(TFSI), respectively. The corresponding ionic liquids have imidazolium salt cation coupled with two anions of Br− and TFSI−, respectively. This study investigates the electrochemical characteristics of PILs and their corresponding IL mixtures used as a solid electrolyte in supercapacitors. Results show that a specific capacitance, maximum power density and energy density of 87 and 58 F·g−1, 40 and 48 kW·kg−1, and 107 and 59.9 Wh·kg−1 were achieved in supercapacitors based on (PIL-M-(Br)) and (PIL-M-(TFSI)) solid electrolytes, respectively. PMID:29642456
DOE Office of Scientific and Technical Information (OSTI.GOV)
Balakrishna, A.; Saxena, A; Mok, H
2009-01-01
The type IVb pilus of the enteropathogenic bacteria Salmonella typhi is a major adhesion factor during the entry of this pathogen into gastrointestinal epithelial cells. Its target of adhesion is a stretch of 10 residues from the first extracellular domain of cystic fibrosis transmembrane conductance regulator (CFTR). The crystal structure of the N-terminal 25 amino acid deleted S. typhi native PilS protein (PilS), which makes the pilus, was determined at 1.9 A resolution by the multiwavelength anomalous dispersion method. Also, the structure of the complex of PilS and a target CFTR peptide, determined at 1.8 A, confirms that residues 113-117more » (NKEER) of CFTR are involved in binding with the pilin protein and gives us insight on the amino acids that are essential for binding. Furthermore, we have also explored the role of a conserved disulfide bridge in pilus formation. The subunit structure and assembly architecture are crucial for understanding pilus functions and designing suitable therapeutics against typhoid.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Balakrishna, A.; Saxena, A; Mok, H
2009-01-01
The type IVb pilus of the enteropathogenic bacteria Salmonella typhi is a major adhesion factor during the entry of this pathogen into gastrointestinal epithelial cells. Its target of adhesion is a stretch of 10 residues from the first extracellular domain of cystic fibrosis transmembrane conductance regulator (CFTR). The crystal structure of the N-terminal 25 amino acid deleted S. typhi native PilS protein (PilS), which makes the pilus, was determined at 1.9 A resolution by the multiwavelength anomalous dispersion method. Also, the structure of the complex of PilS and a target CFTR peptide, determined at 1.8 A, confirms that residues 113-117more » (NKEER) of CFTR are involved in binding with the pilin protein and gives us insight on the amino acids that are essential for binding. Furthermore, we have also explored the role of a conserved disulfide bridge in pilus formation. The subunit structure and assembly architecture are crucial for understanding pilus functions and designing suitable therapeutics against typhoid.« less
Rai, Gitanjali; Kumar, Anil
2014-04-17
The strong hydrogen-bonded network noted in protic ionic liquids (PILs) may lead to stronger interactions of the ionic entities of PILs with solvents (water, methanol, ethylene glycol, dimethylsulfoxide (DMSO), N,N'-dimethylformamide (DMF)) as compared with those of aprotic ionic liquids (APILs). The PILs used in this work are 1-methylimidazolium tetrafluoroborate, 2-methylpyridinium tetrafluoroborate, and N-methylpyrrolodinium tetrafluoroborate in comparison to 1-butyl-3-methylimidazolium tetrafluoroborate, which is classified as an APIL. In this work, the excess partial molar enthalpy, H(E)IL obtained from isothermal calorimetric titrations at 298.15 K is used to probe the nature of interactions of the PIL cations with solvent molecules against those present in APIL-solvent systems. This work also reports interesting flip-flopping in the thermal behavior of these PIL-solvent systems depending upon the structure of the cationic ring of a PIL. In some cases, these flip-flops are the specific fingerprints for specific PILs in a common solvent environment. The excess partial molar enthalpy at infinite dilution, H(E,∞)IL, of these PILs bears a critical dependence on the solvent properties. An analysis of relative apparent molar enthalpies, ϕL, of the PIL solutions by the ion interaction model of Pitzer yields important information on ionic interactions of these systems.
Todaka, Daisuke; Nakashima, Kazuo; Maruyama, Kyonoshin; Kidokoro, Satoshi; Osakabe, Yuriko; Ito, Yusuke; Matsukura, Satoko; Fujita, Yasunari; Yoshiwara, Kyouko; Ohme-Takagi, Masaru; Kojima, Mikiko; Sakakibara, Hitoshi; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko
2012-01-01
The mechanisms for plant growth restriction during stress conditions remains unclear. Here, we demonstrate that a phytochrome-interacting factor-like protein, OsPIL1/OsPIL13, acts as a key regulator of reduced internode elongation in rice under drought conditions. The level of OsPIL1 mRNA in rice seedlings grown under nonstressed conditions with light/dark cycles oscillated in a circadian manner with peaks in the middle of the light period. Under drought stress conditions, OsPIL1 expression was inhibited during the light period. We found that OsPIL1 was highly expressed in the node portions of the stem using promoter-glucuronidase analysis. Overexpression of OsPIL1 in transgenic rice plants promoted internode elongation. In contrast, transgenic rice plants with a chimeric repressor resulted in short internode sections. Alteration of internode cell size was observed in OsPIL1 transgenic plants, indicating that differences in cell size cause the change in internode length. Oligoarray analysis revealed OsPIL1 downstream genes, which were enriched for cell wall-related genes responsible for cell elongation. These data suggest that OsPIL1 functions as a key regulatory factor of reduced plant height via cell wall-related genes in response to drought stress. This regulatory system may be important for morphological stress adaptation in rice under drought conditions. PMID:22984180
Brunelli, C; Bianchi, E; Murru, L; Monformoso, P; Bosisio, M; Gangeri, L; Miccinesi, G; Scrignaro, M; Ripamonti, C; Borreani, C
2012-11-01
The first instruments developed to evaluate specific logotherapeutic dimensions were the Purpose In Life (PIL) and the Seeking Of Noetic Goals (SONG) tests, designed to reflect Frankl's concepts of, respectively, meaning in life attainment and will to meaning. This study aims to perform the Italian cultural adaptation and the psychometric validation of the PIL and SONG questionnaires. We administered the PIL and SONG, culturally adapted into the Italian language, to 266 cancer patients. The psychometric validation appraised construct validity, internal consistency, test-retest reliability, known-group validity, and convergent validity of the two questionnaires with respect to one another. The factorial analysis indicates that the original single-factor solution can be maintained for both instruments (proportion of variance explained by the first factor 77% and 71% for the PIL and SONG, respectively). The results show excellent internal consistency (Cronbach's alpha of 0.91 for the PIL and 0.90 for the SONG) and test-retest reliability (intraclass correlation coefficient of 0.92 for the PIL and 0.81 for the SONG). As expected, males, believers, patients nearer to the diagnosis, and patients not undergoing psychological therapy have higher PIL and lower SONG scores, while expectations for age were not confirmed. The average level for the PIL was 107.3, while for the SONG, it was 66.1, and a negative correlation (-0.47) between PIL and SONG scores indicates good convergent validity of the two instruments. Italian versions of the PIL and SONG are adequate and reliable self-report instruments for evaluating purpose in life and the motivation to find purpose for cancer patient populations.
Targeting of AUF1 to vascular endothelial cells as a novel anti-aging therapy.
He, Jian; Jiang, Ya-Feng; Liang, Liu; Wang, Du-Jin; Wei, Wen-Xin; Ji, Pan-Pan; Huang, Yao-Chan; Song, Hui; Lu, Xiao-Ling; Zhao, Yong-Xiang
2017-08-01
Inhibition of aging of vascular endothelial cells (VECs) may delay aging and prolong life. The goal of this study was to prepare anti-CD31 monoclonal antibody conjugated PEG-modified liposomes containing the AU-rich region connecting factor 1 (AUF1) gene (CD31-PILs-AUF1) and to explore the effects of targeting CD31-PILs-AUF1 to aging VECs. The mean particle sizes of various PEGylated immunoliposomes (PILs) were measured using a Zetasizer Nano ZS. Gel retardation assay was used to confirm whether PILs had encapsulated the AUF1 plasmid successfully. Fluorescence microscopy and flow cytometry were used to quantify binding of CD31-PILs-AUF1 to target cells. Flow cytometry was also used to analyze the cell cycles of aging bEnd3 cells treated with CD31-PILs-AUF1. We also developed an aging mouse model by treating mice with D-galactose. Enzyme-linked immunosorbent assay (ELISA) was used to evaluate the levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). The malondialdehyde (MDA) and the superoxide dismutase (SOD) levels were detected by commercial kits. Hematoxylin-eosin (HE) staining was used to determine whether treatment with CD31-PILs-AUF1 was toxic to the mice. CD31-PILs-AUF1 specifically could targeted bEnd3 VECs and increased the percentage of cells in the S and G2/M phases of aging bEnd3 cells. ELISA showed that content of the IL-6 and TNF-α decreased in CD31-PILs-AUF1 group. The level of SOD increased, whereas MDA decreased in the CD31-PILs-AUF1 group. Additionally, CD31-PILs-AUF1 was not toxic to the mice. CD31-PILs-AUF1 targets VECs and may delay their senescence.
Targeting of AUF1 to vascular endothelial cells as a novel anti-aging therapy
He, Jian; Jiang, Ya-Feng; Liang, Liu; Wang, Du-Jin; Wei, Wen-Xin; Ji, Pan-Pan; Huang, Yao-Chan; Song, Hui; Lu, Xiao-Ling; Zhao, Yong-Xiang
2017-01-01
Background Inhibition of aging of vascular endothelial cells (VECs) may delay aging and prolong life. The goal of this study was to prepare anti-CD31 monoclonal antibody conjugated PEG-modified liposomes containing the AU-rich region connecting factor 1 (AUF1) gene (CD31-PILs-AUF1) and to explore the effects of targeting CD31-PILs-AUF1 to aging VECs. Methods The mean particle sizes of various PEGylated immunoliposomes (PILs) were measured using a Zetasizer Nano ZS. Gel retardation assay was used to confirm whether PILs had encapsulated the AUF1 plasmid successfully. Fluorescence microscopy and flow cytometry were used to quantify binding of CD31-PILs-AUF1 to target cells. Flow cytometry was also used to analyze the cell cycles of aging bEnd3 cells treated with CD31-PILs-AUF1. We also developed an aging mouse model by treating mice with D-galactose. Enzyme-linked immunosorbent assay (ELISA) was used to evaluate the levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). The malondialdehyde (MDA) and the superoxide dismutase (SOD) levels were detected by commercial kits. Hematoxylin-eosin (HE) staining was used to determine whether treatment with CD31-PILs-AUF1 was toxic to the mice. Results CD31-PILs-AUF1 specifically could targeted bEnd3 VECs and increased the percentage of cells in the S and G2/M phases of aging bEnd3 cells. ELISA showed that content of the IL-6 and TNF-α decreased in CD31-PILs-AUF1 group. The level of SOD increased, whereas MDA decreased in the CD31-PILs-AUF1 group. Additionally, CD31-PILs-AUF1 was not toxic to the mice. Conclusion CD31-PILs-AUF1 targets VECs and may delay their senescence. PMID:29089968
Cordero-Vaca, María; Trujillo-Rodríguez, María J; Zhang, Cheng; Pino, Verónica; Anderson, Jared L; Afonso, Ana M
2015-06-01
Four different crosslinked polymeric ionic liquid (PIL)-based sorbent coatings were evaluated in an automated direct-immersion solid-phase microextraction method (automated DI-SPME) in combination with gas chromatography (GC). The crosslinked PIL coatings were based on vinyl-alkylimidazolium- (ViCnIm-) or vinylbenzyl-alkylimidazolium- (ViBzCnIm-) IL monomers, and di-(vinylimidazolium)dodecane ((ViIm)2C12-) or di-(vinylbenzylimidazolium)dodecane ((ViBzIm)2C12-) dicationic IL crosslinkers. In addition, a PIL-based hybrid coating containing multi-walled carbon nanotubes (MWCNTs) was also studied. The studied PIL coatings were covalently attached to derivatized nitinol wires and mounted onto the Supelco assembly to ensure automation when acting as SPME coatings. Their behavior was evaluated in the determination of a group of water pollutants, after proper optimization. A comparison was carried out with three common commercial SPME fibers. It was observed that those PILs containing a benzyl group in their structures, either in the IL monomer and crosslinker (PIL-1-1) or only in the crosslinker (PIL-0-1), were the most efficient sorbents for the selected analytes. The validation of the overall automated DI-SPME-GC-flame ionization detector (FID) method gave limits of detection down to 135 μg · L(-1) for p-cresol when using the PIL-1-1 and down to 270 μg · L(-1) when using the PIL-0-1; despite their coating thickness: ~2 and ~5 μm, respectively. Average relative recoveries with waters were of 85 ± 14 % and 87 ± 15 % for PIL-1-1 and PIL-0-1, respectively. Precision values as relative standard deviation were always lower than 4.9 and 7.6 % (spiked level between 10 and 750 μg · L(-1), as intra-day precision). Graphical Abstract Automated DI-SPME-GC-FID using crosslinked-PILs sorbent coatings for the determination of waterpollutants.
Marko, Victoria A; Kilmury, Sara L N; MacNeil, Lesley T; Burrows, Lori L
2018-05-18
Type IV pili are expressed by a wide range of prokaryotes, including the opportunistic pathogen Pseudomonas aeruginosa. These flexible fibres mediate twitching motility, biofilm maturation, surface adhesion, and virulence. The pilus is composed mainly of major pilin subunits while the low abundance minor pilins FimU-PilVWXE and the putative adhesin PilY1 prime pilus assembly and are proposed to form the pilus tip. The minor pilins and PilY1 are encoded in an operon that is positively regulated by the FimS-AlgR two-component system. Independent of pilus assembly, PilY1 was proposed to be a mechanosensory component that-in conjunction with minor pilins-triggers up-regulation of acute virulence phenotypes upon surface attachment. Here, we investigated the link between the minor pilins/PilY1 and virulence. pilW, pilX, and pilY1 mutants had reduced virulence towards Caenorhabditis elegans relative to wild type or a major pilin mutant, implying a role in pathogenicity that is independent of pilus assembly. We hypothesized that loss of specific minor pilins relieves feedback inhibition on FimS-AlgR, increasing transcription of the AlgR regulon and delaying C. elegans killing. Reporter assays confirmed that FimS-AlgR were required for increased expression of the minor pilin operon upon loss of select minor pilins. Overexpression of AlgR or its hyperactivation via a phosphomimetic mutation reduced virulence, and the virulence defects of pilW, pilX, and pilY1 mutants required FimS-AlgR expression and activation. We propose that PilY1 and the minor pilins inhibit their own expression, and that loss of these proteins leads to FimS-mediated activation of AlgR that suppresses expression of acute-phase virulence factors and delays killing. This mechanism could contribute to adaptation of P. aeruginosa in chronic lung infections, as mutations in the minor pilin operon result in the loss of piliation and increased expression of AlgR-dependent virulence factors-such as alginate-that are characteristic of such infections.
USDA-ARS?s Scientific Manuscript database
Xylella fastidiosa is a Gram-negative, xylem-limited pathogenic bacterium that causes Pierce’s disease of grapevines. Type IV pili of X. fastidiosa are regulated by pilG, a chemotaxis regulator in Pil-Chp operon involving signal transduction pathways. To elucidate the role of pilG in twitching motil...
Protheroe, Joanne; Estacio, Emee Vida; Saidy-Khan, Sirandou
2015-03-01
Government policy in the UK emphasises providing patients with good health information to encourage participation in their health care. Patient information leaflets (PILs) form part of this policy and have been shown to affect patient health outcomes; however, many are poorly written. To describe the PILs in general practice surgeries in Stoke-on-Trent in terms of readability and variety of content. An observational study of randomly selected GP practices (n = 17) across Stoke-on-Trent. PILs were assessed for readability (Flesch Reading Ease and Flesch-Kincaid Grade Level) and compared with national skills level data and with the recommended level for medical information. The PILs were also categorised for content using the Rudd (2007) health material classification framework. A total of 345 PILs were collected and assessed. Only 24.3% meet recommended reading-level criteria. Compared with national skills levels, over 75% of the PILs collected were too complex for at least 15% of the English population. Of the PILs, 47.8% were classified as 'systems navigation' (information regarding services); 22.9% were disease prevention (screening and immunisations); 14.2% personal and public safety; and less than 10% were for managing illness or health promotion. Current PILs in general practices do not all promote health literacy. Information only accessible to a proportion of higher skilled patients may increase inequalities in health. Less than 10% of PILs promote managing illness or healthy lifestyles. Processes must be put in place to improve the readability and variety of content of PILs in GP practices. © British Journal of General Practice 2015.
Cloning and bioinformatics analysis of CcPILS gene of Hickory (Carya cathayensis)
NASA Astrophysics Data System (ADS)
Guo, Wenbin; Yuan, Huwei; Gao, Liuxiao; Guo, Haipeng; Qiu, Lingling; Xu, Dongbin; Yan, Daoliang; Zheng, Bingsong
2017-04-01
PILS is a key auxin efflux carrier protein in the auxin signal transduction. A CcPILS gene related to hickory (Carya carthayensis) grafting process was obtained by RACE techniques. The full length of CcPILS gene was1541bp contained a 1263bp length open reading flame (ORF). The CcPILS encoded 294 amino acids with molecular weight of 46 kDa, PI 5.38 and localized at endoplasmic reticulum membrane. The gene contained a central hydrophilic loop separating two hydrophobic domains of about five transmembrane regions each. The gene of CcPILS belonged to Clade III sub-family of PILS and its sequence had high homology with Arabidopsis. Real Time RT-PCR analysis showed that the gene expressions were weakly induced in bud, inflorescence, fruit, leaf and stem, while strongly in root. The expression levels were strongly induced and reached a peak at the third day of grafting in scion and rootstock of hickory, which were 1.45 and 3.45 times higher, respectively, compared to that of control. The results indicated that CcPILS may be involved in regulating the expression of genes related to auxin signal transduction during hickory graft process.
Octreotide in Hennekam syndrome-associated intestinal lymphangiectasia.
Al Sinani, Siham; Rawahi, Yusria Al; Abdoon, Hamed
2012-11-21
A number of disorders have been described to cause protein losing enteropathy (PLE) in children. Primary intestinal lymphangiectasia (PIL) is one mechanism leading to PLE. Few syndromes are associated with PIL; Hennekam syndrome (HS) is one of them. The principal treatment for PIL is a high protein, low fat diet with medium chain triglycerides supplementation. Supportive therapy includes albumin infusion. Few publications have supported the use of octreotide to diminish protein loss and minimize hypoalbuminemia seen in PIL. There are no publications on the treatment of PIL with octreotide in patients with HS. We report two children with HS and PLE in which we used octreotide to decrease intestinal protein loss. In one patient, octreotide increased serum albumin to an acceptable level without further need for albumin infusions. The other patient responded more dramatically with near normal serum albumin levels and cessation of albumin infusions. In achieving a good response to octreotide in both patients, we add to the publications supporting the use of octreotide in PIL and suggest that octreotide should be tried in patients with PIL secondary to HS. To the best of our knowledge, this is the first case report on the use of octreotide in HS-associated PIL.
Octreotide in Hennekam syndrome-associated intestinal lymphangiectasia
Al Sinani, Siham; Rawahi, Yusria Al; Abdoon, Hamed
2012-01-01
A number of disorders have been described to cause protein losing enteropathy (PLE) in children. Primary intestinal lymphangiectasia (PIL) is one mechanism leading to PLE. Few syndromes are associated with PIL; Hennekam syndrome (HS) is one of them. The principal treatment for PIL is a high protein, low fat diet with medium chain triglycerides supplementation. Supportive therapy includes albumin infusion. Few publications have supported the use of octreotide to diminish protein loss and minimize hypoalbuminemia seen in PIL. There are no publications on the treatment of PIL with octreotide in patients with HS. We report two children with HS and PLE in which we used octreotide to decrease intestinal protein loss. In one patient, octreotide increased serum albumin to an acceptable level without further need for albumin infusions. The other patient responded more dramatically with near normal serum albumin levels and cessation of albumin infusions. In achieving a good response to octreotide in both patients, we add to the publications supporting the use of octreotide in PIL and suggest that octreotide should be tried in patients with PIL secondary to HS. To the best of our knowledge, this is the first case report on the use of octreotide in HS-associated PIL. PMID:23180957
Primary intestinal lymphangiectasia diagnosed by capsule endoscopy and double balloon enteroscopy
Oh, Tak Geun; Chung, Joo Won; Kim, Hee Man; Han, Seok-Joo; Lee, Jin Sung; Park, Jung Yeob; Song, Si Young
2011-01-01
Primary intestinal lymphangiectasia (PIL) is a rare disorder characterized by dilated intestinal lymphatics and the development of protein-losing enteropathy. Patients with PIL develop hypoalbuminemia, hypocalcemia, lymphopenia and hypogammaglobulinemia, and present with bilateral lower limb edema, fatigue, abdominal pain and diarrhea. Endoscopy reveals diffusely elongated, circumferential and polypoid mucosae covered with whitish enlarged villi, all of which indicate intestinal lymphangiectasia. Diagnosis is confirmed by characteristic tissue pathology, which includes dilated intestinal lymphatics with diffusely swollen mucosa and enlarged villi. The prevalence of PIL has increased since the introduction of capsule endoscopy. The etiology and prevalence of PIL remain unknown. Some studies have reported that several genes and regulatory molecules for lymphangiogenesis are related to PIL. We report the case of a patient with PIL involving the entire small bowel that was confirmed by capsule endoscopy and double-balloon enteroscopy-guided tissue pathology who carried a deletion on chromosome 4q25. The relationship between this deletion on chromosome 4 and PIL remains to be investigated. PMID:22110841
Recombinant Mip-PilE-FlaA dominant epitopes vaccine candidate against Legionella pneumophila.
He, Jinlei; Huang, Fan; Chen, Han; Chen, Qiwei; Zhang, Junrong; Li, Jiao; Chen, Dali; Chen, Jianping
2017-06-01
Legionella pneumophila is the main causative agent of Legionnaires' disease, which is a severe multi-system disease with pneumonia as the primary manifestation. We designed a recombinant Mip-PilE-FlaA dominant epitopes vaccine against Legionella pneumophila to prevent the disease and evaluated its immunogenicity and protective immunity. The protein structures of Mip, PilE and FlaA were analyzed using a computer, and the gene sequences of the dominant epitopes of the three proteins were selected to construct and optimize the vaccine. The optimized mip, pilE, flaA and recombinant mip-pilE-flaA gene sequences were cloned, expressed and purified. The purified proteins were used as dominant epitopes vaccines to immunize BALB/c mice and determine the protective immunity and immunogenicity of these purified proteins. The identification confirmed that the recombinant mip-pilE-flaA was successfully cloned and expressed. ELISA revealed that the Mip-PilE-FlaA group produced the highest IgG response, and this protein may considerably improve the production of some cytokines in BALB/c mice. Histopathology analyses of lungs from mice immunized with Mip-PilE-FlaA revealed a certain protective effect. Our work demonstrated that the recombinant dominant epitopes of Mip-PilE-FlaA exhibited strong immunogenicity and immune protection, and this protein may be an efficient epitopes vaccine candidate against Legionella pneumophila. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.
Shreeram, Devesh D; Panmanee, Warunya; McDaniel, Cameron T; Daniel, Susan; Schaefer, Dale W; Hassett, Daniel J
2018-02-01
Pseudomonas aeruginosa is a metabolically voracious bacterium that is easily manipulated genetically. We have previously shown that the organism is also highly electrogenic in microbial fuel cells (MFCs). Polarization studies were performed in MFCs with wild-type strain PAO1 and three mutant strains (pilT, bdlA and pilT bdlA). The pilT mutant was hyperpiliated, while the bdlA mutant was suppressed in biofilm dispersion chemotaxis. The double pilT bdlA mutant was expected to have properties of both mutations. Polarization data indicate that the pilT mutant showed 5.0- and 3.2-fold increases in peak power compared to the wild type and the pilT bdlA mutant, respectively. The performance of the bdlA mutant was surprisingly the lowest, while the pilT bdlA electrogenic performance fell between the pilT mutant and wild-type bacteria. Measurements of biofilm thickness and bacterial viability showed equal viability among the different strains. The thickness of the bdlA mutant, however, was twice that of wild-type strain PAO1. This observation implicates the presence of dead or dormant bacteria in the bdlA mutant MFCs, which increases biofilm internal resistance as confirmed by electrochemical measurements.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mancl, Jordan M.; Black, Wesley P.; Robinson, Howard
Type IV pili (T4P) mediate bacterial motility and virulence. The PilB/GspE family ATPases power the assembly of T4P and type 2 secretion systems. We determined the structure of the ATPase region of PilB (PilB ATP) in complex with ATPγS to provide a model of a T4P assembly ATPase and a view of a PilB/GspE family hexamer at better than 3-Å resolution. Spatial positioning and conformations of the protomers suggest a mechanism of force generation. All six PilB ATP protomers contain bound ATPγS. Two protomers form a closed conformation poised for ATP hydrolysis. The other four molecules assume an open conformationmore » but separate into two pairs with distinct active-site accessibilities. We propose that one pair represents the post-hydrolysis phase while the other pair appears poised for ADP/ATP exchange. In conclusion, collectively, the data suggest that T4P assembly is powered by coordinating concurrent substrate binding with ATP hydrolysis across the PilB hexamer.« less
Petrocelli, Silvana; Arana, Maite R; Cabrini, Marcela N; Casabuono, Adriana C; Moyano, Laura; Beltramino, Matías; Moreira, Leandro M; Couto, Alicia S; Orellano, Elena G
2016-12-01
Type IV pili (Tfp) are widely distributed adhesins of bacterial surfaces. In plant pathogenic bacteria, Tfp are involved in host colonization and pathogenesis. Xanthomonas citri subsp. citri (Xcc) is the phytopathogen responsible for citrus canker disease. In this work, three Tfp structural genes, fimA, fimA1, and pilA from Xcc were studied. A pilA mutant strain from Xcc (XccΔpilA) was constructed and differences in physiological features, such as motilities, adhesion, and biofilm formation, were observed. A structural study of the purified Tfp fractions from Xcc wild-type and Xcc∆pilA showed that pilins are glycosylated in both strains and that FimA and FimA1 are the main structural components of the pili. Furthermore, smaller lesion symptoms and reduced bacterial growth were produced by Xcc∆pilA in orange plants compared to the wild-type strain. These results indicate that the minor pilin-like gene, pilA, is involved in Tfp performance during the infection process.
Mancl, Jordan M.; Black, Wesley P.; Robinson, Howard; ...
2016-09-22
Type IV pili (T4P) mediate bacterial motility and virulence. The PilB/GspE family ATPases power the assembly of T4P and type 2 secretion systems. We determined the structure of the ATPase region of PilB (PilB ATP) in complex with ATPγS to provide a model of a T4P assembly ATPase and a view of a PilB/GspE family hexamer at better than 3-Å resolution. Spatial positioning and conformations of the protomers suggest a mechanism of force generation. All six PilB ATP protomers contain bound ATPγS. Two protomers form a closed conformation poised for ATP hydrolysis. The other four molecules assume an open conformationmore » but separate into two pairs with distinct active-site accessibilities. We propose that one pair represents the post-hydrolysis phase while the other pair appears poised for ADP/ATP exchange. In conclusion, collectively, the data suggest that T4P assembly is powered by coordinating concurrent substrate binding with ATP hydrolysis across the PilB hexamer.« less
Primary intestinal lymphangiectasia with generalized warts.
Lee, Soon Jae; Song, Hyun Joo; Boo, Sun-Jin; Na, Soo-Young; Kim, Heung Up; Hyun, Chang Lim
2015-07-21
Primary intestinal lymphangiectasia (PIL) is a rare protein-losing enteropathy with lymphatic leakage into the small intestine. Dilated lymphatics in the small intestinal wall and mesentery are observed in this disease. Laboratory tests of PIL patients revealed hypoalbuminemia, lymphocytopenia, hypogammaglobulinemia and increased stool α-1 antitrypsin clearance. Cell-mediated immunodeficiency is also present in PIL patients because of loss of lymphocytes. As a result, the patients are vulnerable to chronic viral infection and lymphoma. However, cases of PIL with chronic viral infection, such as human papilloma virus-induced warts, are rarely reported. We report a rare case of PIL with generalized warts in a 36-year-old male patient. PIL was diagnosed by capsule endoscopy and colonoscopic biopsy with histological tissue confirmation. Generalized warts were observed on the head, chest, abdomen, back, anus, and upper and lower extremities, including the hands and feet of the patient.
NASA Astrophysics Data System (ADS)
Patra, Tarak; Yang, Junhong; Cheng, Yiz; Simmons, David
Polymeric ionic liquids (PILs) are very promising materials to enable more environmentally stable high density energy storage devices. Realization of PILs providing high environmental and mechanical stability while maximizing ion conductivity would be accelerated by an improved molecular level understanding of their structure and dynamics. Extensive evidence suggests that both mechanical properties and ion conductivity in anhydrous PILs are intimately related to the PIL's glass formation behavior. This represents a major challenge to the rational design of these materials, given that the basic nature of glass formation and its connection to molecular properties remains a substantial open question in polymer and condensed matter physics. Here we describe coarse-grained and atomistic molecular dynamics simulations probing the relationship between PIL architecture and interactions, glass formation behavior, and ion transport characteristics. These studies provide guidance towards the design of PILs with improved stability and ion conductivity for future energy applications.
Primary intestinal lymphangiectasia with generalized warts
Lee, Soon Jae; Song, Hyun Joo; Boo, Sun-Jin; Na, Soo-Young; Kim, Heung Up; Hyun, Chang Lim
2015-01-01
Primary intestinal lymphangiectasia (PIL) is a rare protein-losing enteropathy with lymphatic leakage into the small intestine. Dilated lymphatics in the small intestinal wall and mesentery are observed in this disease. Laboratory tests of PIL patients revealed hypoalbuminemia, lymphocytopenia, hypogammaglobulinemia and increased stool α-1 antitrypsin clearance. Cell-mediated immunodeficiency is also present in PIL patients because of loss of lymphocytes. As a result, the patients are vulnerable to chronic viral infection and lymphoma. However, cases of PIL with chronic viral infection, such as human papilloma virus-induced warts, are rarely reported. We report a rare case of PIL with generalized warts in a 36-year-old male patient. PIL was diagnosed by capsule endoscopy and colonoscopic biopsy with histological tissue confirmation. Generalized warts were observed on the head, chest, abdomen, back, anus, and upper and lower extremities, including the hands and feet of the patient. PMID:26217101
Roos, Corey R.; Kirouac, Megan; Pearson, Matthew R.; Fink, Brandi C.; Witkiewitz, Katie
2015-01-01
Temptation to drink, defined as the degree to which one feels compelled to drink in the presence of internal or external alcohol-related cues, has been shown to predict alcohol treatment outcomes among individuals with alcohol use disorders (AUDs). Research examining temptation to drink from an existential perspective is lacking and little is known about how existential issues such as purpose in life (PIL) relate to temptation to drink, which is surprising given the role of existential issues in many treatments and mutual help approaches for AUDs. The current study examined the longitudinal associations among temptation to drink, PIL, and drinking outcomes using data from Project MATCH (N = 1726). Parallel process latent growth curve analyses indicated that PIL and temptation to drink were significantly associated across time, such that higher initial levels of PIL and increases in PIL over time were associated with lower initial levels of temptation to drink and decreases in temptation to drink over time. Higher initial levels of temptation to drink, lower initial levels of PIL, increases in temptation to drink, and decreases in PIL were significantly associated with greater intensity and frequency of drinking and greater drinking-related consequences at the 15-month follow-up. Accordingly, temptation to drink and PIL may be important constructs for clinicians to consider throughout the course of treatment. Future studies should examine if and how various kinds of treatments for AUDs are associated with increases in PIL, and whether these increases are related to decreased temptation to drink and reduced drinking. PMID:25730630
Evolutionary Dynamics of Floral Homeotic Transcription Factor Protein–Protein Interactions
Bartlett, Madelaine; Thompson, Beth; Brabazon, Holly; Del Gizzi, Robert; Zhang, Thompson; Whipple, Clinton
2016-01-01
Protein–protein interactions (PPIs) have widely acknowledged roles in the regulation of development, but few studies have addressed the timing and mechanism of shifting PPIs over evolutionary history. The B-class MADS-box transcription factors, PISTILLATA (PI) and APETALA3 (AP3) are key regulators of floral development. PI-like (PIL) and AP3-like (AP3L) proteins from a number of plants, including Arabidopsis thaliana (Arabidopsis) and the grass Zea mays (maize), bind DNA as obligate heterodimers. However, a PIL protein from the grass relative Joinvillea can bind DNA as a homodimer. To ascertain whether Joinvillea PIL homodimerization is an anomaly or indicative of broader trends, we characterized PIL dimerization across the Poales and uncovered unexpected evolutionary lability. Both obligate B-class heterodimerization and PIL homodimerization have evolved multiple times in the order, by distinct molecular mechanisms. For example, obligate B-class heterodimerization in maize evolved very recently from PIL homodimerization. A single amino acid change, fixed during domestication, is sufficient to toggle one maize PIL protein between homodimerization and obligate heterodimerization. We detected a signature of positive selection acting on residues preferentially clustered in predicted sites of contact between MADS-box monomers and dimers, and in motifs that mediate MADS PPI specificity in Arabidopsis. Changing one positively selected residue can alter PIL dimerization activity. Furthermore, ectopic expression of a Joinvillea PIL homodimer in Arabidopsis can homeotically transform sepals into petals. Our results provide a window into the evolutionary remodeling of PPIs, and show that novel interactions have the potential to alter plant form in a context-dependent manner. PMID:26908583
Frontiers in poly(ionic liquid)s: syntheses and applications.
Qian, Wenjing; Texter, John; Yan, Feng
2017-02-20
We review recent works on the synthesis and application of poly(ionic liquid)s (PILs). Novel chemical structures, different synthetic strategies and controllable morphologies are introduced as a supplement to PIL systems already reported. The primary properties determining applications, such as ionic conductivity, aqueous solubility, thermodynamic stability and electrochemical/chemical durability, are discussed. Furthermore, the near-term applications of PILs in multiple fields, such as their use in electrochemical energy materials, stimuli-responsive materials, carbon materials, and antimicrobial materials, in catalysis, in sensors, in absorption and in separation materials, as well as several special-interest applications, are described in detail. We also discuss the limitations of PIL applications, efforts to improve PIL physics, and likely future developments.
Two modes of control of pilA, the gene encoding type 1 pilin in Escherichia coli.
Orndorff, P E; Spears, P A; Schauer, D; Falkow, S
1985-01-01
Type 1 piliation in Escherichia coli is subject to metastable regulation at the transcriptional level (B. I. Eisenstein, Science 214:337-339, 1981). However, the genes controlling in this fashion are not known. We present evidence that the pilA gene, encoding the structural subunit of type 1 pili, is subject to metastable transcriptional regulation. A pilA'-lacZ fusion, constructed in vitro on a recombinant plasmid, was used in conjunction with a recBC sbcB mutant of E. coli K-12 to introduce the fusion into the chromosomal region encoding Pil. This fusion was found to be subject to metastable transcriptional control. The rate of switching from the Lac+ to the Lac- phenotype was 4 X 10(-4) per cell per generation and 6.2 X 10(-4) in the opposite direction. A ca. 10-fold difference in beta-galactosidase activity was observed between phenotypically "ON" (Lac+) and "OFF" (Lac-) populations. P1 transduction experiments showed that the element determining the ON or OFF phenotype was tightly linked to pilA. In addition to the metastable regulation of pilA, a second type of transcriptional regulation was effected by the product of a gene, hyp, adjacent to pilA. By using a recombinant plasmid containing just a pilA'-lacZ fusion and the putative pilA promoter, we found that a lesion in hyp conferred a beta-galactosidase activity about fivefold higher than that of a strain possessing the parental hyp gene. Mutants constructed to have a pilA'-lacZ fusion and a hyp::Tn5-132 mutation in the chromosome exhibited a frequency of switching from Lac+ to Lac- and vice versa indistinguishable from that of the parental strain. However, in the ON mode, hyp::Tn5-132 mutants showed a twofold-higher beta-galactosidase activity. Thus, hyp does not appear to affect metastable variation but does affect the level of transcription of the pilA gene in the ON (transcribed) mode. Images PMID:3930469
Mwingira, Betty; Dowse, Ros
2007-06-01
To design and develop a simple, easily readable patient information leaflet (PIL) for a commonly used antiretroviral (ARV) regimen and to evaluate its readability and acceptability in a Tanzanian population. A PIL incorporating simple text and pictograms was designed for the antiretroviral regimen of stavudine, lamivudine and efavirenz. The PIL was designed according to established good design guidelines, modified during a multi-stage iterative testing process and piloted in a South African Xhosa population. The PIL was made available in both English and Kiswahili. Sixty Tanzanian participants who were not taking ARVs were interviewed. They were asked to read the PIL in the language of their choice and were then asked a series of two-part questions; the first part required participants to locate the information in the PIL, after which they were asked to explain the information in their own words. Acceptability was assessed through close-ended questions and open-ended feedback. The influence of selected patient characteristics on comprehension of the PIL was investigated using one-way ANOVA and t-tests for independent samples with a significance level set at 0.05. Comprehension of the written information in an overall percentage understanding. The overall average percentage comprehension of the PIL was 95%. The target set by the EC guideline that at least 80% of participants correctly locate and understand the information was achieved for 19 of the 20 questions. Five of the six instructions illustrated by pictograms were correctly understood by all participants. The only patient characteristics significantly associated with comprehension were educational level and self-reported ease of reading the PIL. Acceptability of the PIL was high and positive comments were associated with simplicity, good design, easy readability and user-friendliness, the latter enhanced by the inclusion of pictograms. The PIL designed for this study was shown to be effective in communicating information about ARVs. Patient characteristics must be taken into account when developing written information, and the final document must be tested for comprehension in the target population.
Multiple roles of Pseudomonas aeruginosa TBCF10839 PilY1 in motility, transport and infection
Bohn, Yu-Sing Tammy; Brandes, Gudrun; Rakhimova, Elza; Horatzek, Sonja; Salunkhe, Prabhakar; Munder, Antje; van Barneveld, Andrea; Jordan, Doris; Bredenbruch, Florian; Häußler, Susanne; Riedel, Kathrin; Eberl, Leo; Jensen, Peter Østrup; Bjarnsholt, Thomas; Moser, Claus; Hoiby, Niels; Tümmler, Burkhard; Wiehlmann, Lutz
2008-01-01
Polymorphonuclear neutrophils are the most important mammalian host defence cells against infections with Pseudomonas aeruginosa. Screening of a signature tagged mutagenesis library of the non-piliated P. aeruginosa strain TBCF10839 uncovered that transposon inactivation of its pilY1 gene rendered the bacterium more resistant against killing by neutrophils than the wild type and any other of the more than 3000 tested mutants. Inactivation of pilY1 led to the loss of twitching motility in twitching-proficient wild-type PA14 and PAO1 strains, predisposed to autolysis and impaired the secretion of quinolones and pyocyanin, but on the other hand promoted growth in stationary phase and bacterial survival in murine airway infection models. The PilY1 population consisted of a major full-length and a minor shorter PilY1* isoform. PilY1* was detectable in small extracellular quinolone-positive aggregates, but not in the pilus. P. aeruginosa PilY1 is not an adhesin on the pilus tip, but assists in pilus biogenesis, twitching motility, secretion of secondary metabolites and in the control of cell density in the bacterial population. PMID:19054330
Pyrene-Tagged Ionic Liquids: Separable Organic Catalysts for SN2 Fluorination.
Taher, Abu; Lee, Kyo Chul; Han, Hye Ji; Kim, Dong Wook
2017-07-07
We prepared pyrene-substituted imidazolium-based ionic liquids (PILs) as organic catalysts for the S N 2 fluorination using alkali metal fluoride (MF). In this system, the PIL significantly enhanced the reactivity of MF due to the phase-transfer catalytic effect of the imidazolium moiety as well as the metal cation-π (pyrene) interactions. Furthermore, this homogeneous catalyst PIL was easily separated from the reaction mixture using reduced graphene oxide by π-π stacking with the pyrene of PIL.
NASA Astrophysics Data System (ADS)
Nykaza, Jacob Richard
In this study, polymerized ionic liquid (PIL) diblock copolymers were explored as solid-state polymer separators as an anion exchange membrane (AEM) for alkaline fuel cells AFCs and as a solid polymer electrolyte (SPE) for lithium-ion batteries. Polymerized ionic liquid (PIL) block copolymers are a distinct set of block copolymers that combine the properties of both ionic liquids (e.g., high conductivity, high electrochemical stability) and block copolymers (e.g., self-assembly into various nanostructures), which provides the opportunity to design highly conductive robust solid-state electrolytes that can be tuned for various applications including AFCs and lithium-ion batteries via simple anion exchange. A series of bromide conducting PIL diblock copolymers with an undecyl alkyl side chain between the polymer backbone and the imidazolium moiety were first synthesized at various compositions comprising of a PIL component and a non-ionic component. Synthesis was achieved by post-functionalization from its non-ionic precursor PIL diblock copolymer, which was synthesized via the reverse addition fragmentation chain transfer (RAFT) technique. This PIL diblock copolymer with long alkyl side chains resulted in flexible, transparent films with high mechanical strength and high bromide ion conductivity. The conductivity of the PIL diblock copolymer was three times higher than its analogous PIL homopolymer and an order of magnitude higher than a similar PIL diblock copolymer with shorter alkyl side chain length, which was due to the microphase separated morphology, more specifically, water/ion clusters within the PIL microdomains in the hydrated state. Due to the high conductivity and mechanical robustness of this novel PIL block copolymer, its application as both the ionomer and AEM in an AFC was investigated via anion exchange to hydroxide (OH-), where a maximum power density of 29.3 mW cm-1 (60 °C with H2/O2 at 25 psig (172 kPa) backpressure) was achieved. Rotating disk electrode (RDE) experiments determined the interfacial resistance imposed during cell assembly between the AEM, catalyst, and ionomer was a factor in fuel cell performance. Further RDE studies investigated the electrochemical stability of the PIL block copolymer ionomer under applied potentials, where it was determined that potential cycling increased the degradation compared to constant voltage or open circuit voltage studies. The PIL diblock copolymer was then anion exchanged to the bis(trifluoromethane)sulfonamide (TFSI-) anion form and imbibed with a lithium salt and ionic liquid solution for use as a SPE in lithium-ion batteries resulting in a maximum discharge capacity of 112 mAh g-1 at 0.1 C with a Coulombic efficiency greater than 94% over 100 cycles. PIL block copolymers have promising mechanical properties and transport properties (i.e., ion conductivity) in both the hydrated (hydrophilic anions; Br-, OH-) and dry (hydrophobic anions; TFSI-) states resulting in highly conductive, chemically/thermally stable, and mechanically robust solid-state polymer separators for use as AEMs in AFCs and as SPEs in lithium-ion batteries.
Banerjee, Anirban; Kim, Brandon J.; Carmona, Ellese M.; Cutting, Andrew S.; Gurney, Michael A.; Carlos, Chris; Feuer, Ralph; Prasadarao, Nemani V.; Doran, Kelly S.
2011-01-01
Group B Streptococcus (GBS) is the leading cause of meningitis in newborn infants. Bacterial cell surface appendages, known as pili, have been recently described in streptococcal pathogens, including GBS. The pilus tip adhesin, PilA, contributes to GBS adherence to blood-brain barrier (BBB) endothelium; however, the host receptor and the contribution of PilA in central nervous system (CNS) disease pathogenesis are unknown. Here we show that PilA binds collagen, which promotes GBS interaction with the α2β1 integrin resulting in activation of host chemokine expression and neutrophil recruitment during infection. Mice infected with the PilA-deficient mutant exhibit delayed mortality, a decrease in neutrophil infiltration and bacterial CNS dissemination. We find that PilA-mediated virulence is dependent on neutrophil influx as neutrophil depletion results in a decrease in BBB permeability and GBS–BBB penetration. Our results suggest that the bacterial pilus, specifically the PilA adhesin, has a dual role in immune activation and bacterial entry into the CNS. PMID:21897373
Cursino, Luciana; Galvani, Cheryl D; Athinuwat, Dusit; Zaini, Paulo A; Li, Yaxin; De La Fuente, Leonardo; Hoch, Harvey C; Burr, Thomas J; Mowery, Patricia
2011-10-01
Xylella fastidiosa is an important phytopathogenic bacterium that causes many serious plant diseases, including Pierce's disease of grapevines. Disease manifestation by X. fastidiosa is associated with the expression of several factors, including the type IV pili that are required for twitching motility. We provide evidence that an operon, named Pil-Chp, with genes homologous to those found in chemotaxis systems, regulates twitching motility. Transposon insertion into the pilL gene of the operon resulted in loss of twitching motility (pilL is homologous to cheA genes encoding kinases). The X. fastidiosa mutant maintained the type IV pili, indicating that the disrupted pilL or downstream operon genes are involved in pili function, and not biogenesis. The mutated X. fastidiosa produced less biofilm than wild-type cells, indicating that the operon contributes to biofilm formation. Finally, in planta the mutant produced delayed and less severe disease, indicating that the Pil-Chp operon contributes to the virulence of X. fastidiosa, presumably through its role in twitching motility.
(Eco)toxicity and biodegradability of protic ionic liquids.
Oliveira, Maria V S; Vidal, Bruna T; Melo, Claudia M; de Miranda, Rita de C M; Soares, Cleide M F; Coutinho, João A P; Ventura, Sónia P M; Mattedi, Silvana; Lima, Álvaro S
2016-03-01
Ionic liquids (ILs) are often claimed to be "environmentally friendly" compounds however, the knowledge of their potential toxicity towards different organisms and trophic levels is still limited, in particular when protic ionic liquids (PILs) are addressed. This study aims to evaluate the toxicity against various microorganisms and the biodegradability of four PILs namely, N-methyl-2-hydroxyethylammonium acetate, m-2-HEAA; N-methyl-2-hydroxyethylammonium propionate, m-2-HEAPr; N-methyl-2-hydroxyethylammonium butyrate, m-2-HEAB; and N-methyl-2-hydroxyethylammonium pentanoate, m-2-HEAP. The antimicrobial activity was determined against the two bacteria, Sthaplylococcus aureus ATCC-6533 and Escherichia coli CCT-0355; the yeast Candida albicans ATCC-76645; and the fungi Fusarium sp. LM03. The toxicity of all PILs was tested against the aquatic luminescent marine bacterium Vibrio fischeri using the Microtox(®) test. The impact of the PILs was also studied regarding their effect on lettuce seeds (Lactuta sativa). The biodegradability of these PILs was evaluated using the ratio between the biochemical oxygen demand (BOD) and the chemical oxygen demand (COD). The results show that, in general, the elongation of the alkyl chain tends to increase the negative impact of the PILs towards the organisms and biological systems under study. According to these results, m-2-HEAA and m-2-HEAP are the less and most toxic PILs studied in this work, respectively. Additionally, all the PILs have demonstrated low biodegradability. Copyright © 2016. Published by Elsevier Ltd.
Castelain, Mickaël; Duviau, Marie-Pierre; Canette, Alexis; Schmitz, Philippe; Loubière, Pascal; Cocaign-Bousquet, Muriel; Piard, Jean-Christophe; Mercier-Bonin, Muriel
2016-01-01
Pili produced by Lactococcus lactis subsp. lactis are putative linear structures consisting of repetitive subunits of the major pilin PilB that forms the backbone, pilin PilA situated at the distal end of the pilus, and an anchoring pilin PilC that tethers the pilus to the peptidoglycan. We determined the nanomechanical properties of pili using optical-tweezers force spectroscopy. Single pili were exposed to optical forces that yielded force-versus-extension spectra fitted using the Worm-Like Chain model. Native pili subjected to a force of 0–200 pN exhibit an inextensible, but highly flexible ultrastructure, reflected by their short persistence length. We tested a panel of derived strains to understand the functional role of the different pilins. First, we found that both the major pilin PilB and sortase C organize the backbone into a full-length organelle and dictate the nanomechanical properties of the pili. Second, we found that both PilA tip pilin and PilC anchoring pilin were not essential for the nanomechanical properties of pili. However, PilC maintains the pilus on the bacterial surface and may play a crucial role in the adhesion- and biofilm-forming properties of L. lactis. PMID:27010408
Hockenberry, Alyson M; Hutchens, Danielle M; Agellon, Al; So, Magdalene
2016-12-06
Retraction of the type IV pilus (Tfp) mediates DNA uptake, motility, and social and infection behavior in a wide variety of prokaryotes. To date, investigations into Tfp retraction-dependent activities have used a mutant deleted of PilT, the ATPase motor protein that causes the pilus fiber to retract. ΔpilT cells are nontransformable, nonmotile, and cannot aggregate into microcolonies. We tested the hypothesis that these retraction-dependent activities are sensitive to the strength of PilT enzymatic activity by using the pathogen Neisseria gonorrhoeae as a model. We constructed an N. gonorrhoeae mutant with an amino acid substitution in the PilT Walker B box (a substitution of cysteine for leucine at position 201, encoded by pilT L201C ). Purified PilT L201C forms a native hexamer, but mutant hexamers hydrolyze ATP at half the maximal rate. N. gonorrhoeae pilT L201C cells produce Tfp fibers, crawl at the same speed as the wild-type (wt) parent, and are equally transformable. However, the social behavior of pilT L201C cells is intermediate between the behaviors of wt and ΔpilT cells. The infection behavior of pilT L201C is also defective, due to its failure to activate the epidermal growth factor receptor (EGFR)-heparin-binding EGF-like growth factor (HB-EGF) pathway. Our study indicates that pilus retraction, per se, is not sufficient for N. gonorrhoeae microcolony formation or infectivity; rather, these activities are sensitive to the strength of PilT enzymatic activity. We discuss the implications of these findings for Neisseria pathogenesis in the context of mechanobiology. Type IV pili are fibers expressed on the surface of many bacteria. Neisseria gonorrhoeae cells crawl, take up DNA, and communicate with each other and with human cells by retracting these fibers. Here, we show that an N. gonorrhoeae mutant expressing an enzymatically weakened type IV pilus retraction motor still crawls and takes up DNA normally. However, mutant cells exhibit abnormal social behavior, and they are less infective because they fail to activate the epidermal growth factor receptor. Our study shows that N. gonorrhoeae social and infection behaviors are sensitive to the strength of the retraction motor enzyme. Copyright © 2016 Hockenberry et al.
Gillies, Katie; Huang, Wan; Skea, Zoë; Brehaut, Jamie; Cotton, Seonaidh
2014-02-18
Informed consent is regarded as a cornerstone of ethical healthcare research and is a requirement for most clinical research studies. Guidelines suggest that prospective randomised controlled trial (RCT) participants should understand a basic amount of key information about the RCTs they are being asked to enrol in in order to provide valid informed consent. This information is usually provided to potential participants in a patient information leaflet (PIL). There is evidence that some trial participants fail to understand key components of trial processes or rationale. As such, the existing approach to information provision for potential RCT participants may not be optimal. Decision aids have been used for a variety of treatment and screening decisions to improve knowledge, but focus more on overall decision quality, and may be helpful to those making decisions about participating in an RCT. We investigated the feasibility of using a tool to identify which items recommended for good quality decision making are present in UK PILs. PILs were sampled from UK registered Clinical Trials Unit websites across a range of clinical areas. The evaluation tool, which is based on standards for supporting decision making, was applied to 20 PILs. Two researchers independently rated each PIL using the tool. In addition, word count and readability were assessed. PILs scored poorly on the evaluation tool with the majority of leaflets scoring less than 50%. Specifically, presenting probabilities, clarifying and expressing values and structured guidance in deliberation and communication sub-sections scored consistently poorly. Tool score was associated with word count (r=0.802, P <0.01); there was no association between score and readability (r=-0.372, P=0.106). The tool was feasible to use to evaluate PILs for UK RCTs. PILs did not meet current standards of information to support good quality decision making. Writers of information leaflets could use the evaluation tool as a framework during PIL development to help ensure that items are included which promote and support more informed decisions about trial participation. Further research is required to evaluate the inclusion of such information.
Nunn, D; Bergman, S; Lory, S
1990-01-01
The polar pili of Pseudomonas aeruginosa are composed of monomers of the pilin structural subunits. The biogenesis of pili involves the synthesis of pilin precursor, cleavage of a six-amino-acid leader peptide, membrane translocation, and assembly of monomers into a filamentous structure extending from the bacterial surface. This report describes three novel genes necessary for the formation of pili. DNA sequences adjacent to pilA, the pilin structural gene, were cloned and mutagenized with transposon Tn5. Each of the insertions were introduced into the chromosome of P. aeruginosa PAK by gene replacement. The effect of the Tn5 insertions in the bacterial chromosome on pilus assembly was assessed by electron microscopy and sensitivity of mutants to a pilus-specific bacteriophage. The resultant mutants were also tested for synthesis and membrane localization of the pilin antigen in order to define the genes required for maturation, export, and assembly of pilin. A 4.0-kilobase-pair region of DNA adjacent to the pilin structural gene was found to be essential for formation of pili. This region was sequenced and found to contain three open reading frames coding for 62-, 38- to 45-, and 28- to 32-kilodalton proteins (pilB, pilC, and pilD, respectively). Three proteins of similar molecular weight were expressed in Escherichia coli from the 4.0-kilobase-pair fragment flanking pilA with use of a T7 promoter-polymerase expression system. The results of the analyses of the three genes and the implications for pilin assembly and maturation are discussed. Images PMID:1971619
Sabando, Miguel Ormaza; Saavedra, Maira Arias; Sequeira, Gabriel; Kerzberg, Eduardo
2018-04-01
To analyse the level of consistency and updating of the information on pregnancy and lactation provided by patient information leaflets (PILs) of the antirheumatic drugs approved in Argentina. Inconsistencies between the 2016 EULAR Task Force recommendations on the use of anti-rheumatic drugs during pregnancy and lactation and the information provided by PILs of the same drugs approved in Argentina were analysed along with inconsistencies within the PILs of different registered trademarks of these drugs. Eighty-eight PILs of 32 drugs were analysed. Out of the 88 PILs, 50% presented information inconsistencies as to pregnancy. Medications comprised in this group were: hydroxychloroquine, sulfasalazine, azathioprine, tacrolimus, cyclosporine, NSAIDs (during the first two trimesters), celecoxib, some glucocorticoids, colchicine, and some anti-TNF drugs (etanercept, adalimumab and infliximab) during part of the pregnancy. As for lactation, 56% had information inconsistencies. Medications encompassed in this group were: hydroxychloroquine, chloroquine, sulfasalazine, azathioprine, tacrolimus, cyclosporine, NSAIDs, celecoxib, meprednisone, prednisone, colchicine, and anti-TNF drugs. Out of 17 drugs that had more than one registered trademark, information inconsistencies on pregnancy were found in the PILs of sulfasalazine, diclofenac, ibuprofen and methylprednisolone. Concerning lactation, inconsistencies were present in the PILs of hydroxychloroquine, sulfasalazine, diclofenac, ibuprofen, meprednisone, and colchicine. At least half of the PILs of anti-rheumatic drugs analysed in this study had information inconsistencies on pregnancy and lactation. This is a serious state of affairs because the consensual decision-making process between patient and professional may be compromised, which, in turn, may give rise to medical-legal issues.
Panniello, Annamaria; Ingrosso, Chiara; Coupillaud, Paul; Tamborra, Michela; Binetti, Enrico; Curri, Maria Lucia; Agostiano, Angela; Taton, Daniel; Striccoli, Marinella
2014-01-01
Polymeric ionic liquids (PILs) are an interesting class of polyelectrolytes, merging peculiar physical-chemical features of ionic liquids with the flexibility, mechanical stability and processability typical of polymers. The combination of PILs with colloidal semiconducting nanocrystals leads to novel nanocomposite materials with high potential for batteries and solar cells. We report the synthesis and properties of a hybrid nanocomposite made of colloidal luminescent CdSe nanocrystals incorporated in a novel ex situ synthesized imidazolium-based PIL, namely, either a poly(N-vinyl-3-butylimidazolium hexafluorophosphate) or a homologous PIL functionalized with a thiol end-group exhibiting a chemical affinity with the nanocrystal surface. A capping exchange procedure has been implemented for replacing the pristine organic capping molecules of the colloidal CdSe nanocrystals with inorganic chalcogenide ions, aiming to disperse the nano-objects in the PILs, by using a common polar solvent. The as-prepared nanocomposites have been studied by TEM investigation, UV-Vis, steady-state and time resolved photoluminescence spectroscopy for elucidating the effects of the PIL functionalization on the morphological and optical properties of the nanocomposites. PMID:28788477
Paramagnetic ionic liquids for measurements of density using magnetic levitation.
Bwambok, David K; Thuo, Martin M; Atkinson, Manza B J; Mirica, Katherine A; Shapiro, Nathan D; Whitesides, George M
2013-09-03
Paramagnetic ionic liquids (PILs) provide new capabilities to measurements of density using magnetic levitation (MagLev). In a typical measurement, a diamagnetic object of unknown density is placed in a container containing a PIL. The container is placed between two magnets (typically NdFeB, oriented with like poles facing). The density of the diamagnetic object can be determined by measuring its position in the magnetic field along the vertical axis (levitation height, h), either as an absolute value or relative to internal standards of known density. For density measurements by MagLev, PILs have three advantages over solutions of paramagnetic salts in aqueous or organic solutions: (i) negligible vapor pressures; (ii) low melting points; (iii) high thermal stabilities. In addition, the densities, magnetic susceptibilities, glass transition temperatures, thermal decomposition temperatures, viscosities, and hydrophobicities of PILs can be tuned over broad ranges by choosing the cation-anion pair. The low melting points and high thermal stabilities of PILs provide large liquidus windows for density measurements. This paper demonstrates applications and advantages of PILs in density-based analyses using MagLev.
Transcription analysis of pilS and xpsEL genes from Xylella fastidiosa.
Coltri, Patricia P; Rosato, Yoko B
2005-04-01
Xylella fastidiosa is a xylem-limited phytopathogen responsible for diseases in several plants such as citrus and coffee. Analysis of the bacterial genome revealed some putative pathogenicity-related genes that could help to elucidate the molecular mechanisms of plant-pathogen interactions. In the present work, the transcription of three genes of the bacterium, grown in defined and rich media and also in media containing host plant extracts (sweet orange, 'ponkan' and coffee) was analyzed by RT-PCR. The pilS gene, which encodes a sensor histidine kinase responsible for the biosynthesis of fimbriae, was transcribed when the bacterium was grown in more complex media such as PW and in medium containing plant extracts. The xps genes (xpsL and xpsE) which are related to the type II secretion system were also detected when the bacterium was grown in rich media and media with 'ponkan' and coffee extracts. It was thus observed that pilS and xpsEL genes of X. fastidiosa can be modulated by environmental factors and their expression is dependent on the nutritional status of the growth medium.
Polymeric ionic liquid bucky gels as sorbent coatings for solid-phase microextraction.
Zhang, Cheng; Anderson, Jared L
2014-05-30
Novel cross-linked polymeric ionic liquid (PIL) bucky gels were formed by free-radical polymerization of polymerizable ionic liquids gelled with multi-walled carbon nanotubes (MWCNT) and used as sorbent coatings for solid-phase microextraction (SPME). The combination of PIL with MWCNTs significantly enhanced the π-π interaction between the sorbent coatings and the aromatic analytes. Compared to the neat PIL-based sorbent coating, the PIL bucky gel sorbent coatings demonstrated higher extraction efficiency for the extraction of polycyclic aromatic hydrocarbons (PAHs). A partitioning extraction mechanism was observed for the PIL/MWCNT-based sorbent coatings indicating that the addition of MWCNTs did not seem to affect the extraction mechanism of the sorbent coating. The analyte-to-coating partition coefficients (logKfs) were estimated and the limits of detection (LOD) for selected PIL bucky gel sorbent coating were determined to be in the range of 1-2.5 ng L(-1). Recovery studies were also performed for PAHs in river and tap water to validate the applicability of the developed method. Copyright © 2014 Elsevier B.V. All rights reserved.
Li, Yongquan; Li, Hongyu
2014-03-01
Studies on Acidithiobacillus ferrooxidans accepting electrons from Fe(II) have previously focused on cytochrome c. However, we have discovered that, besides cytochrome c, type IV pili (Tfp) can transfer electrons. Here, we report conduction by Tfp of A. ferrooxidans analyzed with a conducting-probe atomic force microscope (AFM). The results indicate that the Tfp of A. ferrooxidans are highly conductive. The genome sequence of A. ferrooxidans ATCC 23270 contains two genes, pilV and pilW, which code for pilin domain proteins with the conserved amino acids characteristic of Tfp. Multiple alignment analysis of the PilV and PilW (pilin) proteins indicated that pilV is the adhesin gene while pilW codes for the major protein element of Tfp. The likely function of Tfp is to complete the circuit between the cell surface and Fe(II) oxides. These results indicate that Tfp of A. ferrooxidans might serve as biological nanowires transferring electrons from the surface of Fe(II) oxides to the cell surface. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Lu, Fei; Gao, Xinpei; Xie, Shuting; Sun, Nan; Zheng, Liqiang
2014-10-21
Chemically modified Nafion composite membranes were successfully fabricated using five kinds of protic ionic liquids (PILs) with different cations, 1-butylammonium methanesulfonate (BA-MS), tributylammonium methanesulfonate (TBA-MS), 2,4,6-trimethylphenylammonium methanesulfonate (TMA-MS), butane-1,4-diammonium methanesulfonate (BDA-MS), and N-(2-aminoethyl)ethane-1,2-diammonium methanesulfonate (DETA-MS). The PIL incorporated Nafion composite membranes were characterized by impedance spectroscopy, small-angle X-ray scattering (SAXS), dynamic-mechanical analysis (DMA) and thermogravimetric analysis (TGA). In general, the Nafion/PIL composite membranes exhibit a significant increase in the ionic conductivities than Nafion under anhydrous conditions. The interactions between the Nafion ionomer and different geometric cations of PILs were also discussed by the comparison of nanostructures, dynamic-mechanical properties and thermal stabilities of the Nafion/PIL composite membranes.
Osteomalacia and osteoporosis associated with primary intestinal lymphangiectasis.
Li, Xin-Ping; Shen, Wen-Bin; Long, Ming-Qing; Meng, Xun-Wu; Lian, Xiao-Lan; Yu, Miao
2012-05-01
Primary Intestinal lymphangiectasia (PIL) is a common cause of protein losing enteropathy (PLE). It will affect enter-hepatic circulation of lipid-soluble vitamin, and absorption of electrolytes, cause malnutrition related osteomalacia or osteoporosis. While seldom health care workers noted to assess and treat osteomalacia or osteoporosis in PIL. Here we report a related case. We found increased parathyroid hormone, decreased 25(OH)D3, low bone mineral density, which indicated that the PIL patient had osteomalacia and/or osteoporosis. Adequate calcium and vitamin D supply can relieve the condition efficaciously. We should pay attention to osteomalacia and osteoporosis in PIL patients.
Vaporization of protic ionic liquids derived from organic superbases and short carboxylic acids.
Ribeiro, Filipe M S; Lima, Carlos F R A C; Vaz, Inês C M; Rodrigues, Ana S M C; Sapei, Erlin; Melo, André; Silva, Artur M S; Santos, Luís M N B F
2017-06-28
This work presents a comprehensive evaluation of the phase behaviour and cohesive enthalpy of protic ionic liquids (PILs) composed of 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) or 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) organic superbases with short-chain length (acetic, propionic and butyric) carboxylic acids. Glass transition temperatures, T g , and enthalpies of vaporization, ΔH vap , were measured for six [BH][A] (1 : 1) PILs (B = DBN, DBU; A = MeCOO, EtCOO, nPrCOO), revealing more significant changes upon increasing the number of -CH 2 - groups in the base than in the acid. The magnitude of ΔH vap evidences that liquid PILs have a high proportion of ions, although the results also indicate that in DBN PILs the concentration of neutral species is not negligible. In the gas phase, these PILs exist as a distribution of ion pairs and isolated neutral species, with speciation being dependent on the temperature and pressure conditions - at high temperatures and low pressures the separated neutral species dominate. The higher T g and ΔH vap of the DBU PILs are explained by the stronger basicity of DBU (as supported by NMR and computational calculations), which increases the extent of proton exchange and the ionic character of the corresponding PILs, resulting in stronger intermolecular interactions in condensed phases.
Variations in Adolescent Purpose in Life and Their Association with Lifetime Substance Use
ERIC Educational Resources Information Center
Abramoski, Kathryn; Pierce, Jennifer; Hauck, Corinne; Stoddard, Sarah
2018-01-01
Purpose in life (PIL) promotes positive development and is associated with decreased substance use. However, to our knowledge, researchers have not investigated how different categories of PIL are associated with substance use behavior among youth. Therefore, we sought to explore categories of PIL and how they are related to substance use in a…
ERIC Educational Resources Information Center
Reker, Gary T.; Cousins, J. B.
1979-01-01
In this study with 240 introductory psychology students, ten interpretable independent dimensions of satisfaction with life were extracted with six factors that loaded on the PIL and four that loaded on the SONG, supporting Crumbaugh's assertion that the SONG is a complementary scale to the PIL. (Author/SJL)
Cagliero, Cecilia; Nan, He; Bicchi, Carlo; Anderson, Jared L
2016-08-12
Nine crosslinked polymeric ionic liquid (PIL)-based SPME sorbent coatings were designed and screened in this study for the trace level determination of acrylamide in brewed coffee and coffee powder using gas chromatography-mass spectrometry (GC-MS). The structure of the ionic liquid (IL) monomer was tailored by introducing different functional groups to the cation and the nature of the IL crosslinker was designed by altering both the structure of the cation as well as counteranions. The extraction efficiency of the new PIL coatings towards acrylamide was investigated and compared to a previously reported PIL sorbent coating. All PIL fibers exhibited excellent analytical precision and linearity. The PIL fiber coating consisting of 50% 1,12-di(3-vinylbenzylbenzimidazolium)dodecane dibis[(trifluoromethyl)sulfonyl]imide as IL crosslinker in 1-vinyl-3-(10-hydroxydecyl)imidazolium bis[(trifluoromethyl)sulfonyl]imide IL monomer resulted in a limit of quantitation of 0.5μgL(-1) with in-solution SPME sampling. The hydroxyl moiety appended to the IL cation was observed to significantly increase the sensitivity of the PIL coating toward acrylamide. The quantitation of acrylamide in brewed coffee and coffee powder was performed using the different PIL-based fibers by the method of standard addition after a quenching reaction using ninhydrin to inhibit the formation of interfering acrylamide in the GC inlet, mainly by asparagine thermal degradation. Excellent repeatability with relative standard deviations below 10% were obtained on the real coffee samples and the structure of the coatings appeared intact by scanning electron microscopy after coffee sampling proving the matrix-compatibility of the PIL sorbent coatings. Copyright © 2016 Elsevier B.V. All rights reserved.
Asmat, Tauseef M; Tenenbaum, Tobias; Jonsson, Ann-Beth; Schwerk, Christian; Schroten, Horst
2014-01-01
The pili and outer membrane proteins of Neisseria meningitidis (meningococci) facilitate bacterial adhesion and invasion into host cells. In this context expression of meningococcal PilC1 protein has been reported to play a crucial role. Intracellular calcium mobilization has been implicated as an important signaling event during internalization of several bacterial pathogens. Here we employed time lapse calcium-imaging and demonstrated that PilC1 of meningococci triggered a significant increase in cytoplasmic calcium in human brain microvascular endothelial cells, whereas PilC1-deficient meningococci could not initiate this signaling process. The increase in cytosolic calcium in response to PilC1-expressing meningococci was due to efflux of calcium from host intracellular stores as demonstrated by using 2-APB, which inhibits the release of calcium from the endoplasmic reticulum. Moreover, pre-treatment of host cells with U73122 (phospholipase C inhibitor) abolished the cytosolic calcium increase caused by PilC1-expressing meningococci demonstrating that active phospholipase C (PLC) is required to induce calcium transients in host cells. Furthermore, the role of cytosolic calcium on meningococcal adherence and internalization was documented by gentamicin protection assay and double immunofluorescence (DIF) staining. Results indicated that chelation of intracellular calcium by using BAPTA-AM significantly impaired PilC1-mediated meningococcal adherence to and invasion into host endothelial cells. However, buffering of extracellular calcium by BAPTA or EGTA demonstrated no significant effect on meningococcal adherence to and invasion into host cells. Taken together, these results indicate that meningococci induce calcium release from intracellular stores of host endothelial cells via PilC1 and cytoplasmic calcium concentrations play a critical role during PilC1 mediated meningococcal adherence to and subsequent invasion into host endothelial cells.
Functional Divergence of FimX in PilZ Binding and Type IV Pilus Regulation
Qi, Yaning; Xu, Linghui; Dong, Xueming; Yau, Yin Hoe; Ho, Chun Loong; Koh, Siew Lee; Shochat, Susana Geifman; Chou, Shan-Ho; Tang, Kai
2012-01-01
Type IV pili (T4P) are polar surface structures that play important roles in bacterial motility, biofilm formation, and pathogenicity. The protein FimX and its orthologs are known to mediate T4P formation in the human pathogen Pseudomonas aeruginosa and some other bacterial species. It was reported recently that FimXXAC2398 from Xanthomonas axonopodis pv. citri interacts with PilZXAC1133 directly through the nonenzymatic EAL domain of FimXXAC2398. Here we present experimental data to reveal that the strong interaction between FimXXAC2398 and PilZXAC1133 is not conserved in P. aeruginosa and likely other Pseudomonas species. In vitro and in vivo binding experiments showed that the interaction between FimX and PilZ in P. aeruginosa is below the measurable limit. Surface plasmon resonance assays further confirmed that the interaction between the P. aeruginosa proteins is at least more than 3 orders of magnitude weaker than that between the X. axonopodis pv. citri pair. The N-terminal lobe region of FimXXAC2398 was identified as the binding surface for PilZXAC1133 by amide hydrogen-deuterium exchange and site-directed mutagenesis studies. Lack of several key residues in the N-terminal lobe region of the EAL domain of FimX is likely to account for the greatly reduced binding affinity between FimX and PilZ in P. aeruginosa. All together, the results suggest that the interaction between PilZ and FimX in Xanthomonas species is not conserved in P. aeruginosa due to the evolutionary divergence among the FimX orthologs. The precise roles of FimX and PilZ in bacterial motility and T4P biogenesis are likely to vary among bacterial species. PMID:22942245
Shrestha, Anmol; Rajesh, V; Dessai, Sneha Shamrao; Stanly, Sharon Mary; Mateti, Uday Venkat
2018-05-25
Patient education is of paramount importance with regard to the condition of the disease and the treatment given besides lifestyle remodelling in order to get the desired therapeutic outcome. When verbal information is provided to the patients, they often tend to forget it. Pictorial aids or pictograms, as they are commonly known, are tools that are widely used for imparting knowledge to the patients. The aim of the study is to prepare and validate a Pictogram-based Patient Information Leaflet (P-PILs) on Tuberculosis (TB). P-PILs have been prepared from tertiary, secondary and primary sources. The knowledge-based questions are prepared with respect to the P-PILs. The baseline knowledge of the volunteers and patients have been analyzed before administering the P-PILs by using the validated questionnaire. The post-knowledge of the volunteers and patients has been analyzed after administering the P-PILs (20 min) by using the same questionnaire and the user-opinion has also been obtained at the end. The study results show that the mean scores of the overall user-testing knowledge assessment are found to have improved significantly from the pre-P-PILs administration score of 62.67 to the post-P-PILs administration score of 91. The overall user-opinion about the P-PILs has been found to be good (75%) followed by average (25%). The present study shows that there is significant improvement in the knowledge levels of the patients and volunteers after reading the validated leaflets. The Pictogram-based Patient Information Leaflets are found to be an effective educational tool for TB patients. Copyright © 2018. Published by Elsevier Ltd.
Wen, Qian; Wang, Yuzhi; Xu, Kaijia; Li, Na; Zhang, Hongmei; Yang, Qin
2016-10-05
A novel magnetic adsorbent, benzyl groups functionalized imidazolium-based polymeric ionic liquid (PIL)-coated magnetic multiwalled carbon nanotubes (MWCNTs) (m-MWCNTs@PIL), has been successfully synthesized and applied for the extraction of Cu, Zn-superoxide dismutase (Cu, Zn-SOD). The m-MWCNTs@PIL were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrometry (FT-IR), thermal gravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), vibrating sample magnetometer (VSM) and zeta-potential nanoparticles. In this method, the m-MWCNTs@PIL could interact with Cu, Zn-SOD through hydrogen bonding, π-π and electrostatic interactions. The extraction performance of the m-MWCNTs@PIL in the magnetic solid-phase extraction (MSPE) procedure was investigated, coupled with the determination by UV-vis spectrophotometer. Compared with m-MWCNTs@IL and m-MWCNTs, the m-MWCNTs@PIL exhibited the highest extraction capacity of 29.1 mg/g for Cu, Zn-SOD. The adsorbed Cu, Zn-SOD remained high specific activity after being eluted from m-MWCNTs@PIL by 1 moL/L NaCl solution. Besides, the m-MWCNTs@PIL could be easily recycled and successfully employed in the extraction of Cu, Zn-SOD from real samples. Under the optimal conditions, the precision, repeatability and stability of the proposed method were investigated and the RSDs were 0.29%, 1.68% and 0.54%, respectively. Recoveries were in the range of 82.7-102.3%, with the RSD between 3.47% and 5.35%. On the basis of these results, the developed method has great potential in the extraction of Cu, Zn-SOD or other analytes from biological samples. Copyright © 2016 Elsevier B.V. All rights reserved.
Poly(ionic liquid) based chemosensors for detection of basic amino acids in aqueous medium
NASA Astrophysics Data System (ADS)
Li, Xinjuan; Wang, Kai; Ma, Nana; Jia, Xianbin
2017-09-01
Naked-eye detection of amino acids in water is of great significance in the field of bio-analytical applications. Herein, polymerized ionic liquids (PILs) with controlled chain length structures were synthesized via reversible addition-fragmentation chain-transfer (RAFT) polymerization and post-quaternization approach. The amino acids recognition performance of PILs with different alkyl chain lengths and molecular weights was evaluated by naked-eye color change and ultraviolet-visible (UV-vis) spectral studies. These PILs were successfully used for highly sensitive and selective detection of Arg, Lys and His in water. The recognition performance was improved effectively with increased molecular weight of PILs. The biosensitivity of the PILs in water was strongly dependent on their aggregation effect and polarization effect. Highly sensitive and selective detection of amino acids was successfully accomplished by introducing positively charged pyridinium moieties and controlled RAFT radical polymerization.
Calcium-Enhanced Twitching Motility in Xylella fastidiosa Is Linked to a Single PilY1 Homolog
Cruz, Luisa F.; Parker, Jennifer K.; Cobine, Paul A.
2014-01-01
The plant-pathogenic bacterium Xylella fastidiosa is restricted to the xylem vessel environment, where mineral nutrients are transported through the plant host; therefore, changes in the concentrations of these elements likely impact the growth and virulence of this bacterium. Twitching motility, dependent on type IV pili (TFP), is required for movement against the transpiration stream that results in basipetal colonization. We previously demonstrated that calcium (Ca) increases the motility of X. fastidiosa, although the mechanism was unknown. PilY1 is a TFP structural protein recently shown to bind Ca and to regulate twitching and adhesion in bacterial pathogens of humans. Sequence analysis identified three pilY1 homologs in X. fastidiosa (PD0023, PD0502, and PD1611), one of which (PD1611) contains a Ca-binding motif. Separate deletions of PD0023 and PD1611 resulted in mutants that still showed twitching motility and were not impaired in attachment or biofilm formation. However, the response of increased twitching at higher Ca concentrations was lost in the pilY1-1611 mutant. Ca does not modulate the expression of any of the X. fastidiosa PilY1 homologs, although it increases the expression of the retraction ATPase pilT during active movement. The evidence presented here suggests functional differences between the PilY1 homologs, which may provide X. fastidiosa with an adaptive advantage in environments with high Ca concentrations, such as xylem sap. PMID:25217013
Calcium-Enhanced Twitching Motility in Xylella fastidiosa Is Linked to a Single PilY1 Homolog.
Cruz, Luisa F; Parker, Jennifer K; Cobine, Paul A; De La Fuente, Leonardo
2014-12-01
The plant-pathogenic bacterium Xylella fastidiosa is restricted to the xylem vessel environment, where mineral nutrients are transported through the plant host; therefore, changes in the concentrations of these elements likely impact the growth and virulence of this bacterium. Twitching motility, dependent on type IV pili (TFP), is required for movement against the transpiration stream that results in basipetal colonization. We previously demonstrated that calcium (Ca) increases the motility of X. fastidiosa, although the mechanism was unknown. PilY1 is a TFP structural protein recently shown to bind Ca and to regulate twitching and adhesion in bacterial pathogens of humans. Sequence analysis identified three pilY1 homologs in X. fastidiosa (PD0023, PD0502, and PD1611), one of which (PD1611) contains a Ca-binding motif. Separate deletions of PD0023 and PD1611 resulted in mutants that still showed twitching motility and were not impaired in attachment or biofilm formation. However, the response of increased twitching at higher Ca concentrations was lost in the pilY1-1611 mutant. Ca does not modulate the expression of any of the X. fastidiosa PilY1 homologs, although it increases the expression of the retraction ATPase pilT during active movement. The evidence presented here suggests functional differences between the PilY1 homologs, which may provide X. fastidiosa with an adaptive advantage in environments with high Ca concentrations, such as xylem sap. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
A Novel Class of Somatic Small RNAs Similar to Germ Cell Pachytene PIWI-interacting Small RNAs*
Ortogero, Nicole; Schuster, Andrew S.; Oliver, Daniel K.; Riordan, Connor R.; Hong, Annie S.; Hennig, Grant W.; Luong, Dickson; Bao, Jianqiang; Bhetwal, Bhupal P.; Ro, Seungil; McCarrey, John R.; Yan, Wei
2014-01-01
PIWI-interacting RNAs (piRNAs) are small noncoding RNAs that bind PIWI family proteins exclusively expressed in the germ cells of mammalian gonads. MIWI2-associated piRNAs are essential for silencing transposons during primordial germ cell development, and MIWI-bound piRNAs are required for normal spermatogenesis during adulthood in mice. Although piRNAs have long been regarded as germ cell-specific, increasing lines of evidence suggest that somatic cells also express piRNA-like RNAs (pilRNAs). Here, we report the detection of abundant pilRNAs in somatic cells, which are similar to MIWI-associated piRNAs mainly expressed in pachytene spermatocytes and round spermatids in the testis. Based on small RNA deep sequencing and quantitative PCR analyses, pilRNA expression is dynamic and displays tissue specificity. Although pilRNAs are similar to pachytene piRNAs in both size and genomic origins, they have a distinct ping-pong signature. Furthermore, pilRNA biogenesis appears to utilize a yet to be identified pathway, which is different from all currently known small RNA biogenetic pathways. In addition, pilRNAs appear to preferentially target the 3′-UTRs of mRNAs in a partially complementary manner. Our data suggest that pilRNAs, as an integral component of the small RNA transcriptome in somatic cell lineages, represent a distinct population of small RNAs that may have functions similar to germ cell piRNAs. PMID:25320077
2000-02-23
eonomical to rotate the stress and the c strain once rather than having to rotate 4th order tensors like c Amat, Bmat , MHS etc. whose...nu2,sigyO real*8 deps(3,3),eps_plastic,dep_plas,dumd(6,6) real*8 det,kll,dphidf,phil,phi2,ftest real*8 el212,e2323,el313,pil212,pi2323,pil313, bmat ...pi2323-f*pi2323 el313=pil313-f*pil313 spath=.true. call Btensor(a,b,c,ad,bd,cd,f,mul,kl,mu2,k2, Bmat ) do 41 i=l,3 do 42 j=l,6 Bmat (i,j)=0.0 42
Enhancement of polar phase and conductivity relaxation in PIL-modified GO/PVDF composites
NASA Astrophysics Data System (ADS)
Xu, Pei; Fu, Weijia; Cui, Zhaopei; Ding, Yunsheng
2018-02-01
To investigate the effect of graphene oxide (GO) modified by polymerized ionic liquid (PIL) on the crystallization and dielectric relaxation of poly(vinylidene fluoride) (PVDF), a series of PVDF composites have been prepared using the solution casting method. The ion-dipole interaction between PIL and >CF2 and the π-dipole interaction between GO and >CF2 can induce synergistically the polar phase, and the π-ion interaction between GO and PIL can strengthen the induction effect of the polar phase and decrease the degree of crystallization of PVDF. The electric modulus and conductivity relaxation are employed to analyze the experimental complex dielectric permittivity. In the frequency spectra of complex permittivity of PVDF composites, space charge polarization and conductivity lead to a large value of dielectric permittivity. The temperature dependence of relaxation time of conductivity relaxation accords with the Arrhenius equation. A low degree of crystallization, more ion concentration, and polar phase in PVDF/PIL/GO enhance the movement of the polymer chain segment and charge carriers.
Mao, Hui; Liang, Jiachen; Zhang, Haifeng; Pei, Qi; Liu, Daliang; Wu, Shuyao; Zhang, Yu; Song, Xi-Ming
2015-08-15
Novel poly(ionic liquids) functionalized polypyrrole/graphene oxide nanosheets (PILs/PPy/GO) were prepared by the polymerization of 1-vinyl-3-ethylimidazole bromide (VEIB) on the surface of N-vinyl imidazolium modified PPy/GO nanosheets. Due to the synergistic effects of GO with well-defined lamellar structures, conductive PPy and biocompatible PILs, PILs/PPy/GO modified glassy carbon electrode (GCE) presented the excellent electrochemical catalytic activity towards dopamine (DA) with good stability, high sensitivity and wide linear range in the present of ascorbic acid (AA) with high concentration. PILs played an essential role for the simultaneous determination of DA and AA in a mixture, whose existence effectively improved the transmission mode of electrons and resulted in the different electrocatalytic performance towards the oxidation of DA and AA. It is indicated that PILs/PPy/GO nanosheets can act as a good steady and sensitive electrode material for the development of improved DA sensors. Copyright © 2015 Elsevier B.V. All rights reserved.
Eisosomes Are Dynamic Plasma Membrane Domains Showing Pil1-Lsp1 Heteroligomer Binding Equilibrium
Olivera-Couto, Agustina; Salzman, Valentina; Mailhos, Milagros; Digman, Michelle A.; Gratton, Enrico; Aguilar, Pablo S.
2015-01-01
Eisosomes are plasma membrane domains concentrating lipids, transporters, and signaling molecules. In the budding yeast Saccharomyces cerevisiae, these domains are structured by scaffolds composed mainly by two cytoplasmic proteins Pil1 and Lsp1. Eisosomes are immobile domains, have relatively uniform size, and encompass thousands of units of the core proteins Pil1 and Lsp1. In this work we used fluorescence fluctuation analytical methods to determine the dynamics of eisosome core proteins at different subcellular locations. Using a combination of scanning techniques with autocorrelation analysis, we show that Pil1 and Lsp1 cytoplasmic pools freely diffuse whereas an eisosome-associated fraction of these proteins exhibits slow dynamics that fit with a binding-unbinding equilibrium. Number and brightness analysis shows that the eisosome-associated fraction is oligomeric, while cytoplasmic pools have lower aggregation states. Fluorescence lifetime imaging results indicate that Pil1 and Lsp1 directly interact in the cytoplasm and within the eisosomes. These results support a model where Pil1-Lsp1 heterodimers are the minimal eisosomes building blocks. Moreover, individual-eisosome fluorescence fluctuation analysis shows that eisosomes in the same cell are not equal domains: while roughly half of them are mostly static, the other half is actively exchanging core protein subunits. PMID:25863055
Bapat, Shweta S; Patel, Harshali K; Sansgiry, Sujit S
2017-10-16
In this study, we evaluate the role of information anxiety and information load on the intention to read information from prescription drug information leaflets (PILs). These PILs were developed based on the principals of information load and consumer information processing. This was an experimental prospective repeated measures study conducted in the United States where 360 (62% response rate) university students (>18 years old) participated. Participants were presented with a scenario followed by exposure to the three drug product information sources used to operationalize information load. The three sources were: (i) current practice; (ii) pre-existing one-page text only; and (iii) interventional one-page prototype PILs designed for the study. Information anxiety was measured as anxiety experienced by the individual when encountering information. The outcome variable of intention to read PILs was defined as the likelihood that the patient will read the information provided in the leaflets. A survey questionnaire was used to capture the data and the objectives were analyzed by performing a repeated measures MANOVA using SAS version 9.3. When compared to current practice and one-page text only leaflets, one-page PILs had significantly lower scores on information anxiety ( p < 0.001) and information load ( p < 0.001). The intention to read was highest and significantly different ( p < 0.001) for PILs as compared to current practice or text only leaflets. Information anxiety and information load significantly impacted intention to read ( p < 0.001). Newly developed PILs increased patient's intention to read and can help in improving the counseling services provided by pharmacists.
Bapat, Shweta S.; Patel, Harshali K.; Sansgiry, Sujit S.
2017-01-01
In this study, we evaluate the role of information anxiety and information load on the intention to read information from prescription drug information leaflets (PILs). These PILs were developed based on the principals of information load and consumer information processing. This was an experimental prospective repeated measures study conducted in the United States where 360 (62% response rate) university students (>18 years old) participated. Participants were presented with a scenario followed by exposure to the three drug product information sources used to operationalize information load. The three sources were: (i) current practice; (ii) pre-existing one-page text only; and (iii) interventional one-page prototype PILs designed for the study. Information anxiety was measured as anxiety experienced by the individual when encountering information. The outcome variable of intention to read PILs was defined as the likelihood that the patient will read the information provided in the leaflets. A survey questionnaire was used to capture the data and the objectives were analyzed by performing a repeated measures MANOVA using SAS version 9.3. When compared to current practice and one-page text only leaflets, one-page PILs had significantly lower scores on information anxiety (p < 0.001) and information load (p < 0.001). The intention to read was highest and significantly different (p < 0.001) for PILs as compared to current practice or text only leaflets. Information anxiety and information load significantly impacted intention to read (p < 0.001). Newly developed PILs increased patient’s intention to read and can help in improving the counseling services provided by pharmacists. PMID:29035337
Wen, Zhe; Tong, Guansheng; Liu, Yong; Meeks, Jacqui K; Ma, Daqing; Yang, Jigang
2014-05-01
The aim of this study was to analyze the imaging characteristics of (99m)Tc-dextran ((99m)Tc-DX) lymphatic imaging in the diagnosis of primary intestinal lymphangiectasia (PIL). Forty-one PIL patients were diagnosed as having PIL with the diagnosis being subsequently confirmed by laparotomy, endoscopy, biopsy, or capsule colonoscopy. Nineteen patients were male and 22 were female. A whole-body (99m)Tc-DX scan was performed at 10 min, 1 h, 3 h, and 6 h intervals after injection. The 10 min and 1 h postinjection intervals were considered the early phase, the 3 h postinjection interval was considered the middle phase, and the 6 h postinjection interval was considered the delayed phase. The imaging characteristics of (99m)Tc-DX lymphatic imaging in PIL were of five different types: (i) presence of dynamic radioactivity in the intestine, associated with radioactivity moving from the small intestine to the ascending and transverse colon; (ii) presence of delayed dynamic radioactivity in the intestine, no radioactivity or little radioactivity distributing in the intestine in the early phase, or significant radioactivity distributing in the intestine in the delayed phase; (iii) radioactivity distributing in the intestine and abdominal cavity; (iv) radioactivity distributing only in the abdominal cavity with no radioactivity in the intestines; and (v) no radioactivity distributing in the intestine and abdominal activity. (99m)Tc-DX lymphatic imaging in PIL showed different imaging characteristics. Caution should be exercised in the diagnosis of PIL using lymphoscintigraphy. Lymphoscintigraphy is a safe and accurate examination method and is a significant diagnostic tool in the diagnosis of PIL.
Primary intestinal lymphangiectasia (Waldmann's disease).
Vignes, Stéphane; Bellanger, Jérôme
2008-02-22
Primary intestinal lymphangiectasia (PIL) is a rare disorder characterized by dilated intestinal lacteals resulting in lymph leakage into the small bowel lumen and responsible for protein-losing enteropathy leading to lymphopenia, hypoalbuminemia and hypogammaglobulinemia. PIL is generally diagnosed before 3 years of age but may be diagnosed in older patients. Prevalence is unknown. The main symptom is predominantly bilateral lower limb edema. Edema may be moderate to severe with anasarca and includes pleural effusion, pericarditis or chylous ascites. Fatigue, abdominal pain, weight loss, inability to gain weight, moderate diarrhea or fat-soluble vitamin deficiencies due to malabsorption may also be present. In some patients, limb lymphedema is associated with PIL and is difficult to distinguish lymphedema from edema. Exsudative enteropathy is confirmed by the elevated 24-h stool alpha1-antitrypsin clearance. Etiology remains unknown. Very rare familial cases of PIL have been reported. Diagnosis is confirmed by endoscopic observation of intestinal lymphangiectasia with the corresponding histology of intestinal biopsy specimens. Videocapsule endoscopy may be useful when endoscopic findings are not contributive. Differential diagnosis includes constrictive pericarditis, intestinal lymphoma, Whipple's disease, Crohn's disease, intestinal tuberculosis, sarcoidosis or systemic sclerosis. Several B-cell lymphomas confined to the gastrointestinal tract (stomach, jejunum, midgut, ileum) or with extra-intestinal localizations were reported in PIL patients. A low-fat diet associated with medium-chain triglyceride supplementation is the cornerstone of PIL medical management. The absence of fat in the diet prevents chyle engorgement of the intestinal lymphatic vessels thereby preventing their rupture with its ensuing lymph loss. Medium-chain triglycerides are absorbed directly into the portal venous circulation and avoid lacteal overloading. Other inconsistently effective treatments have been proposed for PIL patients, such as antiplasmin, octreotide or corticosteroids. Surgical small-bowel resection is useful in the rare cases with segmental and localized intestinal lymphangiectasia. The need for dietary control appears to be permanent, because clinical and biochemical findings reappear after low-fat diet withdrawal. PIL outcome may be severe even life-threatening when malignant complications or serous effusion(s) occur.
Primary intestinal lymphangiectasia (Waldmann's disease)
Vignes, Stéphane; Bellanger, Jérôme
2008-01-01
Primary intestinal lymphangiectasia (PIL) is a rare disorder characterized by dilated intestinal lacteals resulting in lymph leakage into the small bowel lumen and responsible for protein-losing enteropathy leading to lymphopenia, hypoalbuminemia and hypogammaglobulinemia. PIL is generally diagnosed before 3 years of age but may be diagnosed in older patients. Prevalence is unknown. The main symptom is predominantly bilateral lower limb edema. Edema may be moderate to severe with anasarca and includes pleural effusion, pericarditis or chylous ascites. Fatigue, abdominal pain, weight loss, inability to gain weight, moderate diarrhea or fat-soluble vitamin deficiencies due to malabsorption may also be present. In some patients, limb lymphedema is associated with PIL and is difficult to distinguish lymphedema from edema. Exsudative enteropathy is confirmed by the elevated 24-h stool α1-antitrypsin clearance. Etiology remains unknown. Very rare familial cases of PIL have been reported. Diagnosis is confirmed by endoscopic observation of intestinal lymphangiectasia with the corresponding histology of intestinal biopsy specimens. Videocapsule endoscopy may be useful when endoscopic findings are not contributive. Differential diagnosis includes constrictive pericarditis, intestinal lymphoma, Whipple's disease, Crohn's disease, intestinal tuberculosis, sarcoidosis or systemic sclerosis. Several B-cell lymphomas confined to the gastrointestinal tract (stomach, jejunum, midgut, ileum) or with extra-intestinal localizations were reported in PIL patients. A low-fat diet associated with medium-chain triglyceride supplementation is the cornerstone of PIL medical management. The absence of fat in the diet prevents chyle engorgement of the intestinal lymphatic vessels thereby preventing their rupture with its ensuing lymph loss. Medium-chain triglycerides are absorbed directly into the portal venous circulation and avoid lacteal overloading. Other inconsistently effective treatments have been proposed for PIL patients, such as antiplasmin, octreotide or corticosteroids. Surgical small-bowel resection is useful in the rare cases with segmental and localized intestinal lymphangiectasia. The need for dietary control appears to be permanent, because clinical and biochemical findings reappear after low-fat diet withdrawal. PIL outcome may be severe even life-threatening when malignant complications or serous effusion(s) occur. PMID:18294365
Patel, Harshali K; Bapat, Shweta S; Bhansali, Archita H; Sansgiry, Sujit S
2018-01-01
The objective of this study was to develop a one-page (1-page) prescription drug information leaflet (PILs) and assess their impact on the information processing variables, across 2 levels of patient involvement. One-page PILs were developed using cognitive principles to lower mental effort and improve comprehension. An experimental, 3 × 2 repeated measures study was conducted to determine the impact of cognitive effort, manipulated using leaflet type on comprehension across 2 levels (high/low) of patient involvement. Adults (≥18 years) in a university setting in Houston were recruited for the study. Each participant was exposed to 3 different types of prescription drug information leaflet (the current practice, preexisting 1-page text-only, and 1-page PILs) for the 3 drugs (Celebrex, Ventolin HFA, Prezista) for a given involvement scenario. A prevalidated survey instrument was used to measure product knowledge, attitude toward leaflet, and intention to read. Multivariate analysis of variance indicated significant positive effect of cognitive effort, involvement, and their interaction effect across all measured variables. Mean scores for product knowledge, attitude toward leaflet, and intention to read were highest for PILs ( P < .001), indicating that PILs exerted lowest cognitive effort. Univariate and post hoc analysis indicate that product knowledge significantly increases with high involvement. Patients reading PILs have higher comprehension compared with the current practice and text-only prototype leaflets evaluated. Higher levels of involvement further improve participant knowledge about the drug, increase their intention to read the leaflet, and change their attitude toward the leaflet. Implementation of PILs would improve information processing for consumers by reducing their cognitive effort.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bateman, Adam P.; Nizkorodov, Serguei; Laskin, Julia
2010-10-01
This work demonstrates the utility of a particle-into-liquid sampler (PILS) a technique traditionally used for identification of inorganic ions present in ambient or laboratory aerosols for the analysis of water soluble organic aerosol (OA) using high resolution electrospray ionization mass spectrometry (HR ESI-MS). Secondary organic aerosol (SOA) was produced from 0.5 ppm mixing ratios of limonene and ozone in a 5 m3 Teflon chamber. SOA was collected simultaneously using a traditional filter sampler and a PILS. The filter samples were later extracted with either water or acetonitrile, while the aqueous PILS samples were analyzed directly. In terms of peak intensities,more » types of detectable compounds, average O:C ratios, and organic mass to organic carbon ratios, the resulting high resolution mass spectra were essentially identical for the PILS and filter based samples. SOA compounds extracted from both filter/acetonitrile extraction and PILS/water extraction accounted for >95% of the total ion current in ESI mass spectra. This similarity was attributed to high solubility of limonene SOA in water. In contrast, significant differences in detected ions and peak abundances were observed for pine needle biomass burning organic aerosol (BBOA) collected with PILS and filter sampling. The water soluble fraction of BBOA is considerably smaller than for SOA, and a number of unique peaks were detectable only by the filter/acetonitrile method. The combination of PILS collection with HR-ESI-MS analysis offers a new approach for molecular analysis of the water-soluble organic fraction in biogenic SOA, aged photochemical smog, and BBOA.« less
Non-Invasive Gene Therapy of Experimental Parkinson’s Disease
2004-09-01
20 is lethal (7). The hydro- dynamic method involves the rapid intravenous injection of a Weekly Intravenous Gene Therapy volume of saline greater...PILs do not aggregate in saline and have prolonged the TH expression plasmid DNA encapsulated in either the blood residence times (11). PILs have been...weeks. A third control group of rats was treated with brain cancer (12), and PILs have been given to rats for the saline , treatment of experimental
Linear and Star Poly(ionic liquid) Assemblies: Surface Monolayers and Multilayers.
Erwin, Andrew J; Xu, Weinan; He, Hongkun; Matyjaszewski, Krzysztof; Tsukruk, Vladimir V
2017-04-04
The surface morphology and organization of poly(ionic liquid)s (PILs), poly[1-(4-vinylbenzyl)-3-butylimidazolium bis(trifluoromethylsulfonyl)imide] are explored in conjunction with their molecular architecture, adsorption conditions, and postassembly treatments. The formation of stable PIL Langmuir and Langmuir-Blodgett (LB) monolayers at the air-water and air-solid interfaces is demonstrated. The hydrophobic bis(trifluoromethylsulfonyl)imide (Tf 2 N - ) is shown to be a critical agent governing the assembly morphology, as observed in the reversible condensation of LB monolayers into dense nanodroplets. The PIL is then incorporated as an unconventional polyelectrolyte component in the layer-by-layer (LbL) films of hydrophobic character. We demonstrate that the interplay of capillary forces, macromolecular mobility, and structural relaxation of the polymer chains influence the dewetting mechanisms in the PIL multilayers, thereby enabling access to a diverse set of highly textured, porous, and interconnected network morphologies for PIL LbL films that would otherwise be absent in conventional LbL films. Their compartmentalized internal structure is relevant to molecular separation membranes, ultrathin hydrophobic coatings, targeted cargo delivery, and highly conductive films.
Additional Antiepileptic Mechanisms of Levetiracetam in Lithium-Pilocarpine Treated Rats
Al-Shorbagy, Muhammad Y.; El Sayeh, Bahia M.; Abdallah, Dalaal M.
2013-01-01
Several studies have addressed the antiepileptic mechanisms of levetiracetam (LEV); however, its effect on catecholamines and the inflammatory mediators that play a role in epilepsy remain elusive. In the current work, lithium (Li) pretreated animals were administered LEV (500 mg/kg i.p) 30 min before the induction of convulsions by pilocarpine (PIL). Li-PIL-induced seizures were accompanied by increased levels of hippocampal prostaglandin (PG) E2, myeloperoxidase (MPO), tumor necrosis factor-α, and interleukin-10. Moreover, it markedly elevated hippocampal lipid peroxides and nitric oxide levels, while it inhibited the glutathione content. Li-PIL also reduced hippocampal noradrenaline, as well as dopamine contents. Pretreatment with LEV protected against Li-PIL-induced seizures, where it suppressed the severity and delayed the onset of seizures in Li-PIL treated rats. Moreover, LEV reduced PGE2 and MPO, yet it did not affect the level of both cytokines in the hippocampus. LEV also normalized hippocampal noradrenaline, dopamine, glutathione, lipid peroxides, and nitric oxide contents. In conclusion, alongside its antioxidant property, LEV anticonvulsive effect involves catecholamines restoration, as well as inhibition of PGE2, MPO, and nitric oxide. PMID:24098559
NASA Astrophysics Data System (ADS)
Weyman, Alexander; Bier, Markus; Holm, Christian; Smiatek, Jens
2018-05-01
We study generic properties of poly(ionic liquid)s (PILs) via coarse-grained molecular dynamics simulations in bulk solution and under confinement. The influence of different side chain lengths on the spatial properties of the PIL systems and on the ionic transport mechanism is investigated in detail. Our results reveal the formation of apolar and polar nanodomains with increasing side chain length in good agreement with previous results for molecular ionic liquids. The ion transport numbers are unaffected by the occurrence of these domains, and the corresponding values highlight the potential role of PILs as single-ion conductors in electrochemical devices. In contrast to bulk behavior, a pronounced formation of ion conductivity channels in confined systems is initiated in close vicinity to the boundaries. We observe higher ion conductivities in these channels for increasing PIL side chain lengths in comparison with bulk values and provide an explanation for this effect. The appearance of these domains points to an improved application of PILs in modern polymer electrolyte batteries.
High-performance supercapacitors based on poly(ionic liquid)-modified graphene electrodes.
Kim, Tae Young; Lee, Hyun Wook; Stoller, Meryl; Dreyer, Daniel R; Bielawski, Christopher W; Ruoff, Rodney S; Suh, Kwang S
2011-01-25
We report a high-performance supercapacitor incorporating a poly(ionic liquid)-modified reduced graphene oxide (PIL:RG-O) electrode and an ionic liquid (IL) electrolyte (specifically, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide or EMIM-NTf(2)). PIL:RG-O provides enhanced compatibility with the IL electrolyte, thereby increasing the effective electrode surface area accessible to electrolyte ions. The supercapacitor assembled with PIL:RG-O electrode and EMIM-NTf(2) electrolyte showed a stable electrochemical response up to 3.5 V operating voltage and was capable of yielding a maximum energy density of 6.5 W·h/kg with a power density of 2.4 kW/kg. These results demonstrate the potential of the PIL:RG-O material as an electrode in high-performance supercapacitors.
NASA Astrophysics Data System (ADS)
Liu, Chengbao; Du, Peng; Nan, Feng; Zhao, Haichao; Wang, Liping
2018-06-01
Dispersion of graphene nanosheets in a water and polymer matrix has been rarely achieved due to graphene’s hydrophobicity, which thus impedes its potential anticorrosive application. In this study, stable graphene aqueous dispersion was obtained by using imidazole-based polymeric ionic liquid (PIL) as the dispersant with ultrasonic vibration. Stacked graphene sheets were exfoliated to a few layers via cation-π interaction between PIL and graphene nanosheets. Electrochemical impedance measurements were taken to investigate the anticorrosion performance of epoxy coatings with or without polymeric ionic liquid–graphene (PIL–G) hybrids. Results indicated that the PIL–G hybrid significantly enhanced the long-term protective performance of epoxy coatings, which was attributed to the synergistic effects of the corrosion-inhibitive PIL and impermeable graphene nanosheets.
Gorska, B; Timperman, L; Anouti, M; Béguin, F
2017-05-10
The effect of low water content (<20, 150, 1000, 10 000 ppm) in triethylammonium bis[(trifluoromethyl)sulfonyl]imide - [(C 2 H 5 ) 3 N + H][TFSI - ] - protic ionic liquid (PIL) on the performance of activated carbon (AC) electrodes as well as AC/AC electrochemical capacitors (ECs) is reported. Under negative polarization, hydrogen electrosorption onto carbon is enhanced along with the increase of water content in PIL, whereas the resulting desorption peaks are shifted to lower potential values, evidencing lower sorption energy when hydrogen is stored from moisture containing PIL. Cyclic voltammetry (CV) investigations on PIL-based ECs demonstrated that the evolution of the Stern layer nanostructure at positive and negative potentials is asymmetrical. The results revealed comparable electrochemical performance for PIL containing 150 and 1000 ppm of H 2 O, due to similar operation of the positive electrode, where [TFSI - ] anions are adsorbed in the outer Helmholtz plane, and the negative one, where hydrogen is stored through the reduction of the intermediate hydronium cation. By contrast, a cell with "dry" PIL (<20 ppm of water) displayed a distinctive operation due to hydrogen electrosorption directly through reduction of the protonated cation, and selective adsorption of [TFSI - ] anions, which occurs thanks to the high polarizability and image force (IF) created by their induced charge. Galvanostatic cycling with potential limitation (GCPL) showed comparable capacitance values whatever the water content in PILs up to 1000 ppm, yet electrochemical impedance spectroscopy (EIS) revealed higher capacitance as well as better retention at higher frequencies with the PIL containing 150 ppm of water. Hence, 150 ppm is reasoned to be an optimal value for diffusion and adsorption of ions. The nature of current collectors (aluminum or stainless steel) has a determining role in their polarization behavior, and consequently the potential range of electrodes as well as ion diffusion into the activated carbon porosity, influencing the observed capacitance values (C EIS/2.0V : 170 vs. 128 F g -1 , for Al and SSt, respectively).
Cappell, Mitchell S; Edhi, Ahmed; Amin, Mitual
2018-01-01
Primary intestinal lymphangiectasia (PIL) is a rare, presumably congenital lesion that is usually diagnosed in patients < 3 years old, is rarely first diagnosed in adulthood, and when first diagnosed in adulthood typically presents with symptoms for many years. Although PIL is often identified by endoscopic abnormalities, it must be emphasized that the jejunoileum/distal duodenum must be intubated for diagnosis because the lesions are present in these regions. This work demonstrates that 1)-PIL can occur in an octogenarian; 2)-shows that the characteristic endoscopic findings are not found at colonoscopy without terminal ileal intubation; and 3)-may be missed at standard EGD without distal duodenal intubation. A patient initially presented at age 83 with symptoms of watery diarrhea, abdominal distention, 5-Kg-weight-gain, and weakness for one month, and had typical clinical findings of PIL including chylous ascites, pleural effusions, bilateral pitting leg edema, hypoalbuminemia, borderline lymphopenia, hypovitaminosis-D, and hypocalcemia. Protein-losing-enteropathy was demonstrated by positive stool tests for alpha-1-antitrypsin. Standard colonoscopy revealed no significant lesions, but terminal ileal intubation during colonoscopy demonstrated creamy-white, punctate, mucosal lesions in terminal ileum, characteristic of lymphangiectasia. EGD with intubation to mid-descending duodenum revealed no significant lesions, but subsequent enteroscopy demonstrated lesions in distal duodenum/proximal jejunum similar to those in terminal ileum characteristic of lymphangiectasia. Histopathologic analysis of lesions of terminal ileum/distal duodenum demonstrated dilated mucosal vessels, confirmed as lymphatic vessels by immunohistochemistry. PIL was diagnosed after excluding secondary causes of intestinal lymphangiectasia. Patient placed on standard PIL diet: oral supplements of medium-chain triglycerides, a high protein diet, supplements of fat-soluble vitamins, and avoiding long-chain fatty acids, with marked clinical improvement. This work shows that: 1)-standard EGD and colonoscopy may miss characteristic lesions of PIL, 2)-enteroscopy or terminal ileal intubation at colonoscopy may be required for the diagnosis because lesions are typically located in distal duodenum/jejunoileum; and 3)-PIL can first present in the very elderly even with symptoms of short duration. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.
Cappell, Mitchell S.; Edhi, Ahmed; Amin, Mitual
2018-01-01
Abstract Rationale: Primary intestinal lymphangiectasia (PIL) is a rare, presumably congenital lesion that is usually diagnosed in patients < 3 years old, is rarely first diagnosed in adulthood, and when first diagnosed in adulthood typically presents with symptoms for many years. Although PIL is often identified by endoscopic abnormalities, it must be emphasized that the jejunoileum/distal duodenum must be intubated for diagnosis because the lesions are present in these regions. This work demonstrates that 1)-PIL can occur in an octogenarian; 2)-shows that the characteristic endoscopic findings are not found at colonoscopy without terminal ileal intubation; and 3)-may be missed at standard EGD without distal duodenal intubation. Diagnoses: A patient initially presented at age 83 with symptoms of watery diarrhea, abdominal distention, 5-Kg-weight-gain, and weakness for one month, and had typical clinical findings of PIL including chylous ascites, pleural effusions, bilateral pitting leg edema, hypoalbuminemia, borderline lymphopenia, hypovitaminosis-D, and hypocalcemia. Protein-losing-enteropathy was demonstrated by positive stool tests for alpha-1-antitrypsin. Standard colonoscopy revealed no significant lesions, but terminal ileal intubation during colonoscopy demonstrated creamy-white, punctate, mucosal lesions in terminal ileum, characteristic of lymphangiectasia. EGD with intubation to mid-descending duodenum revealed no significant lesions, but subsequent enteroscopy demonstrated lesions in distal duodenum/proximal jejunum similar to those in terminal ileum characteristic of lymphangiectasia. Histopathologic analysis of lesions of terminal ileum/distal duodenum demonstrated dilated mucosal vessels, confirmed as lymphatic vessels by immunohistochemistry. PIL was diagnosed after excluding secondary causes of intestinal lymphangiectasia. Interventions/Outcomes: Patient placed on standard PIL diet: oral supplements of medium-chain triglycerides, a high protein diet, supplements of fat-soluble vitamins, and avoiding long-chain fatty acids, with marked clinical improvement. Lessons: This work shows that: 1)-standard EGD and colonoscopy may miss characteristic lesions of PIL, 2)-enteroscopy or terminal ileal intubation at colonoscopy may be required for the diagnosis because lesions are typically located in distal duodenum/jejunoileum; and 3)-PIL can first present in the very elderly even with symptoms of short duration. PMID:29505002
Identification of Surprisingly Diverse Type IV Pili, across a Broad Range of Gram-Positive Bacteria
Roos, David S.; Pohlschröder, Mechthild
2011-01-01
Background In Gram-negative bacteria, type IV pili (TFP) have long been known to play important roles in such diverse biological phenomena as surface adhesion, motility, and DNA transfer, with significant consequences for pathogenicity. More recently it became apparent that Gram-positive bacteria also express type IV pili; however, little is known about the diversity and abundance of these structures in Gram-positives. Computational tools for automated identification of type IV pilins are not currently available. Results To assess TFP diversity in Gram-positive bacteria and facilitate pilin identification, we compiled a comprehensive list of putative Gram-positive pilins encoded by operons containing highly conserved pilus biosynthetic genes (pilB, pilC). A surprisingly large number of species were found to contain multiple TFP operons (pil, com and/or tad). The N-terminal sequences of predicted pilins were exploited to develop PilFind, a rule-based algorithm for genome-wide identification of otherwise poorly conserved type IV pilins in any species, regardless of their association with TFP biosynthetic operons (http://signalfind.org). Using PilFind to scan 53 Gram-positive genomes (encoding >187,000 proteins), we identified 286 candidate pilins, including 214 in operons containing TFP biosynthetic genes (TBG+ operons). Although trained on Gram-positive pilins, PilFind identified 55 of 58 manually curated Gram-negative pilins in TBG+ operons, as well as 53 additional pilin candidates in operons lacking biosynthetic genes in ten species (>38,000 proteins), including 27 of 29 experimentally verified pilins. False positive rates appear to be low, as PilFind predicted only four pilin candidates in eleven bacterial species (>13,000 proteins) lacking TFP biosynthetic genes. Conclusions We have shown that Gram-positive bacteria contain a highly diverse set of type IV pili. PilFind can be an invaluable tool to study bacterial cellular processes known to involve type IV pilus-like structures. Its use in combination with other currently available computational tools should improve the accuracy of predicting the subcellular localization of bacterial proteins. PMID:22216142
Pili of oral Streptococcus sanguinis bind to fibronectin and contribute to cell adhesion.
Okahashi, Nobuo; Nakata, Masanobu; Sakurai, Atsuo; Terao, Yutaka; Hoshino, Tomonori; Yamaguchi, Masaya; Isoda, Ryutaro; Sumitomo, Tomoko; Nakano, Kazuhiko; Kawabata, Shigetada; Ooshima, Takashi
2010-01-08
Streptococcus sanguinis is a predominant bacterium in the human oral cavity and occasionally causes infective endocarditis. We identified a unique cell surface polymeric structure named pili in this species and investigated its functions in regard to its potential virulence. Pili of S. sanguinis strain SK36 were shown to be composed of three distinctive pilus proteins (PilA, PilB, and PilC), and a pili-deficient mutant demonstrated reduced bacterial adherence to HeLa and human oral epithelial cells. PilC showed a binding ability to fibronectin, suggesting that pili are involved in colonization by this species. In addition, ATCC10556, a standard S. sanguinis strain, was unable to produce pili due to defective pilus genes, which indicates a diversity of pilus expression among various S. sanguinis strains. Copyright 2009 Elsevier Inc. All rights reserved.
[Drug information for patients (Package Leaflets), and user testing in EU].
Yamamoto, Michiko; Doi, Hirohisa; Furukawa, Aya
2015-01-01
Patients and consumers have desired high quality drug information in their pharmacotherapy, and are entitled to receive it. It is desirable that the information should be aimed at shared decision-making between patients and healthcare professionals about medications. The quality of drug information available to patients should also be assured. With an aim to improve the quality of "Drug Guide for Patients", we investigated Patient Information Leaflets (PILs) which are approved by the Medicines and Healthcare Products Regulatory Agency (MHRA) in the United Kingdom (UK) with regard to the criteria of development and user testing for assuring the quality of the PILs. In the European Union (EU), these are called Package Leaflets (PLs). PILs have been a legal requirement in the UK since 1999 for all medications. The user testing of PILs has been implemented as evidence since 2005 so that people can rely on the information provided in the leaflet. Execution of PILs which follow the guidance of the user testing, according to the guidance of this user testing, would reflect the views of patients. Here, we introduce the development process and implementation of user testing of PILs. In terms of readability, accessibility and understandability of drug information for patients, we need to discuss involving the public in decisions on how its quality should be assured and how it can be made easily be comprehensible for patients, in order to make effective use of "Drug Guide for Patients" in the future in Japan.
Yu, Honglian; Merib, Josias; Anderson, Jared L
2016-03-18
Neat crosslinked polymeric ionic liquid (PIL) sorbent coatings for solid-phase microextraction (SPME) compatible with high-performance liquid chromatography (HPLC) are reported for the first time. Six structurally different PILs were crosslinked to nitinol supports and applied for the determination of select pharmaceutical drugs, phenolics, and insecticides. Sampling conditions including sample solution pH, extraction time, desorption solvent, desorption time, and desorption solvent volume were optimized using design of experiment (DOE). The developed PIL sorbent coatings were stable when performing extractions under acidic pH and remained intact in various organic desorption solvents (i.e., methanol, acetonitrile, acetone). The PIL-based sorbent coating polymerized from the IL monomer 1-vinyl-3-(10-hydroxydecyl) imidazolium chloride [VC10OHIM][Cl] and IL crosslinker 1,12-di(3-vinylbenzylimidazolium) dodecane dichloride [(VBIM)2C12] 2[Cl] exhibited superior extraction performance compared to the other studied PILs. The extraction efficiency of pharmaceutical drugs and phenolics increased when the film thickness of the PIL-based sorbent coating was increased while many insecticides were largely unaffected. Satisfactory analytical performance was obtained with limits of detection (LODs) ranging from 0.2 to 2 μg L(-1) for the target analytes. The accuracy of the analytical method was examined by studying the relative recovery of analytes in real water samples, including tap water and lake water, with recoveries varying from 50.2% to 115.9% and from 48.8% to 116.6%, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Wijaya, Emmy C.; Separovic, Frances; Drummond, Calum J.; Greaves, Tamar L.
2018-05-01
There has been a substantial increase in enzyme applications within the biochemical and pharmaceutical industries, for example, as industrial biocatalysts. However, enzymes have narrow marginal stability which makes them prone to become inactive and/or denature with a slight change in the solvent environment. Typically industrial applications require harsher solvent environments than enzyme native environments, and hence there is a need to understand solvent-protein interactions in order to develop strategies to maintain, or enhance, the enzymatic activity under industrially relevant solvent conditions. Previously we have shown that protic ionic liquids (PILs) with water can have a stabilising effect on lysozyme, with a large variation dependent on which PIL ions are present, and the water concentration [E. C. Wijaya et al., Phys. Chem. Chem. Phys. 18(37), 25926-25936 (2016)]. Here we extend on this work using non-stoichiometric aqueous PIL solvents to investigate, and isolate, the role of pH and ionicity on enzymes. We have used the PILs ethylammonium nitrate (EAN) and ethanolammonium formate (EOAF) since our previous work has identified these as good solvents for lysozyme. Solvent libraries were made from these two PILs with an additional precursor acid or base to modify the acidity/basicity of the neutral stoichiometric PIL, and with water added, to have solutions with 4-17 mol. % of the PIL ions in water. Molar ratios of base:acid were varied between 1:1.05 and 2:1 for EAN and 1:1.25 and 2:1 for EOAF, which enabled from highly basic to highly acidic solutions to be obtained. This was to modify the acidity/basicity of the neutral stoichiometric PILs, without the addition of buffers. The structure and stability of hen egg white lysozyme (HEWL) were explored under these solvent conditions using synchrotron small angle X-ray scattering (SAXS), Fourier transform infrared (FTIR), and activity assays. The radius of gyration and Kratky plots obtained from the SAXS data showed little change with varying ionicity or acid:base ratio. FTIR showed that α-helix was maintained in all, except for the most acidic solvent conditions. The activity data show that HEWL was active between pH 0 and 11 for the EA:N-water system and pH 4.4 and 11 for the EOA:F-water system. This work indicates that ionic liquids have the potential to enable enzymes to maintain activity across a broader range of solvent conditions.
Zheng, Zhiqiang; Xu, Qiming; Guo, Jiangna; Qin, Jing; Mao, Hailei; Wang, Bin; Yan, Feng
2016-05-25
The structure-antibacterial activity relationship between the small molecular compounds and polymers are still elusive. Here, imidazolium-type ionic liquid (IL) monomers and their corresponding poly(ionic liquids) (PILs) and poly(ionic liquid) membranes were synthesized. The effect of chemical structure, including carbon chain length of substitution at the N3 position and charge density of cations (mono- or bis-imidazolium) on the antimicrobial activities against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was investigated by determination of minimum inhibitory concentration (MIC). The antibacterial activities of both ILs and PILs were improved with the increase of the alkyl chain length and higher charge density (bis-cations) of imidazolium cations. Moreover, PILs exhibited lower MIC values relative to the IL monomers. However, the antibacterial activities of PIL membranes showed no correlation to those of their analogous small molecule IL monomers and PILs, which increased with the charge density (bis-cations) while decreasing with the increase of alkyl chain length. The results indicated that antibacterial property studies on small molecules and homopolymers may not provide a solid basis for evaluating that in corresponding polymer membranes.
Fage-Butler, Antoinette
2013-01-01
The purpose of this paper is to present an evaluative model of patient-centredness for text and to illustrate how this can be applied to patient information leaflets (PILs) that accompany medication in the European Union. Patients have criticized PILs for sidelining their experiences, knowledge and affective needs, and denying their individuality. The health communication paradigm of patient-centredness provides valuable purchase on these issues, taking its starting point in the dignity and integrity of the patient as a person. Employing this evaluative model involves two stages. First, a Foucauldian Discourse Analysis is performed of sender and receiver and of the main discourses in PILs. These aspects are then evaluated using the perspectives of patient-centredness theory relating to the medical practitioner, patient and content. The evaluative model is illustrated via a PIL for medication for depression and panic attacks. Evaluation reveals a preponderance of biomedical statements, with a cluster of patient-centred statements primarily relating to the construction of the patient. The paper contributes a new method and evaluative approach to PIL and qualitative health research, as well as outlining a method that facilitates the investigation of interdiscursivity, a recent focus of critical genre analysis.
Pain pathways involved in fear conditioning measured with fear-potentiated startle: lesion studies.
Shi, C; Davis, M
1999-01-01
It is well established that the basolateral amygdala is critically involved in the association between an unconditioned stimulus (US), such as a foot shock, and a conditioned stimulus (CS), such as a light, during classic fear conditioning. However, little is known about how the US (pain) inputs are relayed to the basolateral amygdala. The present studies were designed to define potential US pathways to the amygdala using lesion methods. Electrolytic lesions before or after training were placed in caudal granular/dysgranular insular cortex (IC) alone or in conjunction with the posterior intralaminar nuclei of the thalamus (PoT/PIL), and the effects on fear conditioning were examined. Pretraining lesions of both IC and PoT/PIL, but not lesions of IC alone, blocked the acquisition of fear-potentiated startle. However, post-training combined lesions of IC and PoT/PIL did not prevent expression of conditioned fear. Given that previous studies have shown that lesions of PoT/PIL alone had no effect on acquisition of conditioned fear, these results suggest that two parallel cortical (insula-amygdala) and subcortical (PoT/PIL-amygdala) pathways are involved in relaying shock information to the basolateral amygdala during fear conditioning.
DOE Office of Scientific and Technical Information (OSTI.GOV)
He, Hongkun; Zhong, Mingjiang; Adzima, Brian
2013-03-20
Poly(ionic liquid)s (PILs) are an important class of technologically relevant materials. However, characterization of well-defined polyionic materials remains a challenge. Herein, we have developed a simple and versatile gel permeation chromatography (GPC) methodology for molecular weight (MW) characterization of PILs with a variety of anions. PILs with narrow MW distributions were synthesized via atom transfer radical polymerization, and the MWs obtained from GPC were further confirmed via nuclear magnetic resonance end group analysis.
Cagliero, Cecilia; Ho, Tien D; Zhang, Cheng; Bicchi, Carlo; Anderson, Jared L
2016-06-03
This study describes a simple and rapid sampling method employing a polymeric ionic liquid (PIL) sorbent coating in direct immersion solid-phase microextraction (SPME) for the trace-level analysis of acrylamide in brewed coffee and coffee powder. The crosslinked PIL sorbent coating demonstrated superior sensitivity in the extraction of acrylamide compared to all commercially available SPME coatings. A spin coating method was developed to evenly distribute the PIL coating on the SPME support and reproducibly produce fibers with a large film thickness. Ninhydrin was employed as a quenching reagent during extraction to inhibit the production of interfering acrylamide. The PIL fiber produced a limit of quantitation for acrylamide of 10μgL(-1) and achieved comparable results to the ISO method in the analysis of six coffee powder samples. Copyright © 2016 Elsevier B.V. All rights reserved.
Ishida, Riichiro
2012-08-09
The human prefrontal lobe is more evolved than those of other mammals. As such, every person has an innate need to establish a meaningful life, often referred to as "Purpose in life (PIL)/ikigai", using the functioning of their prefrontal lobes. PIL/ikigai psychologically, and the prefrontal lobe physiologically, have common functions such as ambition, regulating emotion, and integrating psychological events. PIL/ikigai contributes to a decrease in anxiety influenced by a need for approval from others and stimulates pleasure and comfort, which may be related to the well-balanced secretion of neurotransmitters such as serotonin, dopamine, and ?-endorphin. Thus, a stutterer feels stress, i.e., anxiety, caused by perceived failure when engaging in conversations with others, which may be related to an imbalanced secretion of serotonin and dopamine. Therefore, previous work has suggested that PIL/ikigai may decrease anxiety in stutterers by decreasing the symptoms associated with stuttering.
Health literacy and the clozapine patient.
Brosnan, Susan; Barron, Elizabeth; Sahm, L J
2012-01-01
To estimate the prevalence of limited health literacy in patients receiving clozapine for schizophrenia. To develop and produce a pharmacist-designed clozapine patient information leaflet (PIL) which has a higher readability score than the company-produced PIL. This was a cross sectional prevalence study. Ethical approval for the study was granted by the local ethics committee. Patients, over 18 years, attending the Clozapine Clinic of a Cork urban teaching hospital, were asked to participate in the study. Demographics such as gender, age, employment and smoking status, were gathered from all participants. The total daily clozapine dose, duration of clozapine treatment, and information regarding the clozapine DVD was also noted. The Rapid Estimate of Adult Literacy in Medicine (REALM) health literacy (HL) screening tool was then administered to each patient. A user-friendly PIL on clozapine was designed by the pharmacist, which was assessed for readability and compared to the company-produced PIL using the FRES and FKGL. Data were analysed using SPSS Version 15. Forty patients (65% male, 95% unemployed and 70% smokers) of average age 38.0 years (+/- 11.2) completed the REALM. The average score was 60.6 (+/- 8.7). Twenty-nine patients (72.5%) were found to have "adequate" health literacy. The remaining eleven patients were found to have either "marginal" or "low" health literacy. The pharmacist-designed PIL would have been readable by 95% of the study population, in contrast to 72.5% with the company-designed PIL. More than a quarter of the population were found to have marginal or low health literacy. Patient information should be matched to the health literacy level of the target population.
B-1 Systems Approach to Training. Control and Display Catalog and Action Verb Thesaurus
1975-07-01
LATITUDE SET SWITCH LAI SET MOVING SCALL KNCb WING-SWEEP SURFACE POS INO RUDDER POSITION INDICATOR STAbiLlZER FOSllION...CUPILOT FClÜ40 2Cb SEN«>ITW£ ALT LCALl INDtX-PIL FLIL^UIK M^ITIVE ALT i>CALb MKK-PIL FC104L1C9 ,-’ StNSITIVl: ALT SCALL 1NÜLX LiNb...ALTUüDE i>uALL-PlL VU It AL.T1TÜÜE SCALL >tKNIb« ALT ^LALt IMUEX-PIL VLRNUK ALTITUDt SLALL-LJP VLI-NUr’ ALT SCALE
Harris, S L; Elliott, D A; Blake, M C; Must, L M; Messenger, M; Orndorff, P E
1990-01-01
The product of the pilE (also called fimH) gene is a minor component of type 1 pili in Escherichia coli. Mutants that have insertions in the pilE gene are fully piliated but unable to bind to and agglutinate guinea pig erythrocytes, a characteristic of wild-type type 1 piliated E. coli. In this paper we describe the isolation of 48 mutants with point lesions that map to the pilE gene. Such mutants were isolated by using mutT mutagenesis and an enrichment procedure devised to favor the growth of individuals that could form a pellicle in static broth containing alpha-methylmannoside, an inhibitor of erythrocyte binding and pellicle formation. Results indicated that the enrichment favored mutants expressing pilE gene products that were defective in mediating erythrocyte binding. Characterization of 12 of the mutants in greater detail revealed that certain lesions affected pilus number and length. In addition, a mutant that was temperature sensitive for erythrocyte binding was isolated and used to provide evidence that pellicle formation relies on the intercellular interaction of pilE gene products. Our results suggest a molecular explanation for the old and paradoxical observations connecting pellicle formation and erythrocyte agglutination by type 1 piliated E. coli. Images PMID:1977736
Clinical outcome of nutrition-oriented intervention for primary intestinal lymphangiectasia.
Tang, Qing-Ya; Wen, Jie; Wu, Jiang; Wang, Ying; Cai, Wei
2011-02-01
primary intestinal lymphangiectasia (PIL) is a rare digestive disease and few studies have focused on the therapeutic effect in PIL patients. This study was undertaken to evaluate nutrition-oriented intervention in children with PIL. four children with PIL were studied. Their medical records were reviewed. Anthropometric measurements and blood tests were performed during a 8-18 month follow-up. during hospitalization, the 4 patients were subjected to diet intervention. Parenteral nutrition (PN) support was also given to 3 of them. Clinical symptoms and laboratory parameters of the patients were significantly improved at discharge. After discharge, the patients continued diet control, 2 of whom received intermittent PN support. The mean follow-up duration of the 4 patients was 13 months (range, 8-18 months) and they all kept in a stable condition without symptoms relapse. Weight, height and body mass index for age were normal during the follow-up, while total protein, albumin and immunoglobulin concentrations were still slightly below normal level. nutrition therapy is effective as a valid and safe therapeutic management for PIL patients. No growth retardation was observed in the 4 children after the therapy, but they are still at risk of nutrient malabsorption. Therefore, they need long-term, regular monitoring and intensive nutritional care.
Litigation as TB Rights Advocacy: A New Delhi Case Study.
McBroom, Kerry
2016-06-01
One thousand people die every day in India as a result of TB, a preventable and treatable disease, even though the Constitution of India, government schemes, and international law guarantee available, accessible, acceptable, quality health care. Failure to address the spread of TB and to provide quality treatment to all affected populations constitutes a public health and human rights emergency that demands action and accountability. As part of a broader strategy, health activists in India employ Public Interest Litigation (PIL) to hold the state accountable for rights violations and to demand new legislation, standards for patient care, accountability for under-spending, improvements in services at individual facilities, and access to government entitlements in marginalized communities. Taking inspiration from right to health PIL cases (PILs), lawyers in a New Delhi-based rights organization used desk research, fact-findings, and the Right To Information Act to build a TB PIL for the Delhi High Court, Sanjai Sharma v. NCT of Delhi and Others (2015). The case argues that inadequate implementation of government TB schemes violates the Constitutional rights to life, health, food, and equality. Although PILs face substantial challenges, this paper concludes that litigation can be a crucial advocacy and accountability tool for people living with TB and their allies.
Litigation as TB Rights Advocacy
2016-01-01
Abstract One thousand people die every day in India as a result of TB, a preventable and treatable disease, even though the Constitution of India, government schemes, and international law guarantee available, accessible, acceptable, quality health care. Failure to address the spread of TB and to provide quality treatment to all affected populations constitutes a public health and human rights emergency that demands action and accountability. As part of a broader strategy, health activists in India employ Public Interest Litigation (PIL) to hold the state accountable for rights violations and to demand new legislation, standards for patient care, accountability for under-spending, improvements in services at individual facilities, and access to government entitlements in marginalized communities. Taking inspiration from right to health PIL cases (PILs), lawyers in a New Delhi-based rights organization used desk research, fact-findings, and the Right To Information Act to build a TB PIL for the Delhi High Court, Sanjai Sharma v. NCT of Delhi and Others (2015). The case argues that inadequate implementation of government TB schemes violates the Constitutional rights to life, health, food, and equality. Although PILs face substantial challenges, this paper concludes that litigation can be a crucial advocacy and accountability tool for people living with TB and their allies. PMID:27781000
DOE Office of Scientific and Technical Information (OSTI.GOV)
Misic, Ana M.; Satyshur, Kenneth A.; Forest, Katrina T.
Type IV pili are bacterial extracellular filaments that can be retracted to create force and motility. Retraction is accomplished by the motor protein PilT. Crystal structures of Pseudomonas aeruginosa PilT with and without bound {beta},{gamma}-methyleneadenosine-5{prime}-triphosphate have been solved at 2.6 {angstrom} and 3.1 {angstrom} resolution, respectively, revealing an interlocking hexamer formed by the action of a crystallographic 2-fold symmetry operator on three subunits in the asymmetric unit and held together by extensive ionic interactions. The roles of two invariant carboxylates, Asp Box motif Glu163 and Walker B motif Glu204, have been assigned to Mg{sup 2+} binding and catalysis, respectively. Themore » nucleotide ligands in each of the subunits in the asymmetric unit of the {beta},{gamma}-methyleneadenosine-5{prime}-triphosphate-bound PilT are not equally well ordered. Similarly, the three subunits in the asymmetric unit of both structures exhibit differing relative conformations of the two domains. The 12{sup o} and 20{sup o} domain rotations indicate motions that occur during the ATP-coupled mechanism of the disassembly of pili into membrane-localized pilin monomers. Integrating these observations, we propose a three-state 'Ready, Active, Release' model for the action of PilT.« less
A framework for the evaluation of patient information leaflets
Garner, Mark; Ning, Zhenye; Francis, Jill
2011-01-01
Abstract Background The provision of patient information leaflets (PILs) is an important part of health care. PILs require evaluation, but the frameworks that are used for evaluation are largely under‐informed by theory. Most evaluation to date has been based on indices of readability, yet several writers argue that readability is not enough. We propose a framework for evaluating PILs that reflect the central role of the patient perspective in communication and use methods for evaluation based on simple linguistic principles. The proposed framework The framework has three elements that give rise to three approaches to evaluation. Each element is a necessary but not sufficient condition for effective communication. Readability (focussing on text) may be assessed using existing well‐established procedures. Comprehensibility (focussing on reader and text) may be assessed using multiple‐choice questions based on the lexical and semantic features of the text. Communicative effectiveness (focussing on reader) explores the relationship between the emotional, cognitive and behavioural responses of the reader and the objectives of the PIL. Suggested methods for assessment are described, based on our preliminary empirical investigations. Conclusions The tripartite model of communicative effectiveness is a patient‐centred framework for evaluating PILs. It may assist the field in moving beyond readability to broader indicators of the quality and appropriateness of printed information provided to patients. PMID:21332620
Stein, Kathryn; Winters, Chelsea; Chiang, Hui-Ling
2017-05-01
Exosomes are small vesicles secreted from virtually every cell from bacteria to humans. Saccharomyces cerevisiae is a model system to study trafficking of small vesicles in response to changes in the environment. When yeast cells are grown in low glucose, vesicles carrying gluconeogenic enzymes are present as free vesicles and aggregated clusters in the cytoplasm. These vesicles are also secreted into the periplasm and account for more than 90% of total extracellular organelles, while less than 10% are larger 100-300 nm structures with unknown functions. When glucose is added to glucose-starved cells, secreted vesicles are endocytosed and then targeted to the vacuole. Recent secretomic studies indicated that more than 300 proteins involved in diverse biological functions are secreted during glucose starvation and endocytosed during glucose re-feeding. We hypothesised that extracellular vesicles are internalised using novel mechanisms independent of clathrin-mediated endocytosis. Our results showed that vesicles carrying metabolic enzymes were endocytosed at a fast rate, whereas vesicles carrying the heat shock protein Ssa1p were endocytosed at a slow rate. The PI3K regulator Vps15p is critical for the fast internalisation of extracellular vesicles. VPS15 regulates the distribution of the 100-300 nm organelles that contain the major eisosome protein Pil1p to the extracellular fraction. These Pil1p-containing structures were purified and showed unique cup-shape with their centres deeper than the peripheries. In the absence of VPS15, PIL1 or when PIL1 was mutated, the 100-300 nm structures were not observed in the extracellular fraction and the rapid internalisation of vesicles was impaired. We conclude that VPS15 regulates the distribution of the 100-300 nm Pil1p-containing organelles to the extracellular fraction required for fast endocytosis of vesicles carrying metabolic enzymes. This work provides the first evidence showing that Pil1p displayed unique distribution patterns in the intracellular and extracellular fractions. This work also demonstrates that endocytosis of vesicles is divided into a fast and a slow pathway. The fast pathway is the predominant pathway and is used by vesicles carrying metabolic enzymes. Cup-shaped Pil1p-containing structures are critical for the rapid endocytosis of vesicles into the cytoplasm. This work provides the first evidence showing that Pil1p displayed unique distribution patterns in the intracellular and extracellular fractions. This work also demonstrates that endocytosis of vesicles is divided into a fast and a slow pathway. The fast pathway is the predominant pathway and is used by vesicles carrying metabolic enzymes. Cup-shaped Pil1p-containing structures are critical for the rapid endocytosis of vesicles into the cytoplasm. © 2017 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.
Primary intestinal lymphangiectasia.
Suresh, N; Ganesh, R; Sankar, Janani; Sathiyasekaran, Malathi
2009-10-01
Primary intestinal lymphangiectasia (PIL) is a rare disease of intestinal lymphatics presenting with hypoproteinemia, bilateral lower limb edema, ascites, and protein losing enteropathy. We report a series of 4 children from Chennai, India presenting with anasarca, recurrent diarrhea, hypoproteinemia and confirmatory features of PIL on endoscopy and histopathology.
Li, Suyun; Liu, Xiaoqian; He, Yuan; Li, Qianyu; Ji, Linlin; Shen, Wenbin; Tong, Guansheng
2017-12-01
Intestinal lymphangiectasia (IL) is a rare enteropathy involving the expansion and rupture of intestinal lymphatic channels. Although several reports have studied cases of primary IL (PIL), this condition is very rare, and is even less commonly encountered in infants. This study aimed to investigate the nutritional therapy and effect assessment of chylous reflux disorder caused by PIL in infants. Infantile patients were enrolled in the Affiliated Beijing Shijitan Hospital of the Capital Medical University between January 2012 and March 2014. The minimum age of onset was 4 months and the maximum age of onset was 16 months, with an average age of 4.9 months. All children were inpatient who had been diagnosed with chylous reflux syndrome (chylothorax and/or chylic abdomen) caused by PIL. Retrospective analysis and individualized nutrition therapy of these cases were carried out. Finally, nutritional therapy and prognosis of PIL were assessed and summarized. All the children survived, showed improvement in the serum total protein, albumin, and HGB levels after nutritional therapy. After comprehensive nutritional therapy, we were able to achieve diarrhea control for all the 9 patients, and after treatment, the children passed soft, yellow stools 1 to 2 times/d. After treatment, the height and weight of all patients increased to within the normal ranges of the World Health Organization standard chart. The mean serum albumin level reached 41.3 g/L. All nutrition-related indicators were found to have significant improvement compared with the baseline levels. The results revealed that nutritional therapy for the 9 children with PIL was effective, and it may be able to improve the clinical syndromes and symptoms of children with PIL and promote recovery. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.
Nutritional therapy and effect assessment of infants with primary intestinal lymphangiectasia
Li, Suyun; Liu, Xiaoqian; He, Yuan; Li, Qianyu; Ji, Linlin; Shen, Wenbin; Tong, Guansheng
2017-01-01
Abstract Rationale: Intestinal lymphangiectasia (IL) is a rare enteropathy involving the expansion and rupture of intestinal lymphatic channels. Although several reports have studied cases of primary IL (PIL), this condition is very rare, and is even less commonly encountered in infants. This study aimed to investigate the nutritional therapy and effect assessment of chylous reflux disorder caused by PIL in infants. Patient concerns: Infantile patients were enrolled in the Affiliated Beijing Shijitan Hospital of the Capital Medical University between January 2012 and March 2014. The minimum age of onset was 4 months and the maximum age of onset was 16 months, with an average age of 4.9 months. Diagnoses: All children were inpatient who had been diagnosed with chylous reflux syndrome (chylothorax and/or chylic abdomen) caused by PIL. Interventions: Retrospective analysis and individualized nutrition therapy of these cases were carried out. Finally, nutritional therapy and prognosis of PIL were assessed and summarized. Outcomes: All the children survived, showed improvement in the serum total protein, albumin, and HGB levels after nutritional therapy. After comprehensive nutritional therapy, we were able to achieve diarrhea control for all the 9 patients, and after treatment, the children passed soft, yellow stools 1 to 2 times/d. After treatment, the height and weight of all patients increased to within the normal ranges of the World Health Organization standard chart. The mean serum albumin level reached 41.3 g/L. All nutrition-related indicators were found to have significant improvement compared with the baseline levels. Lessons: The results revealed that nutritional therapy for the 9 children with PIL was effective, and it may be able to improve the clinical syndromes and symptoms of children with PIL and promote recovery. PMID:29390480
NASA Astrophysics Data System (ADS)
Ma, Y.; Weber, R. J.; Maxwell-Meier, K.; Orsini, D. A.; Lee, Y.-N.; Huebert, B. J.; Howell, S. G.; Bertram, T.; Talbot, R. W.; Dibb, J. E.; Scheuer, E.
2004-08-01
As part of the two field studies, Transport and Chemical Evolution over the Pacific (TRACE-P) and the Asian Aerosol Characterization Experiment (ACE-Asia), the inorganic chemical composition of tropospheric aerosols was measured over the western Pacific from three separate aircraft using various methods. Comparisons are made between the rapid online techniques of the particle into liquid sampler (PILS) for measurement of a suite of fine particle a mist chamber/ion chromatograph (MC/IC) measurement of fine sulfate, and the longer time-integrated filter and micro-orifice impactor (MOI) measurements. Comparisons between identical PILS on two separate aircraft flying in formation showed that they were highly correlated (e.g., sulfate r2 of 0.95), but were systematically different by 10 ± 5% (linear regression slope and 95% confidence bounds), and had generally higher concentrations on the aircraft with a low-turbulence inlet and shorter inlet-to-instrument transmission tubing. Comparisons of PILS and mist chamber measurements of fine sulfate on two different aircraft during formation flying had an r2 of 0.78 and a relative difference of 39% ± 5%. MOI ionic data integrated to the PILS upper measurement size of 1.3 μm sampling from separate inlets on the same aircraft showed that for sulfate, PILS and MOI were within 14% ± 6% and correlated with an r2 of 0.87. Most ionic compounds were within ±30%, which is in the range of differences reported between PILS and integrated samplers from ground-based comparisons. In many cases, direct intercomparison between the various instruments is difficult due to differences in upper-size detection limits. However, for this study, the results suggest that the fine particle mass composition measured from aircraft agree to within 30-40%.
Tran, Victoria B.; Fleiszig, Suzanne M. J.; Evans, David J.; Radke, Clayton J.
2011-01-01
Flagella and pili are appendages that modulate attachment of Pseudomonas aeruginosa to solid surfaces. However, previous studies have mostly reported absolute attachment. Neither the dynamic roles of these appendages in surface association nor those of attachment phenotypes have been quantified. We used video microscopy to address this issue. Unworn, sterile, soft contact lenses were placed in a laminar-flow optical chamber. Initial lens association kinetics for P. aeruginosa strain PAK were assessed in addition to lens-surface association phenotypes. Comparisons were made to strains with mutations in flagellin (fliC) or pilin (pilA) or those in flagellum (motAB) or pilus (pilU) function. PAK and its mutants associated with the contact lens surface at a constant rate according to first-order kinetics. Nonswimming mutants associated ∼30 to 40 times slower than the wild type. PAK and its pilA mutant associated at similar rates, but each ∼4 times faster than the pilU mutant. Lens attachment by wild-type PAK induced multiple phenotypes (static, lateral, and rotational surface movement), each showing only minor detachment. Flagellin (fliC) and flagellar-motility (motAB) mutants did not exhibit surface rotation. Conversely, strains with mutations in pilin (pilA) and pilus retraction (pilU) lacked lateral-surface movement but displayed enhanced surface rotation. Slower surface association of swimming-incapable P. aeruginosa mutants was ascribed to lower convective-diffusion-arrival rates, not to an inability to adhere. Flagellum function (swimming) enhanced lens association, attachment, and rotation; hyperpiliation hindered lens association. P. aeruginosa bound through three different adhesion sites: flagellum, pili, and body. Reduction of bacterial attachment to contact lenses thus requires blockage of multiple adhesion phenotypes. PMID:21498762
Greaves, Tamar L; Kennedy, Danielle F; Weerawardena, Asoka; Tse, Nicholas M K; Kirby, Nigel; Drummond, Calum J
2011-03-10
Small- and wide-angle X-ray scattering (SWAXS) has been used to investigate the effect that water has on the nanoscale structure of protic ionic liquids (PILs) along with their precursor Brønsted acids and bases. The series of PILs consisted of primary, secondary, and tertiary alkylammonium cations in conjunction with formate, nitrate, or glycolate anions. Significant differences were observed for these systems. The nanoscale aggregates present in neat protic ionic liquids were shown to be stable in size on dilution to high concentrations of water, indicating that the water is localized in the ionic region and has little effect on the nonpolar domains. The Brønsted acid-water solutions did not display nanostructure at any water concentration. Primary amine Brønsted bases formed aggregates in water, which generally displayed characteristics of poorly structured microemulsions or a form of bicontinuous phase. Exceptions were butyl- and pentylamine with high water concentrations, for which the SWAXS patterns fitted well to the Teubner-Strey model for microemulsions. Brønsted base amines containing multiple alkyl chains or hydroxyl groups did not display nanostructure at any water concentration. IR spectroscopy was used to investigate the nature of water in the various solutions. For low PIL concentrations, the water was predominately present as bulk water for PIL molar fractions less than 0.4-0.5. At high PIL concentrations, in addition to the bulk water, there was a significant proportion of perturbed water, which is water influenced in some way by the cations and anions. The molecular state of the water in the studied amines was predominately present as bulk water, with smaller contributions from perturbed water than was seen in the PILs. © 2011 American Chemical Society
NASA Technical Reports Server (NTRS)
Ma, Y.; Weber, R. J.; Maxwell-Meier, K.; Orsini, D. A.; Lee, Y.-N.; Huebert, B. J.; Howell, S. G.; Bertram, T.; Talbot, R. W.
2003-01-01
As part of the two field studies, Transport and Chemical Evolution over the Pacific (TRACE-P), and the Asian Aerosol Characterization Experiment (ACEAsia), the inorganic chemical composition of tropospheric aerosols was measured over the western Pacific from three separate aircraft using various methods. Comparisons are made between the rapid online techniques of the Particle Into Liquid Sampler (PILS) for measurement of a suite of fine particle ionic compounds and a mist chamber (MC/IC) measurement of fine sulfate, and the longer time-integrated filter and multi-orifice impactor (MOI) measurements. Comparisons between identical PILS on two separate aircraft flying in formation showed that they were highly correlated (e.g., sulfate r(sup 2) of 0.95), but were systematically different by 10 +/- 5% (linear regression slope and 95% confidence bounds), and had generally higher concentrations on the aircraft with a low turbulence inlet and shorter inlet-to-instrument transmission tubing. Comparisons of PILS and mist chamber measurements of fine sulfate on two different aircraft during formation flying had an 3 of 0.78 and a relative difference of 39% +/- 5%. MOI ionic data integrated to the PILS upper measurement size of 1.3 pm sampling from separate inlets on the same aircraft showed that for sulfate, PILS and MOI were within 14% +/- 6% and correlated with an r(sup 2) of 0.87. Most ionic compounds were within f 30%, which is in the range of differences reported between PILS and integrated samplers from ground-based comparisons. In many cases, direct intercomparison between the various instruments is difficult due to differences in upper-size detection limits. However, for this study, the results suggest that the fine particle mass composition measured from aircraft agree to within 30-40%.
García-Alandete, Joaquín; Ros, Montserrat Cañabate; Salvador, José Heliodoro Marco; Rodríguez, Sandra Pérez
2018-03-01
The aim of this study was to analyze the psychometric properties of the Purpose-In-Life Test (PIL), as well as the age-related differences in meaning in life in women diagnosed with eating disorders. Participants were 250 Spanish women diagnosed with eating disorders who ranged from 12 to 60 years old. Confirmatory Factor Analysis, descriptive analyses, estimation of the internal consistency of the PIL, correlations between the PIL and the Beck Hopelessness Scale (BHS), Overweight Preoccupation Scale (OPS), and Body Investment Scale (BIS), and age differences were calculated. A 19-item model that showed a good fit and internal consistency, a negative correlation between the PIL and both the BHS and OPS, and a positive correlation with the BIS, as well as significant differences between the adolescents and the mature adults, were found. It would be advisable to increase the inclusion of meaning in life in psychotherapeutic interventions with women diagnosed with eating disorders. Copyright © 2017 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Rafiee, Ezzat; Shahebrahimi, Shabnam
2017-07-01
Organic-inorganic hybrid nano porous materials based on poly(ionic liquid)-polyoxometalate (PIL-POM) were reported. These hybrid materials were synthesized by the reaction of 4-vinyl pyridine with 1,3-propanesultone, followed by the polymerization and also sulfonate-functionalized cross-linked poly(4-vinylpyridine) and combining these polymers with H5PMo10V2O40 (PMo10V2). Activity of prepared PIL-PMo10V2 hybrids were investigated as catalysts for oxidation of sulfides with H2O2 as oxidant. For understanding catalytic activities of the PIL-PMo10V2 hybrids in oxidation of sulfides, effect of catalyst composition, substrate, and reaction conditions were studied. The results show that the PIL-PMo10V2 hybrids are active as selective heterogeneous catalysts for oxidation of sulfides and can be recovered and reused. The catalyst was characterized by FT-IR, TGA-DSC, XRD, SEM/EDX, BET, CV and zeta potential measurement. Also, average molecular weight of prepared catalysts were measured.
Correlating morphology to dc conductivity in polymerized ionic liquids
NASA Astrophysics Data System (ADS)
Iacob, Ciprian; Matusmoto, Atsushi; Inoue, Tadashi; Runt, James
Polymerized ionic liquids (PILs) combine the attractive mechanical characteristics of polymers and unique physico-chemical properties of low molecular weight ionic liquids in the same material. PILs have shown remarkable advantages when employed in electrochemical devices such as dye-sensitized solar cells and lithium batteries, among others. Understanding their ionic transport mechanism is the key for designing highly conductive PILs. In the current study, the correlation between morphology and charge transport in two homologous series of PILs with systematic variation of the alkyl chain length and anions is investigated using broadband dielectric spectroscopy, rheology, differential scanning calorimetry and X-ray scattering. As the alkyl chain length increases, the backbone-to-backbone separation increases, and dc-conductivity consequently decreases. The cations dominate structural dynamics since they are attached to the polymer chains, while the anions are smaller and more mobile ionic species thereby controlling the ionic conductivity. Further interpretation of decoupling of dc conductivity from the segmental relaxation enabled the correlation between polymer morphology and dc conductivity. Supported by the National Science Foundation, Polymers Program.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Balakrishna, A.M.; Saxena, A.; Mok, H. Y.-K.
The type IVb pilus of the enteropathogenic bacteria Salmonella typhi is a major adhesion factor during the entry of this pathogen into gastrointestinal epithelial cells. Its target of adhesion is a stretch of 10 residues from the first extracellular domain of cystic fibrosis transmembrane conductance regulator (CFTR). The crystal structure of the N-terminal 25 amino acid deleted S. typhi native PilS protein ({Delta}PilS), which makes the pilus, was determined at 1.9 {angstrom} resolution by the multiwavelength anomalous dispersion method. Also, the structure of the complex of {Delta}PilS and a target CFTR peptide, determined at 1.8 {angstrom}, confirms that residues 113-117more » (NKEER) of CFTR are involved in binding with the pilin protein and gives us insight on the amino acids that are essential for binding. Furthermore, we have also explored the role of a conserved disulfide bridge in pilus formation. The subunit structure and assembly architecture are crucial for understanding pilus functions and designing suitable therapeutics against typhoid.« less
An, Jiwoo; Anderson, Jared L
2018-05-15
A double-confined polymeric ionic liquid (PIL) sorbent coating was fabricated for the determination of nine ultraviolet (UV) filters in sample solutions containing high salt content by direct immersion solid-phase microextraction (DI-SPME) coupled to high-performance liquid chromatography (HPLC). The IL monomer and crosslinker cations and anions, namely, 1-vinyl-3-decylimidazolium styrenesulfonate ([VImC 10 ][SS]) and 1,12-di(3-vinylbenzylimidazolium) dodecane distyrenesulfonate ([(VBIm) 2 C 12 ] 2[SS]), were co-polymerized to create a highly stable sorbent coating which allowed for up to 120 direct-immersion extractions in 25% NaCl (w/v) solution without a decrease in its extraction capability. Extraction and desorption parameters such as desorption solvent, agitation rate, extraction time, desorption solvent volume, and desorption time were evaluated and optimized. The analytical performance of the styrenesulfonate anion-based PIL fiber, PIL fiber containing chloride anions, and a commercially available polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber were compared. Coefficients of determination (R 2 ) for the styrenesulfonate anion-based PIL fiber ranged from 0.995 to 0.999 and the limits of detection (LODs) varied from 0.1 to 5 µg L -1 . The developed method was successfully applied in real water samples including tap, pool, and lake water, and acceptable relative recovery values were obtained. The lifetime of the PIL fiber containing chloride anions as well as the PDMS/DVB fiber were considerably shorter than the PIL fiber containing the styrenesulfonate anion, with both fibers showing a notable decrease in reproducibility and significant damage to the sorbent coating surface after 40 and 70 extractions, respectively. The R 2 values for the chloride anion containing PIL fiber were at or higher than 0.991 with LODs ranging from 0.5 to 5 µg L -1 . For the PDMS/DVB fiber, R 2 values ranged from 0.992 to 0.999 and LODs were found to be as low as 0.2 µg L -1 and as high as 5 µg L -1 . Copyright © 2018 Elsevier B.V. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Orans, Jillian; Johnson, Michael D.L.; Coggan, Kimberly A.
Several bacterial pathogens require the 'twitching' motility produced by filamentous type IV pili (T4P) to establish and maintain human infections. Two cytoplasmic ATPases function as an oscillatory motor that powers twitching motility via cycles of pilus extension and retraction. The regulation of this motor, however, has remained a mystery. We present the 2.1 {angstrom} resolution crystal structure of the Pseudomonas aeruginosa pilus-biogenesis factor PilY1, and identify a single site on this protein required for bacterial translocation. The structure reveals a modified {beta}-propeller fold and a distinct EF-hand-like calcium-binding site conserved in pathogens with retractile T4P. We show that preventing calciummore » binding by PilY1 using either an exogenous calcium chelator or mutation of a single residue disrupts Pseudomonas twitching motility by eliminating surface pili. In contrast, placing a lysine in this site to mimic the charge of a bound calcium interferes with motility in the opposite manner - by producing an abundance of nonfunctional surface pili. Our data indicate that calcium binding and release by the unique loop identified in the PilY1 crystal structure controls the opposing forces of pilus extension and retraction. Thus, PilY1 is an essential, calcium-dependent regulator of bacterial twitching motility.« less
The Complex Conductivity Signature of Geobacter Species in Geological Media
NASA Astrophysics Data System (ADS)
Brown, I.; Atekwana, E. A.; Sarkisova, S.; Achang, M.
2013-12-01
The Complex Conductivity (CC) technique is a promising biogeophysical approach for sensing microbially-induced changes in geological media because of its low-invasive character and sufficient sensitivity to enhanced microbial activity in the near subsurface. Geobacter species have been shown to play important roles in the bioremediation of groundwater contaminated with petroleum and landfill leachate. This capability is based on the ability of Geobacter species to reduce Fe(III) by transferring of electrons from the reduced equivalents to Fe(III) rich minerals through respiration chain and special metallic-like conductors - pili. Only the cultivation of Geobacter species on Fe(III) oxides specifically express pili biosynthesis. Moreover, mutants that cannot produce pili are unable to reduce Fe(III) oxides. However, little is known about the contribution of these molecular conductors (nanowires) to the generation of complex conductivity signatures in geological media. Here, we present the results about the modulation of CC signatures in geological media by Geobacter sulfurreducens (G.s.). Cultures of wild strain G.s. and its pilA(-) mutant were anaerobically cultivated in the presence of the pair of such donors and acceptors of electrons: acetate - fumarate, and acetate - magnetite under anaerobic conditions. Each culture was injected in CC sample holders filled either with N2-CO2 mix (planktonic variant) or with this gases mix and glass beads, d=1 mm, (porous medium variant). Both strains of G.s. proliferated well in a medium supplemented with acetate-fumarate. However, pilA(-) mutant did not multiply in a medium supplemented with ox-red pair yeast extract - magnetite. This observation confirmed that only wild pilA(+) strain is capable of the dissimilatory reduction of Fe(III) within magnetite molecule. The measurement of CC responses from planktonic culture of G.s. wild strain grown with acetate-fumarate did not show linear correlation with their magnitudes but were substantially different from CC responses in sterile medium and pilA(-) mutant planktonic culture. Complex conductivity responses in planktonic cultures of both pilA(+) and pilA(-) strains grown with acetate-fumarate pair were significantly different from magnitudes of φ and σ' in a sterile medium. No notable difference between CC signatures from planktonic cultures of both pilA(+) and pilA(-) strains grown with acetate-fumarate was found. This result has been anticipated because the cultivation of G.s. with ox-red pair acetate-fumarate does not induce the pili biosynthesis. In contrast, the presence of the cells of G.s. pilA(+) strain grown with magnetite in both planktonic and porous media notable shifted to the right of the relaxation peaks of both φ and σ'. Our results taking together suggest that only Geobacter cells administrating Fe(III) dissimilatory reduction and possessing pili can modulate CC responses from subsurface porous media. More experiments and techniques, including different types of microscopy, will be conducted to confirm these observations.
Supercapacitors based on modified graphene electrodes with poly(ionic liquid)
NASA Astrophysics Data System (ADS)
Trigueiro, João Paulo C.; Lavall, Rodrigo L.; Silva, Glaura G.
2014-06-01
The improved accessibility of the electrolyte to the surface of carbon nanomaterials is a challenge to be overcome in supercapacitors based on ionic liquid electrolytes. In this study, we report the preparation of supercapacitors based on reduced graphene oxide (RGO) electrodes and ionic liquid as the electrolyte (specifically, 1-methyl-1-propylpyrrolidinium bis(trifluoromethylsulfonyl)imide or [MPPy][TFSI]). Two types of electrodes were compared: the RGO-based electrode and a poly(ionic liquid)-modified RGO electrode (PIL:RGO). The supercapacitor produced with the PIL:RGO electrode and [MPPy][TFSI] showed an electrochemical stability of 3 V and provided a capacitance of 71.5 F g-1 at room temperature; this capacitance is 130% higher with respect to the RGO-based supercapacitor. The decrease of the specific capacitance after 2000 cycles is only 10% for the PIL:RGO-based device. The results revealed the potential of the PIL:RGO material as an electrode for supercapacitors. This composite electrode increases the compatibility with the ionic liquid electrolyte compared to an RGO electrode, promoting an increase in the effective surface area of the electrode accessible to the electrolyte ions.
Pollack, Sarah F; Geffrey, Alexandra L; Thiele, Elizabeth A; Shah, Uzma
2015-09-01
Primary intestinal lymphangiectasia (PIL) is a rare protein-losing enteropathy characterized by a congenital malformation of the lymphatic vessels of the small intestine causing insufficient drainage and leakage of lymph fluid. Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder characterized by benign hamartomas in multiple organ systems. While the lymphatic system has been implicated in TSC through lymphangioleiomyomatosis (LAM) and lymphedema, this paper reports the first case of PIL in TSC, a female patient with a TSC2 mutation. She developed persistent and significant abdominal distension with chronic diarrhea during her first year of life. Due to lack of treatment options and the involvement of the mTOR pathway in TSC, a trial of an mTOR inhibitor, rapamycin, was initiated. This treatment was highly effective, with improvement in clinical symptoms of PIL as well as abnormal laboratory values including VEGF-C, which was elevated to over seven times the normal upper limit before treatment. This case suggests that PIL is a rare manifestation of TSC, warranting the use of mTOR inhibitors in future studies. © 2015 Wiley Periodicals, Inc.
Joshi, Manishkumar D; Ho, Tien D; Cole, William T S; Anderson, Jared L
2014-01-01
Crosslinked polymeric ionic liquid (PIL)-based sorbent coatings were employed in the extraction of 21 polychlorinated biphenyls (PCBs) from ocean water and bovine milk using solid-phase microextraction (SPME). The extraction temperature, time, and concentration of sodium chloride added to the matrix were optimized in order to determine the best extraction conditions for the extraction of PCBs. The analytical performance of the crosslinked PIL-based SPME fibers was compared with a commercial 7 µm polydimethylsiloxane (PDMS) fiber using gas chromatography (GC) employing an electron capture detector (ECD) and mass spectrometric detection (MS). Higher sensitivities for PCBs were achieved using PIL-based fibers when compared to PDMS fiber due to the incorporation of benzyl moieties into the PIL structures. The limits of detection (LOD) for all PCBs were determined to be in the low ng L(-1) range using the three studied coatings. Recovery studies were performed for PCBs in ocean water and bovine milk to validate the applicability of the current SPME method. © 2013 Published by Elsevier B.V.
Reducing Anxiety in Stutterers through the Association between “Purpose in Life/Ikigai” and Emotions
Ishida, Riichiro
2012-01-01
The prefrontal lobe is more evolved in humans than in other mammals. The functioning of human prefrontal lobes promotes an innate need to establish a meaningful life, often referred to as “Purpose in life (PIL)/ikigai.” PIL/ikigai and the prefrontal lobe psychologically and physiologically, respectively, shape ambition, regulate the development of emotions and integrate psychological events. PIL/ikigai contributes to both a reduction in the anxiety caused by a need for approval from others and the stimulation of pleasure and comfort, which may be related to the well-balanced secretion of neurotransmitters such as serotonin, dopamine, and β-endorphin. Thus, if a stutterer aware that articulate speech is advantageous in communication feels a need for social desirability (SD) based on a need for approval from others, they may develop stress and anxiety caused by their perceived failure when engaging in conversations. This feeling of failure may be related to an imbalanced secretion of serotonin and dopamine. Therefore, previous work has suggested that PIL/ikigai may reduce anxiety in stutterers who seek SD by reducing the symptoms associated with stuttering. PMID:22980384
Lu, Jianyang; Zhai, Hongbo
2017-01-01
Abstract Rationale: Primary intestinal lymphangiectasia (PIL) is a rare disease characterized by dilated intestinal lacteals resulting in lymph leakage into the small bowel lumen. Main clinical features include intermittent diarrhea, hypoproteinemia. Scattered case reports suggested that PIL is compatible to pregnancy, but with increased complications. Patient concerns: A 34-year-old woman with endoscopically diagnosed PIL presented to antenatal our clinic at 10 weeks into gestation. She reported strict adherence to low-fat/high-protein diet with medium-chain triglycerides (MCTs) supplementation. She was general well except for moderate edema and hypoalbuminemia. At 33 weeks, she developed diarrhea, nausea, and vomiting, with decreased fetal movements. One week later, she had an asthma attack. Nonstress test showed frequent variable deceleration. Diagnoses: The diagnosis of PIL was established endoscopically 8 years earlier. Interventions: Hypoalbuminemia was corrected with intravenous albumin administration. She also received corticosteroid therapy to promote fetal lung maturation in anticipation to early termination of the pregnancy. Outcomes: A cesarean section was carried out at 34 weeks due to fetal distress. The baby girl was apparently healthy: weighing 2160 g, with an Apgar score of 9 at both 1 and 5 minutes. Symptoms dissipated rapidly after the delivery. The last follow-up visit at 15 months was unremarkable for both the mother and infant. Lessons: PIL could be compatible with pregnancy, but requires strict adherence to dietary treatment, proper management of the symptoms (e.g., hypoalbuminemia), particularly during late gestation. PMID:28858117
Primary intestinal lymphangiectasia: four case reports and a review of the literature.
Wen, Jie; Tang, Qingya; Wu, Jiang; Wang, Ying; Cai, Wei
2010-12-01
Primary intestinal lymphangiectasia (PIL) is a rare digestive disease and most articles on this condition are isolated case reports. Our purpose is to investigate the clinical characteristics, therapeutic management, and outcome of PIL through case studies. We conducted a retrospective analysis and obtained detailed clinical information for four PIL patients treated at our institution. A MEDLINE database search was also performed using the search term "intestinal lymphangiectasia" and all pertinent literature was carefully reviewed. Four children treated in our department showed elevated IgE and a good response to diet intervention. After reviewing the literature, we conducted statistical analysis on the basis of all the cases, with a total of 84 cases. Thirty-eight cases have been reported with diet treatment, 24 (63%) of whom showed apparent improvement in clinical symptoms and laboratory parameters. Four cases (5%) had a malignant transformation of lymphoma, and the average time from PIL onset to lymphoma diagnosis was 31 years (range, 19-45 years). No difference was observed regarding the presence of major clinical manifestations among children and adults. Diet intervention in children was more effective than that in adults. Diet intervention is the cornerstone of PIL medical management, which was found to be more effective in children than in adults. Early diagnosis and treatment of IL is of great importance for effective diet therapy. An elevated IgE level should be monitored periodically since it could be an indication of malignant transformation-lymphoma.
Lu, Jianyang; Zhai, Hongbo
2017-09-01
Primary intestinal lymphangiectasia (PIL) is a rare disease characterized by dilated intestinal lacteals resulting in lymph leakage into the small bowel lumen. Main clinical features include intermittent diarrhea, hypoproteinemia. Scattered case reports suggested that PIL is compatible to pregnancy, but with increased complications. A 34-year-old woman with endoscopically diagnosed PIL presented to antenatal our clinic at 10 weeks into gestation. She reported strict adherence to low-fat/high-protein diet with medium-chain triglycerides (MCTs) supplementation. She was general well except for moderate edema and hypoalbuminemia. At 33 weeks, she developed diarrhea, nausea, and vomiting, with decreased fetal movements. One week later, she had an asthma attack. Nonstress test showed frequent variable deceleration. The diagnosis of PIL was established endoscopically 8 years earlier. Hypoalbuminemia was corrected with intravenous albumin administration. She also received corticosteroid therapy to promote fetal lung maturation in anticipation to early termination of the pregnancy. A cesarean section was carried out at 34 weeks due to fetal distress. The baby girl was apparently healthy: weighing 2160 g, with an Apgar score of 9 at both 1 and 5 minutes. Symptoms dissipated rapidly after the delivery. The last follow-up visit at 15 months was unremarkable for both the mother and infant. PIL could be compatible with pregnancy, but requires strict adherence to dietary treatment, proper management of the symptoms (e.g., hypoalbuminemia), particularly during late gestation.
Time-resolved molecular characterization of organic aerosols by PILS + UPLC/ESI-Q-TOFMS
NASA Astrophysics Data System (ADS)
Zhang, X.; Dalleska, N. F.; Huang, D. D.; Bates, K. H.; Sorooshian, A.; Flagan, R. C.; Seinfeld, J. H.
2016-04-01
Real-time and quantitative measurement of particulate matter chemical composition represents one of the most challenging problems in the field of atmospheric chemistry. In the present study, we integrate the Particle-into-Liquid Sampler (PILS) with Ultra Performance Liquid Chromatography/Electrospray ionization Quadrupole Time-of-Flight High-Resolution/Mass Spectrometry (UPLC/ESI-Q-TOFMS) for the time-resolved molecular speciation of chamber-derived secondary organic aerosol (SOA). The unique aspect of the combination of these two well-proven techniques is to provide quantifiable molecular-level information of particle-phase organic compounds on timescales of minutes. We demonstrate that the application of the PILS + UPLC/ESI-Q-TOFMS method is not limited to water-soluble inorganic ions and organic carbon, but is extended to slightly water-soluble species through collection efficiency calibration together with sensitivity and linearity tests. By correlating the water solubility of individual species with their O:C ratio, a parameter that is available for aerosol ensembles as well, we define an average aerosol O:C ratio threshold of 0.3, above which the PILS overall particulate mass collection efficiency approaches ∼0.7. The PILS + UPLC/ESI-Q-TOFMS method can be potentially applied to probe the formation and evolution mechanism of a variety of biogenic and anthropogenic SOA systems in laboratory chamber experiments. We illustrate the application of this method to the reactive uptake of isoprene epoxydiols (IEPOX) on hydrated and acidic ammonium sulfate aerosols.
Purpose in life and tobacco use among community-dwelling mothers of early adolescents
Ando, Shuntaro; Koike, Shinsuke; Fujikawa, Shinya; Kanata, Sho; Endo, Kaori; Nakanishi, Miharu; Hatch, Stephani L; Richards, Marcus; Kasai, Kiyoto; Hiraiwa-Hasegawa, Mariko; Nishida, Atsushi
2018-01-01
Objectives The rising prevalence of tobacco use and tobacco-attributable deaths among women is of worldwide concern. In particular, smoking prevention for mothers in early midlife is a significant international public health goal. A higher sense of purpose in life (PIL) is thought to reduce detrimental health behaviours. However, little is known about the association between a sense of PIL and tobacco use. This study investigates this association among community-dwelling mothers of early adolescents. Design This population-based cross-sectional study uses a self-reported questionnaire from the Tokyo Early Adolescence Survey, a large community-based survey conducted in Japan between 2012 and 2015. Setting Participants were randomly recruited from the resident registries of three municipalities in Tokyo, Japan. Participants A total of 4478 children and their primary parents participated. Responses from 4063 mothers with no missing data were analysed (mean age=42.0 years (SD=4.2)). Measures Participants’ tobacco use, including the number of cigarettes smoked per day, was documented using a questionnaire. PIL was assessed using a Purpose in Life scale derived from Ryff’s Psychological Well-Being Scale. Results Greater PIL was associated with a decreased likelihood of tobacco use, even when adjusted for confounders (OR=0.80, 95% CI 0.70 to 0.91). Multinomial logistic regression analyses revealed that PIL was inversely associated with tobacco consumption among mothers. These associations remained after controlling for psychological distress, socioeconomic factors and frequency of alcohol consumption among moderate to heavy smokers (OR=0.70, 95% CI 0.57 to 0.86), while attenuated among light smokers. Conclusions Increasing PIL may be a valuable intervention for reducing tobacco use among women in early midlife. This study can contribute to our understanding of the psychology of smoking behaviour and shed light on the targeted intervention to reduce tobacco use among early midlife mothers. PMID:29678982
Flux Cancellation Leading to Solar Filament Eruptions
NASA Astrophysics Data System (ADS)
Popescu, R. M.; Panesar, N. K.; Sterling, A. C.; Moore, R. L.
2016-12-01
Solar filaments are strands of relatively cool, dense plasma magnetically suspended in the lower density hotter solar corona. They trace magnetic polarity inversion lines (PILs) in the photosphere below, and are supported against gravity at heights of up to 100 Mm above the chromosphere by the magnetic field in and around them. This field erupts when it is rendered unstable by either magnetic flux cancellation or emergence at or near the PIL. We have studied the evolution of photospheric magnetic flux leading to ten observed filament eruptions. Specifically, we look for gradual magnetic changes in the neighborhood of the PIL prior to and during eruption. We use Extreme Ultraviolet (EUV) images from the Atmospheric Imaging Assembly (AIA), and magnetograms from the Helioseismic and Magnetic Imager (HMI), both onboard the Solar Dynamics Observatory (SDO), to study filament eruptions and their photospheric magnetic fields. We examine whether flux cancellation or/and emergence leads to filament eruptions and find that continuous flux cancellation was present at the PIL for many hours prior to each eruption. We present two events in detail and find the following: (a) the pre-eruption filament-holding core field is highly sheared and appears in the shape of a sigmoid above the PIL; (b) at the start of the eruption the opposite arms of the sigmoid reconnect in the middle above the site of (tether-cutting) flux cancellation at the PIL; (c) the filaments first show a slow-rise, followed by a fast-rise as they erupt. We conclude that these two filament eruptions result from flux cancellation in the middle of the sheared field and are in agreement with the standard model for a CME/flare filament eruption from a closed bipolar magnetic field [flux cancellation (van Ballegooijen and Martens 1989 and Moore and Roumelrotis 1992) and runaway tether-cutting (Moore et. al 2001)].
Zhang, Cheng; Park, Rodney A; Anderson, Jared L
2016-04-01
Structurally-tuned ionic liquids (ILs) have been previously applied as the second dimension column in comprehensive two-dimensional gas chromatography (GC×GC) and have demonstrated high selectivity in the separation of individual aliphatic hydrocarbons from other aliphatic hydrocarbons. However, the maximum operating temperatures of these stationary phases limit the separation of analytes with high boiling points. In order to address this issue, a series of polymeric ionic liquid (PIL)-based stationary phases were prepared in this study using imidazolium-based IL monomers via in-column free radical polymerization. The IL monomers were functionalized with long alkyl chain substituents to provide the needed selectivity for the separation of aliphatic hydrocarbons. Columns were prepared with different film thicknesses to identify the best performing stationary phase for the separation of kerosene. The bis[(trifluoromethyl)sulfonyl]imide ([NTf2](-))-based PIL stationary phase with larger film thickness (0.28μm) exhibited higher selectivity for aliphatic hydrocarbons and showed a maximum allowable operating temperature of 300°C. PIL-based stationary phases containing varied amount of IL-based crosslinker were prepared to study the effect of the crosslinker on the selectivity and thermal stability of the resulting stationary phase. The optimal resolution of aliphatic hydrocarbons was achieved when 50% (w/w) of crosslinker was incorporated into the PIL-based stationary phase. The resulting stationary phase exhibited good selectivity for different groups of aliphatic hydrocarbons even after being conditioned at 325°C. Finally, the crosslinked PIL-based stationary phase was compared with SUPELCOWAX 10 and DB-17 columns for the separation of aliphatic hydrocarbons in diesel fuel. Better resolution of aliphatic hydrocarbons was obtained when employing the crosslinked PIL-based stationary phase as the second dimension column. Copyright © 2016 Elsevier B.V. All rights reserved.
Flux Cancellation Leading to CME Filament Eruptions
NASA Technical Reports Server (NTRS)
Popescu, Roxana M.; Panesar, Navdeep K.; Sterling, Alphonse C.; Moore, Ronald L.
2016-01-01
Solar filaments are strands of relatively cool, dense plasma magnetically suspended in the lower density hotter solar corona. They trace magnetic polarity inversion lines (PILs) in the photosphere below, and are supported against gravity at heights of up to approx.100 Mm above the chromosphere by the magnetic field in and around them. This field erupts when it is rendered unstable, often by magnetic flux cancellation or emergence at or near the PIL. We have studied the evolution of photospheric magnetic flux leading to ten observed filament eruptions. Specifically, we look for gradual magnetic changes in the neighborhood of the PIL prior to and during eruption. We use Extreme Ultraviolet (EUV) images from the Atmospheric Imaging Assembly (AIA), and magnetograms from the Helioseismic and Magnetic Imager (HMI), both on board the Solar Dynamics Observatory (SDO), to study filament eruptions and their photospheric magnetic fields. We examine whether flux cancellation or/and emergence leads to filament eruptions. We find that continuous flux cancellation was present at the PIL for many hours prior to each eruption. We present two CME-producing eruptions in detail and find the following: (a) the pre-eruption filament-holding core field is highly sheared and appears in the shape of a sigmoid above the PIL; (b) at the start of the eruption the opposite arms of the sigmoid reconnect in the middle above the site of (tether-cutting) flux cancellation at the PIL; (c) the filaments first show a slow-rise, followed by a fast-rise as they erupt. We conclude that these two filament eruptions result from flux cancellation in the middle of the sheared field, and thereafter evolve in agreement with the standard model for a CME/flare filament eruption from a closed bipolar magnetic field [flux cancellation (van Ballegooijen and Martens 1989 and Moore and Roumelrotis 1992) and runaway tether-cutting (Moore et. al 2001)].
Kudo, Madoka; Kidokoro, Satoshi; Yoshida, Takuya; Mizoi, Junya; Todaka, Daisuke; Fernie, Alisdair R; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko
2017-04-01
Although a variety of transgenic plants that are tolerant to drought stress have been generated, many of these plants show growth retardation. To improve drought tolerance and plant growth, we applied a gene-stacking approach using two transcription factor genes: DEHYDRATION-RESPONSIVE ELEMENT-BINDING 1A (DREB1A) and rice PHYTOCHROME-INTERACTING FACTOR-LIKE 1 (OsPIL1). The overexpression of DREB1A has been reported to improve drought stress tolerance in various crops, although it also causes a severe dwarf phenotype. OsPIL1 is a rice homologue of Arabidopsis PHYTOCHROME-INTERACTING FACTOR 4 (PIF4), and it enhances cell elongation by activating cell wall-related gene expression. We found that the OsPIL1 protein was more stable than PIF4 under light conditions in Arabidopsis protoplasts. Transactivation analyses revealed that DREB1A and OsPIL1 did not negatively affect each other's transcriptional activities. The transgenic plants overexpressing both OsPIL1 and DREB1A showed the improved drought stress tolerance similar to that of DREB1A overexpressors. Furthermore, double overexpressors showed the enhanced hypocotyl elongation and floral induction compared with the DREB1A overexpressors. Metabolome analyses indicated that compatible solutes, such as sugars and amino acids, accumulated in the double overexpressors, which was similar to the observations of the DREB1A overexpressors. Transcriptome analyses showed an increased expression of abiotic stress-inducible DREB1A downstream genes and cell elongation-related OsPIL1 downstream genes in the double overexpressors, which suggests that these two transcription factors function independently in the transgenic plants despite the trade-offs required to balance plant growth and stress tolerance. Our study provides a basis for plant genetic engineering designed to overcome growth retardation in drought-tolerant transgenic plants. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.
Trujillo-Rodríguez, María J; Yu, Honglian; Cole, William T S; Ho, Tien D; Pino, Verónica; Anderson, Jared L; Afonso, Ana M
2014-04-01
The extraction performance of four polymeric ionic liquid (PIL)-based solid-phase microextraction (SPME) coatings has been studied and compared to that of commercial SPME coatings for the extraction of 16 volatile compounds in cheeses. The analytes include 2 free fatty acids, 2 aldehydes, 2 ketones and 10 phenols and were determined by headspace (HS)-SPME coupled to gas chromatography (GC) with flame-ionization detection (FID). The PIL-based coatings produced by UV co-polymerization were more efficient than PIL-based coatings produced by thermal AIBN polymerization. Partition coefficients of analytes between the sample and the coating (Kfs) were estimated for all PIL-based coatings and the commercial SPME fiber showing the best performance among the commercial fibers tested: carboxen-polydimethylsyloxane (CAR-PDMS). For the PIL-based fibers, the highest K(fs) value (1.96 ± 0.03) was obtained for eugenol. The normalized calibration slope, which takes into account the SPME coating thickness, was also used as a simpler approximate tool to compare the nature of the coating within the determinations, with results entirely comparable to those obtained with estimated K(fs) values. The PIL-based materials obtained by UV co-polymerization containing the 1-vinyl-3-hexylimidazolium chloride IL monomer and 1,12-di(3-vinylimiazolium)dodecane dibromide IL crosslinker exhibited the best performance in the extraction of the select analytes from cheeses. Despite a coating thickness of only 7 µm, this copolymeric sorbent coating was capable of quantitating analytes in HS-SPME in a 30 to 2000 µg L(-1) concentration range, with correlation coefficient (R) values higher than 0.9938, inter-day precision values (as relative standard deviation in %) varying from 6.1 to 20%, and detection limits down to 1.6 µg L(-1). Copyright © 2013 Elsevier B.V. All rights reserved.
Wu, Hong-Yan; Zhang, Xiao-Lian; Pan, Qin; Wu, Jianguo
2005-11-01
Salmonella enterica serovar Typhi (S. Typhi) is an important pathogen which infects humans exclusively and causes typhoid or enteric fever. Recently it has been discovered that type IVB pili, encoded by the S. Typhi pil operon located in the major pathogenicity island, may be important in the pathogenesis of epidemic enteric fever. To further investigate the roles of type IVB pili of S. Typhi, a 12-mer peptide (RQERSSLSKPVV), binding to the structural protein PilS of the type IVB pili of S. Typhi, was isolated with a ribosome display system. This peptide was designated as peptide R. We found that peptide R inhibited adhesion to/invasion of human monocytic THP-1 cells by piliated S. Typhi bacteria, but had no effects on nonpiliated S. Typhi bacteria. A random 12-mer peptide, of size and solubility equal to peptide R, served as a control on the specificity of peptide R. The specific interaction and binding equilibrium between the 12-mer peptide R and PilS protein was determined by isothermal titration calorimetry (ITC) and a binding constant Ka determined to be between 0.4 x 10(5) and 2.2 x 10(5)L mol(-1). Our findings suggest that the type IV pili-binding peptide R holds potential as an antibacterial peptide effective against S. Typhi infections, both in terms of prevention and therapeutic treatment. The data further provide insights into the understanding of the pathogenic roles of the type IVB pili of S. Typhi.
Véras, Leiz Maria Costa; Azevedo, Iábita Fabiana Sousa; Biase, Adriele Giaretta; Costa, Joana; Oliveira, Maria Beatriz P. P.; Mafra, Isabel
2017-01-01
Pilocarpus microphyllus Stapf ex Wardleworth (jaborandi, Rutaceae) is one of the most important Brazilian medicinal species owing to its content of pilocarpine (PIL), an alkaloid used for treating glaucoma and xerostomia. This species contains another alkaloid, epiisopiloturine (EPI), which has demonstrated effectiveness against schistosomiasis. The aim of this work was to assess seasonal changes of PIL and EPI in three populations of cultivated P. microphyllus from northeastern Brazil over one year, including the dry and rainy seasons. Alkaloid profiles were correlated to phenotypic and genetic patterns in the morphological and molecular characterizations. PIL was the primary alkaloid and its levels differed among populations in all months except September. The S01 population (green line) showed an especially high PIL content compared to populations S02 and S03 (traditional line), which had similar alkaloid contents. PIL content gradually decreased in the three populations in the rainy season.EPI content was significantly different between the green line (S01) and the traditional line (S02 and S03).S01 had a significantly lower EPI content in all months, demonstrating that it was not the best source for EPI extraction. Inter simple sequence repeat (ISSR) markers and morphological analyses clearly separated S01 from S02 and S03, in agreement with the alkaloid results. This study shows the first correlation between the chemical, morphological, and molecular markers of P. microphyllus and highlights the potential benefits of a multidisciplinary research approach aimed at supporting both industry and conservation of natural resources. PMID:28151972
On the Formation of Filament Channels
NASA Astrophysics Data System (ADS)
Wang, Y.-M.; Muglach, K.
2007-09-01
From the Hα archive of the Big Bear Solar Observatory (BBSO) we have selected three examples showing fibril structures that change their orientation, over 1 or 2 days, from nearly perpendicular to nearly parallel to the polarity inversion line (PIL). In one case, the filament channel forms within a single decaying bipole; in the other two cases, it forms along the boundary between an active region and its surroundings. Comparing the Hα filtergrams with magnetograms from the Michelson Doppler Imager (MDI), we find that the fibrils become aligned with the PIL as supergranular convection brings opposite-polarity magnetic flux together; shearing motions along the PIL, when present, act mainly to accelerate the rate of diffusive annihilation. We conclude that the reorientation of the fibrils is due to the cancellation and submergence of the transverse field component (B⊥), leaving behind the preexisting axial field component (B∥). The latter may have been generated by photospheric differential rotation over longer timescales, or else was already present when the flux emerged. The filament channel forms slowly if B∥/B⊥ is initially small, as along the internal neutral line of a newly emerged bipole, but may appear within hours if this ratio is initially substantial, as where the dipole-like loops of an active region curve around its periphery. In all of our examples, filaments form within a day or so after the fibrils become aligned with the PIL, while barbs appear at a later stage, as flux elements continue to diffuse across the PIL and cancel with the majority-polarity flux on the other side.
Retention of Adult Learners in an Individualized Baccalaureate Degree Program.
ERIC Educational Resources Information Center
Holm, Shirley M.
A study sought to determine the rate of retention of adult students in the University of Minnesota College Program for Individualized Learning (PIL) for the 1983-84 academic year, as well as factors that might relate to this retention rate. A review was made of the 67 applications submitted by students admitted to PIL during that year to determine…
Lyotropic liquid crystalline phase behaviour in amphiphile-protic ionic liquid systems.
Chen, Zhengfei; Greaves, Tamar L; Fong, Celesta; Caruso, Rachel A; Drummond, Calum J
2012-03-21
Approximate partial phase diagrams for nine amphiphile-protic ionic liquid (PIL) systems have been determined by synchrotron source small angle X-ray scattering, differential scanning calorimetry and cross polarised optical microscopy. The binary phase diagrams of some common cationic (hexadecyltrimethyl ammonium chloride, CTAC, and hexadecylpyridinium bromide, HDPB) and nonionic (polyoxyethylene (10) oleyl ether, Brij 97, and Pluronic block copolymer, P123) amphiphiles with the PILs, ethylammonium nitrate (EAN), ethanolammonium nitrate (EOAN) and diethanolammonium formate (DEOAF), have been studied. The phase diagrams were constructed for concentrations from 10 wt% to 80 wt% amphiphile, in the temperature range 25 °C to >100 °C. Lyotropic liquid crystalline phases (hexagonal, cubic and lamellar) were formed at high surfactant concentrations (typically >50 wt%), whereas at <40 wt%, only micelles or polydisperse crystals were present. With the exception of Brij 97, the thermal stability of the phases formed by these surfactants persisted to temperatures above 100 °C. The phase behaviour of amphiphile-PIL systems was interpreted by considering the PIL cohesive energy, liquid nanoscale order, polarity and ionicity. For comparison the phase behaviour of the four amphiphiles was also studied in water.
The eisosome core is composed of BAR domain proteins
Olivera-Couto, Agustina; Graña, Martin; Harispe, Laura; Aguilar, Pablo S.
2011-01-01
Eisosomes define sites of plasma membrane organization. In Saccharomyces cerevisiae, eisosomes delimit furrow-like plasma membrane invaginations that concentrate sterols, transporters, and signaling molecules. Eisosomes are static macromolecular assemblies composed of cytoplasmic proteins, most of which have no known function. In this study, we used a bioinformatics approach to analyze a set of 20 eisosome proteins. We found that the core components of eisosomes, paralogue proteins Pil1 and Lsp1, are distant homologues of membrane-sculpting Bin/amphiphysin/Rvs (BAR) proteins. Consistent with this finding, purified recombinant Pil1 and Lsp1 tubulated liposomes and formed tubules when the proteins were overexpressed in mammalian cells. Structural homology modeling and site-directed mutagenesis indicate that Pil1 positively charged surface patches are needed for membrane binding and liposome tubulation. Pil1 BAR domain mutants were defective in both eisosome assembly and plasma membrane domain organization. In addition, we found that eisosome-associated proteins Slm1 and Slm2 have F-BAR domains and that these domains are needed for targeting to furrow-like plasma membrane invaginations. Our results support a model in which BAR domain protein–mediated membrane bending leads to clustering of lipids and proteins within the plasma membrane. PMID:21593205
Mateti, Uday Venkat; Nagappa, Anantha Naik; Attur, Ravindra Prabhu; Bairy, Manohar; Nagaraju, Shankar Prasad; Mallayasamy, Surulivelrajan; Vilakkathala, Rajesh; Guddattu, Vasudev; Balkrishnan, Rajesh
2015-11-01
Patient information leaflets are universally-accepted resources to educate the patients/users about their medications, disease and lifestyle modification. The objective of the study was to prepare, validate and perform user-testing of pictogram-based patient information leaflets (P-PILs) among hemodialysis (HD) patients. The P-PILs are prepared by referring to the primary, secondary and tertiary resources. The content and pictograms of the leaflet have been validated by an expert committee consisting of three nephrologists and two academic pharmacists. The Baker Able Leaflet Design has been applied to develop the layout and design of the P-PILs. Quasi-experimental pre- and post-test design without control group was conducted on 81 HD patients for user-testing of P-PILs. The mean Baker Able Leaflet Design assessment score for English version of the leaflet was 28, and 26 for Kannada version. The overall user-testing knowledge assessment mean scores were observed to have significantly improved from 44.25 to 69.62 with p value <0.001. The overall user opinion of content and legibility of the leaflets was good. Pictogram-based patient information leaflets can be considered an effective educational tool for HD patients.
Arellanes-Lozada, Paulina; Olivares-Xometl, Octavio; Guzmán-Lucero, Diego; Likhanova, Natalya V; Domínguez-Aguilar, Marco A; Lijanova, Irina V; Arce-Estrada, Elsa
2014-08-07
Compounds of poly(ionic liquid)s (PILs), derived from imidazole with different alkylic chain lengths located in the third position of the imidazolium ring (poly(1-vinyl-3-dodecyl-imidazolium) (PImC 12 ), poly(1-vinyl-3-octylimidazolium) (PImC₈) and poly(1-vinyl-3-butylimidazolium) (PImC₄) hexafluorophosphate) were synthesized. These compounds were tested as corrosion inhibitors on aluminum alloy AA6061 in diluted sulfuric acid (0.1-1 M H₂SO₄) by weight loss tests, polarization resistance measurements and inductively coupled plasma optical emission spectroscopy. Langmuir's isotherms suggested film formation on bare alloy while standard free energy indicated inhibition by a physisorption process. However, compound efficiencies as inhibitors ranked low (PImC 12 > PImC₈ > PImC₄) to reach 61% for PImC 12 in highly diluted acidic solution. Apparently, the high mobility of sulfates favored their adsorption in comparison to PILs. The surface film displayed general corrosion, and pitting occurred as a consequence of PILs' partial inhibition along with a continuous dissolution of defective patchy film on formation. A slight improvement in efficiency was displayed by compounds having high molecular weight and a long alkyl chain, as a consequence of steric hindrance and PIL interactions.
Triggers and Manifestations of Flare Energy Release in the Low Atmosphere
NASA Astrophysics Data System (ADS)
Kosovichev, A. G.; Sharykin, I. N.; Sadykov, V. M.; Vargas, S.; Zimovets, I. V.
2016-12-01
The main goal is to understand triggers and manifestations of the flare energy release in the lower layers of the solar atmosphere (the photosphere and chromosphere) using high-resolution optical observations and magnetic field measurements. As a case study we present results for an M-class flare. We analyze optical images, HMI Dopplergrams and vector magnetograms, and use Non-Linear Force-Free Field (NLFFF) extrapolation for reconstruction of the magnetic topology. The NLFFF modelling reveals interaction of oppositely directed magnetic flux-tubes in the Polarity Inversion Line (PIL). These two interacting magnetic flux tubes are observed as a compact sheared arcade along the PIL in the high-resolution broad-band continuum images from New Solar Telescope (NST). In the vicinity of the PIL, the NST H-alpha observations reveal formation of a thin three-ribbon structure corresponding to the small-scale photospheric magnetic arcade. Magnetic reconnection is triggered by two interacting magnetic flux tubes with forming current sheet extended along the PIL. Presented observational results evidence in favor of location of the primary energy release site in the dense chromosphere where plasma is partially ionized in the region of strong electric currents concentrated near the polarity inversion line.
Cafforio, Paola; Viggiano, Luigi; Mannavola, Francesco; Pellè, Eleonora; Caporusso, Concetta; Maiorano, Eugenio; Felici, Claudia; Silvestris, Francesco
2017-09-29
Mesenchymal/stromal stem cells (MSCs) are favorably regarded in anti-cancer cytotherapies for their spontaneous chemotaxis toward inflammatory and tumor environments associated with an intrinsic cytotoxicity against tumor cells. Placenta-derived or TRAIL-engineered adipose MSCs have been shown to exert anti-tumor activity in both in-vitro and in-vivo models of multiple myeloma (MM) while TRAIL-transduced umbilical cord (UC)-MSCs appear efficient inducers of apoptosis in a few solid tumors. However, apoptosis is not selective for cancer cells since specific TRAIL receptors are also expressed by a number of normal cells. To overcome this drawback, we propose to transduce UC-MSCs with a bicistronic vector including the TRAIL sequence under the control of IL-6 promoter (pIL6) whose transcriptional activation is promoted by the MM milieu. UC-MSCs were transduced with a bicistronic retroviral vector (pMIGR1) encoding for green fluorescent protein (GFP) and modified to include the pIL6 sequence upstream of the full-length human TRAIL cDNA. TRAIL expression after stimulation with U-266 cell conditioned medium, or IL-1α/IL-1β, was evaluated by flow cytometry, confocal microscopy, real-time PCR, western blot analysis, and ELISA. Apoptosis in MM cells was assayed by Annexin V staining and by caspase-8 activation. The cytotoxic effect of pIL6-TRAIL + -GFP + -UC-MSCs on MM growth was evaluated in SCID mice by bioluminescence and ex vivo by caspase-3 activation and X-ray imaging. Statistical analyses were performed by Student's t test, ANOVA, and logrank test for survival curves. pIL6-TRAIL + -GFP + -UC-MSCs significantly expressed TRAIL after stimulation by either conditioned medium or by IL-1α/IL-1β, and induced apoptosis in U-266 cells. Moreover, when systemically injected in SCID mice intratibially xenografted with U-266, those cells underwent within MM tibia lesions and significantly reduced the tumor burden by specific induction of apoptosis in MM cells as revealed by caspase-3 activation. Our tumor microenvironment-sensitive model of anti-MM cytotherapy is regulated by the axis pIL6/IL-1α/IL-1β and appears suitable for further preclinical investigation not only in myeloma bone disease in which UC-MSCs would even participate to bone healing as described, but also in other osteotropic tumors whose milieu is enriched of cytokines triggering the pIL6.
Purpose in Life among Men and Women Aged 85 Years and Older
ERIC Educational Resources Information Center
Hedberg, Pia; Gustafson, Yngve; Brulin, Christine
2010-01-01
The aim of this study was to investigate purpose in life in relation to psychological well-being, social relations, and physical and psychological symptoms among very old women (n = 120) and men (n = 69). Their purpose in life was evaluated using the Purpose in Life (PIL) scale. Women scored lower on this PIL scale than men (102 vs. 108 p =…
Coelho, Vanessa Rodrigues; Vieira, Caroline Gonçalves; de Souza, Luana Pereira; da Silva, Lucas Lima; Pflüger, Pricila; Regner, Gabriela Gregory; Papke, Débora Kuck Mausolff; Picada, Jaqueline Nascimento; Pereira, Patrícia
2016-11-01
The goal of this study was to investigate the effects of rosmarinic acid (RA) and caffeic acid (CA) in the acute pentylenetetrazole (PTZ) and pilocarpine (PIL) seizure models. We also evaluated the effect of RA and CA on the diazepam (DZP)-induced sleeping time test and its possible neuroprotective effect against the genotoxic damage induced by PTZ and PIL. Mice were treated intraperitoneally (i.p.) with saline, RA (2 or 4 mg/kg), or CA (4 or 8 mg/kg) alone or associated to low-dose DZP. After, mice received a single dose of PTZ (88 mg/kg) or PIL (250 mg/kg) and were monitored for the percentage of seizures and the latency to first seizure (LFS) >3 s. Vigabatrin and DZP were used as positive controls. In the DZP-induced sleeping time test, mice were treated with RA and CA and 30 min after receiving DZP (25 mg/kg, i.p.). The alkaline comet assay was performed after acute seizure tests to evaluate the antigenotoxic profiles of RA and CA. The doses of RA and CA tested alone did not reduce the occurrence of seizures induced by PTZ or PIL. The association of 4 mg/kg RA + low-dose DZP was shown to increase LFS in the PTZ model, compared to the group that received only the DZP. In the DZP-induced sleeping time test, the latency to sleep was reduced by 4 mg/kg RA and 8 mg/kg CA. The PTZ-induced genotoxic damage was not prevented by RA or CA, but the PIL-induced genotoxic damage was decreased by pretreatment with 4 mg/kg RA (in cortex) and 4 mg/kg CA (in hippocampus). In conclusion, RA and CA presented neuroprotective effect against PIL-induced genotoxic damage and reduced the latency to DZP-induced sleep. Of the rosmarinic acid, 4 mg/kg enhanced the DZP effect in the increase of latency to clonic PTZ-induced seizures.
Sexual health-related information delivery - are patient information leaflets still relevant?
Varma, Rick; Chung, Charles; Townsend, Amanda; Power, Melissa
2016-06-01
Background Patient information leaflets (PILs) are widely utilised within publically funded sexual health clinics to deliver sexual health-related information (SHRI); however, their continued value to clients in the era of social media is unclear. This study aimed to evaluate clients' opinions on three newly developed PILs and examine client views on other forms of SHRI delivery. An anonymous self-administered questionnaire was completed by clients attending the Western Sydney Sexual Health Centre (WSSHC) in 2012. High-risk population (HRP) vs non-high-risk population (non-HRP) views on PILs vs alternative methods of SHRI delivery were analysed by using Mann-Whitney U, Wilcoxon, McNemar and χ(2) tests. Over half (210/315; (67%)) of the consecutive clients from a culturally diverse population completed the survey. Sex workers (SW) and young people (YP) were significantly likely to have a high school education than non-HRP (P<0.039 and P<0.032). Overall, PILs, a clinic website and the Sexual Health Information Link (SHIL), a state-wide website and telephone line, were ranked significantly higher as a means of SHRI delivery on a Likert scale than newer technologies including Facebook (P<0.001), email (P<0.001), mobile phone applications (P<0.001), TVs in waiting rooms (P<0.001) and business cards (P<0.001). There was no significant difference in opinion between HRP and non-HRP. This study provides evidence for the ongoing use of PILs to deliver SHRI to clinic attendees, in conjunction with other forms of SHRI delivery such as websites and SHIL. Novel methods may require additional consumer engagement and a greater understanding of specific population's needs.
Primary Intestinal Lymphangiectasia Manifested as Unusual Edemas and Effusions: A Case Report.
Wang, Xuefeng; Jin, Hong; Wu, Weilu
2016-03-01
Primary intestinal lymphangiectasia (PIL) is a rare disorder of unknown etiology characterized by diffuse or localized dilation and eventual rupture of the enteric lymphatic vessels in mucosa, submucosa, and/or subserosa. Lymph, rich in all kinds of proteins and lymphocytes, leaks into the gastrointestinal tract via the affected lymphatic vessels causing hypoproteinemia and lymphopenia. The main symptom is variable degrees of pitting edemas of bilateral lower limbs. But edemas of any other parts of body, and mild serous effusions may also occur sometimes. PIL occurs in conjunction with a right hemifacial edema, a right upper limb lymphedema, asymmetric bilateral calves edemas, and a unilateral massive pleural effusion seems never to be reported before. In addition, increased enteric protein loss that may cause severe hypoproteinemia usually get overlooked, and the lymphatic system disorders always put the diagnoses in a dilemma.We described a case of a 17-year-old Chinese girl with a history of gradually progressive swellings of right-sided face, right upper limb, and bilateral calves since 3 to 4 months of age. A right-sided massive pleural effusion, a moderate pericardial effusion, and a mild ascites have been proved unchanged by a series of computerized tomography (CT) scans since 5 years ago. The diagnosis of PIL was finally confirmed by severe hypoproteinemia, endoscopic changes, and histology of jejunum biopsy. Further lymphoscintigraphy and lymphangiography also identified lymph leakage in her bowel and several abnormal lymphatic vessels. A high-protein, low-fat diet supplemented with medium-chain triglycerides (MCT) showed some benefit.This case suggested that PIL was a rare but important etiology of hypoproteinemia, effusions, and edemas. PIL, effusions, and lymphedema can be the features of multisegmental generalized lymphatic dysplasia. In addition, both lymphoscintigraphy and intranodal lymphangiography could be considered when lymphatic system disorders are suspected.
Primary Intestinal Lymphangiectasia Manifested as Unusual Edemas and Effusions
Wang, Xuefeng; Jin, Hong; Wu, Weilu
2016-01-01
Abstract Primary intestinal lymphangiectasia (PIL) is a rare disorder of unknown etiology characterized by diffuse or localized dilation and eventual rupture of the enteric lymphatic vessels in mucosa, submucosa, and/or subserosa. Lymph, rich in all kinds of proteins and lymphocytes, leaks into the gastrointestinal tract via the affected lymphatic vessels causing hypoproteinemia and lymphopenia. The main symptom is variable degrees of pitting edemas of bilateral lower limbs. But edemas of any other parts of body, and mild serous effusions may also occur sometimes. PIL occurs in conjunction with a right hemifacial edema, a right upper limb lymphedema, asymmetric bilateral calves edemas, and a unilateral massive pleural effusion seems never to be reported before. In addition, increased enteric protein loss that may cause severe hypoproteinemia usually get overlooked, and the lymphatic system disorders always put the diagnoses in a dilemma. We described a case of a 17-year-old Chinese girl with a history of gradually progressive swellings of right-sided face, right upper limb, and bilateral calves since 3 to 4 months of age. A right-sided massive pleural effusion, a moderate pericardial effusion, and a mild ascites have been proved unchanged by a series of computerized tomography (CT) scans since 5 years ago. The diagnosis of PIL was finally confirmed by severe hypoproteinemia, endoscopic changes, and histology of jejunum biopsy. Further lymphoscintigraphy and lymphangiography also identified lymph leakage in her bowel and several abnormal lymphatic vessels. A high-protein, low-fat diet supplemented with medium-chain triglycerides (MCT) showed some benefit. This case suggested that PIL was a rare but important etiology of hypoproteinemia, effusions, and edemas. PIL, effusions, and lymphedema can be the features of multisegmental generalized lymphatic dysplasia. In addition, both lymphoscintigraphy and intranodal lymphangiography could be considered when lymphatic system disorders are suspected. PMID:26962779
Jia, Jing; Liang, Xiaojing; Wang, Licheng; Guo, Yong; Liu, Xia; Jiang, Shengxiang
2013-12-13
A nanoporous array anodic titanium-supported co-polymeric ionic liquids (NAAT/PILs) solid-phase microextraction (SPME) fiber was prepared in situ on the titanium wire. NAAT was selected as the substrate, in view of its high surface-to-volume ratio, easy preparation, mechanical stability, and rich titanol groups on its surface which can anchor silica coupling agent containing vinyl and then introduce ionic liquid copolymers as sorbents. In this work, 1-vinyl-3-nonanol imidazolium bromide ([C9OHVIm]Br) and 1,4-di(3-vinylimidazolium) butane dibromide ([(VIM)2C4]2[Br]) were synthesized and used as monomer and crosslinker, respectively. Extraction properties of the NAAT/PILs fiber for polar alcohols and volatile fatty acids (VFAs) in aqueous matrix were examined using gaseous sampling-SPME (GS-SPME) and headspace SPME (HS-SPME) mode, respectively. Combining the superior properties of NAAT substrate and the strong hydrogen bond interaction of PILs to polar compounds, the NAAT/PILs SPME fiber showed much higher adsorption affinity to aliphatic alcohols than bare NAAT and pure PILs fibers. The detection limits (LOD) of established GS-SPME-GC-FID method are in the range of 0.35-17.30ngL(-1) with a linear range from 0.01 to 500ngmL(-1). Also, it showed high extraction performance toward volatile fatty acids (VFAs) compounds from aqueous matrix. Under the optimized SPME conditions, wide linear ranges were obtained with correlation coefficients (R(2)) greater than 0.99 and limits of detection were in the range of 0.85-8.74ngL(-1). Moreover, real-world samples were analyzed and good results were obtained. Copyright © 2013. Published by Elsevier B.V.
Dynamic properties along the neutral line of a delta spot inferred from high-resolution observations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cristaldi, A.; Guglielmino, S. L.; Zuccarello, F.
2014-07-10
Delta (δ) spots are complex magnetic configurations of sunspots characterized by umbrae of opposite polarity sharing a common penumbra. In order to investigate the fine structure of the region separating the two magnetic polarities of a δ spot, we studied the morphology, the magnetic configuration, and the velocity field in such a region using observations of active region (AR) NOAA 11267 obtained with the CRisp Imaging SpectroPolarimeter (CRISP) at the Swedish Solar Telescope on 2011 August 6. The analysis of CRISP data shows upflows and downflows of ∼ ± 3 km s{sup –1} in proximity of the δ spot polaritymore » inversion line (PIL), and horizontal motions along the PIL of the order of ∼1 km s{sup –1}. The results obtained from the SIR inversion of CRISP data also indicate that the transverse magnetic field in the brighter region separating the two opposite magnetic polarities of the δ spot is tilted about ∼45° with respect to the PIL. Solar Dynamics Observatory/Helioseismic and Magnetic Imager observations confirm the presence of motions of ∼ ± 3 km s{sup –1} in proximity of the PIL, which were observed to last 15 hr. From the data analyzed, we conclude that the steady, persistent, and subsonic motions observed along the δ spot PIL can be interpreted as being due to Evershed flows occurring in the penumbral filaments that show a curved, wrapped configuration. The fluting of the penumbral filaments and their bending, continuously increased by the approaching motion of the negative umbra toward the positive one, give rise to the complex line-of-sight velocity maps that we observed.« less
Trujillo-Rodríguez, María J; Nan, He; Anderson, Jared L
2018-03-09
Three crosslinked polymeric ionic liquid (PIL) sorbent coatings were used in headspace solid-phase microextraction for the determination of a group of ultraviolet filters. The developed crosslinked PIL-based materials include two polycations and a double confined PIL. The method, in combination with gas chromatography-mass spectrometry, is simple, solvent free, and does not require of any derivatization step. After proper optimization of the methodologies with each developed fiber, the analytical performance was compared with a commercial polyacrylate fiber. A study of the normalized calibration slopes, obtained by dividing the calibration slope of each analyte by the coating volume, revealed that the crosslinked fibers can be used as alternatives to commercial fibers for the determination of the selected group of compounds. In particular, the coating nature of the PIL containing the 1-vinylbenzyl-3-hexadecylimidazolium bis[(trifluoromethyl)sulfonyl]imide IL as monomer and the 1,12-di(3-vinylbenzylimidazolium)dodecane bis[(trifluoromethyl)sulfonyl]imide IL as crosslinker is the most suitable for the extraction of the selected compounds despite their coating volume, being 3.6 times lower than the commercial polyacrylate fiber. For this fiber, wide linear ranges, correlation coefficients higher than 0.990, limits of detection ranging from 2.8 ng L -1 to 26 ng L -1 and relative standard deviations ranging from 2.5 to 15% were achieved. Finally, all proposed PIL-based fibers were applied towards the analysis of tap water, pool water and lake water, with the majority of the ultraviolet filters being detected and quantified in the last two types of samples. Copyright © 2018 Elsevier B.V. All rights reserved.
Herber, Oliver Rudolf; Gies, Verena; Schwappach, David; Thürmann, Petra; Wilm, Stefan
2014-10-02
The purpose of patient information leaflets (PILs) is to inform patients about the administration, precautions and potential side effects of their prescribed medication. Despite European Commission guidelines aiming at increasing readability and comprehension of PILs little is known about the potential risk information has on patients. This article explores patients' reactions and subsequent behavior towards risk information conveyed in PILs of commonly prescribed drugs by general practitioners (GPs) for the treatment of Type 2 diabetes, hypertension or hypercholesterolemia; the most frequent cause for consultations in family practices in Germany. We conducted six focus groups comprising 35 patients which were recruited in GP practices. Transcripts were read and coded for themes; categories were created by abstracting data and further refined into a coding framework. Three interrelated categories are presented: (i) The vast amount of side effects and drug interactions commonly described in PILs provoke various emotional reactions in patients which (ii) lead to specific patient behavior of which (iii) consulting the GP for assistance is among the most common. Findings show that current description of potential risk information caused feelings of fear and anxiety in the reader resulting in undesirable behavioral reactions. Future PILs need to convey potential risk information in a language that is less frightening while retaining the information content required to make informed decisions about the prescribed medication. Thus, during the production process greater emphasis needs to be placed on testing the degree of emotional arousal provoked in patients when reading risk information to allow them to undertake a benefit-risk-assessment of their medication that is based on rational rather than emotional (fearful) reactions.
Sun, Tao; Zhang, Lei; Yang, Yanjun; Qi, Jianshuang; Yan, Shufeng; Han, Xiaohua; Wang, Huizhong; Shen, Chenjia
2015-01-01
The auxin influx carriers auxin resistant 1/like aux 1 (AUX/LAX), efflux carriers pin-formed (PIN) (together with PIN-like proteins) and efflux/conditional P-glycoprotein (ABCB) are major protein families involved in auxin polar transport. However, how they function in responses to exogenous auxin and abiotic stresses in maize is largely unknown. In this work, the latest updated maize (Zea mays L.) reference genome sequence was used to characterize and analyze the ZmLAX, ZmPIN, ZmPILS and ZmABCB family genes from maize. The results showed that five ZmLAXs, fifteen ZmPINs, nine ZmPILSs and thirty-five ZmABCBs were mapped on all ten maize chromosomes. Highly diversified gene structures, nonconservative transmembrane helices and tissue-specific expression patterns suggested the possibility of function diversification for these genes. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze the expression patterns of ZmLAX, ZmPIN, ZmPILS and ZmABCB genes under exogenous auxin and different environmental stresses. The expression levels of most ZmPIN, ZmPILS, ZmLAX and ZmABCB genes were induced in shoots and were reduced in roots by various abiotic stresses (drought, salt and cold stresses). The opposite expression response patterns indicated the dynamic auxin transport between shoots and roots under abiotic stresses. Analysis of the expression patterns of ZmPIN, ZmPILS, ZmLAX and ZmABCB genes under drought, salt and cold treatment may help us to understand the possible roles of maize auxin transporter genes in responses and tolerance to environmental stresses. PMID:25742625
Abdelhamid, Muhammad E; Murdoch, Timothy; Greaves, Tamar L; O'Mullane, Anthony P; Snook, Graeme A
2015-07-21
We report the synthesis of new protic ionic liquids (PILs) based on aniline derivatives and the use of high-throughput (HT) techniques to screen possible candidates. In this work, a simple HT method was applied to rapidly screen different aniline derivatives against different acids in order to identify possible combinations that produce PILs. This was followed by repeating the HT process with a Chemspeed robotic synthesis platform for more accurate results. One of the successful combinations were then chosen to be synthesised on a larger scale for further analysis. The new PILs are of interest to the fields of ionic liquids, energy storage and especially, conducting polymers as they serve as solvents, electrolytes and monomers at the same time for possible electropolymerisation (i.e. a self-contained polymer precursor).
DOE Office of Scientific and Technical Information (OSTI.GOV)
Qiu, Jiong; Longcope, Dana W.; Cassak, Paul A.
2017-03-20
We present an analysis of the apparent elongation motion of flare ribbons along the polarity inversion line (PIL), as well as the shear of flare loops in several two-ribbon flares. Flare ribbons and loops spread along the PIL at a speed ranging from a few to a hundred km s{sup −1}. The shear measured from conjugate footpoints is consistent with the measurement from flare loops, and both show the decrease of shear toward a potential field as a flare evolves and ribbons and loops spread along the PIL. Flares exhibiting fast bidirectional elongation appear to have a strong shear, whichmore » may indicate a large magnetic guide field relative to the reconnection field in the coronal current sheet. We discuss how the analysis of ribbon motion could help infer properties in the corona where reconnection takes place.« less
Surampalli, Vijay; Ramaswamy, Srinath; Surendran, Deepanjali; Bammigatti, Chanaveerappa; Swaminathan, Rathinam Palamalai
2017-08-01
Primary Intestinal Lymphangiectasia (PIL) is a rare disease of unknown aetiology which presents in the paediatric age group with anasarca, diarrhoea, hypoproteinaemia, lymphoedema and chylous effusions. Tuberculosis, filariasis, chest trauma, malignancies and haematological disorders usually contribute to most cases of secondary lymphangiectasia and chylous effusions. We hereby describe a case of PIL presenting with chylous effusions which remained undiagnosed for eight years.
[Primary intestinal lymphangiectasia (Waldmann's disease)].
Vignes, S; Bellanger, J
2017-08-31
Primary intestinal lymphangiectasia (PIL), Waldmann's disease, is a rare disorder of unknown etiology characterized by dilated intestinal lacteals leading to lymph leakage into the small-bowel lumen and responsible for protein-losing enteropathy leading to lymphopenia, hypoalbuminemia and hypogammaglobulinemia. PIL is generally diagnosed before 3 years of age but may be diagnosed in older patients. The main symptom is bilateral lower limb edema. Edema may be moderate to severe including pleural effusion, pericarditis or ascites. Protein-losing enteropathy is confirmed by the elevated 24-h stool α1-antitrypsin clearance and diagnosis by endoscopic observation of intestinal lymphangiectasia with the corresponding histology of biopsies. Videocapsule endoscopy may be useful when endoscopic findings are not contributive. Several B-cell lymphomas of the gastrointestinal tract or with extra-intestinal localizations were reported in PIL patients. A long-term strictly low-fat diet associated with medium-chain triglyceride and liposoluble vitamin supplementation is the cornerstone of PIL medical management. Octreotide, a somatostatin analog, have been proposed with an inconsistent efficacy in association with diet. Surgical small-bowel resection is useful in the rare cases with segmental and localized intestinal lymphangiectasia. A prolonged clinical and biological follow-up is recommended. Copyright © 2017 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier SAS. All rights reserved.
FILAMENT CHANNEL FORMATION VIA MAGNETIC HELICITY CONDENSATION
DOE Office of Scientific and Technical Information (OSTI.GOV)
Knizhnik, K. J.; Antiochos, S. K.; DeVore, C. R.
2015-08-20
A major unexplained feature of the solar atmosphere is the accumulation of magnetic shear in the form of filament channels at photospheric polarity inversion lines (PILs). In addition to free energy, this shear represents magnetic helicity, which is conserved under reconnection. In this paper we address the problem of filament channel formation and show how filaments acquire their shear and magnetic helicity. The results of three-dimensional (3D) simulations using the Adaptively Refined Magnetohydrodynamics Solver are presented. Our findings support the model of filament channel formation by magnetic helicity condensation that was developed by Antiochos. We consider the small-scale photospheric twistingmore » of a quasi-potential flux system that is bounded by a PIL and contains a coronal hole (CH). The magnetic helicity injected by the small-scale photospheric motions is shown to inverse cascade up to the largest allowable scales that define the closed flux system: the PIL and the CH. This process produces field lines that are both sheared and smooth, and are sheared in opposite senses at the PIL and the CH. The accumulated helicity and shear flux are shown to be in excellent quantitative agreement with the helicity condensation model. We present a detailed analysis of the simulations, including comparisons of our analytical and numerical results, and discuss their implications for observations.« less
Pro-inflammatory cytokines can act as intracellular modulators of commensal bacterial virulence
Mahdavi, Jafar; Royer, Pierre-Joseph; Sjölinder, Hong S.; Azimi, Sheyda; Self, Tim; Stoof, Jeroen; Wheldon, Lee M.; Brännström, Kristoffer; Wilson, Raymond; Moreton, Joanna; Moir, James W. B.; Sihlbom, Carina; Borén, Thomas; Jonsson, Ann-Beth; Soultanas, Panos; Ala'Aldeen, Dlawer A. A.
2013-01-01
Interactions between commensal pathogens and hosts are critical for disease development but the underlying mechanisms for switching between the commensal and virulent states are unknown. We show that the human pathogen Neisseria meningitidis, the leading cause of pyogenic meningitis, can modulate gene expression via uptake of host pro-inflammatory cytokines leading to increased virulence. This uptake is mediated by type IV pili (Tfp) and reliant on the PilT ATPase activity. Two Tfp subunits, PilE and PilQ, are identified as the ligands for TNF-α and IL-8 in a glycan-dependent manner, and their deletion results in decreased virulence and increased survival in a mouse model. We propose a novel mechanism by which pathogens use the twitching motility mode of the Tfp machinery for sensing and importing host elicitors, aligning with the inflamed environment and switching to the virulent state. PMID:24107297
NASA Astrophysics Data System (ADS)
Ng, Chee Hoe; Adnan, M.
2018-01-01
This research aims to investigate the effect of integrating STEM education through Project-based Inquiry Learning (PIL) and the users of the STEM modules which consists of five projects on topic Space in Year One Mathematics Syllabus in Kurikulum Standard Sekolah Rendah (KSSR) of Malaysia. STEM education in primary school focuses on the introduces and awareness of students about the importance of STEM education. The projects in STEM modules are covering the different ethnic cultures in Malaysia. The modules are designed using the four phases in PIL. Concepts and the explanation of STEM education on each project are emphasized and provided in the modules so the teachers able to carry out the projects by using the modules. By using the modules in primary Mathematics, the students and teachers will be more understanding on how to integrate the Mathematics’ concepts in STEM education.
Protic ionic liquid modified electrocatalyst enables robust anode under cell reversal condition
NASA Astrophysics Data System (ADS)
Zhu, Zhengyu; Yan, Xiaocong; Tang, Haolin; Cai, Haopeng; Pan, Mu; Zhang, Haining; Luo, Jiangshui
2017-05-01
Pt/C has been commercially used as anode electrocatalyst for fuel cells but generally exhibits limited durability under conditions of fuel starvation and subsequent cell reversal. Herein we report an improved scaffold concept to simultaneously stabilize the catalyst against particle growth and reduce the adverse effects of cell reversal by modifying Pt/C with suitable protic ionic liquids (PILs). The modified Pt/C catalysts show enhanced cell reversal tolerance because of their high activity towards oxygen evolution reaction (OER), up to 300 mV lower overpotential compared to the unmodified Pt/C. Moreover, the PIL modified catalysts show better resistance to the loss of electrochemical surface area (ECSA) under simulated cell reversal conditions. The results indicate that modification of Pt/C catalysts with PILs is a promising strategy to enhance the stability and durability of electrocatalysts in fuel cell applications with the risk of frequent fuel starvation events, such as automotive fuel cells.
Fornari, Thais A; Donate, Paula B; Assis, Amanda F; Macedo, Claudia; Sakamoto-Hojo, Elza T; Donadi, Eduardo A; Passos, Geraldo A
2015-01-01
In autoimmune type 1 diabetes mellitus (T1D), auto-reactive clones of CD4+ and CD8+ T lymphocytes in the periphery evolve into pancreas-infiltrating T lymphocytes (PILs), which destroy insulin-producing beta-cells through inflammatory insulitis. Previously, we demonstrated that, during the development of T1D in non-obese diabetic (NOD) mice, a set of immune/inflammatory reactivity genes were differentially expressed in T lymphocytes. However, the posttranscriptional control involving miRNA interactions that occur during the evolution of thymocytes into PILs remains unknown. In this study, we postulated that miRNAs are differentially expressed during this period and that these miRNAs can interact with mRNAs involved in auto-reactivity during the progression of insulitis. To test this hypothesis, we used NOD mice to perform, for the first time, a comprehensive survey of miRNA and mRNA expression as thymocytes mature into peripheral CD3+ T lymphocytes and, subsequently, into PILs. Reconstruction of miRNA-mRNA interaction networks for target prediction revealed the participation of a large set of miRNAs that regulate mRNA targets related to apoptosis, cell adhesion, cellular regulation, cellular component organization, cellular processes, development and the immune system, among others. The interactions between miR-202-3p and the Ccr7 chemokine receptor mRNA or Cd247 (Cd3 zeta chain) mRNA found in PILs are highlighted because these interactions can contribute to a better understanding of how the lack of immune homeostasis and the emergence of autoimmunity (e.g., T1D) can be associated with the decreased activity of Ccr7 or Cd247, as previously observed in NOD mice. We demonstrate that these mRNAs are controlled at the posttranscriptional level in PILs.
Macedo, Claudia; Sakamoto-Hojo, Elza T.; Donadi, Eduardo A.; Passos, Geraldo A.
2015-01-01
In autoimmune type 1 diabetes mellitus (T1D), auto-reactive clones of CD4+ and CD8+ T lymphocytes in the periphery evolve into pancreas-infiltrating T lymphocytes (PILs), which destroy insulin-producing beta-cells through inflammatory insulitis. Previously, we demonstrated that, during the development of T1D in non-obese diabetic (NOD) mice, a set of immune/inflammatory reactivity genes were differentially expressed in T lymphocytes. However, the posttranscriptional control involving miRNA interactions that occur during the evolution of thymocytes into PILs remains unknown. In this study, we postulated that miRNAs are differentially expressed during this period and that these miRNAs can interact with mRNAs involved in auto-reactivity during the progression of insulitis. To test this hypothesis, we used NOD mice to perform, for the first time, a comprehensive survey of miRNA and mRNA expression as thymocytes mature into peripheral CD3+ T lymphocytes and, subsequently, into PILs. Reconstruction of miRNA-mRNA interaction networks for target prediction revealed the participation of a large set of miRNAs that regulate mRNA targets related to apoptosis, cell adhesion, cellular regulation, cellular component organization, cellular processes, development and the immune system, among others. The interactions between miR-202-3p and the Ccr7 chemokine receptor mRNA or Cd247 (Cd3 zeta chain) mRNA found in PILs are highlighted because these interactions can contribute to a better understanding of how the lack of immune homeostasis and the emergence of autoimmunity (e.g., T1D) can be associated with the decreased activity of Ccr7 or Cd247, as previously observed in NOD mice. We demonstrate that these mRNAs are controlled at the posttranscriptional level in PILs. PMID:26606254
Pacheco-Fernández, Idaira; Najafi, Ali; Pino, Verónica; Anderson, Jared L; Ayala, Juan H; Afonso, Ana M
2016-09-01
Several crosslinked polymeric ionic liquid (PIL)-based sorbent coatings of different nature were prepared by UV polymerization onto nitinol wires. They were evaluated in a direct-immersion solid-phase microextraction (DI-SPME) method in combination with high-performance liquid chromatography (HPLC) and diode array detection (DAD). The studied PIL coatings contained either vinyl alkyl or vinylbenzyl imidazolium-based (ViCnIm- or ViBCnIm-) IL monomers with different anions, as well as different dicationic IL crosslinkers. The analytical performance of these PIL-based SPME coatings was firstly evaluated for the extraction of a group of 10 different model analytes, including hydrocarbons and phenols, while exhaustively comparing the performance with commercial SPME fibers such as polydimethylsyloxane (PDMS), polyacrylate (PA) and polydimethylsiloxane/divinylbenzene (PDMS/DVB), and using all fibers under optimized conditions. Those fibers exhibiting a high selectivity for polar compounds were selected to carry out an analytical method for a group of 5 alkylphenols, including bisphenol-A (BPA) and nonylphenol (n-NP). Under optimum conditions, average relative recoveries of 108% and inter-day precision values (3 non-consecutive days) lower than 19% were obtained for a spiked level of 10µgL(-1). Correlations coefficients for the overall method ranged between 0.990 and 0.999, and limits of detection were down to 1µgL(-1). Tap water, river water, and bottled water were analyzed to evaluate matrix effects. Comparison with the PA fiber was also performed in terms of analytical performance. Partition coefficients (logKfs) of the alkylphenols to the SPME coating varied from 1.69 to 2.45 for the most efficient PIL-based fiber, and from 1.58 to 2.30 for the PA fiber. These results agree with those obtained by the normalized calibration slopes, pointing out the affinity of these PILs-based coatings. Copyright © 2016 Elsevier B.V. All rights reserved.
Lake, Amelia A; Speed, Chris; Brookes, Anna; Heaven, Ben; Adamson, Ashley J; Moynihan, Paula; Corbett, Sally; McColl, Elaine
2007-01-04
The aim of the LIFELAX randomised controlled trial (diet and lifestyle vs. laxatives in the management of chronic constipation) is to develop and evaluate a cost effective intervention to promote diet and lifestyle in the treatment and management of chronic constipation for older people in Primary Care. Constipation affects the quality of life in around 20% of older people in the community. In the 65 years plus population, a significant proportion of men and women both living in institutions (81% and 75% respectively) and free living (30% and 37% respectively) use laxatives. Approximately 42 million pounds is spent each year on prescribed laxatives in England in addition to laxatives purchased over the counter. Although bowel problems are often multifactorial, diet and lifestyle have an extremely important role in their management. This paper describes one aspect of the main study, the development and piloting of the Patient information leaflets (PILs). Following review of the literature and interviews with practitioners and patients, 8 PILs were designed on: constipation, activity, bowel health, fruit and vegetables, fibre, fluid, alternative therapies and laxatives. To check the patient's understanding of terms used in the PILS and the clarity and accessibility of the information understanding, cognitive interviews (CI) were used with nine patients (selected from 3 GP surgeries), aged > or = 55 years, who had received > or = 3 prescriptions of laxatives over 12 months. Interviews were recorded and transcribed. Changes made following the CI process included the lay-out, words used (e.g. 'exercise' was changed to 'activity', 'gut motility' changed to 'bowel movement') and descriptions and examples were adapted to be more appropriate for the target population. Pilot testing with CIs resulted in improvements in the PILs, which emphasises the need to pilot PILs with the target population before use. The techniques employed are relatively inexpensive and could be routinely used when preparing literature for research or clinical use including those intended for use with healthcare professionals and patients.
Zini, E M; Lanzola, G; Quaglini, S; Cornet, R
2018-01-01
Immunotherapy is effective for treating cancer, but it is also associated with a wide spectrum of adverse events. In order to detect them early, the patients need to be monitored at home, between the therapy administrations, e.g., by asking them to report outcomes, usually including symptoms and quality of life measures. For the collected data to be reusable, the symptoms need to be in a standardized form. The aim of this study is to explore the standardization of the information contained in the patient information leaflets (PILs) of immunotherapy drugs, by creating an interface terminology of immunotherapy-related adverse events, which should support a consistent collection of symptoms from the patients. PILs contain a significant amount of information in free text, but they mix patient-reportable and clinically assessable events. We extracted a list of patient-reportable adverse events, mapped them to reference terminologies and compared the mapping results to choose the best-performing reference terminology. The PILs standardization led to the extraction of 151 symptoms and 424 terms, including both preferred terms and synonyms in English and Italian. Among the reference terminologies we considered, SNOMED CT allowed us to map all concepts and became, hence, the main reference terminology for the resulting interface terminology. A preliminary validation on the PIL of a new immunotherapy drug showed that our interface terminology already contained all the mentioned symptoms. PILs provide a valuable source for determining adverse events. The resulting interface terminology includes Italian and English terms for patient-reportable adverse events for five immunotherapy drugs representative of their category. Further work will be undertaken to evaluate the usability of the interface terminology and the patients' experience and satisfaction with the proposed terms, made available for example through an app, as well as its effectiveness on data quality and quality of care. Copyright © 2017 Elsevier Inc. All rights reserved.
Winstone, Nicola; Wilson, Aaron J.; Morrow, Gavin; Boggiano, Cesar; Chiuchiolo, Maria J.; Lopez, Mary; Kemelman, Marina; Ginsberg, Arielle A.; Mullen, Karl; Coleman, John W.; Wu, Chih-Da; Narpala, Sandeep; Ouellette, Ian; Dean, Hansi J.; Lin, Feng; Sardesai, Niranjan Y.; Cassamasa, Holly; McBride, Dawn; Felber, Barbara K.; Pavlakis, George N.; Schultz, Alan; Hudgens, Michael G.; King, C. Richter; Zamb, Timothy J.; Parks, Christopher L.; McDermott, Adrian B.
2011-01-01
DNA priming has previously been shown to elicit augmented immune responses when administered by electroporation (EP) or codelivered with a plasmid encoding interleukin-12 (pIL-12). We hypothesized that the efficacy of a DNA prime and recombinant adenovirus 5 boost vaccination regimen (DNA/rAd5) would be improved when incorporating these vaccination strategies into the DNA priming phase, as determined by pathogenic simian immunodeficiency virus SIVmac239 challenge outcome. The whole SIVmac239 proteome was delivered in 5 separate DNA plasmids (pDNA-SIV) by EP with or without pIL-12, followed by boosting 4 months later with corresponding rAd5-SIV vaccine vectors. Remarkably, after repeated low-dose SIVmac239 mucosal challenge, we demonstrate 2.6 and 4.4 log reductions of the median SIV peak and set point viral loads in rhesus macaques (RMs) that received pDNA-SIV by EP with pIL-12 compared to the median peak and set point viral loads in mock-immunized controls (P < 0.01). In 5 out of 6 infected RMs, strong suppression of viremia was observed, with intermittent “blips” in virus replication. In 2 RMs, we could not detect the presence of SIV RNA in tissue and lymph nodes, even after 13 viral challenges. RMs immunized without pIL-12 demonstrated a typical maximum of 1.5 log reduction in virus load. There was no significant difference in the overall magnitude of SIV-specific antibodies or CD8 T-cell responses between groups; however, pDNA delivery by EP with pIL-12 induced a greater magnitude of SIV-specific CD4 T cells that produced multiple cytokines. This vaccine strategy is relevant for existing vaccine candidates entering clinical evaluation, and this model may provide insights into control of retrovirus replication. PMID:21734035
Everolimus for Primary Intestinal Lymphangiectasia With Protein-Losing Enteropathy.
Ozeki, Michio; Hori, Tomohiro; Kanda, Kaori; Kawamoto, Norio; Ibuka, Takashi; Miyazaki, Tatsuhiko; Fukao, Toshiyuki
2016-03-01
Primary intestinal lymphangiectasia (PIL), also known as Waldmann's disease, is an exudative enteropathy resulting from morphologic abnormalities in the intestinal lymphatics. In this article, we describe a 12-year-old boy with PIL that led to protein-losing enteropathy characterized by diarrhea, hypoalbuminemia associated with edema (serum albumin level: 1.0 g/dL), and hypogammaglobulinemia (serum IgG level: 144 mg/dL). Severe hypoalbuminemia, electrolyte abnormalities, and tetany persisted despite a low-fat diet and propranolol. Everolimus (1.6 mg/m(2)/day) was added to his treatment as an antiangiogenic agent. With everolimus treatment, the patient's diarrhea resolved and replacement therapy for hypoproteinemia was less frequent. Hematologic and scintigraphy findings also improved (serum albumin level: 2.5 g/dL). There were no adverse reactions during the 12-month follow-up. To the best of our knowledge, this is the first report of everolimus use in a patient with PIL. Copyright © 2016 by the American Academy of Pediatrics.
Pilot utilization plan for satellite data-based service for agriculture in Poland
NASA Astrophysics Data System (ADS)
Gatkowska, Martyna; Paradowski, Karol; Wróbel, Karolina
2017-10-01
The paper aims at demonstrating the assumptions and achievements of the Pilot Utilization Plan Activities performed within the Project ASAP "Advanced Sustainable Agricultural Production", co-financed by European Space Agency under the ARTES IAP Programme. Within the course of the project, the Pilot Utilization Plan (PilUP) activities are performed in order to develop the remote sensing based models, and further calibrate and validate them in order to achieve the accuracy, which meets the requirements of paying customers. The completion of the first PilUP resulted in development of the following models based of Landsat 8 and Sentinel 2 satellite data: model of homogenous polygons demarcation on the basis of comparison of electromagnetic scanning results and bare soil spectral reflectance, model of problematic areas indication and model for yield potential, delivered on the basis of NDVI map developed 1 month before harvest and the map of yield/collected yield derived from Users participating in PilUP. The second edition of the PilUP is being conducted between March 2017 until the end of 2017. This edition includes farmers and insurance companies. The following activities are planned: development of model for delimitation of loses due to unfavorable wintering of winter crops and validation of the model with in-situ data collected by the insurance companies in-field investigators, further enhancement of the model for homogenous polygons delimitation and primary indication of soil productivity and testing of the applicability and viability of map of problematic areas with the farmers.
Information sources used by parents to learn about medications they are giving their children.
Holappa, Miina; Ahonen, Riitta; Vainio, Kirsti; Hämeen-Anttila, Katri
2012-01-01
Previous studies have indicated the use of medication by children to be dependent on the attitudes of knowledge of their parents; however, little is known about sources parents might use in driving medication use decisions. The aim of this study was to describe the information sources that parents use regarding their children's medication and their perceptions of the reliability of these information sources. This study is part of a cross-sectional population survey with a random sample of 6000 children younger than 12 years. The response rate of the questionnaire was 67%. Parents were asked about the use of information sources and their perception of reliability with a list of 16 information sources. The information sources that parents reported having used were physicians (72%), patient information leaflets (PILs) (67%), public or school health nurses (52%), and pharmacists (44%). Regardless of the child's age, physicians were the parents' most-used information source. Physicians were the most-used information source also when the child had at least 1 of the 4 most common long-term diseases among children in Finland (asthma, diabetes, epilepsy, and juvenile idiopathic arthritis). Parents considered physicians (50%), PILs (31%), pharmacists (27%), nurses (20%), and public or school health nurses (17%) very reliable information sources. Finnish parents seek information from health care professionals and PILs when looking for information concerning their children's medication. Furthermore, they find health care professionals and PILs to be reliable information sources. Copyright © 2012 Elsevier Inc. All rights reserved.
Cho, Ye Won; Gonzales, Alfonso; Harwood, Thomas V; Huynh, Jessica; Hwang, Yeji; Park, Jun Sang; Trieu, Anthony Q; Italia, Parth; Pallipuram, Vivek K; Risser, Douglas D
2017-10-01
Many cyanobacteria exhibit surface motility powered by type 4 pili (T4P). In the model filamentous cyanobacterium Nostoc punctiforme, the T4P systems are arrayed in static, bipolar rings in each cell. The chemotaxis-like Hmp system is essential for motility and the coordinated polar accumulation of PilA on cells in motile filaments, while the Ptx system controls positive phototaxis. Using transposon mutagenesis, a gene, designated hmpF, was identified as involved in motility. Synteny among filamentous cyanobacteria and the similar expression patterns for hmpF and hmpD imply that HmpF is part of the Hmp system. Deletion of hmpF produced a phenotype distinct from other hmp genes, but indistinguishable from pilB or pilQ. Both an HmpF-GFPuv fusion protein, and PilA, as assessed by in situ immunofluorescence, displayed coordinated, unipolar localization at the leading pole of each cell. Reversals were modulated by changes in light intensity and preceded by the migration of HmpF-GFPuv to the lagging cell poles. These results are consistent with a model where direct interaction between HmpF and the T4P system activates pilus extension, the Hmp system facilitates coordinated polarity of HmpF to establish motility, and the Ptx system modulates HmpF localization to initiate reversals in response to changes in light intensity. © 2017 John Wiley & Sons Ltd.
NASA Astrophysics Data System (ADS)
Kang, S.; Kim, K.; Park, G.; Ban, J.; Park, D.; Bae, M. S.; Shin, H. J.; Lee, M.; Seo, Y.; Choi, J.; Jung, D.; Seo, S.; Lee, T.; Kim, D. S.
2016-12-01
Aerosols have an important effect from scattering and absorbing the solar energy and indirectly by acting as cloud condensation nuclei and also some of the effects of aerosols are reduction in visibility, deterioration of human health, and deposition of pollutants to ecosystems. In various experimental results were showed that organic compounds have an important fraction from 10 to 70% of the total aerosol mass. Organic carbon contains water-soluble organic carbon (WSOC) and water insoluble organic carbon. WSOC are involved in the most unknown liquid-phase chemistry of wet aerosol and clouds. It is also worked as cloud condensation nuclei (CCN). Formation of secondary organic aerosol by chemical reaction of hydrocarbon compounds is a source of main pollution of WSOC compounds. Study of pollution source of WSOC is important method for creation process of secondary organic aerosol that completely has not studied.Analysis of WSOC is important and need to real-time measurement system for definition of chemical cause and sources. In this study, Particle-into-liquid sampler (PILS) coupled with total organic carbon (TOC) analyser and ion chromatography (PILS-TOC-IC), was used for semi-continuous measurement of WSOC and ionic compounds of PM2.5 during April-June 2016 at Baengnyeong Island Atmospheric Research Center, operated by the Korea National Institute of Environmental Research (NIER). PILS-TOC-IC can provide chemical information about real-time changes from ions composition and concentrations of WSOC and ionic compounds.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Georgoulis, Manolis K.; Titov, Viacheslav S.; Mikic, Zoran
Using solar vector magnetograms of the highest available spatial resolution and signal-to-noise ratio, we perform a detailed study of electric current patterns in two solar active regions (ARs): a flaring/eruptive and a flare-quiet one. We aim to determine whether ARs inject non-neutralized (net) electric currents in the solar atmosphere, responding to a debate initiated nearly two decades ago that remains inconclusive. We find that well-formed, intense magnetic polarity inversion lines (PILs) within ARs are the only photospheric magnetic structures that support significant net current. More intense PILs seem to imply stronger non-neutralized current patterns per polarity. This finding revises previousmore » works that claim frequent injections of intense non-neutralized currents by most ARs appearing in the solar disk but also works that altogether rule out injection of non-neutralized currents. In agreement with previous studies, we also find that magnetically isolated ARs remain globally current-balanced. In addition, we confirm and quantify the preference of a given magnetic polarity to follow a given sense of electric currents, indicating a dominant sense of twist in ARs. This coherence effect is more pronounced in more compact ARs with stronger PILs and must be of sub-photospheric origin. Our results yield a natural explanation of the Lorentz force, invariably generating velocity and magnetic shear along strong PILs, thus setting a physical context for the observed pre-eruption evolution in solar ARs.« less
Effects of art therapy using color on purpose in life in patients with stroke and their caregivers.
Kim, Mi Kyoung; Kang, Sung Don
2013-01-01
Patients with stroke suffer from physical disabilities, followed by mental instability. Their caregivers also suffer from mental instability. The present study attempted to address the degree and the change of the level of Purpose in Life (PIL) in patients with stroke and caregivers by applying art therapy using colors. Twenty-eight stroke patients with a good functional recovery or a moderate disability and their 28 caregivers were selected and evaluated. The period of the study between the stroke and color therapy was more than 6 months. Patients and caregivers were divided into the color therapy (28) and control groups (28). A questionnaire, which measures the level of PIL was conducted separately for patients and caregivers prior to the first session of color therapy (2 hours per week, total 16 sessions). The final examination was performed 5 months after the last color therapy session. There was significant difference between before and after color therapy when the level of PIL was measured both in patients and caregivers (p<0.01). These were the same between the color therapy group, compared with the control group (p<0.01). As color therapy progressed to the late phase, patients and caregivers applied increasing number of colors and color intensity. These results prove that color therapy will improve PIL of the patients with post-stroke disability and caregivers. Furthermore, color therapy would be a useful adjuvant for improving the quality of life of the patients with stroke and their caregivers.
Mokrzan, Elaine M.; Ward, Michael O.
2016-01-01
ABSTRACT Nontypeable Haemophilus influenzae (NTHI), a commensal of the human nasopharynx (hNP), is a common cause of biofilm-associated diseases of the respiratory tract. However, NTHI biofilm biology at the average hNP temperature, i.e., 34°C, has not been well studied. Here we grew NTHI biofilms at 34°C and 37°C, to evaluate relative biofilm growth, expression, and function of the type IV pilus (Tfp), a critical adhesin important for NTHI biofilm formation. The kinetics and regulation of Tfp expression in NTHI biofilms are unclear, especially at 34°C. Tfp expression, as estimated by pilA promoter activity, was distributed throughout the biofilms, with a unique pattern that was dependent on temperature, time in culture, and position within the maturing biofilm. Tfp expression was required for the formation of the characteristic tower structures of NTHI biofilms and was significantly upregulated in NTHI biofilms formed at 34°C versus 37°C. This increase correlated with significantly greater twitching motility at 34°C than at 37°C. Treatment with antisera targeting the major subunit of Tfp (PilA) significantly inhibited NTHI biofilm formation at both temperatures, confirming the importance of this critical adhesin in biofilm formation. Additionally, treatment of preestablished biofilms with antisera against PilA significantly decreased biofilm biomass and mean thickness at both temperatures. These results demonstrated a pivotal role for Tfp in NTHI biofilm formation and stability at the temperature of the hNP, and they underscore the utility of PilA as a vaccine candidate for treatment and/or prevention of NTHI biofilm-associated diseases. IMPORTANCE NTHI is an important cause of chronic respiratory tract infections, including otitis media, chronic rhinosinusitis, and exacerbations of chronic obstructive pulmonary disease and cystic fibrosis. The chronic and recurrent nature of these diseases is attributed to the presence of bacterial biofilms, which are highly resistant to antimicrobials. We characterized NTHI biofilm growth and expression of PilA, the major subunit of the Tfp, at the temperature of the hNP, which is the commensal habitat of NTHI. Our results expand the current understanding of the role of Tfp during biofilm formation and maturation at the temperature of both the hNP and the middle ear, and they strengthen support for PilA as a vaccine candidate for the prevention and treatment of NTHI biofilm-associated diseases. PMID:27044626
Mokrzan, Elaine M; Ward, Michael O; Bakaletz, Lauren O
2016-10-01
Nontypeable Haemophilus influenzae (NTHI), a commensal of the human nasopharynx (hNP), is a common cause of biofilm-associated diseases of the respiratory tract. However, NTHI biofilm biology at the average hNP temperature, i.e., 34°C, has not been well studied. Here we grew NTHI biofilms at 34°C and 37°C, to evaluate relative biofilm growth, expression, and function of the type IV pilus (Tfp), a critical adhesin important for NTHI biofilm formation. The kinetics and regulation of Tfp expression in NTHI biofilms are unclear, especially at 34°C. Tfp expression, as estimated by pilA promoter activity, was distributed throughout the biofilms, with a unique pattern that was dependent on temperature, time in culture, and position within the maturing biofilm. Tfp expression was required for the formation of the characteristic tower structures of NTHI biofilms and was significantly upregulated in NTHI biofilms formed at 34°C versus 37°C. This increase correlated with significantly greater twitching motility at 34°C than at 37°C. Treatment with antisera targeting the major subunit of Tfp (PilA) significantly inhibited NTHI biofilm formation at both temperatures, confirming the importance of this critical adhesin in biofilm formation. Additionally, treatment of preestablished biofilms with antisera against PilA significantly decreased biofilm biomass and mean thickness at both temperatures. These results demonstrated a pivotal role for Tfp in NTHI biofilm formation and stability at the temperature of the hNP, and they underscore the utility of PilA as a vaccine candidate for treatment and/or prevention of NTHI biofilm-associated diseases. NTHI is an important cause of chronic respiratory tract infections, including otitis media, chronic rhinosinusitis, and exacerbations of chronic obstructive pulmonary disease and cystic fibrosis. The chronic and recurrent nature of these diseases is attributed to the presence of bacterial biofilms, which are highly resistant to antimicrobials. We characterized NTHI biofilm growth and expression of PilA, the major subunit of the Tfp, at the temperature of the hNP, which is the commensal habitat of NTHI. Our results expand the current understanding of the role of Tfp during biofilm formation and maturation at the temperature of both the hNP and the middle ear, and they strengthen support for PilA as a vaccine candidate for the prevention and treatment of NTHI biofilm-associated diseases. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
Tang, Sheng; Liu, Shujuan; Guo, Yong; Liu, Xia; Jiang, Shengxiang
2014-08-29
Ionic liquids (ILs) and polymeric ionic liquids (PILs) with unique and fascinating properties have drawn considerable interest for their use in separation science, especially in chromatographic techniques. In this article, significant contributions of ILs and PILs in the improvement of capillary electrophoresis and capillary electrochromatography are described, and a specific overview of the most relevant examples of their applications in the last five years is also given. Accordingly, some general conclusions and future perspectives in these areas are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.
Intestinal lymphangiectasia and reversible high liver stiffness.
Milazzo, Laura; Peri, Anna Maria; Lodi, Lucia; Gubertini, Guido; Ridolfo, Anna Lisa; Antinori, Spinello
2014-08-01
Primary intestinal lymphangiectasia (PIL) is a protein-losing enteropathy characterized by tortuous and dilated lymph channels of the small bowel. The main symptoms are bilateral lower limb edema, serosal effusions, and vitamin D malabsorption resulting in osteoporosis. We report here a case of long-lasting misdiagnosed PIL with a peculiar liver picture, characterized by a very high stiffness value at transient elastography, which decreased with clinical improvement. The complex interplay between lymphatic and hepatic circulatory system is discussed. © 2014 by the American Association for the Study of Liver Diseases.
Ren, Dabin; Almudevar, Anthony L; Murphy, Timothy F; Lafontaine, Eric R; Campagnari, Anthony A; Luke-Marshall, Nicole; Casey, Janet R; Pichichero, Michael E
2015-10-26
There is no licensed vaccine for Moraxella catarrhalis (Mcat), which is a prominent bacterium causing acute otitis media (AOM) in children and lower respiratory tract infections in adults. Nasopharyngeal (NP) colonization caused by respiratory bacteria results in natural immunization of the host. To identify Mcat antigens as vaccine candidates, we evaluated the development of naturally induced antibodies to 5 Mcat surface proteins in children 6-30 months of age during Mcat NP colonization and AOM. Human serum IgG against the recombinant Mcat proteins, outer membrane protein (OMP) CD, oligopeptide permease (Opp)A, hemagglutinin (Hag), Moraxella surface protein (Msp)22, and PilA clade 2 (PilA2) was quantitated by using an ELISA assay. There were 223 Mcat NP colonization episodes documented in 111 (60%) of 184 children in the study. Thirty five Mcat AOM episodes occurred in 30 (16%) of 184 children. All 5 Mcat candidate vaccine antigens evaluated stimulated a significant rise in serum IgG levles over time from 6 to 36 months of age (P<0.001), with a rank order as follows: Msp22=OppA>OMP CD=Hag=PilA2. Children with no detectable Mcat NP colonization showed a higher serum IgG level against OppA, Hag, and Msp22 compared to those with Mcat NP colonization (P<0.05). Individual data showed that some children responded to AOM with an antibody increase to one or more of the studied Mcat proteins but some children failed to respond. Serum antibody to Mcat candidate vaccine proteins OMP CD, OppA, Msp22, Hag, and PilA2 increased with age in naturally immunized children age 6-30 months following Mcat NP colonization and AOM. High antibody levels against OppA, Msp22, and Hag correlated with reduced carriage. The results support further investigation of these vaccine candidates in protecting against Mcat colonization and infection. Copyright © 2015 Elsevier Ltd. All rights reserved.
Ren, Dabin; Almudevar, Anthony L.; Murphy, Timothy F.; Lafontaine, Eric R.; Campagnari, Anthony A.; Luke-Marshall, Nicole; Casey, Janet R.; Pichichero, Michael E.
2015-01-01
Background There is no licensed vaccine for Moraxella catarrhalis (Mcat), which is a prominent bacterium causing acute otitis media (AOM) in children and lower respiratory tract infections in adults. Nasopharyngeal (NP) colonization caused by respiratory bacteria results in natural immunization of the host. To identify Mcat antigens as vaccine candidates, we evaluated the development of naturally induced antibodies to 5 Mcat surface proteins in children 6–30 months of age during Mcat NP colonization and AOM. Methods Human serum IgG against the recombinant Mcat proteins, outer membrane protein (OMP) CD, oligopeptide permease (Opp)A, hemagglutinin (Hag), Moraxella surface protein (Msp)22, and PilA clade 2 (PilA2) was quantitated by using an ELISA assay. Results There were 223 Mcat NP colonization episodes documented in 111 (60%) of 184 children in the study. Thirty five Mcat AOM episodes occurred in 30 (16%) of 184 children. All 5 Mcat candidate vaccine antigens evaluated stimulated a significant rise in serum IgG levles over time from 6 to 36 months of age (P < 0.001), with a rank order as follows: Msp22 = OppA > OMP CD = Hag = PilA2. Children with no detectable Mcat NP colonization showed a higher serum IgG level against OppA, Hag, and Msp22 compared to those with Mcat NP colonization (P < 0.05). Individual data showed that some children responded to AOM with an antibody increase to one or more of the studied Mcat proteins but some children failed to respond. Conclusions Serum antibody to Mcat candidate vaccine proteins OMP CD, OppA, Msp22, Hag, and PilA2 increased with age in naturally immunized children age 6–30 months following Mcat NP colonization and AOM. High antibody levels against OppA, Msp22, and Hag correlated with reduced carriage. The results support further investigation of these vaccine candidates in protecting against Mcat colonization and infection. PMID:26392013
Yang, Jiyong; Jiang, Yufeng; Guo, Ling; Ye, LIyan; Ma, Yanning; Luo, Yanping
2016-06-01
Vancomycin-resistant Enterococcus (VRE) has been identified in China. However, little is known about the spread of VRE isolates. The genetic relatedness of vancomycin-resistant Enterococcus faecium (VREfm) isolates was analyzed by pulsed-field gel electrophoresis (PFGE), their antimicrobial susceptibilities were analyzed by E-test and the VITEK 2 AST-GP67 test Kit, and their sequence types (STs) were investigated by multilocus sequence typing (MLST). S1-PFGE was used for plasmid profiling, and PCR and subsequent sequencing were performed to identify the virulence genes. A total of 96 nonduplicated VREfm isolates were obtained and categorized into 38 PFGE types (type 1-38). The predominant MLST type was ST78, while ST17, ST341, and ST342 were also sporadically identified. All types of clinical VREfm strains harbored the vanA gene; however, they carried plasmids of different sizes. While 92.1%, 71.1%, and 60.5% of VREfm strains carried hyl, scm, and ecbA genes, respectively, all of them were positive for esp, acm, sgrA, pilA, and pilB genes. Clonal VREfm spread was observed, and nonplasmid-mediated horizontal transfer of vancomycin-resistant gene might have conveyed resistance to some vancomycin-susceptible E. faecium strains. E. faecium ST78 carrying vanA gene was the most prevalent clone in this study. The high prevalence of virulence genes, including esp, hyl, acm, scm, ecbA, sgrA, pilA, and pilB, confirmed their important roles in the emergence of VREfm ST78 in nosocomial infections.
Design validation and labeling comprehension study for a new epinephrine autoinjector.
Edwards, Eric S; Edwards, Evan T; Gunn, Ronald; Patterson, Patricia; North, Robert
2013-03-01
To facilitate the correct use of epinephrine autoinjectors (EAIs) by patients and caregivers, a novel EAI (Auvi-Q) was designed to help minimize use-related hazards. To support validation of Auvi-Q final design and assess whether the instructions for use in the patient information leaflet (PIL) are effective in training participants on proper use of Auvi-Q. Healthy participants, 20 adult and 20 pediatric, were assessed for their ability to complete a simulated injection by following the Auvi-Q instructions for use. Participants relied only on the contents of the PIL and other labeling features (device labeling and its instructions for use, electronic voice instructions and visual prompts). The mean ± SD age of the adult and pediatric participants was 39.4 ± 11.6 and 10.9 ± 2.3 years, respectively. In total, 80% of adult and 35% of pediatric participants had prior experience with EAIs. All adults and 95% of pediatric participants completed a simulated injection on the first attempt; 1 pediatric participant required parental training and a second attempt. Three adult and 4 pediatric participants exhibited a noncritical issue while successfully completing the simulated injection. Most participants agreed that the injection steps were easy to follow and the PIL facilitated understanding on using Auvi-Q safely and effectively. The PIL and other labeling features were effective in communicating instructions for successful use of Auvi-Q. This study provided validation support for the final design and anticipated instructions for use of Auvi-Q. Copyright © 2013 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
Dickinson, Rebecca; Raynor, David K; Knapp, Peter; MacDonald, Jan
2017-04-01
Patient information leaflets (PILs) are required with all licensed medicines throughout the European Union (EU) and they must include information about all side effects and their likelihood. This has led to criticism of a lack of balance, with little information included about potential benefits. Recent European Medicines Agency guidance proposed the inclusion of benefit information, and this study examined the current prevalence and type of such information in PILs in the EU. A survey and content analysis of the English translation of PILs in the EUwas carried out. Random quota sampling was used on the most frequently dispensed (n = 50) and newly licensed medicines (n = 50) in 2011/2. Leaflets were searched for benefit information meeting predefined criteria, and data synthesised and categorised into 10 categories. Eighty-five (85%) leaflets described how the medicine works, with 45 providing information about the rationale for treatment (more commonly for newly licensed (32/50) than most commonly dispensed medicines (13/50; P < 0.001). Nearly half (47) did not describe whether the medicine was curative, symptomatic or preventative. The terms used to communicate uncertainty were imprecise (such as 'may help'). None communicated numerical benefit information. Current PILs do not appropriately communicate information about benefit. At the basic level, around a half did not include information about treatment rationale or whether the treatment was to treat symptoms, curative or preventative. However, for true informed decision making, patients need quantitative information about benefits and none of the leaflets provided this. © 2016 Royal Pharmaceutical Society.
DOE Office of Scientific and Technical Information (OSTI.GOV)
McDanel, WM; Cowan, MG; Barton, JA
2015-04-29
New imidazolium- and pyrrolidinium-based bis(epoxide)-functionalized ionic liquid (IL) monorners were synthesized: and reacted with multifunctional amine monomers to produce cross-linked, epoxy-amine poly(ionic liquid) (PIL) resins and PIL/IL ion-gel membranes. The length and chemical nature (i.e., alkyl versus ether) between the irrildazolium group and epokitie groups were studied to determine their effects on CO2 affinity. The CO2 uptake (millimoles per gram) of the epoxy amine resins (between 0.1 and 1 mmol/g) was found to depend predominately on the epoxide-to-amine ratio and the bis(epoxide) IL molecular weight. The effect of using a primary versus a secondary amine-containing multifunctional monoiner was also assessedmore » for the resin-synthesis. Secondary amines can increase CO2 permeability but also increase the iime required for biS(epoxide) coriversion. When either the epoxide or athine monomer structure is changed, the CO2 solubility and permeability of the resulting PIL resins and ion-sel membranes can be tuned.« less
Feng, Xueling; Zhang, Kaihuan; Chen, Peng; Sui, Xiaofeng; Hempenius, Mark A; Liedberg, Bo; Vancso, G Julius
2016-12-01
Highly swellable, dual-responsive hydrogels, consisting of thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) and redox-responsive poly(ferrocenylsilane) (PFS) based poly(ionic liquid)s (PILs) are formed by photo-polymerization. PFS chains bearing cross-linkable vinylimidazolium (VIm) side groups are copolymerized with NIPAM in aqueous solutions under ultraviolet light (λ = 365 nm) in the presence of a photoinitiator. The PFS-PILs serve as a macro-cross-linker and also provide redox responsiveness. The swelling ratio, morphology, and lower critical solution temperature (LCST) of the hydrogels are studied as a function of the PNIPAM/PFS ratio. The value of the LCST is dependent on the choice of the counterion of the PIL and the PNIPAM/PFS ratio. The hydrogel is employed as a reducing environment for the in situ fabrication of gold nanoparticles (AuNPs), forming AuNP-hydrogel composites. The localized surface plasmon resonance peak of the as-synthesized Au nanoparticles inside the hydrogel could be tuned by altering the temperature. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Zhang, Biao; Sudre, Guillaume; Quintard, Guilhem; Serghei, Anatoli; David, Laurent; Bernard, Julien; Fleury, Etienne; Charlot, Aurélia
2017-02-10
In this study, we report on the simple and straightforward preparation of ionogels arising from the addition of guar gum (a plant-based polysaccharide) in a solution of precisely-defined poly(ionic liquid) chains (PIL) in imidazolium-based ionic liquid (IL). The development of intermolecular polar interactions (mainly hydrogen bonds) and topologic chain entanglements induces the formation of physical biohybrid ionogels, whose elastic properties can be easily tuned by varying the composition (up to 30000Pa). The combined presence of guar gum and PIL confers excellent dimensional stability to the ionogels with no IL exudation combined with high thermal properties (up to 310°C). The resulting materials are shown to exhibit gel scattering profiles and high conductivities (> 10 -4 S/cm at 30°C). The benefit linked to the formation of guar/PIL associations in IL medium enables to find a good compromise between the mechanical cohesion and the mobility ensuring the ionic transport. Copyright © 2016 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Sanoja, Gabriel; Popere, Bhooshan; Beckingham, Bryan; Evans, Christopher; Lynd, Nathaniel; Segalman, Rachel
Elucidating the relationship between chemical structure, morphology, and ionic conductivity is essential for designing novel materials for electrochemical applications. In this work, the effect of lamellar domain spacing (d) on ionic conductivity (σ) is investigated for a model system of hydrated block copolymer based on a protic polymerized ionic liquid. We present a strategy that allows for the synthesis of a well-defined series of narrowly dispersed PS- b - PIL with constant volume fraction of ionic liquid moieties (fIL ~ 0.39). These materials self-assemble into ordered lamellar morphologies with variable domain spacing (23-59 nm) as demonstrated by SAXS. PS- b - PIL membranes exhibit ionic conductivities above 10-4 S/cm at room temperature, which are independent of domain spacing. The conductivity scaling relationship demonstrated in this work suggests that a mechanically robust membrane can be designed without compromising its ability to transport ions. In addition, PIL-based membranes exhibit lower water uptake (λ = 10) in comparison with many proton-conducting systems reported elsewhere. The low water content of these materials makes them promising candidates for solar-fuels electrochemical devices.
Khayatan, Behzad; Bains, Divleen K; Cheng, Monica H; Cho, Ye Won; Huynh, Jessica; Kim, Rachelle; Omoruyi, Osagie H; Pantoja, Adriana P; Park, Jun Sang; Peng, Julia K; Splitt, Samantha D; Tian, Mason Y; Risser, Douglas D
2017-05-01
Most species of filamentous cyanobacteria are capable of gliding motility, likely via a conserved type IV pilus-like system that may also secrete a motility-associated polysaccharide. In a subset of these organisms, motility is achieved only after the transient differentiation of hormogonia, which are specialized filaments that enter a nongrowth state dedicated to motility. Despite the fundamental importance of hormogonia to the life cycles of many filamentous cyanobacteria, the molecular regulation of hormogonium development is largely undefined. To systematically identify genes essential for hormogonium development and motility in the model heterocyst-forming filamentous cyanobacterium Nostoc punctiforme , a forward genetic screen was employed. The first gene identified using this screen, designated ogtA , encodes a putative O-linked β- N -acetylglucosamine transferase (OGT). The deletion of ogtA abolished motility, while ectopic expression of ogtA induced hormogonium development even under hormogonium-repressing conditions. Transcription of ogtA is rapidly upregulated (1 h) following hormogonium induction, and an OgtA-GFPuv fusion protein localized to the cytoplasm. In developing hormogonia, accumulation of PilA but not HmpD is dependent on ogtA Reverse transcription-quantitative PCR (RT-qPCR) analysis indicated equivalent levels of pilA transcript in the wild-type and Δ ogtA mutant strains, while a reporter construct consisting of the intergenic region in the 5' direction of pilA fused to gfp produced lower levels of fluorescence in the Δ ogtA mutant strain than in the wild type. The production of hormogonium polysaccharide in the Δ ogtA mutant strain is reduced compared to that in the wild type but comparable to that in a pilA deletion strain. Collectively, these results imply that O -GlcNAc protein modification regulates the accumulation of PilA via a posttranscriptional mechanism in developing hormogonia. IMPORTANCE Filamentous cyanobacteria are among the most developmentally complex prokaryotes. Species such as Nostoc punctiforme develop an array of cell types, including nitrogen-fixing heterocysts, spore-like akinetes, and motile hormogonia, that function in dispersal as well as the establishment of nitrogen-fixing symbioses with plants and fungi. These symbioses are major contributors to global nitrogen fixation. Despite the fundamental importance of hormogonia to the life cycle of filamentous cyanobacteria and the establishment of symbioses, the molecular regulation of hormogonium development is largely undefined. We employed a genetic screen to identify genes essential for hormogonium development and motility in Nostoc punctiforme The first gene identified using this screen encodes a eukaryotic-like O-linked β- N -acetylglucosamine transferase that is required for accumulation of PilA in hormogonia. Copyright © 2017 American Society for Microbiology.
Hou, Xiudan; Guo, Yong; Liang, Xiaojing; Wang, Xusheng; Wang, Lei; Wang, Licheng; Liu, Xia
2016-06-01
A class of novel, environmental friendly ionic liquids (ILs) were synthesized by on-fiber preparation strategy and modified on graphene oxide (GO)-coated stainless steel wire, which was used as a solid-phase microextraction (SPME) fiber for efficient enrichment of polycyclic aromatic hydrocarbons (PAHs) and phthalate esters (PAEs). Surface characteristic of the ILs and polymeric-ILs (PILs) fibers with the wave-structure were inspected by scanning electron microscope. The successfully synthesis of bis(trifluoromethanesulfonyl)imide (NTf2(-))-based ILs were also characterized by energy dispersive spectrometer analysis. Through the chromatograms of the proposed two ILs (1-aminoethyl-3-methylimidazolium bromide (C2NH2MIm(+)Br(-)), C2NH2MIm(+)NTf2(-)) and two PILs (polymeric 1-vinyl-3-hexylimidazolium bromide (poly(VHIm(+)Br(-))), poly(VHIm(+)NTf2(-)))-GO-coated fibers for the extraction of analytes, NTf2(-)-based PIL demonstrated higher extraction capacity for hydrophobic compounds than other as-prepared ILs. Analytical performances of the proposed fibers were investigated under the optimized extraction and desorption conditions coupled with gas chromatography (GC). Compared with the poly(VHIm(+)Br(-))-GO fiber, the poly(VHIm(+)NTf2(-))-GO SPME fiber brought wider linear ranges for analytes with correlation coefficient in the range of 0.9852-0.9989 and lower limits of detection ranging from 0.015-0.025μgL(-1). The obtained results indicated that the newly prepared PILs-GO coating was a feasible, selective and green microextraction medium, which could be suitable for extraction and determination of PAHs and PAEs in potatoes and food-wrap sample, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.
Tomioka, Kimiko; Kurumatani, Norio; Hosoi, Hiroshi
2016-01-01
Background This study’s aim was to clarify the relationship of having hobbies and a purpose in life (PIL; in Japanese, ikigai) with mortality and a decline in the activities of daily living (ADL) and instrumental ADL (IADL) among the community-dwelling elderly. Methods Prospective observational data from residents aged ≥65 years who were at increased risk for death (n = 1853) and developing a decline in ADL (n = 1254) and IADL (n = 1162) were analyzed. Cox proportional hazard models were used for mortality analysis of data from February 2011 to November 2014. ADL and IADL were evaluated using the Barthel Index and the Tokyo Metropolitan Institute of Gerontology Index of Competence, respectively. ADL and IADL were assessed at baseline and follow-up and were evaluated using logistic regression models. Fully adjusted models included terms for age, gender, BMI, income, alcohol intake, smoking history, number of chronic diseases, cognitive function, and depression. Results During the follow-up of eligible participants, 248 had died, 119 saw a decline in ADL, and 178 saw a decline in IADL. In fully adjusted models, having neither hobbies nor PIL was significantly associated with an increased risk of mortality (hazard ratio 2.08; 95% confidence interval [CI], 1.47–2.94), decline in ADL (odds ratio 2.74; 95% CI, 1.44–5.21), and decline in IADL (odds ratio 1.89; 95% CI, 1.01–3.55) compared to having both hobbies and PIL. Conclusions Although effect modifications by cognitive functioning and depression cannot be ruled out, our findings suggest that having hobbies and PIL may extend not only longevity, but also healthy life expectancy among community-dwelling older adults. PMID:26947954
Tomioka, Kimiko; Kurumatani, Norio; Hosoi, Hiroshi
2016-07-05
This study's aim was to clarify the relationship of having hobbies and a purpose in life (PIL; in Japanese, ikigai) with mortality and a decline in the activities of daily living (ADL) and instrumental ADL (IADL) among the community-dwelling elderly. Prospective observational data from residents aged ≥65 years who were at increased risk for death (n = 1853) and developing a decline in ADL (n = 1254) and IADL (n = 1162) were analyzed. Cox proportional hazard models were used for mortality analysis of data from February 2011 to November 2014. ADL and IADL were evaluated using the Barthel Index and the Tokyo Metropolitan Institute of Gerontology Index of Competence, respectively. ADL and IADL were assessed at baseline and follow-up and were evaluated using logistic regression models. Fully adjusted models included terms for age, gender, BMI, income, alcohol intake, smoking history, number of chronic diseases, cognitive function, and depression. During the follow-up of eligible participants, 248 had died, 119 saw a decline in ADL, and 178 saw a decline in IADL. In fully adjusted models, having neither hobbies nor PIL was significantly associated with an increased risk of mortality (hazard ratio 2.08; 95% confidence interval [CI], 1.47-2.94), decline in ADL (odds ratio 2.74; 95% CI, 1.44-5.21), and decline in IADL (odds ratio 1.89; 95% CI, 1.01-3.55) compared to having both hobbies and PIL. Although effect modifications by cognitive functioning and depression cannot be ruled out, our findings suggest that having hobbies and PIL may extend not only longevity, but also healthy life expectancy among community-dwelling older adults.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gosain, S., E-mail: sgosain@nso.edu; Udaipur Solar Observatory, P.O. Box 198, Dewali, Udaipur, Rajasthan 313001
2012-04-10
We use high-resolution Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly observations to study the evolution of the coronal loops in a flaring solar active region, NOAA 11158. We identify three distinct phases of the coronal loop dynamics during this event: (1) slow-rise phase: slow rising motion of the loop-tops prior to the flare in response to the slow rise of the underlying flux rope; (2) collapse phase: sudden contraction of the loop-tops, with the lower loops collapsing earlier than the higher loops; and (3) oscillation phase: the loops exhibit global kink oscillations after the collapse phase at different periods, with themore » period decreasing with the decreasing height of the loops. The period of these loop oscillations is used to estimate the field strength in the coronal loops. Furthermore, we also use SDO/Helioseismic and Magnetic Imager (HMI) observations to study the photospheric changes close to the polarity inversion line (PIL). The longitudinal magnetograms show a stepwise permanent decrease in the magnetic flux after the flare over a coherent patch along the PIL. Furthermore, we examine the HMI Stokes I, Q, U, V profiles over this patch and find that the Stokes-V signal systematically decreases while the Stokes-Q and U signals increase after the flare. These observations suggest that close to the PIL the field configuration became more horizontal after the flare. We also use HMI vector magnetic field observations to quantify the changes in the field inclination angle and find an inward collapse of the field lines toward the PIL by {approx}10 Degree-Sign . These observations are consistent with the 'coronal implosion' scenario and its predictions about flare-related photospheric field changes.« less
Imprecise intron losses are less frequent than precise intron losses but are not rare in plants.
Ma, Ming-Yue; Zhu, Tao; Li, Xue-Nan; Lan, Xin-Ran; Liu, Heng-Yuan; Yang, Yu-Fei; Niu, Deng-Ke
2015-05-27
In this study, we identified 19 intron losses, including 11 precise intron losses (PILs), six imprecise intron losses (IILs), one de-exonization, and one exon deletion in tomato and potato, and 17 IILs in Arabidopsis thaliana. Comparative analysis of related genomes confirmed that all of the IILs have been fixed during evolution. Consistent with previous studies, our results indicate that PILs are a major type of intron loss. However, at least in plants, IILs are unlikely to be as rare as previously reported. This article was reviewed by Jun Yu and Zhang Zhang. For complete reviews, see the Reviewers' Reports section.
CO2 Responsive Imidazolium-Type Poly(Ionic Liquid) Gels.
Zhang, Jing; Xu, Dan; Guo, Jiangna; Sun, Zhe; Qian, Wenjing; Zhang, Ye; Yan, Feng
2016-07-01
Poly(ionic liquid) (PIL) gels with CO2 stimulus responsiveness have been synthesized through the copolymerization of an imidazolium-type ionic liquid monomer with 2-(dimethyl amino) ethyl methacrylate. Upon bubbling with CO2 gas, the prepared PIL solution is converted to a transparent and stable gel, which can be turned back to the initial solution state after N2 bubbling. The reversible sol-gel phase transition behavior is proved by the reversible values of viscosity and ionic conductivity. The possible mechanism for such a reversible sol-gel phase transition is demonstrated by NMR, conductivity, and rheological measurements. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Ionic Liquids and Poly(ionic liquid)s for Morphosynthesis of Inorganic Materials.
Gao, Min-Rui; Yuan, Jiayin; Antonietti, Markus
2017-04-24
Ionic liquids (ILs) are new, innovative ionic solvents with rich physicochemical properties and intriguing pre-organized solvent structures; these materials offer great potential to impact across versatile areas of scientific research, for example, synthetic inorganic chemistry. Recent use of ILs as precursors, templates, and solvents has led to inorganic materials with tailored sizes, dimensionalities, morphologies, and functionalities that are difficult to obtain, or even not accessible, by using conventional solvents. Poly(ionic liquid)s (PILs) polymerized from IL monomers also raise the prospect of modifying nucleation, growth, and crystallization of inorganic objects, shedding light on the synthesis of a wide range of new materials. Here we survey recent key progress in using ILs and PILs in the field of synthetic inorganic chemistry. As well as highlighting the unique features of ILs and PILs that enable advanced synthesis, the effects of adding other solvents to the final products, along with the emerging applications of the created inorganic materials will be discussed. We finally provide an outlook on several development opportunities that could lead to new advancements of this exciting research field. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Studies of pilocarpine:carbomer intermolecular interactions.
Zoppi, Ariana; Linck, Yamila Garro; Monti, Gustavo A; Genovese, Diego B; Jimenez Kairuz, Alvaro F; Manzo, Rubén H; Longhi, Marcela R
2012-05-10
The interactions between pilocarpine (PIL) and the anionic polyelectrolyte carbomer (CBR) were investigated. The effects of the chemical interactions on the chemical stability of the drug also were evaluated. The binary system was characterized by nuclear magnetic resonance techniques, Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction, scanning electron microscopy (SEM) and thermal analysis. The experiments showed that the complex, prepared by freeze-drying, is a solid amorphous form different from its precursors, thereby offering an interesting alternative for the preparation of extended release matrices. The solution stability of PIL was studied at pH 7 and 8, at 70 °C. The PIL solution stability was evaluated alone and in the presence of CBR. Results indicated that the drug in the presence of the polymer is 3.3 and 3.5 times more stable, at pH 7 and pH 8, respectively, than the drug without CBR. The activation energy and the frequency factor, according to Arrhenius plot, were estimated to be 13.9 ± 0.4 and 14.8 ± 0.5 kcalmol(-1), and 6.1 ± 0.3 and 7.6 ± 0.3, with and without the polymer, respectively. Copyright © 2012 Elsevier B.V. All rights reserved.
2017-01-01
We report on the synthesis and structure–property relations of a novel, dual-responsive organometallic poly(ionic liquid) (PIL), consisting of a poly(ferrocenylsilane) backbone of alternating redox-active, silane-bridged ferrocene units and tetraalkylphosphonium sulfonate moieties in the side groups. This PIL is redox responsive due to the presence of ferrocene in the backbone and also exhibits a lower critical solution temperature (LCST)-type thermal responsive behavior. The LCST phase transition originates from the interaction between water molecules and the ionic substituents and shows a concentration-dependent, tunable transition temperature in aqueous solution. The PIL’s LCST-type transition temperature can also be influenced by varying the redox state of ferrocene in the polymer main chain. As the polymer can be readily cross-linked and is easily converted into hydrogels, it represents a new dual-responsive materials platform. Interestingly, the as-formed hydrogels display an unusual, strongly hysteretic volume-phase transition indicating useful thermal memory properties. By employing the dispersing abilities of this cationic PIL, CNT-hydrogel composites were successfully prepared. These hybrid conductive composite hydrogels showed bi-stable states and tunable resistance in heating–cooling cycles. PMID:28654756
Okafuji, Akiyoshi; Kohno, Yuki; Ohno, Hiroyuki
2016-07-01
Here, a thermoresponsive phase behavior of polymerized ionic liquids (PILs) composed of poly([tri-n-alkyl(vinylbenzyl)phosphonium]chloride) (poly([Pnnn VB ]Cl) is reported, where n (the number of carbon atoms of an alkyl chain) = 4, 5, or 6 after mixing with aqueous sodium chloride solutions. Both monomeric [P555VB ]Cl and the resulting poly([P555VB ]Cl) linear homopolymer show a lower critical solution temperature (LCST)-type phase behavior in aq. NaCl solutions. The phase transition temperature of the PIL shifts to lower value by increasing concentration of NaCl. Also the swelling degree of cross-linked poly([P555VB ]Cl) gel decreases by increasing NaCl concentration, clearly suggesting the "salting-out" effect of NaCl results in a significant dehydration of the poly([P555VB ]Cl) gel. The absorbed water in the PIL gel is desorbed by moderate heating via the LCST behavior, and the absolute absorption/desorption amount is improved by copolymerization of [P555VB ]Cl with more hydrophilic [P444VB ]Cl monomer. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
NASA Astrophysics Data System (ADS)
Kasyan, V. V.
2018-03-01
The species composition, density, biomass, and distribution of zooplankton of the northeastern Sakhalin shelf, Sea of Okhotsk (Chaivo, Pil'tunskii, and Morskoi regions) were studied in October 2014. Zooplankton was represented by 15 taxonomic groups, which were dominated by Copepoda (13 species). The average density and biomass was highest in the Chaivo region (14112 ± 4322 ind./m3, 395 ± 107 mg/m3) and in the Pil'tunskii region (16692 ± 10707 ind./m3, 346 ± 233 mg/m3); the abundance of detected taxonomic groups was minimal (8-12). The average density and biomass of zooplankton was up to 4304 ± 2441 ind./m3, 133 ± 77 mg/m3 in the Morskoi region and increased with depth; the abundance of taxa was maximum (15). Four species of copepods made up the majority of the density and biomass of zooplankton: Acartia hudsonica, Eurytemora herdmani, Pseudocalanus newmani, and Oithona similis. In the Chaivo region, species of the genera Acartia, Eurytemora, and Oithona dominated and subdominated; in Pil'tunskii region, species of the genera Acartia and Oithona dominated and subdominated; and in the Morskoi region, species of the genera Oithona, Pseudocalanus, and Acartia dominated and subdominated.
Differential expression of genes of Xylella fastidiosa in xylem fluid of citrus and grapevine.
Shi, Xiangyang; Bi, Jianlong; Morse, Joseph G; Toscano, Nick C; Cooksey, Donald A
2010-03-01
Xylella fastidiosa causes a serious Pierce's disease (PD) in grapevine. Xylella fastidiosa cells from a PD strain were grown in a pure xylem fluid of a susceptible grapevine cultivar vs. xylem fluid from citrus, which is not a host for this strain of X. fastidiosa. When grown in grapevine xylem fluid, cells of the PD strain formed clumps and biofilm formed to a greater extent than in citrus xylem fluid, although the PD strain did grow in xylem fluid of three citrus varieties. The differential expression of selected genes of a PD X. fastidiosa strain cultured in the two xylem fluids was analyzed using a DNA macroarray. Compared with citrus xylem fluid, grapevine xylem fluid stimulated the expression of X. fastidiosa genes involved in virulence regulation, such as gacA, algU, xrvA, and hsq, and also genes involved in the biogenesis of pili and twitching motility, such as fimT, pilI, pilU, and pilY1. Increased gene expression likely contributes to PD expression in grapevine, whereas citrus xylem fluid did not support or possibly suppressed the expression of these virulence genes.
M13 bacteriophage purification using poly(ionic liquids) as alternative separation matrices.
Jacinto, Maria João; Patinha, David J S; Marrucho, Isabel M; Gonçalves, João; Willson, Richard C; Azevedo, Ana M; Aires-Barros, M Raquel
2018-01-12
M13 is a filamentous, non-lytic bacteriophage that infects Escherichia coli via the F pilus. Currently, phage M13 is widely used in phage display technology and bio-nanotechnology, and is considered a possible antibacterial therapeutic agent, among other applications. Conventional phage purification involves 5-7 operational steps, with high operational costs and significant product loss (approximately 60%). In this work, we propose a scalable purification process for M13 bacteriophage using a novel stationary phase based on a polymeric ionic liquid (PIL) with a positively charged backbone structure. Poly (1-vinyl-3-ethyl imidazolium bis(trifluoromethylsulfonyl) imide) - poly(VEIM-TFSI) predominantly acted as an anion exchanger under binding-elution mode. This revealed to be a rapid and simple method for the recovery of phage M13 with an overall separation yield of over 70% after a single downstream step. To the best of our knowledge, PILs have never been used as separation matrices for biological products and the results obtained, together with the large number of cations and anions available to prepare PILs, illustrate well the large potential of the proposed methodology. Copyright © 2017 Elsevier B.V. All rights reserved.
The role of pili in Bacillus cereus intraocular infection.
Callegan, Michelle C; Parkunan, Salai Madhumathi; Randall, C Blake; Coburn, Phillip S; Miller, Frederick C; LaGrow, Austin L; Astley, Roger A; Land, Craig; Oh, So-Young; Schneewind, Olaf
2017-06-01
Bacterial endophthalmitis is a potentially blinding intraocular infection. The bacterium Bacillus cereus causes a devastating form of this disease which progresses rapidly, resulting in significant inflammation and loss of vision within a few days. The outer surface of B. cereus incites the intraocular inflammatory response, likely through interactions with innate immune receptors such as TLRs. This study analyzed the role of B. cereus pili, adhesion appendages located on the bacterial surface, in experimental endophthalmitis. To test the hypothesis that the presence of pili contributed to intraocular inflammation and virulence, we analyzed the progress of experimental endophthalmitis in mouse eyes infected with wild type B. cereus (ATCC 14579) or its isogenic pilus-deficient mutant (ΔbcpA-srtD-bcpB or ΔPil). One hundred CFU were injected into the mid-vitreous of one eye of each mouse. Infections were analyzed by quantifying intraocular bacilli and retinal function loss, and by histology from 0 to 12 h postinfection. In vitro growth and hemolytic phenotypes of the infecting strains were also compared. There was no difference in hemolytic activity (1:8 titer), motility, or in vitro growth (p > 0.05, every 2 h, 0-18 h) between wild type B. cereus and the ΔPil mutant. However, infected eyes contained greater numbers of wild type B. cereus than ΔPil during the infection course (p ≤ 0.05, 3-12 h). Eyes infected with wild type B. cereus experienced greater losses in retinal function than eyes infected with the ΔPil mutant, but the differences were not always significant. Eyes infected with ΔPil or wild type B. cereus achieved similar degrees of severe inflammation. The results indicated that the intraocular growth of pilus-deficient B. cereus may have been better controlled, leading to a trend of greater retinal function in eyes infected with the pilus-deficient strain. Although this difference was not enough to significantly alter the severity of the inflammatory response, these results suggest a potential role for pili in protecting B. cereus from clearance during the early stages of endophthalmitis, which is a newly described virulence mechanism for this organism and this infection. Copyright © 2017 Elsevier Ltd. All rights reserved.
[Kim Pil Soon, a great doctor].
Park, H W
1998-01-01
Kim Pil Soon was born at Sorae Village of Hwang Hye Province, the birth place of the Protestantism in Korea. He was brought up under the strong influence of Christianity and received modern education at Pae Chae School according to the recommendation of Rev. Underwood. In 1899, Kim Pil Soon, who had been working at Je Joon Won as an assistant and interpreter of Dr. Sharrocks, was employed by Dr. Avison to help prepare medical textbooks and was asked to participate in the medical education. He acquired medical knowledge through his work of translating various medical texts, which enabled him to teach other medical students. He participated in the administration of the Hospital, taking charge of the provision of meals for in-patients as well as directing the construction of Severance Hospital buildings. His experience of treating soldiers wounded during the turmoil of the forced dismission of the Korean Army by the Japanese led him to reflect seriously on Korea's fate in peril. In addition, he became a member of Sinmin Society, a secret political association, to engage in the independence movement. In 1908, Kim Pil Soon graduated from Severance Hospital Medical School as one of the first seven graduates. On graduation, he was appointed as a professor and took the charge of school affairs in 1910. At first, he worked as an assistant physician of ward and surgery, then he took the responsibility of the outpatient clinic in 1911. But suddenly, in December 1911, he exiled to China to escape from the Japanese police who was in pursuit of him on account of his involvement in the so-called 105-Person Affair, a fabricated affair served as a pretext for the persecution of the independence movement. He continued the independence movement in the form of an ideal village movement and in the training of the Independence Army. In 1919, however, he was poisoned to death in a mysterious way. Kim Pil Soon dedicated himself to the independence movement that demanded personal sacrifice: giving up his prospective career as a doctor, professor, and hospital administrator. He no longer remained as an ordinary clinician who treats only diseased persons, but transformed himself to the Great Doctor, a time-old ideal type of doctor in the East Asian countries who treats and cures the diseased nation, by dedicating himself to the independence movement.
NASA Astrophysics Data System (ADS)
Kuckein, C.; Martínez Pillet, V.; Centeno, R.
2012-03-01
Aims: A thorough multiwavelength, multiheight study of the vector magnetic field in a compact active region filament (NOAA 10781) on 2005 July 3 and 5 is presented. We suggest an evolutionary scenario for this filament. Methods: Two different inversion codes were used to analyze the full Stokes vectors acquired with the Tenerife Infrared Polarimeter (TIP-II) in a spectral range that comprises the chromospheric He i 10 830 Å multiplet and the photospheric Si i 10 827 Å line. In addition, we used SOHO/MDI magnetograms, as well as BBSO and TRACE images, to study the evolution of the filament and its active region (AR). High-resolution images of the Dutch Open Telescope were also used. Results: An active region filament (formed before our observing run) was detected in the chromospheric helium absorption images on July 3. The chromospheric vector magnetic field in this portion of the filament was strongly sheared (parallel to the filament axis), whereas the photospheric field lines underneath had an inverse polarity configuration. From July 3 to July 5, an opening and closing of the polarities on either side of the polarity inversion line (PIL) was recorded, resembling the recently discovered process of the sliding door effect seen by Hinode. This is confirmed with both TIP-II and SOHO/MDI data. During this time, a newly created region that contained pores and orphan penumbrae at the PIL was observed. On July 5, a normal polarity configuration was inferred from the chromospheric spectra, while strongly sheared field lines aligned with the PIL were found in the photosphere. In this same data set, the spine of the filament is also observed in a different portion of the field of view and is clearly mapped by the silicon line core. Conclusions: The inferred vector magnetic fields of the filament suggest a flux rope topology. Furthermore, the observations indicate that the filament is divided in two parts, one which lies in the chromosphere and another one that stays trapped in the photosphere. Therefore, only the top of the helical structure is seen by the helium lines. The pores and orphan penumbrae at the PIL appear to be the photospheric counterpart of the extremely low-lying filament. We suggest that orphan penumbrae are formed in very narrow PILs of compact ARs and are the photospheric manifestation of flux ropes in the photosphere.
NASA Astrophysics Data System (ADS)
Mancini, Pedro M. E.; Kneeteman, María N.; Cainelli, Mauro; Ormachea, Carla M.; Domingo, Luis R.
2017-11-01
The behaviors of N-tosylnitropyrroles acting as electrophilic dienophiles in polar Diels-Alder reactions joint to different dienes of increeased nucleophilicity are analyzed. The reactions were developed under microwave irradiation using toluene or protic ionic liquids (PILs) as solvents and in free solvent conditions. In all the cases explored we observed good yields in short reaction times. For these reactions, the free solvent condition and the use of protic ionic liquids as solvents offer similar results. However, the free solvent conditions favor environmental sustainability. The role of PILs in these polar Diels-Alder reactions has been theoretically studied within the Molecular Electron Density Theory.
Orndorff, P E; Falkow, S
1984-01-01
The recombinant plasmid pSH2 confers type 1 piliation (Pil+) on a nonpiliated (Pil-) strain of Escherichia coli K-12. At least four plasmid-encoded gene products are involved in pilus biosynthesis and expression. We present evidence which indicates that one gene encodes an inhibitor of piliation. Hyperpiliated (Hyp) mutants were isolated after Tn5 insertion mutagenesis of pSH2 and introduction of the plasmid DNA into a Pil- strain of E. coli as unique small, compact colonies. Also, Hyp mutants clumped during growth in static broth and were piliated under several cultural conditions that normally suppressed piliation. Electron microscopic examination of Hyp mutants associated an observed 40-fold increase in pilin antigen with an increase in the number and length of pili per cell. All Hyp mutants examined failed to produce a 23-kilodalton protein that was encoded by a gene adjacent to the structural (pilin) gene for type 1 pili, and all Tn5 insertion mutations that produced the Hyp phenotype mapped in this region (hyp). Piliation in Hyp mutants could be reduced to near parental levels by introducing a second plasmid containing a parental hyp gene. Thus the 23-kilodalton (hyp) protein appears to act in trans to regulate the level of piliation. Images PMID:6148338
Sun, Xiaoli; Shen, Wenbin; Chen, Xiaobai; Wen, Tingguo; Duan, Yongli; Wang, Rengui
2017-10-01
To analyse the findings of multiple detector computed tomography (MDCT) after direct lymphangiography in primary intestinal lymphangiectasia (PIL). Fifty-five patients with PIL were retrospectively reviewed. All patients underwent MDCT after direct lymphangiography. The pathologies of 16 patients were confirmed by surgery and the remaining 39 patients were confirmed by gastroendoscopy and/or capsule endoscopy. After direct lymphangiography, MDCT found intra- and extraintestinal as well as lymphatic vessel abnormalities. Among the intra- and extraintestinal disorders, 49 patients had varying degrees of intestinal dilatation, 46 had small bowel wall thickening, 9 had pleural and pericardial effusions, 21 had ascites, 41 had mesenteric oedema, 20 had mesenteric nodules and 9 had abdominal lymphatic cysts. Features of lymphatic vessel abnormalities included intestinal trunk reflux (43.6%, n = 24), lumbar trunk reflux (89.1%, n = 49), pleural and pulmonary lymph reflux (14.5%, n = 8), pericardial and mediastinal lymph reflux (16.4%, n = 9), mediastinal and pulmonary lymph reflux (18.2%, n = 10), and thoracic duct outlet obstruction (90.9%, n = 50). Multiple detector computed tomography after direct lymphangiography provides a safe and accurate examination method and is an excellent tool for the diagnosis of PIL. © 2017 The Royal Australian and New Zealand College of Radiologists.
Innovative Poly(Ionic Liquid)s by the Polymerization of Deep Eutectic Monomers.
Isik, Mehmet; Ruiperez, Fernando; Sardon, Haritz; Gonzalez, Alba; Zulfiqar, Sonia; Mecerreyes, David
2016-07-01
The incorporation of ionic liquid (IL) chemistry into functional polymers has extended the properties and applications of polyelectrolytes. However, ILs are expensive due to the presence of fluorinated anions or complicated synthetic steps which limit their technological viability. Here, we show a new family of poly(ionic liquid)s (PILs) which are based in cheap and renewable chemicals and involves facile synthetic approaches. Thus, deep eutectic monomers (DEMs) are prepared for the first time by using quaternary ammonium compounds and various hydrogen bond donors such as citric acid, terephthalic acid or an amidoxime. The deep eutectic formation is made through a simple mixing of the ingredients. Differential scanning calorimetry, nuclear magnetic resonance (NMR) and computational studies reveal the formation of the DEMs due to the ionic interactions. The resulting DEMs are liquid which facilitates their polymerization using mild photopolymerization or polycondensation strategies. Spectroscopic characterizations reveal the successful formation of the polymers. By this way, a new family of PILs can be synthesized which can be used for different applications. As an example, the polymers show promising performance as solid CO2 sorbents. Altogether the deep eutectic monomer route can lead to non-toxic, cheap and easy-to-prepare alternatives to current PILs for different applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Chen, Chunyan; Liang, Xiaotong; Wang, Jianping; Zou, Ying; Hu, Huiping; Cai, Qingyun; Yao, Shouzhuo
2014-06-27
A novel solid-phase microextraction (SPME) fiber was developed by chemical binding of a crosslinked polymeric ionic liquid (PIL) on the surface of an anodized Ti wire, and was applied in direct-immersion mode for the extraction of perfluorinated compounds (PFCs) from water samples coupled with high performance liquid chromatography-tandem mass spectrometry analysis. The PIL coatings were synthesized by using 1-vinyl-3-hexylimidazolium hexafluorophosphate as monomer and methylacryloyl-substituted polyhedral oligomeric silsesquioxane (POSS) as cross-linker via free radical reaction. The proposed fiber coating exhibited high mechanical stability due to the chemical bonding between the coating and the Ti wire surface. The integration of POSS reagent enhanced the organic solvent resistance of the coating. The parameters affecting the extraction performance of the fiber coating including extraction time, pH of solution, ionic strength and desorption conditions were optimized. The developed PIL-POSS fiber showed good linearity (R<0.998) between 0.1 and 50ngmL(-1) with method detection limits ranging from 0.005 to 0.08ngmL(-1) depending on the analyte, and with relative standard deviation for single-fiber repeatability and fiber-to-fiber reproducibility less than 8.6% and 9.5%, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.
Cowles, Kimberly N; Gitai, Zemer
2010-06-01
Spatial organization of bacterial proteins influences many cellular processes, including division, chromosome segregation and motility. Virulence-associated proteins also localize to specific destinations within bacterial cells. However, the functions and mechanisms of virulence factor localization remain largely unknown. In this work, we demonstrate that polar assembly of the Pseudomonas aeruginosa PAO1 type IV pilus is regulated by surface association in a manner that affects gene transcription, protein levels and protein localization. We also uncover one mechanism for this regulation that acts through the actin homologue MreB. Inactivation of MreB leads to mislocalization of the pilus retraction ATPase PilT, mislocalization of the pili themselves and a reduction in motility. Furthermore, the role of MreB in polar localization of PilT is modulated by surface association, corroborating our results that environmental factors influence the regulation of pilus production. Specifically, MreB mediates both the initiation and maintenance of PilT localization when cells are grown in suspension but only affects the initiation of localization when cells are grown on a surface. Together, these results suggest that the bacterial cytoskeleton provides a mechanism for the polar localization of P. aeruginosa pili and demonstrate that protein localization may represent an important aspect of virulence factor regulation in bacterial pathogens.
Arellanes-Lozada, Paulina; Olivares-Xometl, Octavio; Guzmán-Lucero, Diego; Likhanova, Natalya V.; Domínguez-Aguilar, Marco A.; Lijanova, Irina V.; Arce-Estrada, Elsa
2014-01-01
Compounds of poly(ionic liquid)s (PILs), derived from imidazole with different alkylic chain lengths located in the third position of the imidazolium ring (poly(1-vinyl-3-dodecyl-imidazolium) (PImC12), poly(1-vinyl-3-octylimidazolium) (PImC8) and poly(1-vinyl-3-butylimidazolium) (PImC4) hexafluorophosphate) were synthesized. These compounds were tested as corrosion inhibitors on aluminum alloy AA6061 in diluted sulfuric acid (0.1–1 M H2SO4) by weight loss tests, polarization resistance measurements and inductively coupled plasma optical emission spectroscopy. Langmuir’s isotherms suggested film formation on bare alloy while standard free energy indicated inhibition by a physisorption process. However, compound efficiencies as inhibitors ranked low (PImC12 > PImC8 > PImC4) to reach 61% for PImC12 in highly diluted acidic solution. Apparently, the high mobility of sulfates favored their adsorption in comparison to PILs. The surface film displayed general corrosion, and pitting occurred as a consequence of PILs’ partial inhibition along with a continuous dissolution of defective patchy film on formation. A slight improvement in efficiency was displayed by compounds having high molecular weight and a long alkyl chain, as a consequence of steric hindrance and PIL interactions. PMID:28788156
Numerical Modeling of Flare-productive Active Regions of the Sun
NASA Astrophysics Data System (ADS)
Toriumi, S.; Takasao, S.
2017-12-01
It is known that strong flare events on the Sun take place in active regions (ARs), especially in delta sunspots with closely-packed positive and negative polarities. The delta spots are produced as a result of complex magnetic flux emergence and have strong-field, highly-sheared polarity inversion lines (PILs). Here we report on the numerical simulations of four types of such flare-productive ARs, namely, (1) Spot-Spot, a complex AR with AR-sized PIL, (2) Spot-Satellite, in which a newly-emerging bipole appears next to the pre-existing sunspot, (3) Quadrupole, where two emerging bipoles collide against each other, and (4) Inter-AR, the flares occurring between two separated ARs. We reproduced these four cases by conducting a series of 3D MHD flux emergence simulations and found, for example, that the sheared PILs in these ARs are created through the stretching and advection of horizontal magnetic fields due to relative spot motions. As ARs develop, free magnetic energy becomes stored in the corona, which could be eventually released through flare eruptions. In the presentation, we also mention the relationship between the HMI/SHARP parameters measured in the photosphere and the free energy stored in the corona, and discuss why these parameters successfully predict the flares.
Shi, Qing Xuan; Xia, Qing; Xiang, Xiao; Ye, Yun Sheng; Peng, Hai Yan; Xue, Zhi Gang; Xie, Xiao Lin; Mai, Yiu-Wing
2017-09-04
Composite polymeric and ionic liquid (IL) electrolytes are some of the most promising electrolyte systems for safer battery technology. Although much effort has been directed towards enhancing the transport properties of polymer electrolytes (PEs) through nanoscopic modification by incorporating nano-fillers, it is still difficult to construct ideal ion conducting networks. Here, a novel class of three-dimensional self-assembled polymeric ionic liquid (PIL)-functionalized cellulose nano-crystals (CNC) confining ILs in surface-grafted PIL polymer chains, able to form colloidal crystal polymer electrolytes (CCPE), is reported. The high-strength CNC nano-fibers, decorated with PIL polymer chains, can spontaneously form three-dimensional interpenetrating nano-network scaffolds capable of supporting electrolytes with continuously connected ion conducting networks with IL being concentrated in conducting domains. These new CCPE have exceptional ionic conductivities, low activation energies (close to bulk IL electrolyte with dissolved Li salt), high Li + transport numbers, low interface resistances and improved interface compatibilities. Furthermore, the CCPE displays good electrochemical properties and a good battery performance. This approach offers a route to leak-free, non-flammable and high ionic conductivity solid-state PE in energy conversion devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
The scaffolding and signaling functions of a localization factor impact polar development
Curtis, Patrick D.; Quardokus, Ellen M.; Lawler, Melanie L.; Guo, Xiaoyun; Klein, David; Chen, Joseph C.; Arnold, Randy J.; Brun, Yves V.
2012-01-01
SUMMARY In the differentiating alphaproteobacterium Caulobacter crescentus, organelle synthesis at cell poles is critical to forming different progeny after cell division. Coordination of polar organelle synthesis, including pili and holdfast, and flagellum ejection, is mediated in part by the scaffolding protein PodJ. At the time of cell division, PodJ undergoes regulated processing to a short form that persists at the flagellar pole of swarmer cells. This study analyzes how PodJ’s role in structural and signaling protein localization impacts organelle synthesis. A PodJ mutant with an internal deletion exhibits reduced sensitivity to pili-tropic phage ΦCbK, resulting from reduced pilA gene expression, which can be linked to altered signaling protein localization. The phage sensitivity defect of a ΔpodJ mutant can be partially suppressed by ectopic pilA expression. Induction of PodJ processing, by manipulation of podJ itself or controlled perP expression, resulted in decreased pilus biogenesis and, when coupled with a podJ mutation that reduced pilA expression, led to complete loss of phage sensitivity. As a whole, the results show that PodJ’s scaffolding role for structural and signaling proteins both contribute to flagellar pole organelle development. PMID:22512778
Phase Behavior and Physical Properties of New Biobased Ionic Liquid Crystals.
Toledo Hijo, Ariel A C; Maximo, Guilherme J; Costa, Mariana C; Cunha, Rosiane L; Pereira, Jorge F B; Kurnia, Kiki A; Batista, Eduardo A C; Meirelles, Antonio J A
2017-04-13
Protic ionic liquids (PILs) have emerged as promising compounds and attracted the interest of the industry and the academy community, due to their easy preparation and unique properties. In the context of green chemistry, the use of biocompounds, such as fatty acids, for their synthesis could disclose a possible alternative way to produce ILs with a low or nontoxic effect and, consequently, expanding their applicability in biobased processes or in the development of bioproducts. This work addressed efforts to a better comprehension of the complex solid-[liquid crystal]-liquid thermodynamic equilibrium of 20 new PILs synthesized by using fatty acids commonly found in vegetable oils, as well as their rheological profile and self-assembling ability. The work revealed that their phase equilibrium and physical properties are significantly impacted by the structure of the ions used for their synthesis. The use of unsaturated fatty acids and bis(2-hydroxyethyl)ammonium for the synthesis of these biobased ILs led to a drastic decreasing of their melting temperatures. Also, the longest alkyl chain fatty acids promoted higher self-assembling and more stable mesophases. Besides their sustainable appeal, the marked high viscosity, non-Newtonian profile, and very low critical micellar concentration values of the PIL crystals here disclosed make them interesting renewable compounds with potential applications as emulsifiers, stabilizers, thickeners, or biolubricants.
Schäper, Simon; Steinchen, Wieland; Krol, Elizaveta; Altegoer, Florian; Skotnicka, Dorota; Bange, Gert; Becker, Anke
2017-01-01
Cyclic dimeric GMP (c-di-GMP) has emerged as a key regulatory player in the transition between planktonic and sedentary biofilm-associated bacterial lifestyles. It controls a multitude of processes including production of extracellular polysaccharides (EPSs). The PilZ domain, consisting of an N-terminal “RxxxR” motif and a β-barrel domain, represents a prototype c-di-GMP receptor. We identified a class of c-di-GMP–responsive proteins, represented by the AraC-like transcription factor CuxR in plant symbiotic α-proteobacteria. In Sinorhizobium meliloti, CuxR stimulates transcription of an EPS biosynthesis gene cluster at elevated c-di-GMP levels. CuxR consists of a Cupin domain, a helical hairpin, and bipartite helix-turn-helix motif. Although unrelated in sequence, the mode of c-di-GMP binding to CuxR is highly reminiscent to that of PilZ domains. c-di-GMP interacts with a conserved N-terminal RxxxR motif and the Cupin domain, thereby promoting CuxR dimerization and DNA binding. We unravel structure and mechanism of a previously unrecognized c-di-GMP–responsive transcription factor and provide insights into the molecular evolution of c-di-GMP binding to proteins. PMID:28559336
Feng, Juanjuan; Sun, Min; Xu, Lili; Wang, Shuai; Liu, Xia; Jiang, Shengxiang
2012-12-14
Because of the occurrence of ion exchange between high-ionic-strength solution and anions of polymeric ionic liquids (PILs), PILs based solid-phase microextraction (SPME) fibers were rarely used in direct immersion mode to high-salt-added samples. In this work, a novel double-confined PIL sorbent was prepared by co-polymerization of cation and anion of 1-vinyl-3-octylimidzaolium p-styrenesulfonate (VOIm(+)SS(-)). The poly(VOIm(+)-SS(-)) was chemically bonded onto functionalized stainless steel wire via surface radical chain-transfer reaction. Stability of poly(VOIm(+)-SS(-)) in high-ionic-strength solution was investigated and compared with that of poly(1-vinyl-3-octylimidzaolium benzenesulfonate) (poly(VOIm(+)BS(-))) by elemental analysis of sulfur element, and results turned out that the poly(VOIm(+)-SS(-)) was more stable. Coupled to gas chromatography (GC), the poly(VOIm(+)-SS(-)) fiber was used to extract three sorts of compounds including anilines, phenols and phthalate esters in aqueous solution. The as-established method showed good linearity, low detection limits, and acceptable repeatability. The direct immersion SPME-GC method was applied to determine the model phthalate esters in bottled mineral water. The determination results were satisfactory. Copyright © 2012 Elsevier B.V. All rights reserved.
2016-01-01
The obligate human pathogen Neisseria gonorrhoeae is the sole aetiologic agent of the sexually transmitted infection, gonorrhea. Required for gonococcal infection, Type IV pili (Tfp) mediate many functions including adherence, twitching motility, defense against neutrophil killing, and natural transformation. Critical for immune escape, the gonococcal Tfp undergoes antigenic variation, a recombination event at the pilE locus that varies the surface exposed residues of the major pilus subunit PilE (pilin) in the pilus fiber. This programmed recombination system has the potential to produce thousands of pilin variants and can produce strains with unproductive pilin molecules that are completely unable to form Tfp. Saturating mutagenesis of the 3’ third of the pilE gene identified 68 unique single nucleotide mutations that each resulted in an underpiliated colony morphology. Notably, all isolates, including those with undetectable levels of pilin protein and no observable surface-exposed pili, retained an intermediate level of transformation competence not exhibited in ΔpilE strains. Site-directed, nonsense mutations revealed that only the first 38 amino acids of the mature pilin N-terminus (the N-terminal domain or Ntd) are required for transformation competence, and microscopy, ELISAs and pilus purification demonstrate that extended Tfp are not required for competence. Transformation in strains producing only the pilin Ntd has the same genetic determinants as wild-type transformation. The Ntd corresponds to the alternative product of S-pilin cleavage, a specific proteolysis unique to pathogenic Neisseria. Mutation of the S-pilin cleavage site demonstrated that S-pilin cleavage mediated release of the Ntd is required for competence when a strain produces unproductive pilin molecules that cannot assemble into a Tfp through mutation or antigenic variation. We conclude that S-pilin cleavage evolved as a mechanism to maintain competence in nonpiliated antigenic variants and suggest there are alternate forms of the Tfp assembly apparatus that mediate various functions including transformation. PMID:27213957
Geometrical Relationship Between Interplanetary Flux Ropes and Their Solar Sources
NASA Astrophysics Data System (ADS)
Marubashi, K.; Akiyama, S.; Yashiro, S.; Gopalswamy, N.; Cho, K.-S.; Park, Y.-D.
2015-05-01
We investigated the physical connection between interplanetary flux ropes (IFRs) near Earth and coronal mass ejections (CMEs) by comparing the magnetic field structures of IFRs and CME source regions. The analysis is based on the list of 54 pairs of ICMEs (interplanetary coronal mass ejections) and CMEs that are taken to be the most probable solar source events. We first attempted to identify the flux rope structure in each of the 54 ICMEs by fitting models with a cylinder and torus magnetic field geometry, both with a force-free field structure. This analysis determined the possible geometries of the identified flux ropes. Then we compared the flux rope geometries with the magnetic field structure of the solar source regions. We obtained the following results: (1) Flux rope structures are seen in 51 ICMEs out of the 54. The result implies that all ICMEs have an intrinsic flux rope structure, if the three exceptional cases are attributed to unfavorable observation conditions. (2) It is possible to find flux rope geometries with the main axis orientation close to the orientation of the magnetic polarity inversion line (PIL) in the solar source regions, the differences being less than 25°. (3) The helicity sign of an IFR is strongly controlled by the location of the solar source: flux ropes with positive (negative) helicity are associated with sources in the southern (northern) hemisphere (six exceptions were found). (4) Over two-thirds of the sources in the northern hemisphere are concentrated along PILs with orientations of 45° ± 30° (measured clockwise from the east), and over two-thirds in the southern hemisphere along PILs with orientations of 135° ± 30°, both corresponding to the Hale boundaries. These results strongly support the idea that a flux rope with the main axis parallel to the PIL erupts in a CME and that the erupted flux rope propagates through the interplanetary space with its orientation maintained and is observed as an IFR.
van der Palen, Job; Thomas, Mike; Chrystyn, Henry; Sharma, Raj K; van der Valk, Paul Dlpm; Goosens, Martijn; Wilkinson, Tom; Stonham, Carol; Chauhan, Anoop J; Imber, Varsha; Zhu, Chang-Qing; Svedsater, Henrik; Barnes, Neil C
2016-11-24
Errors in the use of different inhalers were investigated in patients naive to the devices under investigation in a multicentre, single-visit, randomised, open-label, cross-over study. Patients with chronic obstructive pulmonary disease (COPD) or asthma were assigned to ELLIPTA vs DISKUS (Accuhaler), metered-dose inhaler (MDI) or Turbuhaler. Patients with COPD were also assigned to ELLIPTA vs Handihaler or Breezhaler. Patients demonstrated inhaler use after reading the patient information leaflet (PIL). A trained investigator assessed critical errors (i.e., those likely to result in the inhalation of significantly reduced, minimal or no medication). If the patient made errors, the investigator demonstrated the correct use of the inhaler, and the patient demonstrated inhaler use again. Fewer COPD patients made critical errors with ELLIPTA after reading the PIL vs: DISKUS, 9/171 (5%) vs 75/171 (44%); MDI, 10/80 (13%) vs 48/80 (60%); Turbuhaler, 8/100 (8%) vs 44/100 (44%); Handihaler, 17/118 (14%) vs 57/118 (48%); Breezhaler, 13/98 (13%) vs 45/98 (46%; all P<0.001). Most patients (57-70%) made no errors using ELLIPTA and did not require investigator instruction. Instruction was required for DISKUS (65%), MDI (85%), Turbuhaler (71%), Handihaler (62%) and Breezhaler (56%). Fewer asthma patients made critical errors with ELLIPTA after reading the PIL vs: DISKUS (3/70 (4%) vs 9/70 (13%), P=0.221); MDI (2/32 (6%) vs 8/32 (25%), P=0.074) and significantly fewer vs Turbuhaler (3/60 (5%) vs 20/60 (33%), P<0.001). More asthma and COPD patients preferred ELLIPTA over the other devices (all P⩽0.002). Significantly, fewer COPD patients using ELLIPTA made critical errors after reading the PIL vs other inhalers. More asthma and COPD patients preferred ELLIPTA over comparator inhalers.
A comprehensive and scalable database search system for metaproteomics.
Chatterjee, Sandip; Stupp, Gregory S; Park, Sung Kyu Robin; Ducom, Jean-Christophe; Yates, John R; Su, Andrew I; Wolan, Dennis W
2016-08-16
Mass spectrometry-based shotgun proteomics experiments rely on accurate matching of experimental spectra against a database of protein sequences. Existing computational analysis methods are limited in the size of their sequence databases, which severely restricts the proteomic sequencing depth and functional analysis of highly complex samples. The growing amount of public high-throughput sequencing data will only exacerbate this problem. We designed a broadly applicable metaproteomic analysis method (ComPIL) that addresses protein database size limitations. Our approach to overcome this significant limitation in metaproteomics was to design a scalable set of sequence databases assembled for optimal library querying speeds. ComPIL was integrated with a modified version of the search engine ProLuCID (termed "Blazmass") to permit rapid matching of experimental spectra. Proof-of-principle analysis of human HEK293 lysate with a ComPIL database derived from high-quality genomic libraries was able to detect nearly all of the same peptides as a search with a human database (~500x fewer peptides in the database), with a small reduction in sensitivity. We were also able to detect proteins from the adenovirus used to immortalize these cells. We applied our method to a set of healthy human gut microbiome proteomic samples and showed a substantial increase in the number of identified peptides and proteins compared to previous metaproteomic analyses, while retaining a high degree of protein identification accuracy and allowing for a more in-depth characterization of the functional landscape of the samples. The combination of ComPIL with Blazmass allows proteomic searches to be performed with database sizes much larger than previously possible. These large database searches can be applied to complex meta-samples with unknown composition or proteomic samples where unexpected proteins may be identified. The protein database, proteomic search engine, and the proteomic data files for the 5 microbiome samples characterized and discussed herein are open source and available for use and additional analysis.
Evidence of Twisted Flux-Tube Emergence in Active Regions
NASA Astrophysics Data System (ADS)
Poisson, M.; Mandrini, C. H.; Démoulin, P.; López Fuentes, M.
2015-03-01
Elongated magnetic polarities are observed during the emergence phase of bipolar active regions (ARs). These extended features, called magnetic tongues, are interpreted as a consequence of the azimuthal component of the magnetic flux in the toroidal flux-tubes that form ARs. We develop a new systematic and user-independent method to identify AR tongues. Our method is based on determining and analyzing the evolution of the AR main polarity inversion line (PIL). The effect of the tongues is quantified by measuring the acute angle [ τ] between the orientation of the PIL and the direction orthogonal to the AR main bipolar axis. We apply a simple model to simulate the emergence of a bipolar AR. This model lets us interpret the effect of magnetic tongues on parameters that characterize ARs ( e.g. the PIL inclination and the tilt angles, and their evolution). In this idealized kinematic emergence model, τ is a monotonically increasing function of the twist and has the same sign as the magnetic helicity. We systematically apply our procedure to a set of bipolar ARs (41 ARs) that were observed emerging in line-of-sight magnetograms over eight years. For most of the cases studied, the tongues only have a small influence on the AR tilt angle since tongues have a much lower magnetic flux than the more concentrated main polarities. From the observed evolution of τ, corrected for the temporal evolution of the tilt angle and its final value when the AR is fully emerged, we estimate the average number of turns in the subphotospherically emerging flux-rope. These values for the 41 observed ARs are below unity, except for one. This indicates that subphotospheric flux-ropes typically have a low amount of twist, i.e. highly twisted flux-tubes are rare. Our results demonstrate that the evolution of the PIL is a robust indicator of the presence of tongues and constrains the amount of twist in emerging flux-tubes.
Gumz, Antje; Neubauer, Karolin; Horstkotte, Julia Katharina; Geyer, Michael; Löwe, Bernd; Murray, Alexandra M.; Kästner, Denise
2017-01-01
Objective Knowing which specific verbal techniques “good” therapists use in their daily work is important for training and evaluation purposes. In order to systematize what is being practiced in the field, our aim was to empirically identify verbal techniques applied in psychodynamic sessions and to differentiate them according to their basic semantic features using a bottom-up, qualitative approach. Method Mixed-Method-Design: In a comprehensive qualitative study, types of techniques were identified at the level of utterances based on transcribed psychodynamic therapy sessions using Qualitative Content Analysis (4211 utterances). The definitions of the identified categories were successively refined and modified until saturation was achieved. In a subsequent quantitative study, inter-rater reliability was assessed both at the level of utterances (n = 8717) and at the session level (n = 38). The convergent validity of the categories was investigated by analyzing associations with the Interpretive and Supportive Technique Scale (ISTS). Results The inductive approach resulted in a classification system with 37 categories (Psychodynamic Interventions List, PIL). According to their semantic content, the categories can be allocated to three dimensions: form (24 categories), thematic content (9) and temporal focus (4). Most categories showed good or excellent inter-rater reliability and expected associations with the ISTS were predominantly confirmed. The rare use of the residual category “Other” suggests that the identified categories might comprehensively describe the breadth of applied techniques. Conclusions The atheoretical orientation and the clear focus on overt linguistic features should enable the PIL to be used without intensive training or prior theoretical knowledge. The PIL can be used to investigate the links between verbal techniques derived from practice and micro-outcomes (at the session level) as well as the overall therapeutic outcomes. This approach might enable us to determine to what extent the outcome of therapy is due to unintended or non-theoretically relevant techniques. PMID:28837582
van der Palen, Job; Thomas, Mike; Chrystyn, Henry; Sharma, Raj K; van der Valk, Paul DLPM; Goosens, Martijn; Wilkinson, Tom; Stonham, Carol; Chauhan, Anoop J; Imber, Varsha; Zhu, Chang-Qing; Svedsater, Henrik; Barnes, Neil C
2016-01-01
Errors in the use of different inhalers were investigated in patients naive to the devices under investigation in a multicentre, single-visit, randomised, open-label, cross-over study. Patients with chronic obstructive pulmonary disease (COPD) or asthma were assigned to ELLIPTA vs DISKUS (Accuhaler), metered-dose inhaler (MDI) or Turbuhaler. Patients with COPD were also assigned to ELLIPTA vs Handihaler or Breezhaler. Patients demonstrated inhaler use after reading the patient information leaflet (PIL). A trained investigator assessed critical errors (i.e., those likely to result in the inhalation of significantly reduced, minimal or no medication). If the patient made errors, the investigator demonstrated the correct use of the inhaler, and the patient demonstrated inhaler use again. Fewer COPD patients made critical errors with ELLIPTA after reading the PIL vs: DISKUS, 9/171 (5%) vs 75/171 (44%); MDI, 10/80 (13%) vs 48/80 (60%); Turbuhaler, 8/100 (8%) vs 44/100 (44%); Handihaler, 17/118 (14%) vs 57/118 (48%); Breezhaler, 13/98 (13%) vs 45/98 (46%; all P<0.001). Most patients (57–70%) made no errors using ELLIPTA and did not require investigator instruction. Instruction was required for DISKUS (65%), MDI (85%), Turbuhaler (71%), Handihaler (62%) and Breezhaler (56%). Fewer asthma patients made critical errors with ELLIPTA after reading the PIL vs: DISKUS (3/70 (4%) vs 9/70 (13%), P=0.221); MDI (2/32 (6%) vs 8/32 (25%), P=0.074) and significantly fewer vs Turbuhaler (3/60 (5%) vs 20/60 (33%), P<0.001). More asthma and COPD patients preferred ELLIPTA over the other devices (all P⩽0.002). Significantly, fewer COPD patients using ELLIPTA made critical errors after reading the PIL vs other inhalers. More asthma and COPD patients preferred ELLIPTA over comparator inhalers. PMID:27883002
Variations of the Photospheric Magnetic Field Following the Eruptive Event on June 7, 2011
NASA Astrophysics Data System (ADS)
Fainshtein, V. G.; Egorov, Ya. I.; Rudenko, G. V.
2017-12-01
Field variations in the region of the eruptive event on June 7, 2011 are studied based on vector measurements of the photospheric magnetic field by the SDO/HMI instrument. Variations of the modulus ( B), the radial ( B r) and the transverse ( B t) components of the magnetic induction, and the inclination angle (α) of the field lines to the radial direction from the center of the Sun are analyzed. It is found that, in the part of the flare region near the polarity inversion line (PIL) after the onset of the flare, the magnitude and the transverse component of the magnetic induction as well as the angles α abruptly increase. During the slow rise of filament near its channel, the inclination angles of the field lines decrease. It is shown that diverging flare ribbons are above the regions of the photosphere with local maxima of the field modulus and with deep minima of the inclination angles of the field lines at all stages of their existence over their entire length with the exception of small areas. It is established that the azimuth decreases after the onset of the flare near the PIL of the photospheric magnetic field, which means an increase in the shear. On the contrary, at a distance from the PIL there is a slight decrease in the shear.
Electric-current Neutralization, Magnetic Shear, and Eruptive Activity in Solar Active Regions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, Yang; Sun, Xudong; Török, Tibor
The physical conditions that determine whether or not solar active regions (ARs) produce strong flares and coronal mass ejections (CMEs) are not yet well understood. Here, we investigate the association between electric-current neutralization, magnetic shear along polarity inversion lines (PILs), and eruptive activity in four ARs: two emerging and two well-developed ones. We find that the CME-producing ARs are characterized by a strongly non-neutralized total current, while the total current in the ARs that did not produce CMEs is almost perfectly neutralized. The difference in the PIL shear between these two groups is much less pronounced, which suggests that themore » degree of current neutralization may serve as a better proxy for assessing the ability of ARs to produce CMEs.« less
Cowan, Matthew G; Gin, Douglas L; Noble, Richard D
2016-04-19
The recycling or sequestration of carbon dioxide (CO2) from the waste gas of fossil-fuel power plants is widely acknowledged as one of the most realistic strategies for delaying or avoiding the severest environmental, economic, political, and social consequences that will result from global climate change and ocean acidification. For context, in 2013 coal and natural gas power plants accounted for roughly 31% of total U.S. CO2 emissions. Recycling or sequestering this CO2 would reduce U.S. emissions by ca. 1800 million metric tons-easily meeting the U.S.'s currently stated CO2 reduction targets of ca. 17% relative to 2005 levels by 2020. This situation is similar for many developed and developing nations, many of which officially target a 20% reduction relative to 1990 baseline levels by 2020. To make CO2 recycling or sequestration processes technologically and economically viable, the CO2 must first be separated from the rest of the waste gas mixture-which is comprised mostly of nitrogen gas and water (ca. 85%). Of the many potential separation technologies available, membrane technology is particularly attractive due to its low energy operating cost, low maintenance, smaller equipment footprint, and relatively facile retrofit integration with existing power plant designs. From a techno-economic standpoint, the separation of CO2 from flue gas requires membranes that can process extremely high amounts of CO2 over a short time period, a property defined as the membrane "permeance". In contrast, the membrane's CO2/N2 selectivity has only a minor effect on the overall cost of some separation processes once a threshold permeability selectivity of ca. 20 is reached. Given the above criteria, the critical properties when developing membrane materials for postcombustion CO2 separation are CO2 permeability (i.e., the rate of CO2 transport normalized to the material thickness), a reasonable CO2/N2 selectivity (≥20), and the ability to be processed into defect-free thin-films (ca. 100-nm-thick active layer). Traditional polymeric membrane materials are limited by a trade-off between permeability and selectivity empirically described by the "Robeson upper bound"-placing the desired membrane properties beyond reach. Therefore, the investigation of advanced and composite materials that can overcome the limitations of traditional polymeric materials is the focus of significant academic and industrial research. In particular, there has been substantial work on ionic-liquid (IL)-based materials due to their gas transport properties. This review provides an overview of our collaborative work on developing poly(ionic liquid)/ionic liquid (PIL/IL) ion-gel membrane technology. We detail developmental work on the preparation of PIL/IL composites and describe how this chemical technology was adapted to allow the roll-to-roll processing and preparation of membranes with defect-free active layers ca. 100 nm thick, CO2 permeances of over 6000 GPU, and CO2/N2 selectivity of ≥20-properties with the potential to reduce the cost of CO2 removal from coal-fired power plant flue gas to ca. $15 per ton of CO2 captured. Additionally, we examine the materials developments that have produced advanced PIL/IL composite membranes. These advancements include cross-linked PIL/IL blends, step-growth PIL/IL networks with facilitated transport groups, and PIL/IL composites with microporous additives for CO2/CH4 separations.
Real-time measurements of levoglucosan in fine aerosols (PM2.5) in the region of Paris (France)
NASA Astrophysics Data System (ADS)
Sciare, J.; Bonnaire, N.; Mocnik, G.; Nicolas, J.; Petit, J. E.; Bressi, M.; Sarda-Estève, R.; Drinovic, L.
2012-04-01
Levoglucosan - one the major monosaccharide anhydride compounds produced by the combustion of cellulose and hemicellulose - is emitted in large amounts by wildfires or residential wood burning (during winter months). Over the past few years, this specific tracer has received more and more attention at it can be used in a quantitative way to derive atmospheric concentrations of biomass burning aerosols [Favez et al., 2010] which aerosol source has strong implications for climate and air quality studies. A new technique has been developed and is presented here to investigate real-time concentrations of levoglucosan in fine aerosols (PM2.5). This technique is based on a Particle-into-liquid-sampler (PILS, Brechtel Manufacturing inc., model 4002) used "on-line" and coupled with an electrospray ionisation source - tandem mass spectrometry (ESI-MS/MS, AB SCIEX model 3200 QTRAP). Air was drawn in the PILS at 15LPM and removed from particles larger than 2.5μm aerodynamic diameter (AD) using a very sharp cyclone. Water-soluble aerosols were collected in the PILS and sent in the 10μl loop of the ESI-MS/MS at a flowrate of 50μl/min. Flow injection analysis (FIA) was then performed every 2.5min for the quantification of levoglucosan using a specific transition 161-113 m/z (negative mode), by Multiple Reaction Monitoring (MRM) mode. An internal levoglucosan standard was injected every 10 samples (i.e. every 25min) in order to check the stability of the mass spectrometry calibration. Field blanks were performed using a total filter upstream of the PILS instrument and did not show any detectable amount of levoglucosan. A limit of quantification (LOQ) better than 1 ng/m3 was calculated here for levoglucosan in FIA mode. Based on these settings, unattended measurements of levoglucosan by PILS-ESI-MS/MS have been performed every 2.5 min in the region of Paris for a couple of weeks during the winter 2011 showing concentrations ranging from below 1ng/m3 to more than 500ng/m3. These measurements were compared to measurements of Black Carbon from wood burning obtained in parallel every 5 min using a 7 wavelength aethalometer (Magee Scientific, models AE31 and AE33,) and the use of the "aethalometer" model [Sandradewi et al., 2008; Sciare et al., 2001]. A very good agreement was observed between these 2 tracers of biomass burning aerosols, providing valuable information on the strong temporality of the domestic wood burning source. This new tool, in conjunction with other real-time analyzers, may offer new opportunities to investigate the fast atmospheric processes of biomass burning aerosols which have been reported in smog chamber studies [Grieshop et al., 2009].
Ren, Dabin; Murphy, Timothy F.; Lafontaine, Eric R.; Pichichero, Michael E.
2017-01-01
Moraxella catarrhalis (Mcat) is a prominent mucosal pathogen causing acute otitis media (AOM). We studied Mcat nasopharyngeal (NP) colonization, AOM frequency and mucosal antibody responses to four vaccine candidate Mcat proteins: outer membrane protein (OMP) CD, oligopeptide permease (Opp) A, hemagglutinin (Hag), and Pilin A clade 2 (PilA2) from stringently defined otitis prone (sOP) children, who experience the greatest burden of disease, compared to non-otitis prone (NOP) children. sOP children had higher NP colonization of Mcat (30 vs. 22%, P = 0.0003) and Mcat-caused AOM rates (49 vs. 24%, P < 0.0001) than NOP children. Natural acquisition of mucosal antibodies to Mcat proteins OMP CD (IgG, P < 0.0001), OppA (IgG, P = 0.018), Hag (IgG and IgA, both P < 0.0001), and PilA2 (IgA, P < 0.0001) was lower in sOP than NOP children. Higher levels of mucosal IgG to Hag (P = 0.039) and PilA2 (P = 0.0076), and IgA to OMP CD (P = 0.010), OppA (P = 0.030), and PilA2 (P = 0.043) were associated with lower carriage of Mcat in NOP but not sOP children. Higher levels of mucosal IgG to OMP CD (P = 0.0070) and Hag (P = 0.0003), and IgA to Hag (P = 0.0067) at asymptomatic colonization than those at onset of AOM were associated with significantly lower rate of Mcat NP colonization progressing to AOM in NOP compared to sOP children (3 vs. 26%, P < 0.0001). In conclusion, sOP children had a diminished mucosal antibody response to Mcat proteins, which was associated with higher frequencies of asymptomatic NP colonization and NP colonization progressing to Mcat-caused AOM. Enhancing Mcat antigen-specific mucosal immune responses to levels higher than achieved by natural exposure will be necessary to prevent AOM in sOP children. PMID:28848555
Ren, Dabin; Murphy, Timothy F; Lafontaine, Eric R; Pichichero, Michael E
2017-01-01
Moraxella catarrhalis ( Mcat ) is a prominent mucosal pathogen causing acute otitis media (AOM). We studied Mcat nasopharyngeal (NP) colonization, AOM frequency and mucosal antibody responses to four vaccine candidate Mcat proteins: outer membrane protein (OMP) CD, oligopeptide permease (Opp) A, hemagglutinin (Hag), and Pilin A clade 2 (PilA2) from stringently defined otitis prone (sOP) children, who experience the greatest burden of disease, compared to non-otitis prone (NOP) children. sOP children had higher NP colonization of Mcat (30 vs. 22%, P = 0.0003) and Mcat -caused AOM rates (49 vs. 24%, P < 0.0001) than NOP children. Natural acquisition of mucosal antibodies to Mcat proteins OMP CD (IgG, P < 0.0001), OppA (IgG, P = 0.018), Hag (IgG and IgA, both P < 0.0001), and PilA2 (IgA, P < 0.0001) was lower in sOP than NOP children. Higher levels of mucosal IgG to Hag ( P = 0.039) and PilA2 ( P = 0.0076), and IgA to OMP CD ( P = 0.010), OppA ( P = 0.030), and PilA2 ( P = 0.043) were associated with lower carriage of Mcat in NOP but not sOP children. Higher levels of mucosal IgG to OMP CD ( P = 0.0070) and Hag ( P = 0.0003), and IgA to Hag ( P = 0.0067) at asymptomatic colonization than those at onset of AOM were associated with significantly lower rate of Mcat NP colonization progressing to AOM in NOP compared to sOP children (3 vs. 26%, P < 0.0001). In conclusion, sOP children had a diminished mucosal antibody response to Mcat proteins, which was associated with higher frequencies of asymptomatic NP colonization and NP colonization progressing to Mcat -caused AOM. Enhancing Mcat antigen-specific mucosal immune responses to levels higher than achieved by natural exposure will be necessary to prevent AOM in sOP children.
NASA Astrophysics Data System (ADS)
Lee, Taehyoung; Yu, Xiao-Ying; Kreidenweis, Sonia M.; Malm, William C.; Collett, Jeffrey L.
To improve understanding of the nature and variability of the ionic fraction of atmospheric fine aerosol particles in non-urban environments, one to two month measurement campaigns were conducted at several rural locations in the United States. Study sites included Yosemite National Park (NP) (July-September 2002), Bondville, Illinois (February 2003), San Gorgonio Wilderness Area, California (April and July 2003), Grand Canyon National Park, Arizona (May 2003), Brigantine National Wildlife Refuge (NWR), New Jersey (November 2003), and Great Smoky Mountains National Park, Tennessee (July/August 2004). PM 2.5 ion composition was measured at 15 min intervals using a Particle-Into-Liquid-Sampler (PILS) coupled to two ion chromatographs. Comparisons of PILS measurements with parallel traditional 24 h denuder/filter-pack measurements reveal generally good agreement between the two techniques for major species, although PILS measurements of PM 2.5 NH 4+ are biased low by approximately 4-20%. High time resolution PILS aerosol concentration measurements provide better estimates of the range of aerosol concentrations at the rural locations than the 24 h integrated filter data. Ratios of peak 15 min to 24 h nitrate concentrations, for example, ranged from 1.7 at Brigantine NWR to 7.0 at Great Smoky Mountains NP. A strong influence of diurnal upslope/downslope transport patterns was observed on aerosol concentrations at several locations, including Yosemite NP, San Gorgonio Wilderness Area, and Great Smoky Mountains NP, with peak concentrations typically occurring during afternoon upslope transport. High time resolution aerosol composition measurements also provide new insight into relationships between individual aerosol species and the influence of environmental conditions on aerosol composition. Observations at several locations revealed important information about mechanisms of particle nitrate formation. At Yosemite and Grand Canyon National Parks, for example, evidence was observed for reaction of nitric acid or its precursors with sea salt or soil dust. Observations from several sites also revealed the importance of aerosol acidity (Great Smoky Mountains NP, Bondville) and temperature/humidity (San Gorgonio) on fine particle ammonium nitrate formation.
Zhao, Feijun; Wu, Yimou; Zhang, Xiaohong; Yu, Jian; Gu, Weiming; Liu, Shuangquan; Zeng, Tiebing; Zhang, Yuejun; Wang, Shiping
2011-10-01
In this study, the immune-modulatory and protective efficacy of using an interleukin-2 (IL-2) expression plasmid as a genetic adjuvant and chitosan (CS) nanoparticles as vectors to enhance a Tp92 DNA vaccine candidate were investigated in a Treponema pallidum (Tp) rabbit challenge model. CS vectoring of pTp92 or pIL-2 were both demonstrated to augment anti-Tp92 antibody levels induced by pTp92 DNA vaccines. Interestingly, the combination of CS vectored Tp92 and pIL-2 led to the greatest enhancements of anti-Tp92 antibodies and T-cell proliferation (p < 0.05). At week 10 after the first immunization, 15 of the 18 rabbits in each group were challenged with Tp Nichols strain and monitored for skin lesions and ulcer lesions. Ratios of positive skin lesions and ratios of ulcer lesions in groups immunized with pTp92 were significantly lower than those of the empty vector or PBS groups (p < 0.05), demonstrating that pTp92 immunization elicited significant protective efficacy against the Tp Nichols strain challenge. CS vectored and pIL-2 adjuvanted pTp92 immunized animals exhibited the lowest rates of positive skin and ulcer lesions. Male New Zealand white rabbits were randomly assigned to groups (n = 18/group) and immunized intramuscularly with pTp92 based plasmid DNA constructs (100 μg of DNA/rabbit/immunization). Two weeks before Tp challenge (Week 8), three rabbits from each group were used to determine cytokine measurements and fifteen rabbits from each group were used for Tp challenge studies. Intramuscular injection of pTp92 induced strong humoral and cellular immune responses and conferred protection from Tp challenge in rabbits. The use of CS as a pTp92 vector or pIL-2 as an adjuvant achieved a superior level of protective efficacy against Tp challenge, however CS vectored, IL-2 adjuvanted pTp92 immunization conferred the highest level of protective efficacy.
Carvalho, Nayára B; Vidal, Bruna T; Barbosa, Anderson S; Pereira, Matheus M; Mattedi, Silvana; Freitas, Lisiane Dos S; Lima, Álvaro S; Soares, Cleide M F
2018-06-21
Treated silica xerogel with protic ionic liquid (PIL) and bifunctional agents (glutaraldehyde and epichlorohydrin) is a novel support strategy used in the effective immobilization of lipase from Burkholderia cepacia (LBC) by covalent binding. As biocatalysts with the highest activity recovery yields, LBC immobilized by covalent binding with epichlorohydrin without (203%) and with PIL (250%), was assessed by the following the hydrolysis reaction of olive oil and characterized biochemically (Michaelis⁻Menten constant, optimum pH and temperature, and operational stability). Further, the potential transesterification activity for three substrates: sunflower, soybean, and colza oils, was also determined, achieving a conversion of ethyl esters between 70 and 98%. The supports and the immobilized lipase systems were characterized using Fourier transform infrared spectra (FTIR), scanning electron microscopy (SEM), elemental analysis, and thermogravimetric (TG) analysis.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tomopy is a Python toolbox to perform x-ray data processing, image reconstruction and data exchange tasks at synchrotron facilities. The dependencies of the software are currently as follows: -Python related python standard library (http://docs.python.org/2/library/) numpy (http://www.numpy.org/) scipy (http://scipy.org/) matplotlib (http://matplotlip.org/) sphinx (http://sphinx-doc.org) pil (http://www.pythonware.com/products/pil/) pyhdf (http://pysclint.sourceforge.net/pyhdf/) h5py (http://www.h5py.org) pywt (http://www.pybytes.com/pywavelets/) file.py (https://pyspec.svn.sourceforge.net/svnroot/pyspec/trunk/pyspec/ccd/files.py) -C/C++ related: gridec (anonymous?? C-code written back in 1997 that uses standard C library) fftw (http://www.fftw.org/) tomoRecon (multi-threaded C++ verion of gridrec. Author: Mark Rivers from APS. http://cars9.uchicago.edu/software/epics/tomoRecon.html) epics (http://www.aps.anl.gov/epics/)
Elliptical-P cells in the avian perilymphatic interface of the Tegmentum vasculosum
NASA Technical Reports Server (NTRS)
Fermin, C. D.; Lee, D. H.; Martin, D. S.
1995-01-01
Elliptical cells (E-P) are present at the perilymphatic interface lumen (PIL) of the lagena. The E-P cells often separate from the tegmentum vasculosum (TV) and have touching processes that form a monolayer between the K+ rich perilymph and the Na+ rich endolymph, similar to the mammalian Reissner's membrane. We examined the TV of chicks (Gallus domesticus) and quantitated the expression of anti-S100 alphaalphabetabeta and S100 beta. There was a 30% increase of S100 beta saturation in the light cells facing the PIL when compared to other TV light cells. We show that: (1) the dimer anti- S100 alphaalphabetabeta and the monomer anti-S100 beta are expressed preferentially in the light cells and the E-P cells of TV; (2) expression of S100 beta is higher in light cells facing the PIL than in adjacent cells; (3) the expression of the dimer S100 alphaalphabetabeta and monomer S100 beta overlaps in most inner ear cell types, including the cells of the TV, most S100 alphaalphabetabeta positive cells express S 100 beta, but S100 beta positive cells do not always express S100 alphaalphabetabeta; and (4) the S100 beta expression in light cells, the abundant Na+-K+ ATPase on dark cells of the TV, and previously demonstrated co-localization of S100 beta/GABA in sensory cells suggest that S100 beta could have, in the inner ear, a dual neurotrophic-ionic modulating function.
Merdivan, Melek; Pino, Verónica; Anderson, Jared L
2017-08-01
A benzyl-functionalized crosslinked polymeric ionic liquid (PIL), produced through the co-polymerization of the 1-vinylbenzyl-3-hexadecylimidazolium bis[(trifluoromethyl)sulfonyl]imide (VBHDIM-NTf 2 ) ionic liquid (IL) monomer and 1,12-di(3-vinylbenzylimidazolium)dodecane bis[(trifluoromethyl)sulfonyl]imide ((DVBIM) 2 C 12- 2NTf 2 ) IL crosslinker, was successfully used as a sorbent coating in headspace solid-phase microextraction (SPME) coupled to gas chromatography (GC) with flame-ionization detection (FID) to determine seven volatile polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. Optimum extraction conditions for the PAHs when using the novel sorbent include an extraction temperature of 50°C, an ionic strength content adjusted with 30% (w/v) NaCl in the aqueous sample, and an extraction time of 60 min. The extraction performance of the crosslinked PIL fiber was compared to the SPME commercial coating polydimethylsiloxane fiber. The calibration ranges of the studied PAHs were linear in the range of 0.02-20 µg L -1 for the crosslinked PIL fiber. The accuracy of the proposed method was demonstrated by examining the spiked recoveries of seven PAHs which produced values ranging from 67.2% to 130% (for river- and seawater samples), and precision values lower than 9.4% for a spiked level of 1 µg L -1 , and detection limits between 0.01 and 0.04 µg L -1 , which supports the sensitivity of the method using GC-FID.
77 FR 24712 - Notice of Agreements Filed
Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-25
..., Morocco, and the U.S. East Coast. Agreement No.: 012167. Title: KL/PIL Space Charter and Sailing Agreement..., coordinate their sailings, and cooperate in the carriage of cargo between China and the U.S. West Coast. By...
[Surgical therapy of segmental jejunal, primary intestinal lymphangiectasia].
Kneist, W; Drescher, D G; Hansen, T; Kreitner, K F; Lang, H
2013-06-01
Primary intestinal lymphangiectasia (PIL) is a protein-losing, exsudative gastroenteropathy causing lymphatic obstruction. Diagnosis depends on clinical examination and histological findings. Conservative treatment modalities include a low-fat diet and enteral nutritional therapy in order to reduce enteric protein loss and to improve fat metabolism. Other treatment options consist of administration of antiplasmin or octreotide to lower lymph flow and secretion. We report on a 58-year-old patient who underwent exploratory laparotomy due to a worsening physical status, recurrent chylaskos and leg oedema under conservative dietary therapy. Intraoperative findings showed a typical PIL of the jejunum about 20 cm distal to the Treitz's ligament. Histological examinations confirmed this diagnosis. One year after segmental small bowel resection (105 cm) with end-to-end anastomosis the patient is healthy, free of symptoms, has gained weight and his serum protein level has increased. Intraabdominal ascites and leg oedema have not reoccurred since.
Oxidative desulfurization of model diesel via dual activation by a protic ionic liquid.
Lü, Hongying; Wang, Shunan; Deng, Changliang; Ren, Wanzhong; Guo, Baocun
2014-08-30
A novel and green carboxylate-anion-based protic ionic liquid (PIL), [Hnmp]HCOO, was prepared through a simple and atom economic neutralization reaction between N-methyl-2-pyrrolidonium (NMP) and formic acids. Both FT-IR spectra and (1)H NMR confirmed its simple salt structure. [Hnmp]HCOO exhibited so high catalytic activity that the dibenzothiophene (DBT) removal reached 99% at 50°C in 3h under conditions of VPIL/Vmodel oil=1:10 and H2O2/DBT (O/S, molar ratio)=5. The catalytic oxidation reactivity of S-compounds was found to be in the order of DBT>4,6-dimethyldibenzothiophene (4,6-DMDBT)>benzothiophene (BT). The investigation on mechanism showed that oxidative desulfurization was realized through dual activation of PIL. Moreover, [Hnmp]HCOO can be recycled for five times with an unnoticeable decrease in desulfurization activity. Copyright © 2014 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Hu, Chenchen; Zhao, Enbo; Nitta, Naoki; Magasinski, Alexandre; Berdichevsky, Gene; Yushin, Gleb
2016-09-01
Nanocomposites based on polyoxometalates (POMs) nanoconfined in microporous carbons have been synthesized and used as electrodes for supercapacitors. The addition of the pseudocapacitance from highly reversible redox reaction of POMs to the electric double-layer capacitance of carbon lead to an increase in specific capacitance of ∼90% at 1 mV s-1. However, high solubility of POM in traditional aqueous electrolytes leads to rapid capacity fading. Here we demonstrate that the use of aqueous solutions of protic ionic liquids (P-IL) as electrolyte instead of aqueous sulfuric acid solutions offers an opportunity to significantly improve POM cycling stability. Virtually no degradation in capacitance was observed in POM-based positive electrode after 10,000 cycles in an asymmetric capacitor with P-IL aqueous electrolyte. As such, POM-based carbon composites may now present a viable solution for enhancing energy density of electrical double layer capacitors (EDLC) based on pure carbon electrodes.
Comparison of Learning Styles of Pharmacy Students and Faculty Members
Crawford, Stephanie Y.; Alhreish, Suhail K.
2012-01-01
Objectives. To compare dominant learning styles of pharmacy students and faculty members and between faculty members in different tracks. Methods. Gregorc Style Delineator (GSD) and Zubin’s Pharmacists’ Inventory of Learning Styles (PILS) were administered to students and faculty members at an urban, Midwestern college of pharmacy. Results. Based on responses from 299 students (classes of 2008, 2009, and 2010) and 59 faculty members, GSD styles were concrete sequential (48%), abstract sequential (18%), abstract random (13%), concrete random (13%), and multimodal (8%). With PILS, dominant styles were assimilator (47%) and converger (30%). There were no significant differences between faculty members and student learning styles nor across pharmacy student class years (p>0.05). Learning styles differed between men and women across both instruments (p<0.01), and between faculty members in tenure and clinical tracks for the GSD styles (p=0.01). Conclusion. Learning styles differed among respondents based on gender and faculty track. PMID:23275657
Multiple Vibrio fischeri genes are involved in biofilm formation and host colonization
Chavez-Dozal, Alba; Hogan, David; Gorman, Clayton; Quintanal-Villalonga, Alvaro; Nishiguchi, Michele K.
2012-01-01
Biofilms are increasingly recognized as the predominant form for survival in the environment for most bacteria. The successful colonization of Vibrio fischeri in its squid host Euprymna tasmanica, involves complex microbe-host interactions mediated by specific genes that are essential for biofilm formation and colonization. In the present investigation, structural and regulatory genes were selected to study their role in biofilm formation and host colonization. We have mutated several genes (pilT, pilU, flgF, motY, ibpA and mifB) by an insertional inactivation strategy. Results demonstrate that structural genes responsible for synthesis of type IV pili and flagella are crucial for biofilm formation and host infection. Moreover, regulatory genes affect colony aggregation by various mechanisms including alteration of synthesis of transcriptional factors and regulation of extracellular polysaccharide production. These results reflect the significance of how genetic alterations influence communal behavior, which is important in understanding symbiotic relationships. PMID:22486781
NASA Astrophysics Data System (ADS)
Nkanga, Christian Isalomboto; Krause, Rui Werner Maçedo
2018-05-01
Tuberculosis (TB) remains the leading cause of mortality from infectious diseases. Extended TB treatment and frequent adverse effects, due to poor bioavailability of anti-tubercular drugs (ATBDs), represent the main rationales behind liposomal encapsulation for controlled delivery. Liposomes have been reported as potential vehicles for targeted delivery of ATBDs due to their rapid uptake by macrophages, which are known as the main host cells for TB causative agent (Mycobacterium tuberculosis). Additionally, the need for controlled release of ATBDs arises because leakage is part of the key liposome challenges for hydrophilic compounds like isoniazid (INH). In this study, INH was conjugated to a highly hydrophobic photosensitizer, zinc (II) phthalocyanine (PC), through hydrazone bonding. The obtained conjugate (PC-INH) was encapsulated in liposomes by film hydration method. PC-INH loaded liposomes (PILs) were characterized using dynamic light scattering, transmission electron microscopy, energy-dispersive X-ray spectrometry and UV-Vis absorption spectrometry, which was used also for estimation of encapsulation efficiency (%EE). INH release was evaluated in different pH media using dialysis. Particle size, zeta potential and %EE of PILs were about 506 nm, - 55 mV and 72%, respectively. Over 12 h, PILs exhibited 22, 41, 97 and 100% of INH, respectively, released in pH 7.4, 6.4, 5.4 and 4.4 media. This pH-dependent behavior is attractive for site-specific delivery. These findings suggest the conjugation of chemotherapeutics to phthalocyanines using pH-labile linkages as a potential strategy for liposomal controlled release.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Elias, Dwayne A; Zane, Mr. Grant M.; Auer, Dr. Manfred
2010-01-01
Extracellular electron transfer has been investigated over several decades via forms of soluble electron transfer proteins that are exported for extracellular reoxidation. More recently, several organisms have been shown to reduce extracellular metals via the direct transfer of electron through appendages; also known as nanowires. They have been reported most predominantly in Shewanella and Geobacter. While the relevancy and composition of these structures in each genus has been debated, both possess outer membrane cytochrome complexes that could theoretically come into direct contact with solid phase oxidized metals. Members of the genus Desulfovibrio apparently have no such cytochromes although similar appendagesmore » are present, are electrically conductive, and are different from flagella. Upon U(VI)-reduction, the structures in Desulfovibrio become coated with U(IV). Deletion of flagellar genes did not alter soluble or amorphous Fe(III) or U(VI) reduction, or appendage appearance. Removal of the chromosomal pilA gene hampered amorphous Fe(III)-reduction by ca. 25%, but cells lacking the native plasmid, pDV1, reduced soluble Fe(III) and U(VI) at ca. 50% of the wild type rate while amorphous Fe(III)-reduction slowed to ca. 20% of the wild type rate. Appendages were present in all deletions as well as pDV1, except pilA. Gene complementation restored all activities and morphologies to wild type levels. This suggests that pilA encodes the structural component, whereas genes within pDV1 may provide the reactive members. How such appendages function without outer membrane cytochromes is under investigation.« less
Maglalang, Dale Dagar; Yoo, Grace J; Ursua, Rhodora A; Villanueva, Carissa; Chesla, Catherine A; Bender, Melinda S
2017-01-01
Filipino Americans have the highest risk for obesity-related type 2 diabetes and related complications compared with all major Asian American subgroups. Identifying effective interventions to improve Filipino health outcomes are needed to reduce this health disparity. To assess the acceptability and cultural relevance of the PilAm Go4Health program - a culturally adapted mobile health weight-loss lifestyle intervention including virtual social networking for Filipino Americans with type 2 diabetes. Qualitative semi-structured post-program interviews explored perceptions of 45 Filipino Americans with type 2 diabetes in Northern California regarding their perceptions of the acceptability and cultural relevance of PilAm Go4Health. Participants' mean age was 57.6 years. Sixty-seven interviews were recorded, transcribed, and thematically analyzed by four independent coders. Over half (n=26, 57.8%) of the respondents found that a culturally tailored intervention program enhanced their engagement. All (n=45) of the respondents felt that mobile health technology promoted their self-efficacy. A majority of the respondents (n=29, 64.4%) expressed that they progressed from despair to self-efficacy as a result of their participation in the intervention. More than one-fourth of the participants (n=13, 28.8%) discussed that the intervention needed further cultural tailoring. Overall, PilAm Go4Health - a mobile health weight-loss lifestyle intervention - was acceptable and culturally relevant for Filipino Americans with type 2 diabetes. Findings may help inform clinician and researchers on effective intervention strategies for diabetes self-management when designing interventions for diverse populations.
[Reliability and validity of Meaningful Life Measure-Chinese Revised in Chinese college students].
Xiao, Rong; Lai, Qiao-Zhen; Yang, Jia-Ping
2016-04-20
To test the reliability and validity of Meaningful Life Measure-Chinese Revised (MLM-CR) in Chinese college students. A total of 1035 college students were evaluated with MLM-CR, Satisfaction with Life Scale (SWLS), Purpose in Life (PIL) and Patient Health Questionnaire-2 (PHQ-2), and 120 of the students were examined with PIL-SF twice. All the items in MLM-CR had good discrimination indexes (r=0.753-0.838, P<0.001). Confirmatory factor analysis confirmed the hypothesized five-factor model of MLM-CR (Χ 2 /df=3.4, GFI=0.946, AGFI=0.924, RMR=0.069, NFI=0.953, CFI=0.966, RMSEA=0.048). The total internal consistency reliability of MLM-CR was 0.942, and the alpha coefficients of the 5 dimensions ranged from 0.782 to 0.877; the total split-half reliability was 0.920, and the split-half reliability of the 5 dimensions ranged from 0.752 to 0.830; the total test-retest reliability was 0.871, and the test-retest reliability of the 5 dimensions ranged from 0.783 to 0.805. The criterion validity of MLM-CR in correlation with SWLS, PIL and PHQ-2 was 0.66, 0.755 and -0.388, respectively (P<0.01). The Average score of MLM-CR of the college students was 5.20∓0.90, and the scores were significantly higher in female students than in the male students (P<0.001). MLM-CR has good psychometric properties for application in comprehensive evaluation of personal meaning in life.
Webster, Rebecca K; Weinman, John; Rubin, G James
2017-12-01
To establish how the terms recommended by the European Commission to describe side-effect risk in patient information leaflets (PILs) influences expectations of side-effects and to identify factors associated with these side-effect expectations. A cross-sectional online survey was carried out by a market research company. Data were collected in England between 18th March and 1st April 2016. A total of 1003 adults aged between 18 and 65. Self-reported expectation that the described side-effects would affect participants if they took the medicine, measured on a likelihood scale from 1 (very unlikely) to 5 (very likely). Participants formed high expectations of side-effects for "very common" and "common" side-effects, with 51.9% and 45.0% of participants rating these as "very likely" or "likely" to happen to them, respectively. This fell to 8.1% for "uncommon," 5.8% for "rare" and 4.1% for "very rare." For each descriptor, higher expectations of side-effects were more associated with women or being from an ethnic minority, or having less education, a household illness, high perceived sensitivity to medicines or negative beliefs about medicines. The current use of verbal descriptors to communicate side-effect risk in PILs leads to high side-effect expectations. These expectations could contribute to nocebo-induced medication side-effects experienced by patients. Additional work is required to identify ways to improve the way risk information is conveyed in PILs. © 2017 The Authors Health Expectations Published by John Wiley & Sons Ltd.
Morelle, Sandrine; Carbonnelle, Etienne; Nassif, Xavier
2003-01-01
Interaction with host cells is essential in meningococcal pathogenesis especially at the blood-brain barrier. This step is likely to involve a common regulatory pathway allowing coordinate regulation of genes necessary for the interaction with endothelial cells. The analysis of the genomic sequence of Neisseria meningitidis Z2491 revealed the presence of many repeats. One of these, designated REP2, contains a −24/−12 type promoter and a ribosome binding site 5 to 13 bp before an ATG. In addition most of these REP2 sequences are located immediately upstream of an ORF. Among these REP2-associated genes are pilC1 and crgA, described as being involved in steps essential for the interaction of N. meningitidis with host cells. Furthermore, the REP2 sequences located upstream of pilC1 and crgA correspond to the previously identified promoters known to be induced during the initial localized adhesion of N. meningitidis with human cells. This characteristic led us to hypothesize that at least some of the REP2-associated genes were upregulated under the same circumstances as pilC1 and crgA. Quantitative PCR in real time demonstrated that the expression of 14 out of 16 REP2-associated genes were upregulated during the initial localized adhesion of N. meningitidis. Taken together, these data suggest that these repeats control a set of genes necessary for the efficient interaction of this pathogen with host cells. Subsequent mutational analysis was performed to address the role of these genes during meningococcus-cell interaction. PMID:12670987
Yu, Lei; Pizio, Benjamin S; Vaden, Timothy D
2012-06-07
Protic ionic liquids (PILs) are promising alternatives to water for swelling Nafion as a fuel cell proton exchange membrane (PEM). PILs can significantly improve the high-temperature performance of a PEM. The proton dissociation and solvation mechanisms in a PIL, which are keys to understanding the proton transportation and conductivity, have not been fully explored. In this paper, we used FTIR, Raman, and electronic spectroscopy with computational simulation techniques to explore the spectroscopic properties of bis(trifluoromethanesulfonyl)imide (HTFSI) solutions in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMITFSI) ionic liquid at concentrations from ∼0.1 to as high as ∼1.0 M. Solution conductivities were measured at room temperature and elevated temperatures up to ∼65 °C. The solution structure and properties depend on the concentration of HTFSI. At lower concentration, around 0.1 M, the HTFSI solution has higher conductivity than pure BMITFSI. However, the conductivity decreases when the concentration increases from 0.1 to 1.0 M. Temperature-dependent conductivities followed the Vogel-Fulcher-Tamman equation at all concentrations. Conductivity and spectroscopy results elucidate the complicated ionization and solvation mechanism of HTFSI in BMITFSI solutions. Raman spectroscopy and density functional theory (DFT) calculations are consistent with the complete ionization of HTFSI to generate solvated H(+) at low concentrations. FTIR, Raman, and electronic spectroscopic results as well as DFT computational simulation indicated that when the concentration is as high as 1.0 M, a significant amount of TFSI(-) is protonated, most likely at the imide nitrogen.
Trigger of Successive Filament Eruptions Observed by SDO and STEREO
NASA Astrophysics Data System (ADS)
Dhara, Sajal Kumar; Belur, Ravindra; Kumar, Pankaj; Banyal, Ravinder Kumar; Mathew, Shibu K.; Joshi, Bhuwan
2017-10-01
Using multiwavelength observations from the Solar Dynamics Observatory (SDO) and the Solar Terrestrial Relations Observatory (STEREO), we investigate the mechanism of two successive eruptions (F1 and F2) of a filament in active region NOAA 11444 on 27 March 2012. The filament was inverse J-shaped and lay along a quasi-circular polarity inversion line (PIL). The first part of the filament erupted at ˜2{:}30 UT on 27 March 2012 (F1), the second part at around 4:20 UT on the same day (F2). A precursor or preflare brightening was observed below the filament main axis about 30 min before F1. The brightening was followed by a jet-like ejection below the filament, which triggered its eruption. Before the eruption of F2, the filament seemed to be trapped within the overlying arcade loops for almost 1.5 h before it successfully erupted. Interestingly, we observe simultaneously contraction (˜12 km s^{-1}) and expansion (˜20 km s^{-1}) of arcade loops in the active region before F2. Magnetograms obtained with the Helioseismic and Magnetic Imager (HMI) show converging motion of the opposite polarities, which result in flux cancellation near the PIL. We suggest that flux cancellation at the PIL resulted in a jet-like ejection below the filament main axis, which triggered F1, similar to the tether-cutting process. F2 was triggered by removal of the overlying arcade loops via reconnection. Both filament eruptions produced high-speed (˜1000 km s^{-1}) coronal mass ejections.
de Oliveira, Vera Lucia Ferreira; Gerlach, Raquel Fernanda; Martins, Lourdes Conceição; de Souza Guerra, Carolina; Frazão, Paulo; Braga, Alfésio Luis Ferreira; Pereira, Luiz Alberto Amador
2017-06-01
Heavy metal contamination is a long-standing and very well-known public health problem, and its exposure can cause damage to several organs of human body, especially on the central nervous system of young children and teenagers. The aim of this article is to evaluate lead, cadmium, and manganese contamination in 125 children from 6 to 13 years old living in contaminated areas during the period from 2006 to 2009 (São Vicente, Cubatão Downtown, Bertioga and Cubatão Pilões/Água Fria). This estuary area is the most important example of environmental degradation by chemicals from industrial sources. This is a cross-sectional study through clinical examinations and dental enamel tests. All mothers from these children lived in the area since before the pregnancy. Lead, cadmium, and manganese levels (μg/g) were measured on dental enamel samples through graphite furnace atomic absorption spectrometry, searching for the occurrence of heavy metals. The mean lead concentrations were 139.48 μg/g in Cubatão Pilões/Água Fria, 170.45 μg/g in Cubatão Downtown, 213.52 μg/g in São Vicente, and 151.89 μg/g in Bertioga. The mean cadmium concentrations were 10.83 μg/g in Cubatão Pilões/Água Fria, 12.58 μg/g in Cubatão Downtown, 10.92 μg/g in São Vicente, and 14.57 μg/g in Bertioga. The mean manganese concentrations were 23.49 μg/g in Cubatão Pilões/Água Fria, 30.90 μg/g in Cubatão Downtown, 41.46 μg/g in São Vicente, and 42.00 μg/g in Bertioga. Dental surface enamel may be used as an efficient biomarker of past environmental exposure to lead, manganese, and cadmium which are associated to well-known sources of heavy metal contamination. The results suggest that the evaluated children were exposed to sources of lead, cadmium, and manganese since before their conceptions. Although Bertioga initially was chosen as a control area of this study, it was also was verified to have heavy metal contamination on examined children.
Formation of a solar Hα filament from orphan penumbrae
NASA Astrophysics Data System (ADS)
Buehler, D.; Lagg, A.; van Noort, M.; Solanki, S. K.
2016-05-01
Aims: The formation and evolution of an Hα filament in active region (AR) 10953 is described. Methods: Observations from the Solar Optical Telescope (SOT) aboard the Hinode satellite starting from UT 18:09 on 27th April 2007 until UT 06:08 on 1st May 2007 were analysed. 20 scans of the 6302 Å Fe I line pair recorded by SOT/SP were inverted using the spatially coupled version of the SPINOR code. The inversions were analysed together with co-spatial SOT/BFI G-band and Ca II H and SOT/NFI Hα observations. Results: Following the disappearance of an initial Hα filament aligned along the polarity inversion line (PIL) of the AR, a new Hα filament formed in its place some 20 h later, which remained stable for, at least, another 1.5 days. The creation of the new Hα filament was driven by the ascent of horizontal magnetic fields from the photosphere into the chromosphere at three separate locations along the PIL. The magnetic fields at two of these locations were situated directly underneath the initial Hα filament and formed orphan penumbrae already aligned along the Hα filament channel. The 700 G orphan penumbrae were stable and trapped in the photosphere until the disappearance of the overlying initial Hα filament, after which they started to ascend into the chromosphere at 10 ± 5 m/s. Each ascent was associated with a simultaneous magnetic flux reduction of up to 50% in the photosphere. The ascended orphan penumbrae formed dark seed structures in Hα in parallel with the PIL, which elongated and merged to form an Hα filament. The filament channel featured horizontal magnetic fields of on average 260 G at log (τ) = -2 suspended above the nearly field-free lower photosphere. The fields took on an overall inverse configuration at log (τ) = -2 suggesting a flux rope topology for the new Hα filament. The destruction of the initial Hα filament was likely caused by the flux emergence at the third location along the PIL. Conclusions: We present a new interpretation of the Hα filament formation in AR 10953 whereby the mainly horizontal fields of orphan penumbrae, aligned along the Hα filament channel, ascend into the chromosphere, forming seed fragments for a new, second Hα filament. The orphan penumbral fields ascend into the chromosphere ~9-24 h before the Hα filament is fully formed.
Lanters, Eva A H; Teuwen, Christophe P; Yaksh, Ameeta; Kik, Charles; van der Does, Lisette J M E; Mouws, Elisabeth M J P; Knops, Paul; van Groningen, Nicole J; Hokken, Thijmen; Bogers, Ad J J C; de Groot, Natasja M S
2018-03-10
Early postoperative atrial fibrillation (EPoAF) is associated with thromboembolic events, prolonged hospitalization, and development of late PoAF (LPoAF). It is, however, unknown if EPoAF can be predicted by intraoperative AF inducibility. The aims of this study are therefore to explore (1) the value of intraoperative inducibility of AF for development of both EPoAF and LPoAF and (2) the predictive value of de novo EPoAF for recurrence of LPoAF. Patients (N=496, 75% male) undergoing cardiothoracic surgery for coronary and/or valvular heart disease were included. AF induction was attempted by atrial pacing, before extracorporeal circulation. All patients were on continuous rhythm monitoring until discharge to detect EPoAF. During a follow-up period of 2 years, LPoAF was detected by ECGs and Holter recordings. Sustained AF was inducible in 56% of patients. There was no difference in patients with or without AF before surgery ( P =0.159), or between different types of surgery ( P =0.687). In patients without a history of AF, incidence of EPoAF and LPoAF was 37% and 2%, respectively. EPoAF recurred in 58% patients with preoperative AF, 53% developed LPoAF. There were no correlations between intraoperative inducibility and EPoAF or LPoAF ( P >0.05). EPoAF was not correlated with LPoAF in patients without a history of AF ( P =0.116), in contrast to patients with AF before surgery ( P <0.001). Intraoperative AF inducibility does not predict development of either EPoAF or LPoAF. In patients with AF before surgery, EPoAF is correlated with LPoAF recurrences. This correlation is absent in patients without AF before surgery. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.
Pilot performance and workload using simulated GPS track angle error displays
DOT National Transportation Integrated Search
1995-01-01
The effect on simulated GPS instrument approach performance and workload resulting from the addition of Track Angle Error (TAE) information to cockpit RNAV receiver displays in explicit analog form was studied experimentally (S display formats, 6 pil...
NASA Astrophysics Data System (ADS)
Vemareddy, P.
2017-08-01
We study the magnetic field evolution in AR 12371, related to its successive eruptive nature. During the disk transit of seven days, the active region (AR) launched four sequential fast coronal mass ejections (CMEs), which are associated with long duration M-class flares. Morphological study delineates a pre-eruptive coronal sigmoid structure above the polarity inversion line (PIL) similar to Moore et al.’s study. The velocity field derived from tracked magnetograms indicates persistent shear and converging motions of polarity regions about the PIL. While these shear motions continue, the crossed arms of two sigmoid elbows are being brought to interaction by converging motions at the middle of the PIL, initiating the tether-cutting reconnection of field lines and the onset of the CME explosion. The successive CMEs are explained by a cyclic process of magnetic energy storage and release referred to as “sigmoid-to-arcade-to-sigmoid” transformation driven by photospheric flux motions. Furthermore, the continued shear motions inject helicity flux with a dominant negative sign, which contributes to core field twist and its energy by building a twisted flux rope (FR). After a limiting value, the excess coronal helicity is expelled by bodily ejection of the FR, which is initiated by some instability as realized by intermittent CMEs. This AR is in contrast with the confined AR 12192 with a predominant negative sign and larger helicity flux, but much weaker (-0.02 turns) normalized coronal helicity content. While predominant signed helicity flux is a requirement for CME eruption, our study suggests that the magnetic flux normalized helicity flux is a necessary condition accommodating the role of background flux and appeals to a further study of a large sample of ARs.
Phenotypic analysis of prostate-infiltrating lymphocytes reveals TH17 and Treg skewing.
Sfanos, Karen Sandell; Bruno, Tullia C; Maris, Charles H; Xu, Lauren; Thoburn, Christopher J; DeMarzo, Angelo M; Meeker, Alan K; Isaacs, William B; Drake, Charles G
2008-06-01
Pathologic examination of prostate glands removed from patients with prostate cancer commonly reveals infiltrating CD4+ and CD8+ T cells. Little is known about the phenotype of these cells, despite accumulating evidence suggesting a potential role for chronic inflammation in the etiology of prostate cancer. We developed a technique that samples the majority of the peripheral prostate through serial needle aspirates. CD4+ prostate-infiltrating lymphocytes (PIL) were isolated using magnetic beads and analyzed for subset skewing using both flow cytometry and quantitative reverse transcription-PCR. The transcriptional profile of fluorescence-activated cell sorted prostate-infiltrating regulatory T cells (CD4+, CD25+, GITR+) was compared with naïve, peripheral blood T cells using microarray analysis. CD4+ PIL showed a paucity of TH2 (interleukin-4-secreting) cells, a surprising finding given the generally accepted association of these cells with chronic, smoldering inflammation. Instead, CD4+ PIL seemed to be skewed towards a regulatory Treg phenotype (FoxP3+) as well as towards the TH17 phenotype (interleukin-17+). We also found that a preponderance of TH17-mediated inflammation was associated with a lower pathologic Gleason score. These protein level data were reflected at the message level, as analyzed by quantitative reverse transcription-PCR. Microarray analysis of pooled prostate-infiltrating T(reg) revealed expected Treg-associated transcripts (FoxP3, CTLA-4, GITR, LAG-3) as well as a number of unique cell surface markers that may serve as additional Treg markers. Taken together, these data suggest that TH17 and/or Treg CD4+ T cells (rather than TH2 T cells) may be involved in the development or progression of prostate cancer.
Ren, Dabin; Almudevar, Anthony L; Murphy, Timothy F; Lafontaine, Eric R; Campagnari, Anthony A; Luke-Marshall, Nicole; Pichichero, Michael E
2017-07-26
Moraxella catarrhalis (Mcat) is a frequent pathogen of acute otitis media (AOM) in young children. Here we prospectively assessed naturally-induced serum antibodies to four Mcat vaccine candidate proteins in stringently defined otitis prone (sOP) and non-otitis prone (NOP) children age 6-36months old following nasopharyngeal (NP) colonization, at onset of AOM and convalescence from AOM. Serum IgG and IgM antibody against recombinant Mcat proteins, oligopeptide permease A (OppA), outer membrane protein (OMP) CD, hemagglutinin (Hag), and PilA clade 2 (PilA2), were quantitated by ELISA. During NP colonization by Mcat all four antigens were immunogenic in both sOP and NOP children. However, sOP children had lower antibody responses than NOP children across age 6-36months, similar to our findings for protein vaccine candidates of Streptococcus pneumoniae (Spn) and Nontypeable Haemophilus influenzae (NTHi). sOP children displayed a later and lower peak of antibody rise than NOP children for all four antigens during NP colonization of Mcat. The age-dependent increase of antibody ranked as OppA>Hag5-9>OMP CD>PilA2 in both sOP and NOP children. Lower serum antibody levels to the Mcat antigens were measured in sOP compared to NOP children at the onset of AOM. We did not find a consistent significant increase of antibody at the convalescence phase after an AOM event. sOP children is a highly vulnerable population that mount lower serum antibody responses to Mcat candidate vaccine proteins compared to NOP children during asymptomatic NP carriage and at onset of AOM. Copyright © 2017 Elsevier Ltd. All rights reserved.
Global-Scale Consequences of Magnetic-Helicity Injection and Condensation on the Sun
NASA Technical Reports Server (NTRS)
Mackay, Duncan H.; DeVore, C. Richard; Antiochos, Spiro K.
2013-01-01
In the recent paper of Antiochos, a new concept for the injection of magnetic helicity into the solar corona by small-scale convective motions and its condensation onto polarity inversion lines (PILs) has been developed. We investigate this concept through global simulations of the Sun's photospheric and coronal magnetic fields and compare the results with the hemispheric pattern of solar filaments. Assuming that the vorticity of the cells is predominately counter-clockwise/clockwise in the northern/southern hemisphere, the convective motions inject negative/positive helicity into each hemisphere. The simulations show that: (i) On a north-south orientated PIL, both differential rotation and convective motions inject the same sign of helicity which matches that required to reproduce the hemispheric pattern of filaments. (ii) On a high latitude east-west orientated polar crown or sub-polar crown PIL, the vorticity of the cells has to be approximately 2-3 times greater than the local differential rotation gradient in order to overcome the incorrect sign of helicity injection from differential rotation. (iii) In the declining phase of the cycle, as a bipole interacts with the polar field, in some cases helicity condensation can reverse the effect of differential rotation along the East-West lead arm, but not in all cases. The results show that this newly developed concept of magnetic helicity injection and condensation is a viable method to explain the hemispheric pattern of filaments in conjunction with the mechanisms used in Yeates et al. (2008). Future observational studies should focus on determining the vorticity component within convective motions to determine, both its magnitude and latitudinal variation relative to the differential rotation gradient on the Sun.
NASA Astrophysics Data System (ADS)
Fukami, Christine S.; Sullivan, Amy P.; Ryan Fulgham, S.; Murschell, Trey; Borch, Thomas; Smith, James N.; Farmer, Delphine K.
2016-07-01
Particle-into-Liquid Samplers (PILS) have become a standard aerosol collection technique, and are widely used in both ground and aircraft measurements in conjunction with off-line ion chromatography (IC) measurements. Accurate and precise background samples are essential to account for gas-phase components not efficiently removed and any interference in the instrument lines, collection vials or off-line analysis procedures. For aircraft sampling with PILS, backgrounds are typically taken with in-line filters to remove particles prior to sample collection once or twice per flight with more numerous backgrounds taken on the ground. Here, we use data collected during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) to demonstrate that not only are multiple background filter samples are essential to attain a representative background, but that the chemical background signals do not follow the Gaussian statistics typically assumed. Instead, the background signals for all chemical components analyzed from 137 background samples (taken from ∼78 total sampling hours over 18 flights) follow a log-normal distribution, meaning that the typical approaches of averaging background samples and/or assuming a Gaussian distribution cause an over-estimation of background samples - and thus an underestimation of sample concentrations. Our approach of deriving backgrounds from the peak of the log-normal distribution results in detection limits of 0.25, 0.32, 3.9, 0.17, 0.75 and 0.57 μg m-3 for sub-micron aerosol nitrate (NO3-), nitrite (NO2-), ammonium (NH4+), sulfate (SO42-), potassium (K+) and calcium (Ca2+), respectively. The difference in backgrounds calculated from assuming a Gaussian distribution versus a log-normal distribution were most extreme for NH4+, resulting in a background that was 1.58× that determined from fitting a log-normal distribution.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Brot,N.; Collet, J.; Johnson, L.
2006-01-01
The PilB protein from Neisseria gonorrhoeae is located in the periplasm and made up of three domains. The N-terminal, thioredoxin-like domain (NT domain) is fused to tandem methionine sulfoxide reductase A and B domains (MsrA/B). We show that the {alpha} domain of Escherichia coli DsbD is able to reduce the oxidized NT domain, which suggests that DsbD in Neisseria can transfer electrons from the cytoplasmic thioredoxin to the periplasm for the reduction of the MsrA/B domains. An analysis of the available complete genomes provides further evidence for this proposition in other bacteria where DsbD/CcdA, Trx, MsrA, and MsrB gene homologsmore » are all located in a gene cluster with a common transcriptional direction. An examination of wild-type PilB and a panel of Cys to Ser mutants of the full-length protein and the individually expressed domains have also shown that the NT domain more efficiently reduces the MsrA/B domains when in the polyprotein context. Within this framework there does not appear to be a preference for the NT domain to reduce the proximal MsrA domain over MsrB domain. Finally, we report the 1.6 {angstrom} crystal structure of the NT domain. This structure confirms the presence of a surface loop that makes it different from other membrane-tethered, Trx-like molecules including TlpA, CcmG and ResA. Subtle differences are observed in this loop when compared to the N. meningitidis NT domain structure. The data taken together supports the formation of specific NT domain interactions with the MsrA/B domains and its in vivo recycling partner, DsbD.« less
Baynham, Patricia J; Ramsey, Deborah M; Gvozdyev, Borys V; Cordonnier, Ellen M; Wozniak, Daniel J
2006-01-01
Pseudomonas aeruginosa is an opportunistic pathogen that is commonly found in water and soil. In order to colonize surfaces with low water content, P. aeruginosa utilizes a flagellum-independent form of locomotion called twitching motility, which is dependent upon the extension and retraction of type IV pili. This study demonstrates that AlgZ, previously identified as a DNA-binding protein absolutely required for transcription of the alginate biosynthetic operon, is required for twitching motility. AlgZ may be required for the biogenesis or function of type IV pili in twitching motility. Transmission electron microscopy analysis of an algZ deletion in nonmucoid PAO1 failed to detect surface pili. To examine expression and localization of PilA (the major pilin subunit), whole-cell extracts and cell surface pilin preparations were analyzed by Western blotting. While the PilA levels present in whole-cell extracts were similar for wild-type P. aeruginosa and P. aeruginosa with the algZ deletion, the amount of PilA on the surface of the cells was drastically reduced in the algZ mutant. Analysis of algZ and algD mutants indicates that the DNA-binding activity of AlgZ is essential for the regulation of twitching motility and that this is independent of the role of AlgZ in alginate expression. These data show that AlgZ DNA-binding activity is required for twitching motility independently of its role in alginate production and that this involves the surface localization of type IV pili. Given this new role in twitching motility, we propose that algZ (PA3385) be designated amrZ (alginate and motility regulator Z).
Crucello, Juliana; Miron, Luiz F O; Ferreira, Victor H C; Nan, He; Marques, Marcia O M; Ritschel, Patricia S; Zanus, Mauro C; Anderson, Jared L; Poppi, Ronei J; Hantao, Leandro W
2018-05-28
In this study, a series of polymeric ionic liquid (PIL) sorbent coatings is evaluated for the extraction of polar volatile organic compounds (VOCs) from Brazilian wines using headspace solid-phase microextraction (HS-SPME), including samples from 'Isabella' and 'BRS Magna' cultivars-the latter was recently introduced by the Brazilian Agricultural Research Corporation - National Grape & Wine Research Center. The structurally tuned SPME coatings were compared to the commercial SPME phases, namely poly(acrylate) (PA) and divinylbenzene/carboxen/poly(dimethylsiloxane) (DVB/CAR/PDMS). The separation, detection and identification of the aroma profiles were obtained using comprehensive two-dimensional gas chromatography mass spectrometry (GC×GC-MS). The best performing PIL-based SPME fiber, namely 1-hexadecyl-3-vinylimidazolium bis[(trifluoromethyl)sulfonyl]imide with 1,12-di(3-vinylimidazolium)dodecane dibis[(trifluoromethyl)sulfonyl]imide incorporated cross-linker supported on an elastic nitinol wire, exhibited superior performance to DVB/CAR/PDMS regarding the average number of extracted peaks and extracted more polar analytes providing additional insight into the aroma profile of 'BRS Magna' wines. Four batches of wine were evaluated, namely 'Isabella' and 'BRS Magna' vintages 2015 and 2016, using highly selective PIL-based SPME coatings and enabled the detection of 350+ peaks. Furthermore, this is the first report evaluating the aroma of 'BRS Magna' wines. A hybrid approach that combined pixel-based Fisher ratio and peak table-based data comparison was used for data handling. This proof-of-concept experiment provided reliable and statistically valid distinction of wines that may guide regulation agencies to create high sample throughput protocols to screen wines exported by Brazilian vintners. Graphical abstract Highly selective extraction of wine aroma using polymeric ionic liquid.
FLUX CANCELLATION AND THE EVOLUTION OF THE ERUPTIVE FILAMENT OF 2011 JUNE 7
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yardley, S. L.; Green, L. M.; Williams, D. R.
We investigate whether flux cancellation is responsible for the formation of a very massive filament resulting in the spectacular eruption on 2011 June 7. We analyze and quantify the amount of flux cancellation that occurs in NOAA AR 11226 and its two neighboring active regions (ARs 11227 and 11233) using line-of-sight magnetograms from the Heliospheric Magnetic Imager. During a 3.6 day period building up to the eruption of the filament, 1.7 × 10{sup 21} Mx, 21% of AR 11226's maximum magnetic flux, was canceled along the polarity inversion line (PIL) where the filament formed. If the flux cancellation continued atmore » the same rate up until the eruption then up to 2.8 × 10{sup 21} Mx (34% of the AR flux) may have been built into the magnetic configuration that contains the filament plasma. The large flux cancellation rate is due to an unusual motion of the positive-polarity sunspot, which splits, with the largest section moving rapidly toward the PIL. This motion compresses the negative polarity and leads to the formation of an orphan penumbra where one end of the filament is rooted. Dense plasma threads above the orphan penumbra build into the filament, extending its length, and presumably injecting material into it. We conclude that the exceptionally strong flux cancellation in AR 11226 played a significant role in the formation of its unusually massive filament. In addition, the presence and coherent evolution of bald patches in the vector magnetic field along the PIL suggest that the magnetic field configuration supporting the filament material is that of a flux rope.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vemareddy, P., E-mail: vemareddy@iiap.res.in
We study the magnetic field evolution in AR 12371, related to its successive eruptive nature. During the disk transit of seven days, the active region (AR) launched four sequential fast coronal mass ejections (CMEs), which are associated with long duration M-class flares. Morphological study delineates a pre-eruptive coronal sigmoid structure above the polarity inversion line (PIL) similar to Moore et al.’s study. The velocity field derived from tracked magnetograms indicates persistent shear and converging motions of polarity regions about the PIL. While these shear motions continue, the crossed arms of two sigmoid elbows are being brought to interaction by convergingmore » motions at the middle of the PIL, initiating the tether-cutting reconnection of field lines and the onset of the CME explosion. The successive CMEs are explained by a cyclic process of magnetic energy storage and release referred to as “sigmoid-to-arcade-to-sigmoid” transformation driven by photospheric flux motions. Furthermore, the continued shear motions inject helicity flux with a dominant negative sign, which contributes to core field twist and its energy by building a twisted flux rope (FR). After a limiting value, the excess coronal helicity is expelled by bodily ejection of the FR, which is initiated by some instability as realized by intermittent CMEs. This AR is in contrast with the confined AR 12192 with a predominant negative sign and larger helicity flux, but much weaker (−0.02 turns) normalized coronal helicity content. While predominant signed helicity flux is a requirement for CME eruption, our study suggests that the magnetic flux normalized helicity flux is a necessary condition accommodating the role of background flux and appeals to a further study of a large sample of ARs.« less
One-pot integrated biofuel production using low-cost biocompatible protic ionic liquids
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sun, Jian; Konda, N. V. S. N. Murthy; Parthasarathi, Ramakrishnan
The transformation of biomass into liquid fuels is of great importance. Previous work has demonstrated the capability of specific ionic liquids (ILs), such as 1-ethyl-3-methylimidazolium acetate ([C(2)C(1)Im][OAc]) and cholinium lysinate ([Ch][Lys]), to be effective biomass pretreatment solvents. Using these ILs for an integrated biomass-to-biofuel configuration is still challenging due to a significant water-wash related to the high toxicity of [C(2)C(1)Im][OAc] and pH adjustment prior to saccharification for the highly basic [Ch][Lys]. In this work, we demonstrate, for the first time, that a one-pot integrated biofuel production is enabled by a low cost (similar to$1 per kg) and biocompatible protic ILmore » (PIL), ethanolamine acetate, without pH adjustments, water-wash and solid-liquid separations. After pretreatment, the whole slurry is directly used for simultaneous saccharification and fermentation (SSF) with commercial enzyme cocktails and wild type yeast strains, generating 70% of the theoretical ethanol yield (based on switchgrass). The structure-performance relationships of PILs in terms of lignin removal, net basicity, and pH value are systematically studied. A technoeconomic analysis (TEA) revealed that an integrated biorefinery concept based on this PIL process could potentially reduce the minimum ethanol selling price by more than 40% compared to scenarios that require pH adjustment prior to SSF. Improvement of the economic performance will be made by reducing the dilution and enzyme loading during SSF as identified by TEA. This study demonstrates the impact of a biocompatible IL in terms of process optimization and conversion efficiency, and opens up avenues for realizing an IL based efficiently integrated biomass conversion technology.« less
Phenotypic Analysis of Prostate-Infiltrating Lymphocytes Reveals TH17 and Treg Skewing
Sfanos, Karen Sandell; Bruno, Tullia C.; Maris, Charles H.; Xu, Lauren; Thoburn, Christopher J.; DeMarzo, Angelo M.; Meeker, Alan K.; Isaacs, William B.; Drake, Charles G.
2011-01-01
Purpose Pathologic examination of prostate glands removed from patients with prostate cancer commonly reveals infiltrating CD4+ and CD8+ T cells. Little is known about the phenotype of these cells, despite accumulating evidence suggesting a potential role for chronic inflammation in the etiology of prostate cancer. Experimental Design We developed a technique that samples the majority of the peripheral prostate through serial needle aspirates. CD4+ prostate-infiltrating lymphocytes (PIL) were isolated using magnetic beads and analyzed for subset skewing using both flow cytometry and quantitative reverse transcription-PCR. The transcriptional profile of fluorescence-activated cell sorted prostate-infiltrating regulatory T cells (CD4+, CD25+, GITR+) was compared with naïve, peripheral blood T cells using microarray analysis. Results CD4+ PIL showed a paucity of TH2 (interleukin-4– secreting) cells, a surprising finding given the generally accepted association of these cells with chronic, smoldering inflammation. Instead, CD4+ PIL seemed to be skewed towards a regulatory Treg phenotype (FoxP3+) as well as towards the TH17 phenotype (interleukin-17+). We also found that a preponderance of TH17-mediated inflammation was associated with a lower pathologic Gleason score. These protein level data were reflected at the message level, as analyzed by quantitative reverse transcription-PCR. Microarray analysis of pooled prostate-infiltrating Treg revealed expected Treg-associated transcripts (FoxP3, CTLA-4, GITR, LAG-3) as well as a number of unique cell surface markers that may serve as additional Treg markers. Conclusion Taken together, these data suggest that TH17 and/or Treg CD4+ T cells (rather than TH2 T cells) may be involved in the development or progression of prostate cancer. PMID:18519750
Triggering Process of the X1.0 Three-ribbon Flare in the Great Active Region NOAA 12192
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bamba, Yumi; Inoue, Satoshi; Kusano, Kanya
The solar magnetic field in a flare-producing active region (AR) is much more complicated than theoretical models, which assume a very simple magnetic field structure. The X1.0 flare, which occurred in AR 12192 on 2014 October 25, showed a complicated three-ribbon structure. To clarify the trigger process of the flare and to evaluate the applicability of a simple theoretical model, we analyzed the data from Hinode /Solar Optical Telescope and the Solar Dynamics Observatory /Helioseismic and Magnetic Imager, Atmospheric Imaging Assembly. We investigated the spatio-temporal correlation between the magnetic field structures, especially the non-potentiality of the horizontal field, and themore » bright structures in the solar atmosphere. As a result, we determined that the western side of the positive polarity, which is intruding on a negative polarity region, is the location where the flare was triggered. This is due to the fact that the sign of the magnetic shear in that region was opposite that of the major shear of the AR, and the significant brightenings were observed over the polarity inversion line (PIL) in that region before flare onset. These features are consistent with the recently proposed flare-trigger model that suggests that small reversed shear (RS) magnetic disturbances can trigger solar flares. Moreover, we found that the RS field was located slightly off the flaring PIL, contrary to the theoretical prediction. We discuss the possibility of an extension of the RS model based on an extra numerical simulation. Our result suggests that the RS field has a certain flexibility for displacement from a highly sheared PIL, and that the RS field triggers more flares than we expected.« less
In vitro characterization of biofilms formed by Kingella kingae.
Kaplan, J B; Sampathkumar, V; Bendaoud, M; Giannakakis, A K; Lally, E T; Balashova, N V
2017-08-01
The Gram-negative bacterium Kingella kingae is part of the normal oropharyngeal mucosal flora of children <4 years old. K. kingae can enter the submucosa and cause infections of the skeletal system in children, including septic arthritis and osteomyelitis. The organism is also associated with infective endocarditis in children and adults. Although biofilm formation has been coupled with pharyngeal colonization, osteoarticular infections, and infective endocarditis, no studies have investigated biofilm formation in K. kingae. In this study we measured biofilm formation by 79 K. kingae clinical isolates using a 96-well microtiter plate crystal violet binding assay. We found that 37 of 79 strains (47%) formed biofilms. All strains that formed biofilms produced corroding colonies on agar. Biofilm formation was inhibited by proteinase K and DNase I. DNase I also caused the detachment of pre-formed K. kingae biofilm colonies. A mutant strain carrying a deletion of the pilus gene cluster pilA1pilA2fimB did not produce corroding colonies on agar, autoaggregate in broth, or form biofilms. Biofilm forming strains have higher levels of pilA1 expression. The extracellular components of biofilms contained 490 μg cm -2 of protein, 0.68 μg cm -2 of DNA, and 0.4 μg cm -2 of total carbohydrates. We concluded that biofilm formation is common among K. kingae clinical isolates, and that biofilm formation is dependent on the production of proteinaceous pili and extracellular DNA. Biofilm development may have relevance to the colonization, transmission, and pathogenesis of this bacterium. Extracellular DNA production by K. kingae may facilitate horizontal gene transfer within the oral microbial community. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Eosinophils contribute to early clearance of Pneumocystis murina infection
Eddens, Taylor; Elsegeiny, Waleed; Nelson, Michael P.; Horne, William; Campfield, Brian T.; Steele, Chad; Kolls, Jay K.
2015-01-01
Pneumocystis pneumonia remains a common opportunistic infection in the diverse immunosuppressed population. One clear risk factor for susceptibility to Pneumocystis is a declining CD4+ T-cell counts in the setting of HIV/AIDS or primary immunodeficiency. Non-HIV infected individuals taking immunosuppressive drug regimens targeting T-cell activation are also susceptible. Given the crucial role of CD4+ T-cells in host defense against Pneumocystis, we used RNA-sequencing of whole lung early in infection in wild type and CD4-depleted animals as an unbiased approach to examine mechanisms of fungal clearance. In wild type mice, a strong eosinophil signature was observed at day 14 post-Pneumocystis challenge and eosinophils were increased in the bronchoalveolar lavage fluid of wild type mice. Furthermore, eosinophilopoiesis-deficient Gata1tm6Sho/J mice were more susceptible to Pneumocystis infection when compared to BALB/c controls and bone marrow derived eosinophils had in vitro Pneumocystis killing activity. To drive eosinophilia in vivo, Rag1−/− mice were treated with a plasmid expressing IL-5 (pIL5) or an empty plasmid control via hydrodynamic injection. pIL5 treated mice had increased serum IL-5 and eosinophilia in the lung, as well as reduced Pneumocystis burden compared to mice treated with control plasmid. Additionally, pIL5 treatment could induce eosinophilia and reduce Pneumocystis burden in CD4-depleted C57Bl/6 and BALB/c mice, but not eosinophilopoiesis-deficient Gata1tm6Sho/J mice. Taken together, these results demonstrate that an early role of CD4+ T-cells is to recruit eosinophils to the lung and that eosinophils are a novel candidate for future therapeutic development for Pneumocystis pneumonia in the immunosuppressed population. PMID:25994969
Dai, Xingping; Wang, Dongsheng; Li, Hui; Chen, Yanyi; Gong, Zhicheng; Xiang, Haiyan; Shi, Shuyun; Chen, Xiaoqing
2017-02-10
Polar and hydrophilic properties of hydroxybenzoic acids usually made them coelute with interferences in high performance liquid chromatography (HPLC) analysis. Then selective analysis of them was necessary. Herein, hollow porous ionic liquids composite polymers (PILs) based solid phase extraction (SPE) was firstly fabricated and coupled online with HPLC for selective analysis of hydroxybenzoic acids from complex matrices. Hollow porous PILs were firstly synthesized using Mobil Composition of Matter No. 48 (MCM-48) spheres as sacrificial support, 1-vinyl-3-methylimidazolium chloride (VMIM + Cl - ) as monomer, and ethylene glycol dimethacrylate (EGDMA) as cross-linker. Various parameters affecting synthesis, adsorption and desorption behaviors were investigated and optimized. Steady-state adsorption studies showed the resulting hollow porous PILs exhibited high adsorption capacity, fast adsorption kinetics, and excellent specific adsorption. Subsequently, the application of online SPE system was studied by selective analysis of protocatechuic acid (PCA), 4-hydroxybenzoic acid (4-HBA), and vanillic acid (VA) from Pollen Typha angustifolia. The obtained limit of detection (LOD) varied from 0.002 to 0.01μg/mL, the linear range (0.05-5.0μg/mL) was wide with correlation coefficient (R) from 0.9982 to 0.9994, and the average recoveries at three spiking levels ranged from 82.7 to 102.4%, with column-to-column relative standard deviation (RSD) below 8.1%. The proposed online method showed good accuracy, precision, specificity and convenience, which opened up a universal and efficient route for selective analysis of hydroxybenzoic acids from complex samples. Copyright © 2017 Elsevier B.V. All rights reserved.
Investigating the link between imipenem resistance and biofilm formation by Pseudomonas aeruginosa.
Musafer, Hadeel K; Kuchma, Sherry L; Naimie, Amanda A; Schwartzman, Joseph D; Al-Mathkhury, Harith J Fahad; O'Toole, George A
2014-07-01
Pseudomonas aeruginosa, a ubiquitous environmental organism, is a difficult-to-treat opportunistic pathogen due to its broad-spectrum antibiotic resistance and its ability to form biofilms. In this study, we investigate the link between resistance to a clinically important antibiotic, imipenem, and biofilm formation. First, we observed that the laboratory strain P. aeruginosa PAO1 carrying a mutation in the oprD gene, which confers resistance to imipenem, showed a modest reduction in biofilm formation. We also observed an inverse relationship between imipenem resistance and biofilm formation for imipenem-resistant strains selected in vitro, as well as for clinical isolates. We identified two clinical isolates of P. aeruginosa from the sputum of cystic fibrosis patients that formed robust biofilms, but were sensitive to imipenem (MIC ≤ 2 μg/ml). To test the hypothesis that there is a general link between imipenem resistance and biofilm formation, we performed transposon mutagenesis of these two clinical strains to identify mutants defective in biofilm formation, and then tested these mutants for imipenem resistance. Analysis of the transposon mutants revealed a role for previously described biofilm factors in these clinical isolates of P. aeruginosa, including mutations in the pilY1, pilX, pilW, algC, and pslI genes, but none of the biofilm-deficient mutants became imipenem resistant (MIC ≥ 8 μg/ml), arguing against a general link between biofilm formation and resistance to imipenem. Thus, assessing biofilm formation capabilities of environmental isolates is unlikely to serve as a good predictor of imipenem resistance. We also discuss our findings in light of the limited literature addressing planktonic antibiotic resistance factors that impact biofilm formation.
Cluster of linezolid-resistant Enterococcus faecium ST117 in Norwegian hospitals.
Hegstad, Kristin; Longva, Jørn-Åge; Hide, Reidar; Aasnæs, Bettina; Lunde, Tracy M; Simonsen, Gunnar Skov
2014-10-01
A linezolid-resistant, vancomycin-susceptible Enterococcus faecium strain was isolated from 3 patients who had not received linezolid. The first patient was hospitalized in the same hospitals and wards as the 2 following patients. The E. faecium isolates were resistant to linezolid (minimum inhibitory concentration 8-32 mg/l), ampicillin, and high levels of gentamicin. Resistance to linezolid was associated with a G2576T mutation in 23S rDNA. The cfr linezolid resistance gene was not detected. The 3 isolates showed identical DNA fingerprints by pulsed-field gel electrophoresis, belonged to ST117, and harboured virulence genes esp, hyl, acm, efaAfm, srgA, ecbA, scm, pilA, pilB, and pstD typically associated with high-risk E. faecium genotypes. The linezolid-resistant E. faecium high-risk clone caused bacteraemia in the first 2 cancer patients and survived in the hospital environment for more than a year before appearing in the urethral catheter of the third patient.
Jelescu-Bodos, Anca
2013-01-01
Objective. To characterize and compare learning styles of pharmacy practice residents and their faculty preceptors, and identify teaching perspectives of faculty preceptors. Methods. Twenty-nine pharmacy residents and 306 pharmacy faculty members in British Columbia were invited to complete the Pharmacists’ Inventory of Learning Styles (PILS). Faculty preceptors also were asked to complete the Teaching Perspectives Inventory (TPI). Results. One hundred percent of residents and 61% of faculty members completed the PILS, and 31% of faculty members completed the TPI. The most common dominant learning style among residents and faculty preceptors was assimilator, and 93% were assimilators, convergers, or both. The distribution of dominant learning styles between residents and faculty members was not different (p=0.77). The most common dominant teaching perspective among faculty members was apprenticeship. Conclusion. Residents and preceptors mostly exhibited learning styles associated with abstract over concrete thinking or watching over doing. Residency programs should steer residents more toward active learning and doing, and maximize interactions with patients and other caregivers. PMID:24159204
EVALUATION OF THE EFFECT OF SCR ON MERCURY SPECIATION AND EMISSIONS
The paper presents the results of an investigation on the impact that selective catalytic reduction (SCR) has on both the total emissions and the speciation of mercury (Hg). SCR systems can be used as multipollutant technologies if they enhance Hg conversion/capture. Previous pil...
Drugs and alcohol in civil aviation accident pilot fatalities from 2004-2008.
DOT National Transportation Integrated Search
2011-09-01
The FAA Office of Aerospace Medicine sets medical standards needed to protect the public and pilots from death : or injury due to incapacitation of the pilot. As a part of this process, toxicology testing is performed by the FAA : on almost every pil...
Paavo, Maarjaliis; Zhao, Jin; Kim, Hye Jin; Lee, Winston; Zernant, Jana; Cai, Carolyn; Allikmets, Rando; Tsang, Stephen H.; Sparrow, Janet R.
2018-01-01
Purpose We sought to advance interpretations and quantification of short-wavelength fundus autofluorescence (SW-AF) emitted from bisretinoid lipofuscin and near-infrared autofluoresence (NIR-AF) originating from melanin. Methods Carriers of mutations in X-linked GPR143/OA1, a common form of ocular albinism; patients with confirmed mutations in ABCA4 conferring increased SW-AF; and subjects with healthy eyes were studied. SW-AF (488 nm excitation, 500–680 nm emission) and NIR-AF (excitation 787 nm, emission >830 nm) images were acquired with a confocal scanning laser ophthalmoscope. SW-AF images were analyzed for quantitative autofluoresence (qAF). Analogous methods of image acquisition and analysis were performed in albino and pigmented Abca4−/− mice and wild-type mice. Results Quantitation of SW-AF (qAF), construction of qAF color-coded maps, and examination of NIR-AF images from GPR143/OA1 carriers revealed mosaics in which patches of fundus exhibiting NIR-AF signal had qAF levels within normal limits whereas the hypopigmented areas in the NIR-AF image corresponded to foci of elevated qAF. qAF also was increased in albino versus pigmented mice. Although melanin contributes to fundus infrared reflectance, the latter appeared to be uniform in en face reflectance images of GPR143/OA1-carriers. In patients diagnosed with ABCA4-associated disease, NIR-AF increased in tandem with increased qAF originating in bisretinoid lipofuscin. Similarly in Abca4−/− mice having increased SW-AF, NIR-AF was more pronounced than in wild-type mice. Conclusions These studies corroborate RPE melanin as the major source of NIR-AF but also indicate that bisretinoid lipofuscin, when present at sufficient concentrations, contributes to the NIR-AF signal. Ocular melanin attenuates the SW-AF signal.
Wiesel, Joseph; Abraham, Saji; Messineo, Frank C
2013-06-01
Asymptomatic atrial fibrillation (AF) is a common cause of strokes. Physician screening for AF has been recommended. Home screening for AF may increase the likelihood of detecting asymptomatic AF in patients at risk for stroke because of AF. The aim of this study was to assess the feasibility and accuracy of screening for AF when taking home blood pressure (BP) measurements using an automatic AF-detecting BP monitor. Subjects aged >64 years or those with hypertension, diabetes, congestive heart failure, or previous stroke were enrolled by their primary physicians and given the AF-BP monitor and an electrocardiographic event monitor to use at home for 30 days. The AF-BP monitor reading was compared with the electrocardiographic reading to calculate the sensitivity and specificity of the device for detecting AF. A total of 160 subjects were enrolled, with 10 withdrawing, 1 excluded, and 10 with no AF-BP monitor logs or electrocardiographic recordings. Of the 139 subjects included, 14 had known AF. There was a total of 3,316 days with AF-BP monitor readings and electrocardiographic readings. On the basis of the initial daily AF-BP monitor readings, the AF-BP monitor demonstrated sensitivity of 99.2% and specificity of 92.9% for detecting AF. Two subjects with no histories of AF had AF-BP monitor readings of AF that were confirmed by the electrocardiographic monitor. One of these subjects was started on warfarin. In conclusion, home screening for asymptomatic AF while taking BP measurements can be performed accurately. This can be used to detect new AF, allowing treatment with anticoagulation to reduce the future risk for stroke. Copyright © 2013 Elsevier Inc. All rights reserved.
The association between atrial fibrillation and cognitive function in patients with heart failure.
Yang, Huifeng; Niu, Weihua; Zang, Xiaoying; Lin, Mei; Zhao, Yue
2017-02-01
Atrial fibrillation (AF) is associated with cognitive impairment in heart failure (HF). The purpose of this study was to examine whether AF independently predicted cognitive function in HF patients after controlling for more demographic, medical and psychological characteristics, and whether the timing of AF onset in relation to HF diagnosis independently contributed to cognitive function in HF patients with AF. A total of 188 hospitalized HF patients (62.8% male, age 66.3±10.6 years) completed cognitive function assessment with the Montreal Cognitive Assessment (MoCA). A history of AF, along with other medical characteristics, was ascertained through a review of participants' medical charts. The timing of AF onset in relation to HF diagnosis was categorized into AF occurring prior to HF diagnosis (i.e. prior AF) and AF developing after HF diagnosis (i.e. incident AF). Altogether 72 participants had a positive diagnostic history of AF. Specifically, 41 had prior AF, and 31 developed AF subsequently. In HF patients, AF was associated with poorer performance on cognitive function after controlling for more confounders (β=-0.112, ΔR 2 =0.010, p=0.046). Among HF patients with AF, incident AF independently predicted poorer cognitive function (β=-0.238, ΔR 2 =0.027, p=0.047). AF independently contributes to cognitive function in HF patients after adjusting for more confounding variables. The timing of AF onset in relation to HF diagnosis independently predicts cognitive function in HF patients with AF. Prospective studies are needed to elucidate possible mechanisms for the association between AF and cognitive function in HF populations.
Magnetic viscosity phenomena in exchange coupled CoFe /MnIr bilayers
NASA Astrophysics Data System (ADS)
Kim, Dong Young; Kim, C. O.; Tsunoda, M.; Yamaguchi, M.; Yabugami, S.; Takahashi, M.
2007-05-01
The complex permeability spectra were measured in the low (10Hz-1MHz) and microwave (100MHz-9GHz) frequency ranges in CoFe /MnIr bilayers. The low frequency permeability spectra showed the magnetic viscosity effect below the critical antiferromagnet thickness (tcAF), but not at tAF
Thermo- and electro-dual responsive poly(ionic liquid) electrolyte based smart windows.
Chen, Fei; Ren, Yongyuan; Guo, Jiangna; Yan, Feng
2017-01-31
Thermo- and electro-dual responsive poly(ionic liquid) (PIL) based electrolytes were synthesized by co-polymerization of N-isopropylacrylamide (NIPAM) with (or without) 3-butyl-1-vinyl-imidazolium bromide ([BVIm][Br]) using diallyl-viologen (DAV) as both the cross-linking agent and electrochromic material.
Uptake of organic sulfur and nitrogen compounds by aerosols
USDA-ARS?s Scientific Manuscript database
Efforts have been undertaken to monitor and model the uptake of medium-sized organic compounds found above agricultural waste. Field effects performed by our collaborators monitor both the gas phase compounds present in a chicken house in Kentucky; using PILS-IC sampling, the contents of PM2.5 parti...
INTEGRATED BIOREACTOR SYSTEM FOR THE TREATMENT OF CYANIDE, METALS AND NITRATES IN MINE PROCESS WATER
An innovative biological process is described for the tratment of cyanide-, metals- and nitrate-contaminated mine process water. The technology was tested for its ability to detoxify cyanide and nitrate and to immobilize metals in wastewater from agitation cyanide leaching. A pil...
Contributory Factors to Teachers' Sense of Community in Public Urban Elementary Schools
ERIC Educational Resources Information Center
Kirkhus, Debra
2011-01-01
The purpose of this study was to investigate factors that contribute to teachers' sense of community within public, urban, elementary schools. Because previous research has touted the benefits of teacher communities within schools (Kruse, 2001; Leana & Pil, 2006; Ware & Kitsantas, 2007) educational leaders are challenged with creating…
U.S. EPA, Pesticide Product Label, TAT AREA FOGGER II, 06/22/1993
2011-04-14
... ARBA POGGBR II Kill. Pli •• , Cockroach •• , Pl~a., Sav-'footh.4 Grain B •• tl •• , 'fick., Confu •• 4 Plour B •• tl •• , Ric. • •• vil., S .. ll Plying Moth., Pil1bug. ...
Hobbelt, Anne H; Siland, Joylene E; Geelhoed, Bastiaan; Van Der Harst, Pim; Hillege, Hans L; Van Gelder, Isabelle C; Rienstra, Michiel
2017-02-01
Atrial fibrillation (AF) may present variously in time, and AF may progress from self-terminating to non-self-terminating AF, and is associated with impaired prognosis. However, predictors of AF types are largely unexplored. We investigate the clinical, biomarker, and genetic predictors of development of specific types of AF in a community-based cohort. We included 8042 individuals (319 with incident AF) of the PREVEND study. Types of AF were compared, and multivariate multinomial regression analysis determined associations with specific types of AF. Mean age was 48.5 ± 12.4 years and 50% were men. The types of incident AF were ascertained based on electrocardiograms; 103(32%) were classified as AF without 2-year recurrence, 158(50%) as self-terminating AF, and 58(18%) as non-self-terminating AF. With multivariate multinomial logistic regression analysis, advancing age (P< 0.001 for all three types) was associated with all AF types, male sex was associated with AF without 2-year recurrence and self-terminating AF (P= 0.031 and P= 0.008, respectively). Increasing body mass index and MR-proANP were associated with both self-terminating (P= 0.009 and P< 0.001) and non-self-terminating AF (P= 0.003 and P< 0.001). The only predictor associated with solely self-terminating AF is prescribed anti-hypertensive treatment (P= 0.019). The following predictors were associated with non-self-terminating AF; lower heart rate (P= 0.018), lipid-lowering treatment prescribed (P= 0.009), and eGFR <60 mL/min/1.73 m2 (P= 0.006). Three known AF-genetic variants (rs6666258, rs6817105, and rs10821415) were associated with self-terminating AF. We found clinical, biomarker and genetic predictors of specific types of incident AF in a community-based cohort. The genetic background seems to play a more important role than modifiable risk factors in self-terminating AF.
Steinberg, Benjamin A; Gao, Haiyan; Shrader, Peter; Pieper, Karen; Thomas, Laine; Camm, A John; Ezekowitz, Michael D; Fonarow, Gregg C; Gersh, Bernard J; Goldhaber, Samuel; Haas, Sylvia; Hacke, Werner; Kowey, Peter R; Ansell, Jack; Mahaffey, Kenneth W; Naccarelli, Gerald; Reiffel, James A; Turpie, Alexander; Verheugt, Freek; Piccini, Jonathan P; Kakkar, Ajay; Peterson, Eric D; Fox, Keith A A
2017-12-01
Atrial fibrillation (AF) is the most common cardiac arrhythmia in the world. We aimed to provide comprehensive data on international patterns of AF stroke prevention treatment. Demographics, comorbidities, and stroke risk of the patients in the GARFIELD-AF (n=51,270), ORBIT-AF I (n=10,132), and ORBIT-AF II (n=11,602) registries were compared (overall N=73,004 from 35 countries). Stroke prevention therapies were assessed among patients with new-onset AF (≤6 weeks). Patients from GARFIELD-AF were less likely to be white (63% vs 89% for ORBIT-AF I and 86% for ORBIT-AF II) or have coronary artery disease (19% vs 36% and 27%), but had similar stroke risk (85% CHA 2 DS 2 -VASc ≥2 vs 91% and 85%) and lower bleeding risk (11% with HAS-BLED ≥3 vs 24% and 15%). Oral anticoagulant use was 46% and 57% for patients with a CHA 2 DS 2 -VASc=0 and 69% and 87% for CHA 2 DS 2 -VASc ≥2 in GARFIELD-AF and ORBIT-AF II, respectively, but with substantial geographic heterogeneity in use of oral anticoagulant (range: 31%-93% [GARFIELD-AF] and 66%-100% [ORBIT-AF II]). Among patients with new-onset AF, non-vitamin K antagonist oral anticoagulant use increased over time to 43% in 2016 for GARFIELD-AF and 71% for ORBIT-AF II, whereas use of antiplatelet monotherapy decreased from 36% to 17% (GARFIELD-AF) and 18% to 8% (ORBIT-AF I and II). Among new-onset AF patients, non-vitamin K antagonist oral anticoagulant use has increased and antiplatelet monotherapy has decreased. However, anticoagulation is used frequently in low-risk patients and inconsistently in those at high risk of stroke. Significant geographic variability in anticoagulation persists and represents an opportunity for improvement. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.
Duncker, Tobias; Marsiglia, Marcela; Lee, Winston; Zernant, Jana; Tsang, Stephen H.; Allikmets, Rando; Greenstein, Vivienne C.; Sparrow, Janet R.
2014-01-01
Purpose. Short-wavelength (SW) fundus autofluorescence (AF) is considered to originate from lipofuscin in retinal pigment epithelium (RPE) and near-infrared (NIR) AF from melanin. In patients with recessive Stargardt disease (STGD1), we correlated SW-AF and NIR-AF with structural information obtained by spectral-domain optical coherence tomography (SD-OCT). Methods. Twenty-four STGD1 patients (45 eyes; age 8 to 61 years) carrying confirmed disease-associated ABCA4 mutations were studied prospectively. Short-wavelength AF, NIR-AF, and SD-OCT images were acquired. Results. Five phenotypes were identified according to features of the central lesion and extent of fundus change. Central zones of reduced NIR-AF were typically larger than areas of diminished SW-AF and reduced NIR-AF usually approximated areas of ellipsoid zone (EZ) loss identified by SD-OCT (group 1; r, 0.93, P < 0.0001). In patients having a central lesion with overlapping parafoveal rings of increased NIR-AF and SW-AF (group 3), the extent of EZ loss was strongly correlated with the inner diameter of the NIR-AF ring (r, 0.89, P < 0.0001) and the eccentricity of the outer border of the NIR-AF ring was greater than that of the SW-AF ring. Conclusions. Lesion areas were more completely delineated in NIR-AF images than with SW-AF. In most cases, EZ loss was observed only at locations where NIR-AF was reduced or absent, indicating that RPE cell atrophy occurs in advance of photoreceptor cell degeneration. Because SW-AF was often increased within the central area of EZ disruption, degenerating photoreceptor cells may produce lipofuscin at accelerated levels. Consideration is given to mechanisms underlying hyper–NIR-AF in conjunction with increased SW-AF. PMID:25342616
Chen, Lin Y; Chung, Mina K; Allen, Larry A; Ezekowitz, Michael; Furie, Karen L; McCabe, Pamela; Noseworthy, Peter A; Perez, Marco V; Turakhia, Mintu P
2018-05-15
Our understanding of the risk factors and complications of atrial fibrillation (AF) is based mostly on studies that have evaluated AF in a binary fashion (present or absent) and have not investigated AF burden. This scientific statement discusses the published literature and knowledge gaps related to methods of defining and measuring AF burden, the relationship of AF burden to cardiovascular and neurological outcomes, and the effect of lifestyle and risk factor modification on AF burden. Many studies examine outcomes by AF burden classified by AF type (paroxysmal versus nonparoxysmal); however, quantitatively, AF burden can be defined by longest duration, number of AF episodes during a monitoring period, and the proportion of time an individual is in AF during a monitoring period (expressed as a percentage). Current guidelines make identical recommendations for anticoagulation regardless of AF pattern or burden; however, a review of recent evidence suggests that higher AF burden is associated with higher risk of stroke. It is unclear whether the risk increases continuously or whether a threshold exists; if a threshold exists, it has not been defined. Higher burden of AF is also associated with higher prevalence and incidence of heart failure and higher risk of mortality, but not necessarily lower quality of life. A structured and comprehensive risk factor management program targeting risk factors, weight loss, and maintenance of a healthy weight appears to be effective in reducing AF burden. Despite this growing understanding of AF burden, research is needed into validation of definitions and measures of AF burden, determination of the threshold of AF burden that results in an increased risk of stroke that warrants anticoagulation, and discovery of the mechanisms underlying the weak temporal correlations of AF and stroke. Moreover, developments in monitoring technologies will likely change the landscape of long-term AF monitoring and could allow better definition of the significance of changes in AF burden over time. © 2018 American Heart Association, Inc.
Johnson, Timothy D.; Dittgen, Felix; Nichols, Thomas E.; Malzahn, Uwe; Veltkamp, Roland
2017-01-01
Objective Atrial fibrillation (AF) is frequently detected after ischemic stroke for the first time, and brain regions involved in autonomic control have been suspected to trigger AF. We examined whether specific brain regions are associated with newly detected AF after ischemic stroke. Methods Patients with acute cerebral infarctions on diffusion-weighted magnetic resonance imaging were included in this lesion mapping study. Lesions were mapped and modeled voxelwise using Bayesian Spatial Generalised Linear Mixed Modeling to determine differences in infarct locations between stroke patients with new AF, without AF and with AF already known before the stroke. Results 582 patients were included (median age 68 years; 63.2% male). AF was present in 109/582 patients [(18.7%); new AF: 39/109 (35.8%), known AF: 70/109 (64.2%)]. AF patients had larger infarct volumes than patients without AF (mean: 29.7 ± 45.8 ml vs. 15.2 ± 35.1 ml; p<0.001). Lesions in AF patients accumulated in the right central middle cerebral artery territory. Increasing stroke size predicted progressive cortical but not pontine and thalamic involvement. Patients with new AF had more frequently lesions in the right insula compared to patients without AF when stroke size was not accounted for, but no specific brain region was more frequently involved after adjustment for infarct volume. Controlled for stroke size, left parietal involvement was less likely for patients with new AF than for those without AF or with known AF. Conclusions In the search for brain areas potentially triggering cardiac arrhythmias infarct size should be accounted for. After controlling for infarct size, there is currently no evidence that ischemic stroke lesions of specific brain areas are associated with new AF compared to patients without AF. This challenges the neurogenic hypothesis of AF according to which a relevant proportion of new AF is triggered by ischemic brain lesions of particular locations. PMID:28542605
Billon-Galés, Audrey; Krust, Andrée; Fontaine, Coralie; Abot, Anne; Flouriot, Gilles; Toutain, Céline; Berges, Hortense; Gadeau, Alain-Pierre; Lenfant, Françoise; Gourdy, Pierre; Chambon, Pierre; Arnal, Jean-François
2011-01-01
17β-Estradiol (E2) regulates estrogen receptor-α (ERα) target gene transcription through the two independent activation functions (AFs), AF1 and AF2, located in the N-terminal and ligand binding domain of ERα, respectively. We previously reported that ERα is required for the E2 atheroprotective action as well as for its accelerative action on endothelial healing, but its AF1 function is dispensable. Here, we investigated the role of ERαAF2 in these two major beneficial actions of E2 by electively targeting ERαAF2 (named ERαAF20). Our results prove four points. (i) Compared with WT ERα, the ability of ERαAF20 to stimulate the C3 complement or the estrogen response element-thymidine kinase promoter in two cell lines was dramatically decreased, confirming the importance of AF2 in the E2-induced transcriptional activity of ERα. (ii) The uterotrophic action of E2 was totally absent in ERαAF20 mice, showing the crucial role of ERαAF2 in E2-induced uterus hyperplasia. (iii) ERαAF2 was dispensable for the accelerative action of E2 on endothelial healing, underlining the functionality of ERαAF20 in vivo. (iv) Finally, the atheroprotective effect of E2 was abrogated in ERαAF20 LDL-r−/− mice. Thus, whereas ERαAF1 and ERαAF2 are both required for the uterotrophic action of E2, we show that only ERαAF2 is necessary for its atheroprotective effect. PMID:21788522
High burden of Aspergillus fumigatus infection among chronic respiratory diseases.
Fukuda, Yosuke; Homma, Tetsuya; Suzuki, Shintaro; Takuma, Takahiro; Tanaka, Akihiko; Yokoe, Takuya; Ohnishi, Tsukasa; Niki, Yoshihito; Sagara, Hironori
2018-01-01
Aspergillus fumigatus (AF) is a ubiquitous fungus in our environment and causes severe airway disorders. Chronic respiratory diseases (CRDs) are a series of chronic airway and lung diseases. Although both are chronic disorders, however, the relationships between AF and CRDs are still unclear. Therefore, we examined 104 Aspergillus species (spp.) isolated samples in our hospital during three consecutive years to further elucidate the relationships between Aspergillus spp. and CRDs. Based on sample isolates, we then grouped these into two groups, AF and non-AF, to retrospectively analyse the clinical features and to clarify the relationships between AF and CRDs. Importantly, the manifestation of CRD was more frequent in the AF group than in the non-AF group ( p = 0.035). Among CRDs, lung fibrosis was more evident in the AF group ( p = 0.025). Moreover, diabetes mellitus was tended to be evident in AF group than non-AF group ( p = 0.035). In conclusion, CRDs, especially lung fibrosis, were highly prevalent in AF group than non-AF group.
Ehsan Bari; Hamid Reza Taghiyari; Behbood Mohebby; Carol A. Clausen; Olaf Schmidt; Mohammad Ali Tajick Ghanbary; Mohammad Javad Vaseghi
2015-01-01
The effects of exposing specimens of Oriental beech [Fagus sylvatica subsp. orientalis (Lipsky) Greuter and Burdet] to the white-rot fungi Pleurotus ostreatus (Jacq.: Fr.) Kummer and Trametes versicolor (L.: Fr.) Pilát strain 325 have been studied concerning the mechanical properties and...
Airborne characterization of smoke marker ratios from prescribed burning
A. P. Sullivan; A. A. May; T. Lee; G. R. McMeeking; S. M. Kreidenweis; S. K. Akagi; R. J. Yokelson; S. P. Urbanski; J. L. Collett
2014-01-01
A Particle-Into-Liquid Sampler - Total Organic Carbon (PILS-TOC) and fraction collector system was flown aboard a Twin Otter aircraft sampling prescribed burning emissions in South Carolina in November 2011 to obtain smoke marker measurements. The fraction collector provided 2 min time-integrated offline samples for carbohydrate (i.e., smoke markers levoglucosan,...
NASA Astrophysics Data System (ADS)
Toriumi, Shin; Takasao, Shinsuke
2017-11-01
Solar active regions (ARs) that produce strong flares and coronal mass ejections (CMEs) are known to have a relatively high non-potentiality and are characterized by δ-sunspots and sheared magnetic structures. In this study, we conduct a series of flux emergence simulations from the convection zone to the corona and model four types of active regions that have been observationally suggested to cause strong flares, namely the spot-spot, spot-satellite, quadrupole, and inter-AR cases. As a result, we confirm that δ-spot formation is due to the complex geometry and interaction of emerging magnetic fields, and we find that the strong-field, high-gradient, highly sheared polarity inversion line (PIL) is created by the combined effect of the advection, stretching, and compression of magnetic fields. We show that free magnetic energy builds up in the form of a current sheet above the PIL. It is also revealed that photospheric magnetic parameters that predict flare eruptions reflect the stored free energy with high accuracy, while CME-predicting parameters indicate the magnetic relationship between flaring zones and entire ARs.
Brønsted acidity of protic ionic liquids: a modern ab initio valence bond theory perspective.
Patil, Amol Baliram; Mahadeo Bhanage, Bhalchandra
2016-09-21
Room temperature ionic liquids (ILs), especially protic ionic liquids (PILs), are used in many areas of the chemical sciences. Ionicity, the extent of proton transfer, is a key parameter which determines many physicochemical properties and in turn the suitability of PILs for various applications. The spectrum of computational chemistry techniques applied to investigate ionic liquids includes classical molecular dynamics, Monte Carlo simulations, ab initio molecular dynamics, Density Functional Theory (DFT), CCSD(t) etc. At the other end of the spectrum is another computational approach: modern ab initio Valence Bond Theory (VBT). VBT differs from molecular orbital theory based methods in the expression of the molecular wave function. The molecular wave function in the valence bond ansatz is expressed as a linear combination of valence bond structures. These structures include covalent and ionic structures explicitly. Modern ab initio valence bond theory calculations of representative primary and tertiary ammonium protic ionic liquids indicate that modern ab initio valence bond theory can be employed to assess the acidity and ionicity of protic ionic liquids a priori.
The role of Shewanella oneidensis MR-1 outer surface structures in extracellular electron transfer
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bouhenni, Rachida; Vora, Gary J.; Biffinger, Justin C.
2010-04-20
Shewanella oneidensis is a facultative anaerobe that uses more than 14 different terminal electron acceptors for respiration. These include metal oxides and hydroxyoxides, and toxic metals such as uranium and chromium. Mutants deficient in metal reduction were isolated using the mariner transposon derivative, minihimar RB1. These included mutants with transposon insertions in the prepilin peptidase and type II secretion system genes. All mutants were deficient in Fe(III) and Mn(IV) reduction, and exhibited slow growth when DMSO was used as the electron acceptor. The genome sequence of S. oneidensis contains one prepilin peptidase gene, pilD. A similar prepilin peptidase that maymore » function in the processing of type II secretion prepilins was not found. Single and multiple chromosomal deletions of four putative type IV pilin genes did not affect Fe(III) and Mn(IV) reduction. These results indicate that PilD in S. oneidensis is responsible for processing both type IV and type II secretion prepilin proteins. Type IV pili do not appear to be required for Fe(III) and Mn(IV) reduction.« less
Ionic liquids in solid-phase microextraction: a review.
Ho, Tien D; Canestraro, Anthony J; Anderson, Jared L
2011-06-10
Solid-phase microextraction (SPME) has undergone a surge in popularity within the field of analytical chemistry in the past two decades since its introduction. Owing to its nature of extraction, SPME has become widely known as a quick and cost-effective sample preparation technique. Although SPME has demonstrated extraordinary versatility in sampling capabilities, the technique continues to experience a tremendous growth in innovation. Presently, increasing efforts have been directed towards the engineering of novel sorbent material in order to expand the applicability of SPME for a wider range of analytes and matrices. This review highlights the application of ionic liquids (ILs) and polymeric ionic liquids (PILs) as innovative sorbent materials for SPME. Characterized by their unique physico-chemical properties, these compounds can be structurally-designed to selectively extract target analytes based on unique molecular interactions. To examine the advantages of IL and PIL-based sorbent coatings in SPME, the field is reviewed by gathering available experimental data and exploring the sensitivity, linear calibration range, as well as detection limits for a variety of target analytes in the methods that have been developed. Copyright © 2011 Elsevier B.V. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kaneko, Takafumi; Yokoyama, Takaaki, E-mail: kaneko@eps.s.u-tokyo.ac.jp
2014-11-20
We investigate the triggering mechanisms of plasma eruptions in the solar atmosphere due to interactions between emerging flux and coronal arcade fields by using two-dimensional MHD simulations. We perform parameter surveys with respect to arcade field height, magnetic field strength, and emerging flux location. Our results show that two possible mechanisms exist, and which mechanism is dominant depends mostly on emerging flux location. One mechanism appears when the location of emerging flux is close to the polarity inversion line (PIL) of an arcade field. This mechanism requires reconnection between the emerging flux and the arcade field, as pointed out bymore » previous studies. The other mechanism appears when the location of emerging flux is around the edge of an arcade field. This mechanism does not require reconnection between the emerging flux and the arcade field but does demand reconnection in the arcade field above the PIL. Furthermore, we found that the eruptive condition for this mechanism can be represented by a simple formula.« less
Swerdlow, C D; Schsls, W; Dijkman, B; Jung, W; Sheth, N V; Olson, W H; Gunderson, B D
2000-02-29
To distinguish prolonged episodes of atrial fibrillation (AF) that require cardioversion from self-terminating episodes that do not, an atrial implantable cardioverter-defibrillator (ICD) must be able to detect AF continuously for extended periods. The ICD should discriminate between atrial tachycardia/flutter (AT), which may be terminated by antitachycardia pacing, and AF, which requires cardioversion. We studied 80 patients with AT/AF and ventricular arrhythmias who were treated with a new atrial/dual-chamber ICD. During a follow-up period lasting 6+/-2 months, we validated spontaneous, device-defined AT/AF episodes by stored electrograms in all patients. In 58 patients, we performed 80 Holter recordings with telemetered atrial electrograms, both to validate the continuous detection of AT/AF and to determine the sensitivity of the detection of AT/AF. Detection was appropriate in 98% of 132 AF episodes and 88% of 190 AT episodes (98% of 128 AT episodes with an atrial cycle length <300 ms). Intermittent sensing of far-field R waves during sinus tachycardia caused 27 inappropriate AT/AF detections; these detections lasted 2.6+/-2.0 minutes. AT/AF was detected continuously in 27 of 28 patients who had spontaneous episodes of AT/AF (96%). The device memory recorded 90 appropriate AT/AF episodes lasting >1 hour, for a total of 2697 hours of continuous detection of AT/AF. During Holter monitoring, the sensitivity of the detection of AT/AF (116 hours) was 100%; the specificity of the detection of non-AT/AF rhythms (1290 hours) was 99.99%. Of 166 appropriate episodes detected as AT, 45% were terminated by antitachycardia pacing. A new ICD detects AT/AF accurately and continuously. Therapy may be programmed for long-duration AT/AF, with a low risk of underdetection. Discrimination of AT from AF permits successful pacing therapy for a significant fraction of AT.
Sass, Gabriele; Stevens, David A
2017-01-01
Abstract Background Pa and Af are pathogens frequently found together in airways of immunocompromised patients and patients with cystic fibrosis (CF). Hence, interactions of Pa and Af require understanding. Both Pa and Af are crucially dependent on the availability of iron, and therefore are competitors in their microenvironment. We have shown, using deletion mutants of Pa, that the Pa siderophore pyoverdine, the dominant Pa inhibitor of Af, interferes with Af biofilms by iron chelation, and denial of iron to the fungus. Methods Protective compounds in Af supernatants were evaluated using assays for the quantification of Af biofilm metabolism by XTT measurement, spectrometric pyoverdine measurement, as well as Chrome Azorole S (CAS) assay for the determination of siderophore production. Results Here we provide evidence that whereas iron usage by Af promotes pyoverdine production by Pa, Af has developed a defense mechanism against anti-fungal pyoverdine effects. The ability of Af to produce hydroxamate siderophores, and shed these into the surrounding medium, where they sequester and transport iron, is a key factor for Af self-defense against Pa. Under low iron conditions, such as in the presence of high amounts of the Pa siderophore pyoverdine, siderophore-bound iron is then fed to Af, protecting the fungus from iron starvation. Af with a deletion mutation in sidA, a gene essential for the production of hydroxamate siderophores, was significantly more sensitive to Pa supernatants, as well as pure pyoverdine, than wild-type Af. Af supernatants, produced in the presence of celastrol, an inhibitor of SidA-generated biosynthesis of siderophores, or produced by the sidA mutant, were not able to protect Af from iron starvation. Conclusion Interference with the iron-dependent Af self-defense mechanism might represent a new approach for therapy against aspergillosis. Disclosures All authors: No reported disclosures.
Huang, Henry D; Waks, Jonathan W; Steinhaus, Daniel A; Zimetbaum, Peter
2016-07-01
Dofetilide is a class III antiarrhythmic drug approved for the treatment of atrial fibrillation (AF). Dofetilide-induced corrected QT (QTc) interval prolongation is a surrogate for the degree of drug effect, but the relationships between drug-induced QTc interval prolongation, pharmacological cardioversion (PCV), and freedom from recurrent AF are unclear. The purpose of this study was to assess associations between QTc interval change during dofetilide initiation and PCV and long-term AF recurrence. We performed retrospective analyses of a prospective cohort of patients with AF admitted for dofetilide initiation between 2001 and 2014. Clinical characteristics and electrocardiographic variables were assessed. We evaluated outcomes of successful PCV in patients with persistent AF and time to recurrence of AF in patients with paroxysmal and persistent AF. During the study, 243 patients with persistent AF and 176 patients with paroxysmal AF initiated dofetilide. PCV occurred in 93/243 (41.7%) patients with persistent AF. After multivariable adjustment, QTc interval change was associated with PCV (adjusted odds ratio 1.21; P = .003 per 10-ms QTc increase). Inhospital QTc interval change was associated with long-term freedom from AF in patients with persistent AF (adjusted hazard ratio 0.92; P = .011 at 4 years per 10-ms QTc increase), but not in patients with paroxysmal AF. In patients with persistent AF, PCV was also associated with long-term freedom from recurrent AF (adjusted hazard ratio 0.62; P = .009 at 4 years). The magnitude of QTc interval prolongation during dofetilide initiation is an independent predictor of successful PCV and long-term freedom from arrhythmia in patients with persistent AF. QTc interval change had no association with AF recurrence in patients with paroxysmal AF, suggesting that different mechanisms of arrhythmogenesis may be operant in different AF types. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
Santos-Beneit, Fernando; Rodríguez-García, Antonio; Martín, Juan F.
2011-01-01
The afsS gene of several Streptomyces species encodes a small sigma factor-like protein that acts as an activator of several pathway-specific regulatory genes (e.g., actII-ORF4 and redD in Streptomyces coelicolor). The two pleiotropic regulators AfsR and PhoP bind to overlapping sequences in the −35 region of the afsS promoter and control its expression. Using mutated afsS promoters containing specific point mutations in the AfsR and PhoP binding sequences, we proved that the overlapping recognition sequences for AfsR and PhoP are displaced by 1 nucleotide. Different nucleotide positions are important for binding of AfsR or PhoP, as shown by electrophoretic mobility shift assays and by reporter studies using the luxAB gene coupled to the different promoters. Mutant promoter M5 (with a nucleotide change at position 5 of the consensus box) binds AfsR but not PhoP with high affinity (named “superAfsR”). Expression of the afsS gene from this promoter led to overproduction of actinorhodin. Mutant promoter M16 binds PhoP with extremely high affinity (“superPhoP”). Studies with ΔafsR and ΔphoP mutants (lacking AfsR and PhoP, respectively) showed that both global regulators are competitive transcriptional activators of afsS. AfsR has greater influence on expression of afsS than PhoP, as shown by reverse transcriptase PCR (RT-PCR) and promoter reporter (luciferase) studies. These two high-level regulators appear to integrate different nutritional signals (particularly phosphate limitation sensed by PhoR), S-adenosylmethionine, and other still unknown environmental signals (leading to AfsR phosphorylation) for the AfsS-mediated control of biosynthesis of secondary metabolites. PMID:21378195
Soliman, Elsayed Z; Prineas, Ronald J; Case, L Douglas; Zhang, Zhu-ming; Goff, David C
2009-04-01
The paradox of the reported low prevalence of atrial fibrillation (AF) in blacks compared with whites despite higher stroke rates in the former could be related to limitations in the current methods used to diagnose AF in population-based studies. Hence, this study aimed to use the ethnic distribution of ECG predictors of AF as measures of AF propensity in different ethnic groups. The distribution of baseline measures of P-wave terminal force, P-wave duration, P-wave area, and PR duration (referred to as AF predictors) were compared by ethnicity in 15 429 participants (27% black) from the Atherosclerosis Risk in Communities (ARIC) study by unpaired t test, chi(2), and logistic-regression analysis, as appropriate. Cox proportional-hazards analysis was used to separately examine the association of AF predictors with incident AF and ischemic stroke. Whereas AF was significantly less common in blacks compared with whites (0.24% vs 0.95%, P<0.0001), similar to what has been reported in previous studies, blacks had significantly higher and more abnormal values of AF predictors (P<0.0001 for all comparisons). Black ethnicity was significantly associated with abnormal AF predictors compared with whites; odds ratios for different AF predictors ranged from 2.1 to 3.1. AF predictors were significantly and independently associated with AF and ischemic stroke with no significant interaction between ethnicity and AF predictors, findings that further justify using AF predictors as an earlier indicator of future risk of AF and stroke. There is a disconnect between the ethnic distribution of AF predictors and the ethnic distribution of AF, probably because the former, unlike the latter, do not suffer from low sensitivity. These results raise the possibility that blacks might actually have a higher prevalence of AF that might have been missed by previous studies owing to limited methodology, a difference that could partially explain the greater stroke risk in blacks.
Chang, Shang-Hung; Kuo, Chang-Fu; Chou, I-Jun; See, Lai-Chu; Yu, Kuang-Hui; Luo, Shue-Fen; Huang, Lu-Hsiang; Zhang, Weiya; Doherty, Michael; Wen, Ming-Shien; Kuo, Chi-Tai; Yeh, Yung-Hsin
2017-08-01
The heritability of atrial fibrillation (AF), the contribution of genetic and environmental factors, and the association of a family history of AF with prognosis are unclear. To measure genetic and environmental factors in the familial aggregation of AF and to estimate the association of a family history of AF with major adverse cardiovascular events (MACE). In this Taiwanese nationwide population-based study among more than 23 million people, a custom data set was obtained using the data of all patients having a diagnosis of AF recorded between January 1996 and December 2013 in the Taiwan National Health Insurance Research Database. The study population comprised all 23 422 955 individuals registered with the database in 2013, of whom 177 770 had a diagnosis of AF and were included in the heritability estimation. From the latter, a subgroup of patients having newly diagnosed AF with a first-degree relative affected by AF between 2000 and 2010 were selected and matched 1:4 to controls without a family history for estimating MACE-free survival. The dates of analysis were January 2010 to December 2013. The prevalence and relative risk of AF in relatives of patients with AF, as well as the relative contributions of heritability and shared and nonshared environmental factors to AF susceptibility. Also measured was MACE-free survival after AF was diagnosed. In total, 1510 patients (204 [13.5%] female; mean [SD] age, 57.9 [9.2] years) had newly diagnosed AF with a first-degree relative affected by AF. Individuals with a first-degree relative affected by AF had a relative risk of 1.92 (95% CI, 1.84-1.99) for AF. The accountability for the phenotypic variance of AF was 19.9% for genetic factors (heritability), 3.5% for shared environmental factors, and 76.6% for nonshared environmental factors. After matching for age, sex, hypertension, type 2 diabetes, previous stroke, and anticoagulation, incident AF patients with vs without an affected first-degree relative had similar MACE-free survival. Genetic and environmental factors were associated with AF, with nonshared environmental factors accounting for three-fourths of the phenotypic variance in Taiwan. Patients having AF with a first-degree relative affected by AF did not have more MACE. Therefore, family history may not be particularly informative in the diagnosis or management of AF.
Shoemaker, M. Benjamin; Muhammad, Raafia; Parvez, Babar; White, Brenda W.; Streur, Megan; Song, Yanna; Stubblefield, Tanya; Kucera, Gayle; Blair, Marcia; Rytlewski, Jason; Parvathaneni, Sunthosh; Nagarakanti, Rangadham; Saavedra, Pablo; Ellis, Christopher; Whalen, S. Patrick; Roden, Dan M; Darbar, Dawood
2012-01-01
Background Common single nucleotide polymorphisms (SNPs) at chromosome 4q25 (rs2200733, rs10033464) are associated with both lone and typical AF. Risk alleles at 4q25 have recently been shown to predict recurrence of AF after ablation in a population of predominately lone AF, but lone AF represents only 5–30% of AF cases. Objective To test the hypothesis that 4q25 AF risk alleles can predict response to AF ablation in the majority of AF cases. Methods Patients enrolled in the Vanderbilt AF Registry underwent 378 catheter-based AF ablations (median age 60 years, 71% male, 89% typical AF) between 2004 and 2011. The primary endpoint was time to recurrence of any non-sinus atrial tachyarrhythmia (atrial tachycardia, atrial flutter, or AF; [AT/AF]). Results Two-hundred AT/AF recurrences (53%) were observed. In multivariable analysis, the rs2200733 risk allele predicted a 24% shorter recurrence-free time (survival time ratio 0.76 95% confidence interval [CI] 0.6–0.95, P=0.016) compared with wild-type. The heterozygous haplotype demonstrated a 21% shorter recurrence-free time (survival time ratio = 0.79, 95% CI 0.62–0.99) and the homozygous risk allele carriers a 39% shorter recurrence-free time (survival time ratio = 0.61, 95% CI 0.37–1.0) (P=0.037). Conclusion Risk alleles at the 4q25 loci predict impaired clinical response to AF ablation in a population of predominately typical AF patients. Our findings suggest the rs2200733 polymorphism may hold promise as an as an objectively measured patient characteristic that can used as a clinical tool for selection of patients for AF ablation. PMID:23178686
Sithigorngul, Paisarn; Jarecki, Jessica L.; Stretton, Antony O.W.
2016-01-01
A monoclonal antibody, AF1-003, highly specific to the Ascaris suum neuropeptide AF1 (KNEFIRFamide), was generated. This antibody binds strongly to AF1 and extremely weakly to other peptides with C-terminal FIR-Famide: AF5 (SGKPTFIRFamide), AF6 (FIRFamide), and AF7 (AGPRFIRFamide). It does not recognize 35 other AF (A. suum FMRFamide-like) peptides at the highest concentration tested, nor does it recognize FMRFamide. When crude peptide extracts of A. suum are fractionated by two-step HPLC, the only fractions recognized by AF1-003 are those comigrating with synthetic AF1. By immunocytochemistry, antibody AF1-003 recognizes a small subset of the 298 neurons of A. suum: these include the paired URX and RIP neurons, two pairs of lateral ganglion neurons in the head, and the unpaired PQR and PDA or -B tail neurons that send processes to the head along the dorsal and ventral nerve cords, respectively. AF1 immunoreactivity is also seen in three pairs of pharyngeal neurons. Mass spectroscopy (MS) shows the presence of AF1 in the head, pharynx, and dorsal and ventral nerve cords. In A. suum, the neurons that contain AF1 show little overlap with neurons that express green fluorescent protein constructs targeting the flp-8 gene, which encodes AF1 in Caenorhabditis elegans (Kim and Li [2004] J. Comp. Neurol. 475:540– 550); the URX neurons express AF1 in both species, but, in C. elegans, flp-8 expression was not detected in RIP, PQR, and PDA or -B or in the pharynx. Other, less specific monoclonal antibodies recognize AF1, as well as other peptides to differing degrees; these antibodies are useful reagents for determination of neuronal morphology. PMID:21452223
Kollias, Anastasios; Destounis, Antonios; Kalogeropoulos, Petros; Kyriakoulis, Konstantinos G; Ntineri, Angeliki; Stergiou, George S
2018-07-01
This study assessed the diagnostic accuracy of a novel 24-hour ambulatory blood pressure (ABP) monitor (Microlife WatchBP O3 Afib) with implemented algorithm for automated atrial fibrillation (AF) detection during each ABP measurement. One hundred subjects (mean age 70.6±8.2 [SD] years; men 53%; hypertensives 85%; 17 with permanent AF; 4 paroxysmal AF; and 79 non-AF) had simultaneous 24-hour ABP monitoring and 24-hour Holter monitoring. Among a total of 6410 valid ABP readings, 1091 (17%) were taken in ECG AF rhythm. In reading-to-reading ABP analysis, the sensitivity, specificity, and accuracy of ABP monitoring in detecting AF were 93%, 87%, and 88%, respectively. In non-AF subjects, 12.8% of the 24-hour ABP readings indicated false-positive AF, of whom 27% were taken during supraventricular premature beats. There was a strong association between the proportion of false-positive AF readings and that of supraventricular premature beats ( r =0.67; P <0.001). Receiver operating characteristic curve revealed that in paroxysmal AF and non-AF subjects, AF-positive readings at 26% during 24-hour ABP monitoring had 100%/85% sensitivity/specificity (area under the curve 0.91; P <0.01) for detecting paroxysmal AF. These findings suggest that in elderly hypertensives, a novel 24-hour ABP monitor with AF detector has high sensitivity and moderate specificity for AF screening during routine ABP monitoring. Thus, in elderly hypertensives, a 24-hour ABP recording with at least 26% of the readings suggesting AF indicates a high probability for AF diagnosis and should be regarded as an indication for performing 24-hour Holter monitoring. © 2018 American Heart Association, Inc.
NASA Astrophysics Data System (ADS)
Cerully, K. M.; Bougiatioti, A.; Hite, J. R., Jr.; Guo, H.; Xu, L.; Ng, N. L.; Weber, R.; Nenes, A.
2014-12-01
The formation of secondary organic aerosol (SOA) combined with the partitioning of semi-volatile organic components can impact numerous aerosol properties including cloud condensation nuclei (CCN) activity, hygroscopicity and volatility. During the summer 2013 Southern Oxidant and Aerosol Study (SOAS) field campaign in a rural site in the Southeastern United States, a suite of instruments including a CCN counter, a thermodenuder (TD) and a high resolution time-of-flight aerosol mass spectrometer (AMS) were used to measure CCN activity, aerosol volatility, composition and oxidation state. Particles were either sampled directly from ambient or through a Particle Into Liquid Sampler (PILS), allowing the investigation of the water-soluble aerosol component. Ambient aerosol exhibited size-dependent composition with larger particles being more hygroscopic. The hygroscopicity of thermally-denuded aerosol was similar between ambient and PILS-generated aerosol and showed limited dependence on volatilization. Results of AMS 3-factor Positive Matrix Factorization (PMF) analysis for the PILS-generated aerosol showed that the most hygroscopic components are most likely the most and the least volatile features of the aerosol. No clear relationship was found between organic hygroscopicity and oxygen-to-carbon ratio; in fact, Isoprene organic aerosol (Isoprene-OA) was found to be the most hygroscopic factor, while at the same time being the least oxidized and likely most volatile of all PMF factors. Considering the diurnal variation of each PMF factor and its associated hygroscopicity, Isoprene-OA and More Oxidized - Oxidized Oxygenated Organic Aerosol (MO-OOA) are the prime contributors to hygroscopicity and covary with Less Oxidized - Oxidized Oxygenated Organic Aerosol (LO-OOA) in a way that induces the observed diurnal invariance in total organic hygroscopicity. Biomass Burning Organic Aerosol (BBOA) contributed little to aerosol hygroscopicity, which is expected since there was little biomass burning activity during the sampling period examined.
Bonsa, Anne-Marie; Paschek, Dietmar; Zaitsau, Dzmitry H; Emel'yanenko, Vladimir N; Verevkin, Sergey P; Ludwig, Ralf
2017-05-19
Key properties for the use of ionic liquids as electrolytes in batteries are low viscosities, low vapor pressure and high vaporization enthalpies. Whereas the measurement of transport properties is well established, the determination of vaporization enthalpies of these extremely low volatile compounds is still a challenge. At a first glance both properties seem to describe different thermophysical phenomena. However, eighty years ago Eyring suggested a theory which related viscosities and vaporization enthalpies to each other. The model is based on Eyring's theory of absolute reaction rates. Recent attempts to apply Eyring's theory to ionic liquids failed. The motivation of our study is to show that Eyring's theory works, if the assumptions specific for ionic liquids are fulfilled. For that purpose we measured the viscosities of three well selected protic ionic liquids (PILs) at different temperatures. The temperature dependences of viscosities were approximated by the Vogel-Fulcher-Tamann (VFT) relation and extrapolated to the high-temperature regime up to 600 K. Then the VFT-data could be fitted to the Eyring-model. The values of vaporization enthalpies for the three selected PILs predicted by the Eyring model have been very close to the experimental values measured by well-established techniques. We conclude that the Eyring theory can be successfully applied to the chosen set of PILs, if the assumption that ionic pairs of the viscous flow in the liquid and the ionic pairs in the gas phase are similar is fulfilled. It was also noticed that proper transfer of energies can be only derived if the viscosities and the vaporization energies are known for temperatures close to the liquid-gas transition temperature. The idea to correlate easy measurable viscosities of ionic liquids with their vaporization enthalpies opens a new way for a reliable assessment of these thermodynamic properties for a broad range of ionic liquids. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Mitov, Ivan; Strateva, Tanya; Markova, Boyka
2010-01-01
The aim of this study was to evaluate the prevalence of some virulence genes among 202 Pseudomonas aeruginosa isolates from cystic fibrosis (CF) patients (n=42) and non-CF in-patients (n=160) and to analyze the values according to the patient groups, infection localization and antimicrobial resistance. The following frequencies in all studied strains were established: algD (encoding GDP-mannose 6-dehydrogenase AlgD) – 91.1%, pilB (type IV fimbrial biogenesis protein PilB) – 23.8%, nan1 (neuraminidase) – 21.3%, lasB (elastase LasB) – 100%, plcH (haemolytic phospholipase C precursor) – 91.6%, exoS (exoenzyme S) – 62.4%, and exoU (exoenzyme U) – 30.2%. The prevalence of nan1 was significantly higher (P<0.01) in CF isolates (38.1%) than that in non-CF isolates (16.9%). The nan1–positive CF strains were cultured from 16 patients with recurrent lung exacerbations. This study revealed a statistically significant difference (P<0.01) between the portion of multidrug-resistant (MDR) nosocomial P. aeruginosa strains containing a large number (≥5) of virulence genes (38.1%) and the respective part of non-MDR isolates (17.6%). Moreover, pilB, exoU and nan1 manifested a higher spread (P<0.001) among MDR than in non-MDR strains (respectively, 39.1% vs. 13.2%; 40.2% vs. 17.7% and 26.1% vs. 4.4%). In conclusion, the dissemination of nan1 in CF isolates was moderate and correlated with the lower proportion of patients with lung exacerbations. The molecular-genetic detection of this gene may be used as an indirect measure of CF pulmonary disease evolution. Simultaneous determination of virulence factors and antimicrobial resistance is the contemporary approach for examination of the microbiological aspects of infections caused by P. aeruginosa. PMID:24031533
NASA Astrophysics Data System (ADS)
Gömöry, P.; Balthasar, H.; Kuckein, C.; Koza, J.; Veronig, A. M.; González Manrique, S. J.; Kučera, A.; Schwartz, P.; Hanslmeier, A.
2017-06-01
Aims: Changes of the magnetic field and the line-of-sight velocities in the photosphere are being reported for an M-class flare that originated at a δ-spot belonging to active region NOAA 11865. Methods: High-resolution ground-based near-infrared spectropolarimetric observations were acquired simultaneously in two photospheric spectral lines, Fe I 10783 Å and Si I 10786 Å, with the Tenerife Infrared Polarimeter at the Vacuum Tower Telescope (VTT) in Tenerife on 2013 October 15. The observations covered several stages of the M-class flare. Inversions of the full-Stokes vector of both lines were carried out and the results were put into context using (extreme)-ultraviolet filtergrams from the Solar Dynamics Observatory (SDO). Results: The active region showed high flaring activity during the whole observing period. After the M-class flare, the longitudinal magnetic field did not show significant changes along the polarity inversion line (PIL). However, an enhancement of the transverse magnetic field of approximately 550 G was found that bridges the PIL and connects umbrae of opposite polarities in the δ-spot. At the same time, a newly formed system of loops appeared co-spatially in the corona as seen in 171 Å filtergrams of the Atmospheric Imaging Assembly (AIA) on board SDO. However, we cannot exclude that the magnetic connection between the umbrae already existed in the upper atmosphere before the M-class flare and became visible only later when it was filled with hot plasma. The photospheric Doppler velocities show a persistent upflow pattern along the PIL without significant changes due to the flare. Conclusions: The increase of the transverse component of the magnetic field after the flare together with the newly formed loop system in the corona support recent predictions of flare models and flare observations. The movie associated to Figs. 4 and 5 is available at http://www.aanda.org
Panesso, Diana; Reyes, Jinnethe; Rincón, Sandra; Díaz, Lorena; Galloway-Peña, Jessica; Zurita, Jeannete; Carrillo, Carlos; Merentes, Altagracia; Guzmán, Manuel; Adachi, Javier A.; Murray, Barbara E.; Arias, Cesar A.
2010-01-01
Enterococcus faecium has emerged as an important nosocomial pathogen worldwide, and this trend has been associated with the dissemination of a genetic lineage designated clonal cluster 17 (CC17). Enterococcal isolates were collected prospectively (2006 to 2008) from 32 hospitals in Colombia, Ecuador, Perú, and Venezuela and subjected to antimicrobial susceptibility testing. Genotyping was performed with all vancomycin-resistant E. faecium (VREfm) isolates by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. All VREfm isolates were evaluated for the presence of 16 putative virulence genes (14 fms genes, the esp gene of E. faecium [espEfm], and the hyl gene of E. faecium [hylEfm]) and plasmids carrying the fms20-fms21 (pilA), hylEfm, and vanA genes. Of 723 enterococcal isolates recovered, E. faecalis was the most common (78%). Vancomycin resistance was detected in 6% of the isolates (74% of which were E. faecium). Eleven distinct PFGE types were found among the VREfm isolates, with most belonging to sequence types 412 and 18. The ebpAEfm-ebpBEfm-ebpCEfm (pilB) and fms11-fms19-fms16 clusters were detected in all VREfm isolates from the region, whereas espEfm and hylEfm were detected in 69% and 23% of the isolates, respectively. The fms20-fms21 (pilA) cluster, which encodes a putative pilus-like protein, was found on plasmids from almost all VREfm isolates and was sometimes found to coexist with hylEfm and the vanA gene cluster. The population genetics of VREfm in South America appear to resemble those of such strains in the United States in the early years of the CC17 epidemic. The overwhelming presence of plasmids encoding putative virulence factors and vanA genes suggests that E. faecium from the CC17 genogroup may disseminate in the region in the coming years. PMID:20220167
Wijaya, Emmy C; Separovic, Frances; Drummond, Calum J; Greaves, Tamar L
2016-09-21
Improving protein stabilisation is important for the further development of many applications in the pharmaceutical, specialty chemical, consumer product and agricultural sectors. However, protein stabilization is highly dependent on the solvent environment and, hence, it is very complex to tailor protein-solvent combinations for stable protein maintenance. Understanding solvent features that govern protein stabilization will enable selection or design of suitable media with favourable solution environments to retain protein native conformation. In this work the structural conformation and activity of lysozyme in 29 solvent systems were investigated to determine the role of various solvent features on the stability of the enzyme. The solvent systems consisted of 19 low molecular weight polar solvents and 4 protic ionic liquids (PILs), both at different water content levels, and 6 aqueous salt solutions. Small angle X-ray scattering, Fourier transform infrared spectroscopy and UV-vis spectroscopy were used to investigate the tertiary and secondary structure of lysozyme along with the corresponding activity in various solvation systems. At low non-aqueous solvent concentrations (high water content), the presence of solvents and salts generally maintained lysozyme in its native structure and enhanced its activity. Due to the presence of a net surface charge on lysozyme, electrostatic interactions in PIL-water systems and salt solutions enhanced lysozyme activity more than the specific hydrogen-bond interactions present in non-ionic molecular solvents. At higher solvent concentrations (lower water content), solvents with a propensity to exhibit the solvophobic effect, analogous to the hydrophobic effect in water, retained lysozyme native conformation and activity. This solvophobic effect was observed particularly for solvents which contained hydroxyl moieties. Preferential solvophobic effects along with bulky chemical structures were postulated to result in less competition with water at the specific hydration layer around the protein, thus reducing protein-solvent interactions and retaining lysozyme's native conformation. The structure-property links established in this study are considered to be applicable to other proteins.
Drummond, Colin; Deluca, Paolo; Coulton, Simon; Bland, Martin; Cassidy, Paul; Crawford, Mike; Dale, Veronica; Gilvarry, Eilish; Godfrey, Christine; Heather, Nick; McGovern, Ruth; Myles, Judy; Newbury-Birch, Dorothy; Oyefeso, Adenekan; Parrott, Steve; Patton, Robert; Perryman, Katherine; Phillips, Tom; Shepherd, Jonathan; Touquet, Robin; Kaner, Eileen
2014-01-01
Background Alcohol misuse is common in people attending emergency departments (EDs) and there is some evidence of efficacy of alcohol screening and brief interventions (SBI). This study investigated the effectiveness of SBI approaches of different intensities delivered by ED staff in nine typical EDs in England: the SIPS ED trial. Methods and Findings Pragmatic multicentre cluster randomized controlled trial of SBI for hazardous and harmful drinkers presenting to ED. Nine EDs were randomized to three conditions: a patient information leaflet (PIL), 5 minutes of brief advice (BA), and referral to an alcohol health worker who provided 20 minutes of brief lifestyle counseling (BLC). The primary outcome measure was the Alcohol Use Disorders Identification Test (AUDIT) status at 6 months. Of 5899 patients aged 18 or more presenting to EDs, 3737 (63·3%) were eligible to participate and 1497 (40·1%) screened positive for hazardous or harmful drinking, of whom 1204 (80·4%) gave consent to participate in the trial. Follow up rates were 72% (n = 863) at six, and 67% (n = 810) at 12 months. There was no evidence of any differences between intervention conditions for AUDIT status or any other outcome measures at months 6 or 12 in an intention to treat analysis. At month 6, compared to the PIL group, the odds ratio of being AUDIT negative for brief advice was 1·103 (95% CI 0·328 to 3·715). The odds ratio comparing BLC to PIL was 1·247 (95% CI 0·315 to 4·939). A per protocol analysis confirmed these findings. Conclusions SBI is difficult to implement in typical EDs. The results do not support widespread implementation of alcohol SBI in ED beyond screening followed by simple clinical feedback and alcohol information, which is likely to be easier and less expensive to implement than more complex interventions. Trial Registration Current Controlled Trials ISRCTN 93681536 PMID:24963731
Recurrent flares in active region NOAA 11283
NASA Astrophysics Data System (ADS)
Romano, P.; Zuccarello, F.; Guglielmino, S. L.; Berrilli, F.; Bruno, R.; Carbone, V.; Consolini, G.; de Lauretis, M.; Del Moro, D.; Elmhamdi, A.; Ermolli, I.; Fineschi, S.; Francia, P.; Kordi, A. S.; Landi Degl'Innocenti, E.; Laurenza, M.; Lepreti, F.; Marcucci, M. F.; Pallocchia, G.; Pietropaolo, E.; Romoli, M.; Vecchio, A.; Vellante, M.; Villante, U.
2015-10-01
Context. Flares and coronal mass ejections (CMEs) are solar phenomena that are not yet fully understood. Several investigations have been performed to single out their related physical parameters that can be used as indices of the magnetic complexity leading to their occurrence. Aims: In order to shed light on the occurrence of recurrent flares and subsequent associated CMEs, we studied the active region NOAA 11283 where recurrent M and X GOES-class flares and CMEs occurred. Methods: We use vector magnetograms taken by HMI/SDO to calculate the horizontal velocity fields of the photospheric magnetic structures, the shear and the dip angles of the magnetic field, the magnetic helicity flux distribution, and the Poynting fluxes across the photosphere due to the emergence and the shearing of the magnetic field. Results: Although we do not observe consistent emerging magnetic flux through the photosphere during the observation time interval, we detected a monotonic increase of the magnetic helicity accumulated in the corona. We found that both the shear and the dip angles have high values along the main polarity inversion line (PIL) before and after all the events. We also note that before the main flare of X2.1 GOES class, the shearing motions seem to inject a more significant energy than the energy injected by the emergence of the magnetic field. Conclusions: We conclude that the very long duration (about 4 days) of the horizontal displacement of the main photospheric magnetic structures along the PIL has a primary role in the energy release during the recurrent flares. This peculiar horizontal velocity field also contributes to the monotonic injection of magnetic helicity into the corona. This process, coupled with the high shear and dip angles along the main PIL, appears to be responsible for the consecutive events of loss of equilibrium leading to the recurrent flares and CMEs. A movie associated to Fig. 4 is available in electronic form at http://www.aanda.org
Massicotte-Azarniouch, David; Kuwornu, John Paul; Carrero, Juan-Jesus; Lam, Ngan N; Molnar, Amber O; Zimmerman, Deborah; McCallum, Megan K; Garg, Amit X; Sood, Manish M
2018-02-01
The association of atrial fibrillation (AF), estimated glomerular filtration rate (eGFR), and adverse events remains unknown. Population-based retrospective cohort study from Ontario, Canada. 1,422,978 adult residents with eGFRs < 90mL/min/1.73m 2 from April 1, 2006, through March 31, 2015. A diagnosis of AF at hospitalization. Congestive heart failure (CHF), myocardial infarction (MI), end-stage kidney disease, all-cause mortality. All adverse events were more frequent in individuals with AF (93,414 propensity score matched) compared to no AF, and this difference was more pronounced within the first 6 months of the index date (CHF: 3.04% [AF] vs 0.28% [no AF], subdistribution HR [sHR] of 11.57 [95% CI, 10.26-13.05]; MI: 0.97% [AF] vs 0.21% [no AF], sHR of 4.76 [95% CI, 4.17-5.43]; end-stage kidney disease: 0.16% [AF] vs 0.03% [no AF], sHR of 5.84 [95% CI, 3.82-8.93]; and all-cause mortality: 6.11% [AF] vs 2.50% [no AF], HR of 2.62 [95% CI, 2.50-2.76]) than in the period more than 6 months after the index date (CHF: 6.87% [AF] vs 2.87% [no AF], sHR of 2.64 [95% CI, 2.55-2.74]; MI: 2.21% [AF] vs 1.81% [no AF], sHR of 1.24 [95% CI, 1.18-1.30]; end-stage kidney disease: 0.52% [AF] vs 0.32% [no AF], sHR of 1.75 [95% CI, 1.57-1.95]; and all-cause mortality: 15.55% [AF] vs 15.10% [no AF], HR of 1.07 [95% CI, 1.04-1.10]). The results accounted for the competing risk for mortality. eGFR level modified the effect of AF on CHF (P for interaction < 0.05). Observational study design does not permit determination of causality; only a single outpatient eGFR measure was used; medication data were not included. Incident AF is associated with a high risk for adverse outcomes in patients with eGFRs < 90mL/min/1.73m 2 . Because the risk is exceedingly high within the first 6 months after AF diagnosis, therapeutic interventions and monitoring may improve outcomes. Copyright © 2017 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.
Health Information in Somali (Af-Soomaali )
... Af-Soomaali (Somali) Bilingual PDF Health Information Translations Pendulum Exercises for Shoulder - Af-Soomaali (Somali) Bilingual PDF ... Af-Soomaali (Somali) Bilingual PDF Health Information Translations Pendulum Exercises for Shoulder - Af-Soomaali (Somali) Bilingual PDF ...
Bisson, Arnaud; Clementy, Nicolas; Bodin, Alexandre; Angoulvant, Denis; Babuty, Dominique; Lip, Gregory Y H; Fauchier, Laurent
2017-10-01
There remains uncertainty as whether newly diagnosed atrial fibrillation (AF) after ischemic stroke reflects underlying heart disease and represents an increased risk of cardioembolic stroke, or whether it is triggered by neurogenic mechanisms. We aimed to determine whether cardiovascular comorbidities in patients with new AF after ischemic stroke differ from patients with previous known AF or without AF. This French longitudinal cohort study was based on the database covering hospital care from 2009 to 2012 for the entire population. Of 336 291 patients with ischemic stroke, 240 459 (71.5%) had no AF and 95 832 (28.5%) had previously known AF at baseline. Patients without previous AF had a mean CHA 2 DS 2 -VASc score of 4.98±1.63 SD. During a mean follow-up of 7.9±11.5 months, 14 095 (5.9%) of these patients had incident AF, representing an annual incidence of AF after ischemic stroke of 8.9 per 100 person-years (95% confidence interval, 8.8-9.0). New AF patients had higher CHA 2 DS 2 -VASc score, more likely comorbidities, and more frequent history of previous transient ischemic attack than patients with previous known AF or without AF. Preexisting cardiovascular comorbidities underlie AF newly diagnosed after stroke. Consequently, these high-risk patients should be closely monitored for incident AF to facilitate an earlier diagnosis of AF and avoid stroke with appropriate thromboprophylaxis. © 2017 American Heart Association, Inc.
Early, de novo atrial fibrillation after coronary artery bypass grafting: Facts and features.
Yaksh, Ameeta; Kik, Charles; Knops, Paul; van Ettinger, Maarten J B; Bogers, Ad J J C; de Groot, Natasja M S
2017-02-01
Knowledge of the mechanism underlying post-operative atrial fibrillation (PoAF) is essential for development of preventive measures. The incidence and characteristics of both PoAF and supraventricular premature beats triggering PoAF, their interrelationship and alterations over time have never been examined. The goal of this study is therefore to examine the correlation between the incidence and characteristics of supraventricular premature beats (SVPBs) and PoAF episodes in patients undergoing CABG in the first five post-operative days. PoAF episodes (N=327) and SVPBs (N=141,873) were characterized in 29 patients (63±9 years; 22 (76%) male) undergoing coronary artery bypass grafting and compared with a control group of patients without PoAF by using continuous cardiac rhythm monitoring during the first 5 days after surgery. Most patients (N=18, 62%) had multiple PoAF episodes; the median number of PoAF episodes per patient was 3 and varied between 1 and 139. The majority of PoAF episodes developed on the second and third post-operative day (55%). The averaged median duration of PoAF episodes per patient was 469±1085 min. Patients with PoAF had a higher SVPBs burden compared to subjects without PoAF (0.9% vs 0.2%, P<.001). SVPBs initiating PoAF had shorter coupling intervals than SVPBs which did not initiate PoAF episodes (58% vs 64% (P<.001) and were preceded by heart rate acceleration. PoAF episodes are mainly repetitive though transient in nature. There was a considerable inter-individual variation in both AF and SVPB characteristics, despite a similar underlying clinical profile. The SVPB burden is higher in patients with PoAF and the mode of onset is characterized by short coupled SVPBs. Determination of individual post-operative dysrhythmia profiles enables identification of patients at risk for developing PoAF. Copyright © 2016 Elsevier Inc. All rights reserved.
García-Seara, Javier; Gude Sampedro, Francisco; Martínez Sande, Jose L; Fernández López, Xesus Alberte; Rodríguez Mañero, Moisés; González Melchor, Laila; Alvarez Alvarez, Belén; Iglesias Alvarez, Diego; González Juanatey, José Ramón
2016-09-01
We determined the effectiveness of the HATCH score in patients with typical atrial flutter (AFl) undergoing cavotricuspid isthmus (CTI) ablation to predict long-term atrial fibrillation (AF). We conducted an observational retrospective single-center cohort study including all patients admitted to our hospital for a CTI ablation between 1998 and 2010. The patients were divided into four categories: 1) new-onset AF (no prior AF and AF during follow-up (FU)); 2) old AF (prior AF and no AF during FU); 3) prior and post AF (AF prior and post CTI ablation); and 4) no AF. Four hundred and eight patients were included. In patients without prior AF, the hazard ratio (HR) for new-onset AF during FU was 0.98 (CI 95%: 0.65-1.50; p = 0.95) and 1.00 (CI 95%: 0.57-1.77; p = 0.98) for HATCH ≥ 2 and HATCH ≥ 3, respectively. In patients with prior AF, the HR for AF was 1.41 (CI 95%: 0.87-2.28; p = 0.17) and 1.79 (CI 95%: 0.96-3.35; p = 0.06), for HATCH ≥ 2 and HATCH ≥ 3, respectively. Left atrial enlargement was positively correlated with the occurrence of AF during FU, especially in the subgroup without prior AF, which had a HR of 2.44 (CI 95%: 1.35-4.40; p = 0.003), a HR of 2.88 (CI 95%: 1.36-6.10; p = 0.006) and a HR of 3.68 (CI 95%: 1.71-7.94; p = 0.001), for slight, moderate and severely dilated left atrial dimension, respectively, compared with a normal value. HATCH score did not predict AF in patients with typical AFl who underwent CTI ablation. Basal left atrium dimension could help predict new-onset AF.
Kralovicova, Jana; Knut, Marcin; Cross, Nicholas C. P.; Vorechovsky, Igor
2015-01-01
The auxiliary factor of U2 small nuclear RNA (U2AF) is a heterodimer consisting of 65- and 35-kD proteins that bind the polypyrimidine tract (PPT) and AG dinucleotides at the 3′ splice site (3′ss). The gene encoding U2AF35 (U2AF1) is alternatively spliced, giving rise to two isoforms U2AF35a and U2AF35b. Here, we knocked down U2AF35 and each isoform and characterized transcriptomes of HEK293 cells with varying U2AF35/U2AF65 and U2AF35a/b ratios. Depletion of both isoforms preferentially modified alternative RNA processing events without widespread failure to recognize 3′ss or constitutive exons. Over a third of differentially used exons were terminal, resulting largely from the use of known alternative polyadenylation (APA) sites. Intronic APA sites activated in depleted cultures were mostly proximal whereas tandem 3′UTR APA was biased toward distal sites. Exons upregulated in depleted cells were preceded by longer AG exclusion zones and PPTs than downregulated or control exons and were largely activated by PUF60 and repressed by CAPERα. The U2AF(35) repression and activation was associated with a significant interchange in the average probabilities to form single-stranded RNA in the optimal PPT and branch site locations and sequences further upstream. Although most differentially used exons were responsive to both U2AF subunits and their inclusion correlated with U2AF levels, a small number of transcripts exhibited distinct responses to U2AF35a and U2AF35b, supporting the existence of isoform-specific interactions. These results provide new insights into function of U2AF and U2AF35 in alternative RNA processing. PMID:25779042
NASA Astrophysics Data System (ADS)
Stockwell, Chelsea E.; Kupc, Agnieszka; Witkowski, Bartłomiej; Talukdar, Ranajit K.; Liu, Yong; Selimovic, Vanessa; Zarzana, Kyle J.; Sekimoto, Kanako; Warneke, Carsten; Washenfelder, Rebecca A.; Yokelson, Robert J.; Middlebrook, Ann M.; Roberts, James M.
2018-05-01
The chemical composition of aerosol particles is a key aspect in determining their impact on the environment. For example, nitrogen-containing particles impact atmospheric chemistry, air quality, and ecological N deposition. Instruments that measure total reactive nitrogen (Nr = all nitrogen compounds except for N2 and N2O) focus on gas-phase nitrogen and very few studies directly discuss the instrument capacity to measure the mass of Nr-containing particles. Here, we investigate the mass quantification of particle-bound nitrogen using a custom Nr system that involves total conversion to nitric oxide (NO) across platinum and molybdenum catalysts followed by NO-O3 chemiluminescence detection. We evaluate the particle conversion of the Nr instrument by comparing to mass-derived concentrations of size-selected and counted ammonium sulfate ((NH4)2SO4), ammonium nitrate (NH4NO3), ammonium chloride (NH4Cl), sodium nitrate (NaNO3), and ammonium oxalate ((NH4)2C2O4) particles determined using instruments that measure particle number and size. These measurements demonstrate Nr-particle conversion across the Nr catalysts that is independent of particle size with 98 ± 10 % efficiency for 100-600 nm particle diameters. We also show efficient conversion of particle-phase organic carbon species to CO2 across the instrument's platinum catalyst followed by a nondispersive infrared (NDIR) CO2 detector. However, the application of this method to the atmosphere presents a challenge due to the small signal above background at high ambient levels of common gas-phase carbon compounds (e.g., CO2). We show the Nr system is an accurate particle mass measurement method and demonstrate its ability to calibrate particle mass measurement instrumentation using single-component, laboratory-generated, Nr-containing particles below 2.5 µm in size. In addition we show agreement with mass measurements of an independently calibrated online particle-into-liquid sampler directly coupled to the electrospray ionization source of a quadrupole mass spectrometer (PILS-ESI/MS) sampling in the negative-ion mode. We obtain excellent correlations (R2 = 0.99) of particle mass measured as Nr with PILS-ESI/MS measurements converted to the corresponding particle anion mass (e.g., nitrate, sulfate, and chloride). The Nr and PILS-ESI/MS are shown to agree to within ˜ 6 % for particle mass loadings of up to 120 µg m-3. Consideration of all the sources of error in the PILS-ESI/MS technique yields an overall uncertainty of ±20 % for these single-component particle streams. These results demonstrate the Nr system is a reliable direct particle mass measurement technique that differs from other particle instrument calibration techniques that rely on knowledge of particle size, shape, density, and refractive index.
[Clinical analysis of intestinal lymphangiectasia in 47 children].
Guo, S; Song, L; Guan, D X; Mei, T L; Zhou, J; Yu, F H; Wang, G L; Zhang, J; Shen, H Q; Xu, X W
2017-12-02
Objective: To analyze the clinical manifestations, diagnosis, treatment and prognosis of intestinal lymphangiectasia (IL) in children in order to improve the skills of diagnosis and treatment of IL. Method: Clinical manifestations, laboratory findings, gastroscopic findings, histopathological examinations and lymphatic radionuclide imaging assessments were analyzed retrospectively among 47 IL patients who were hospitalized in the Gastroenterology Department of Beijing Children's Hospital Affiliated to Capital Medical University from June 2007 to December 2015. All patients were followed up by telephone. According to the various causes, the patients were divided into the primary intestinal lymphangiectasia (PIL) group and secondary IL group, and their clinical manifestations were compared by t test, Rank sum test or Chi-square test. Result: In 47 IL patients, there were 38 children (81%) younger than 3 years old. There were 43 PIL patients (91%) and 4 secondary IL patients (9%). Between PIL and secondary IL, there were statistical differences in serum albumin ( t=- 3.950, P< 0.005) , globulin( t=- 2.850, P= 0.007), age of onset( U =27.000, P= 0.024), age at diagnosis( U =29.000, P= 0.030) and course of disease( U =26.500, P= 0.023), whereas there were no statistical differences in lymphocyte count, IgG, lymphatic radionuclide imaging, histopathology and gender(all P> 0.05). Edema (44 cases, 94%), diarrhea (42 cases, 89%), accompanied with infection (35 cases, 74%) and ascites (30 cases, 64%) were the main clinical manifestations. In 47 IL patients, 45 patients were done gastroscopy and histopathological examinations, and there were 31 patients' histopathological examinations(69%) were positive. Forty patients were done lymphatic radionuclide imaging, and there was evidence of protein losing from gut via lymphatic radionuclide imaging in 39 patients(98%). Among 47 patients, 35 patients (74%) were followed up, 32 patients had good prognosis, 2 patient failed to show evidence of improvement, 1 patient died and no patient experienced a relapse till the end of the follow-up. In 35 patients, 28 patients were treated with medium chain triglycerides (MCT) dietary therapy, 26 patients showed improvement in symptoms, and 2 patients had no improvement. Among 35 patients with follow-up, there were 6 patients received surgical treatment, and their symptoms were improved. Conclusion: PIL are the majority of IL in children younger than 3 years old. The main clinical manifestations are edema, diarrhea, accompanied with infection and ascites. For the patients without the evidence of lymphangiectasia from duodenum histopathological examination, further consideration of lymphatic radionuclide imaging, clinical manifestations, and laboratory studies are needed to make a final diagnosis. MCT dietary therapy is the cornerstone of IL medical management.
The Role of U2AF1 Mutations in the Pathogenesis of Myelodysplastic Syndromes
2015-10-01
mutation, U2AF1(S34F), on hematopoiesis and pre-mRNA splicing in vivo, we created doxycycline-inducible U2AF1(WT) and U2AF1(S34F) transgenic mice...U2AF1(S34F) versus U2AF1(WT). Together, these results suggest that mutant U2AF1 expression contributes to the altered hematopoiesis and pre-mRNA...Spliceosome, Mouse Model, Hematopoiesis , RNA-seq, U2AF1 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME
1985-09-01
GM SILTY GRAVEL GP POORLY GRADED GRAVEL SM SILTY SAND SP POORLY GRADED SAND SW WELL GRADED SAND ML LOW PLASTICITY SILT SOURCE: INSTALLATION DOCUMENTS... plastic on the side toward th’e beach in an attempt to prevent migration of fuel. to the beach. During the site visit for this Phase I IRP study the...Force have included garbage, refuse, incinerator ash (since 1975), wood, metal, plastic and bulky - materials such as construction and demolition debris
Factors effecting impact of Aspergillus fumigatus sensitization in cystic fibrosis.
Kanthan, Senthooran Kathirgama; Bush, Andrew; Kemp, Michael; Buchdahl, Roger
2007-09-01
The clinical impact of Aspergillus fumigatus (Af) sensitization in cystic fibrosis (CF) is controversial. We examined the effect of Af sensitization (Afs) on pulmonary function and growth using a retrospective cohort analysis over two 5-year study periods: 1996-2000 (19 Afs cases and 19 controls) and 2001-2005 (24 Afs cases and 23 controls). Sensitization was defined as Af specific radioallergosorbent test (RAST) >or= 17.5 iu/ml and total serum IgE level >or=150 iu/ml. We examined the impact of changing treatment schedules over these periods. Afs cases had lower median FEV(1) %predicted (%PR) compared to matched controls 1996: 67 versus 80, P < 0.01; 2001: 78 versus 93, P < 0.01. Afs cases in the 2001 cohort had a higher FEV(1) %PR compared to Afs cases in the 1996 cohort: 78 versus 67, P < 0.01. For the 1996 Afs cohort FEV(1) %PR fell significantly over 5 years but not for the 2001 Afs cohort. Af RAST and total IgE reflected the changes in pulmonary function. Children in the 2001 Afs cohort were prescribed significantly more oral antifungal treatment (odds ratio 4.3, 95%CI 1.2-15.7, P = 0.03). Afs children continue to have poorer lung function compared to controls but this observational, hypothesis generating study, suggests that the use of antifungal treatment is associated with better lung function. (c) 2007 Wiley-Liss, Inc.
Oba, Kageyuki; Maeda, Minetaka; Maimaituxun, Gulinu; Yamaguchi, Satoshi; Arasaki, Osamu; Fukuda, Daiju; Yagi, Shusuke; Hirata, Yukina; Nishio, Susumu; Iwase, Takashi; Takao, Shoichiro; Kusunose, Kenya; Yamada, Hirotsugu; Soeki, Takeshi; Wakatsuki, Tetsuzo; Harada, Masafumi; Masuzaki, Hiroaki; Sata, Masataka; Shimabukuro, Michio
2018-05-25
Although increasing evidence suggests that epicardial adipose tissue volume (EATV) is associated with atrial fibrillation (AF), it is controversial whether there is a dose-response relationship of increasing EATV along the continuum of AF. We evaluated the effect of the EATV on the prevalence of paroxysmal AF (PAF) and persistent AF (PeAF) and the relationships with cardiac structure and functional remodeling.Methods and Results:Subjects who underwent multidetector computed tomography (MDCT) coronary angiography because of symptoms suggestive of coronary artery disease were divided into sinus rhythm (SR) (n=112), PAF (n=133), and PeAF (n=71) groups. The EATV index (EATV/body surface area, mL/m 2 ) was strongly associated with the prevalence of PAF and PeAF on the model adjusted for known AF risk factors. The effect of the EATV index on the prevalence of PeAF, but not on that of PAF, was modified by the left atrial (LA) dimension, suggesting that extension of the LA dimension is related to EATV expansion in PeAF. The cutoff value of the EATV index for the prevalence was higher in PeAF than in PAF (64 vs. 55 mL/m 2 , P<0.01). The EATV index is associated with the prevalence of PAF and PeAF, and its cutoff values are predictive for PAF and PeAF development independently of other AF risk factors.
Maximizing Performance: Augmented Feedback, Focus of Attention, and/or Reward?
Wälchli, Michael; Ruffieux, Jan; Bourquin, Yann; Keller, Martin; Taube, Wolfgang
2016-04-01
Different approaches like providing augmented feedback (aF), applying an external focus of attention (EF), or rewarding participants with money (RE) have been shown to instantly enhance motor performance. So far, these approaches have been tested either in separate studies or directly against each other. However, there is no study that combined aF, EF, and/or RE to test whether this provokes additional benefits. The aim of the present study was therefore to identify the most powerful combination. Eighteen participants performed maximal countermovement jumps in six different conditions: neutral (NE), aF, RE, aF + EF, aF + RE, and aF + EF + RE. Participants demonstrated the highest jump heights with aF + EF, followed by aF + EF + RE, aF + RE, aF, RE, and finally, NE. Activity of the M. rectus femoris differed significantly between conditions resulting in lower muscular activity in aF + EF and aF + EF + RE compared with NE. All other parameters, such as ground reaction forces and joint angles, were comparable across conditions. This is the first study showing superior performance when combining aF with EF. As reduced muscular activity was found only in conditions with EF, it is argued in line with the constrained action hypothesis that adopting an EF improves movement efficiency. In contrast, aF seems to rather enhance (intrinsic) motivation. However, monetary reward did not further amplify performance.
Voigt, Niels; Trausch, Anne; Knaut, Michael; Matschke, Klaus; Varró, András; Van Wagoner, David R; Nattel, Stanley; Ravens, Ursula; Dobrev, Dobromir
2010-10-01
Recent evidence suggests that atrial fibrillation (AF) is maintained by high-frequency reentrant sources with a left-to-right-dominant frequency gradient, particularly in patients with paroxysmal AF (pAF). Unequal left-to-right distribution of inward rectifier K(+) currents has been suggested to underlie this dominant frequency gradient, but this hypothesis has never been tested in humans. Currents were measured with whole-cell voltage-clamp in cardiomyocytes from right atrial (RA) and left (LA) atrial appendages of patients in sinus rhythm (SR) and patients with AF undergoing cardiac surgery. Western blot was used to quantify protein expression of I(K1) (Kir2.1 and Kir2.3) and I(K,ACh) (Kir3.1 and Kir3.4) subunits. Basal current was ≈2-fold larger in chronic AF (cAF) versus SR patients, without RA-LA differences. In pAF, basal current was ≈2-fold larger in LA versus RA, indicating a left-to-right atrial gradient. In both atria, Kir2.1 expression was ≈2-fold greater in cAF but comparable in pAF versus SR. Kir2.3 levels were unchanged in cAF and RA-pAF but showed a 51% decrease in LA-pAF. In SR, carbachol-activated (2 μmol/L) I(K,ACh) was 70% larger in RA versus LA. This right-to-left atrial gradient was decreased in pAF and cAF caused by reduced I(K,ACh) in RA only. Similarly, in SR, Kir3.1 and Kir3.4 proteins were greater in RA versus LA and decreased in RA of pAF and cAF. Kir3.1 and Kir3.4 expression was unchanged in LA of pAF and cAF. Our results support the hypothesis that a left-to-right gradient in inward rectifier background current contributes to high-frequency sources in LA that maintain pAF. These findings have potentially important implications for development of atrial-selective therapeutic approaches.
Soliman, Elsayed Z.; Prineas, Ronald J.; Case, L. Douglas; Zhang, Zhu-ming; Goff, David C.
2009-01-01
Background and Purpose The paradox of the reported low prevalence of atrial fibrillation (AF) in blacks compared with whites despite higher stroke rates in the former could be related to limitations in the current methods used to diagnose AF in population-based studies. Hence, this study aimed to use the ethnic distribution of ECG predictors of AF as measures of AF propensity in different ethnic groups. Methods The distribution of baseline measures of P-wave terminal force, P-wave duration, P-wave area, and PR duration (referred to as AF predictors) were compared by ethnicity in 15 429 participants (27% black) from the Atherosclerosis Risk in Communities (ARIC) study by unpaired t test, χ2, and logistic-regression analysis, as appropriate. Cox proportional-hazards analysis was used to separately examine the association of AF predictors with incident AF and ischemic stroke. Results Whereas AF was significantly less common in blacks compared with whites (0.24% vs 0.95%, P<0.0001), similar to what has been reported in previous studies, blacks had significantly higher and more abnormal values of AF predictors (P<0.0001 for all comparisons). Black ethnicity was significantly associated with abnormal AF predictors compared with whites; odds ratios for different AF predictors ranged from 2.1 to 3.1. AF predictors were significantly and independently associated with AF and ischemic stroke with no significant interaction between ethnicity and AF predictors, findings that further justify using AF predictors as an earlier indicator of future risk of AF and stroke. Conclusions There is a disconnect between the ethnic distribution of AF predictors and the ethnic distribution of AF, probably because the former, unlike the latter, do not suffer from low sensitivity. These results raise the possibility that blacks might actually have a higher prevalence of AF that might have been missed by previous studies owing to limited methodology, a difference that could partially explain the greater stroke risk in blacks. PMID:19213946
Voigt, Niels; Trausch, Anne; Knaut, Michael; Matschke, Klaus; Varró, András; Van Wagoner, David R.; Nattel, Stanley; Ravens, Ursula; Dobrev, Dobromir
2018-01-01
Background Recent evidence suggests that atrial fibrillation (AF) is maintained by high-frequency reentrant sources with a left-to-right–dominant frequency gradient, particularly in patients with paroxysmal AF (pAF). Unequal left-to-right distribution of inward rectifier K+ currents has been suggested to underlie this dominant frequency gradient, but this hypothesis has never been tested in humans. Methods and Results Currents were measured with whole-cell voltage-clamp in cardiomyocytes from right atrial (RA) and left (LA) atrial appendages of patients in sinus rhythm (SR) and patients with AF undergoing cardiac surgery. Western blot was used to quantify protein expression of IK1 (Kir2.1 and Kir2.3) and IK,ACh (Kir3.1 and Kir3.4) subunits. Basal current was ≈2-fold larger in chronic AF (cAF) versus SR patients, without RA-LA differences. In pAF, basal current was ≈2-fold larger in LA versus RA, indicating a left-to-right atrial gradient. In both atria, Kir2.1 expression was ≈2-fold greater in cAF but comparable in pAF versus SR. Kir2.3 levels were unchanged in cAF and RA-pAF but showed a 51% decrease in LA-pAF. In SR, carbachol-activated (2 μmol/L) IK,ACh was 70% larger in RA versus LA. This right-to-left atrial gradient was decreased in pAF and cAF caused by reduced IK,ACh in RA only. Similarly, in SR, Kir3.1 and Kir3.4 proteins were greater in RA versus LA and decreased in RA of pAF and cAF. Kir3.1 and Kir3.4 expression was unchanged in LA of pAF and cAF. Conclusions Our results support the hypothesis that a left-to-right gradient in inward rectifier background current contributes to high-frequency sources in LA that maintain pAF. These findings have potentially important implications for development of atrial-selective therapeutic approaches. PMID:20657029
Silent Atrial Fibrillation in Elderly Pacemaker Users: A Randomized Trial Using Home Monitoring.
Lima, Ceb; Martinelli, M; Peixoto, G L; Siqueira, S F; Wajngarten, Maurício; Silva, Rodrigo Tavares; Costa, Roberto; Filho, Roberto; Ramires, José Antônio Franchini
2016-05-01
Pacemaker with remote monitoring (PRM) may be useful for silent atrial fibrillation (AF) detection. The aims of this study were to evaluate the incidence of silent AF, the role of PRM, and to determine predictors of silent AF occurrence. Three hundred elderly patients with permanent pacemaker (PPM) were randomly assigned to the remote group (RG) or control group (CG). All patients received PPM with remote monitoring capabilities. Primary end point was AF occurrence rate and the secondary end points were time to AF detection and number of days with AF. During the average follow-up of 15.7±7.7 months, AF episodes were detected in 21.6% (RG = 24% vs CG = 19.3%, P = 0.36]. There was no difference in the time to detect the first AF episode. However, the median time to detect AF recurrence in the RG was lower than that in the CG (54 days vs 100 days, P = 0.004). The average number of days with AF was 16.0 and 51.2 in the RG and CG, respectively (P = 0.028). Predictors of silent AF were left atrial diameter (odds ratio [OR] 1.2; 95% CI = 1.1-1.3; P < 0.001) and diastolic dysfunction (OR 4.8; 95% CI = 1.6-14.0; P = 0.005). The incidence of silent AF is high in elderly patients with pacemaker; left atrial diameter and diastolic dysfunction were predictors of its occurrence. AF monitoring by means of pacemaker is a valuable tool for silent AF detection and continuous remote monitoring allows early AF recurrence detection and reduces the number of days with AF. © 2015 Wiley Periodicals, Inc.
Sardana, Mayank; Ogunsua, Adedotun A; Spring, Matthew; Shaikh, Amir; Asamoah, Owusu; Stokken, Glenn; Browning, Clifford; Ennis, Cynthia; Donahue, J Kevin; Rosenthal, Lawrence S; Floyd, Kevin C; Aurigemma, Gerard P; Parikh, Nisha I; McManus, David D
2016-12-01
Although catheter ablation (CA) for atrial fibrillation (AF) is commonly used to improve symptoms, AF recurrence is common and new tools are needed to better inform patient selection for CA. Left atrial function index (LAFI), an echocardiographic measure of atrial mechanical function, has shown promise as a noninvasive predictor of AF. We hypothesized that LAFI would relate to AF recurrence after CA. All AF patients undergoing index CA were enrolled in a prospective institutional AF Treatment Registry between 2011 and 2014. LAFI was measured post hoc from pre-ablation clinical echocardiographic images in 168 participants. Participants were mostly male (33% female), middle-aged (60 ± 10 years), obese and had paroxysmal AF (64%). Mean LAFI was 25.9 ± 17.6. Over 12 months of follow-up, 78 participants (46%) experienced a late AF recurrence. In logistic regression analyses adjusting for factors known to be associated with AF, lower LAFI remained associated with AF recurrence after CA [OR 0.04 (0.01-0.67), P = 0.02]. LAFI discriminated AF recurrence after CA slightly better than CHADS2 (C-statistic 0.60 LAFI, 0.57 CHADS2). For participants with persistent AF, LAFI performed significantly better than CHADS2 score (C statistic = 0.79 LAFI, 0.56 CHADS2, P = 0.02). LAFI, an echocardiographic measure of atrial function, is associated with AF recurrence after CA and has improved ability to discriminate AF recurrence as compared to the CHADS-2 score, especially among persistent AF patients. Since LAFI can be calculated using standard 2D echocardiographic images, it may be a helpful tool for predicting AF recurrence. © 2016 Wiley Periodicals, Inc.
Heiferman, Michael J; Fawzi, Amani A
2016-12-01
To identify the origin and significance of discordance between blue-light autofluorescence (BL-AF; 488 nm) and near-infrared autofluorescence (NI-AF; 787 nm) in patients with age-related macular degeneration (AMD). A total of 86 eyes of 59 patients with a diagnosis of AMD were included in this cross-sectional study conducted between March 9, 2015 and May 1, 2015. A masked observer examined the BL-AF, NI-AF, and spectral-domain optical coherence tomography images. Areas with discordance of autofluorescence patterns between NI-AF and BL-AF images were correlated with structural findings at the corresponding location in optical coherence tomography scans. Seventy-nine eyes had discordance between BL-AF and NI-AF. The most common optical coherence tomography finding accounting for these discrepancies was pigment migration accounting for 35 lesions in 21 eyes. The most clinically relevant finding was geographic atrophy missed on BL-AF in 7 eyes. Our findings indicate that variations in the distribution of lipofuscin, melanin and melanolipofuscin account for the majority of discordance between BL-AF and NI-AF. Given our finding of missed geographic atrophy lesions on BL-AF in 24% of eyes with geographic atrophy (7/29 eyes), clinicians should consider multimodal imaging, including NI-AF and optical coherence tomography, especially in clinical trials of geographic atrophy.
Heiferman, Michael J.; Fawzi, Amani A.
2016-01-01
Purpose To identify the origin and significance of discordance between blue-light autofluorescence (BL-AF; 488nm) and near-infrared autofluorescence (NI-AF; 787nm) in patients with age-related macular degeneration (AMD). Methods A total of 86 eyes of 59 patients with a diagnosis of AMD were included in this cross-sectional study conducted between March 9, 2015 and May 1, 2015. A masked observer examined the BL-AF, NI-AF, and spectral-domain optical coherence tomography (OCT) images. Areas with discordance of autofluorescence patterns between NI-AF and BL-AF images were correlated with structural findings at the corresponding location in OCT scans. Results 79 eyes had discordance between BL-AF and NI-AF. The most common OCT finding accounting for these discrepancies was pigment migration accounting for 35 lesions in 21 eyes. The most clinically relevant finding was geographic atrophy missed on BL-AF in seven eyes. Conclusions Our findings indicate that variations in the distribution of lipofuscin, melanin and melanolipofuscin account for the majority of discordance between BL-AF and NI-AF. Given our finding of missed geographic atrophy lesions on BL-AF in 24% of eyes with geographic atrophy (7/29 eyes), clinicians should consider multimodal imaging, including NI-AF and OCT, especially in clinical trials of geographic atrophy. PMID:28005672
Hong, Sung-Ryong; Na, Wonshik; Kang, Jang-Mook
2010-01-01
This study suggests an approach to effective transmission of multimedia content in a rapidly changing Internet environment including smart-phones. Guaranteeing QoS in networks is currently an important research topic. When transmitting Assured Forwarding (AF) packets in a Multi-DiffServ network environment, network A may assign priority in an order AF1, AF2, AF3 and AF4; on the other hand, network B may reverse the order to a priority AF4, AF3, AF2 and AF1. In this case, the AF1 packets that received the best quality of service in network A will receive the lowest in network B, which may result in dropping of packets in network B and vice versa. This study suggests a way to guarantee QoS between hosts by minimizing the loss of AF packet class when one network transmits AF class packets to another network with differing principles. It is expected that QoS guarantees and their experimental value may be utilized as principles which can be applied to various mobile-web environments based on smart-phones.
Hong, Sung-Ryong; Na, Wonshik; Kang, Jang-Mook
2010-01-01
This study suggests an approach to effective transmission of multimedia content in a rapidly changing Internet environment including smart-phones. Guaranteeing QoS in networks is currently an important research topic. When transmitting Assured Forwarding (AF) packets in a Multi-DiffServ network environment, network A may assign priority in an order AF1, AF2, AF3 and AF4; on the other hand, network B may reverse the order to a priority AF4, AF3, AF2 and AF1. In this case, the AF1 packets that received the best quality of service in network A will receive the lowest in network B, which may result in dropping of packets in network B and vice versa. This study suggests a way to guarantee QoS between hosts by minimizing the loss of AF packet class when one network transmits AF class packets to another network with differing principles. It is expected that QoS guarantees and their experimental value may be utilized as principles which can be applied to various mobile-web environments based on smart-phones. PMID:22163453
Aschmann, André; Knechtle, Beat; Cribari, Marco; Rüst, Christoph Alexander; Onywera, Vincent; Rosemann, Thomas; Lepers, Romuald
2013-01-01
Background Endurance running performance of African (AF) and non-African (NAF) athletes is investigated, with better performances seen for Africans. To date, no study has compared the age of peak performance between AF and NAF runners. The present research is an analysis of the age and running performance of top AF and NAF athletes, using the hypothesis that AF athletes were younger and faster than NAF athletes. Methods Age and performance of male and female AF and NAF athletes in half-marathons and marathons held in Switzerland in 2000–2010 were investigated using single and multilevel hierarchical regression analyses. Results For half-marathons, male NAF runners were older than male AF runners (P = 0.02; NAF, 31.1 years ± 6.4 years versus AF, 26.2 years ± 4.9 years), and their running time was longer (P = 0.02; NAF, 65.3 minutes ± 1.7 minutes versus AF, 64.1 minutes ± 0.9 minutes). In marathons, differences between NAF and AF male runners in age (NAF, 33.0 years ± 4.8 years versus AF, 28.6 years ± 3.8 years; P < 0.01) and running time (NAF, 139.5 minutes ± 5.6 minutes versus AF, 133.3 minutes ± 2.7 minutes; P < 0.01) were more pronounced. There was no difference in age (NAF, 31.0 years ± 7.0 years versus AF, 26.7 years ± 6.0 years; P > 0.05) or running time (NAF, 75.0 minutes ± 3.7 minutes versus AF, 75.6 minutes ± 5.3 minutes; P > 0.05) between NAF and AF female half-marathoners. For marathoners, NAF women were older than AF female runners (P = 0.03; NAF, 31.6 years ± 4.8 years versus AF, 27.8 years ± 5.3 years), but their running times were similar (NAF, 162.4 minutes ± 7.2 minutes versus AF, 163.0 minutes ± 7.0 minutes; P > 0.05). Conclusion In Switzerland, the best AF male half-marathoners and marathoners were younger and faster than the NAF counterpart runners. In contrast to the results seen in men, AF and NAF female runners had similar performances. Future studies need to investigate performance and age of AF and NAF marathoners in the World Marathon Majors Series. PMID:24379724
Arao, Yukitomo; Hamilton, Katherine J.; Coons, Laurel A.; Korach, Kenneth S.
2013-01-01
A ligand-dependent nuclear transcription factor, ERα has two transactivating functional domains (AF), AF-1 and AF-2. AF-1 is localized in the N-terminal region, and AF-2 is distributed in the C-terminal ligand-binding domain (LBD) of the ERα protein. Helix 12 (H12) in the LBD is a component of the AF-2, and the configuration of H12 is ligand-inducible to an active or inactive form. We demonstrated previously that the ERα mutant (AF2ER) possessing L543A,L544A mutations in H12 disrupts AF-2 function and reverses antagonists such as fulvestrant/ICI182780 (ICI) or 4-hydoxytamoxifen (OHT) into agonists in the AF2ER knock-in mouse. Our previous in vitro studies suggested that the mode of AF2ER activation is similar to the partial agonist activity of OHT for WT-ERα. However, it is still unclear how antagonists activate ERα. To understand the molecular mechanism of antagonist reversal activity, we analyzed the correlation between the ICI-dependent estrogen-responsive element-mediated transcription activity of AF2ER and AF2ER-LBD dimerization activity. We report here that ICI-dependent AF2ER activation correlated with the activity of AF2ER-LBD homodimerization. Prevention of dimerization impaired the ICI-dependent ERE binding and transcription activity of AF2ER. The dislocation of H12 caused ICI-dependent LBD homodimerization involving the F-domain, the adjoining region of H12. Furthermore, F-domain truncation also strongly depressed the dimerization of WT-ERα-LBD with antagonists but not with E2. AF2ER activation levels with ICI, OHT, and raloxifene were parallel with the degree of AF2ER-LBD homodimerization, supporting a mechanism that antagonist-dependent LBD homodimerization involving the F-domain results in antagonist reversal activity of H12-mutated ERα. PMID:23733188
Stroke event rates in anticoagulated patients with paroxysmal atrial fibrillation.
Lip, G Y H; Frison, L; Grind, M
2008-07-01
To test the hypothesis that stroke and systemic embolic events (SEE) in the stroke prevention using an oral thrombin inhibitor in atrial fibrillation (SPORTIF) III and V trials are different between paroxysmal and persistent atrial fibrillation (AF). Data analysis from two cohorts of patients enrolled in the prospective SPORTIF III and V clinical trials (n = 7329); 836 subjects (11.4%) with paroxysmal AF [mean age 70.1 years (SD = 9.5)] were compared with 6493 subjects with persistent AF for this ancillary study. The annual event rates for stroke/SEE are 1.73% for persistent AF and 0.93% for paroxysmal AF. In a multivariate analysis, after adjusting for stroke risk factors, gender and aspirin usage, the differences remained statistically significant with a higher hazard ratio (HR) for stroke/SEE in persistent AF [vs. paroxysmal AF, HR 1.87, 95% confidence interval (CI) 1.04-3.36; P = 0.037]. In 'high risk' patients (with >or=2 stroke risk factors) annual event rates for stroke/SEE were 2.08% for persistent AF and 1.27% for paroxysmal AF (adjusted HR = 1.68, 95% CI 0.91-3.1, P = 0.098). Elderly patients had annual event rates for stroke/SEE of 2.38% for persistent AF and 1.13% for paroxysmal AF (adjusted HR = 2.27, 95% CI 0.92-5.59, P = 0.075). Vitamin K antagonist (VKA)-naive paroxysmal AF patients had a 1.89%/year stroke/SEE rate, compared with 0.61% for previous VKA takers (HR = 0.33, 95% CI 0.11-1.01, P = 0.052). In this large clinical trial cohort of anticoagulated AF patients, those with paroxysmal AF had stroke rates which were lower than for patients with persistent AF, although both groups had broadly similar stroke risk factors. Subjects with paroxysmal AF at 'high risk' had stroke/SEE rates that were not significantly different to persistent AF subjects.
Kochhäuser, Simon; Jiang, Chen-Yang; Betts, Timothy R; Chen, Jian; Deisenhofer, Isabel; Mantovan, Roberto; Macle, Laurent; Morillo, Carlos A; Haverkamp, Wilhelm; Weerasooriya, Rukshen; Albenque, Jean-Paul; Nardi, Stefano; Menardi, Endrj; Novak, Paul; Sanders, Prashanthan; Verma, Atul
2017-04-01
Controversy exists about the impact of acute atrial fibrillation (AF) termination and prolongation of atrial fibrillation cycle length (AFCL) during ablation on long-term procedural outcome. The purpose of this study was to analyze the influence of AF termination and AFCL prolongation on freedom from AF in patients from the STAR AF II (Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Trial-Part II) trial. Acute changes in AFCL and AF termination were collected during the index procedure of the STAR AF II trial and compared to recurrence of AF at 18 months. Recurrence was assessed by ECG, Holter (3, 6, 9, 12, 18 months), and weekly transtelephonic ECG monitoring for 18 months. AF terminated in 8% of the pulmonary vein isolation (PVI) arm, 45% in the PVI+complex electrogram arm, and 22% of the PVI+linear ablation arm (P <.001), but freedom from AF did not differ among the 3 groups (P = .15). Freedom from AF was significantly higher in patients who presented to the laboratory in sinus rhythm (SR) compared to those without AF termination (63% vs 44%, P = .007). Patients with AF termination had an intermediate outcome (53%) that was not significantly different from those in SR (P = .84) or those who did not terminate (P = .08). AF termination was a univariable predictor of success (P = .007), but by multivariable analysis, presence of early SR was the strongest predictor of success (hazard ratio 0.67, P = .004). Prolongation of AFCL was not predictive of 18-month freedom from AF. Acute AF termination and prolongation in AFCL did not consistently predict 18-month freedom from AF. Presence of SR before or early during the ablation was the strongest predictor of better outcome. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
ERIC Educational Resources Information Center
Bhanji, Zahra
2012-01-01
The purpose of this article is to explore Microsoft Corporation as a new international actor shaping educational reforms and practices. This study examines how the implementation of Microsoft's global Partners in Learning (PiL) program varied and was mediated by national politics and national institutional practices in two different contexts,…
The Effect of Group Logotherapy on Meaning in Life and Depression Levels of Iranian Students
ERIC Educational Resources Information Center
Robatmili, Somaye; Sohrabi, Faramarz; Shahrak, Mohammad Ali; Talepasand, Siavash; Nokani, Mostafa; Hasani, Mohaddese
2015-01-01
This paper identifies the effectiveness of group logotherapy in reducing depression and increasing meaning in life levels of university students in Iran. A randomized controlled trial was conducted with a pre- post- and follow-up test design. The instruments used were the "Purpose in Life" (PIL) test and the "Beck Depression…
Stroke as the Initial Manifestation of Atrial Fibrillation: The Framingham Heart Study.
Lubitz, Steven A; Yin, Xiaoyan; McManus, David D; Weng, Lu-Chen; Aparicio, Hugo J; Walkey, Allan J; Rafael Romero, Jose; Kase, Carlos S; Ellinor, Patrick T; Wolf, Philip A; Seshadri, Sudha; Benjamin, Emelia J
2017-02-01
To prevent strokes that may occur as the first manifestation of atrial fibrillation (AF), screening programs have been proposed to identify patients with undiagnosed AF who may be eligible for treatment with anticoagulation. However, the frequency with which patients with AF present with stroke as the initial manifestation of the arrhythmia is unknown. We estimated the frequency with which AF may present as a stroke in 1809 community-based Framingham Heart Study participants with first-detected AF and without previous strokes, by tabulating the frequencies of strokes occurring on the same day, within 30 days before, 90 days before, and 365 days before first-detected AF. Using previously reported AF incidence rates, we estimated the incidence of strokes that may represent the initial manifestation of AF. We observed 87 strokes that occurred ≤1 year before AF detection, corresponding to 1.7% on the same day, 3.4% within 30 days before, 3.7% within 90 days before, and 4.8% ≤1 year before AF detection. We estimated that strokes may present as the initial manifestation of AF at a rate of 2 to 5 per 10 000 person-years, in both men and women. We observed that stroke is an uncommon but measureable presenting feature of AF. Our data imply that emphasizing cost-effectiveness of population-wide AF-screening efforts will be important given the relative infrequency with which stroke represents the initial manifestation of AF. © 2017 American Heart Association, Inc.
Singh, Sheldon M; d'Avila, Andre; Kim, Young-Hoon; Aryana, Arash; Mangrum, J Michael; Michaud, Gregory F; Dukkipati, Srinivas R; Barrett, Conor D; Heist, E Kevin; Parides, Michael K; Thorpe, Kevin E; Reddy, Vivek Y
2017-10-01
Controversy on the optimal ablation strategy for persistent atrial fibrillation (AF) exists with limited work evaluating a strategy of pulmonary vein isolation (PVI) alone when AF terminates during PVI. Thirty-five patients had AF termination during PVI in the Modified Ablation Guided by Ibutilide Use in Chronic Atrial Fibrillation (MAGIC-AF; ClinicalTrials.gov number: NCT01014741) study. The objective of the current study is to report the 1-year outcome after PVI alone in this unique patient group. The 1-year single procedure freedom from atrial arrhythmia off anti-arrhythmic drugs was reported for the 35 patients in the MAGIC-AF study with persistent AF termination during or upon completion of PVI. Freedom from recurrent atrial arrhythmia was achieved in 60% of patients where AF terminated during PVI. Cavotricuspid isthmus flutter was common when AF terminated to a macro re-entrant flutter during PVI, and responsible for 92% of all flutter circuits with AF termination. Persistent AF termination during PVI may identify a subgroup of patients who experience a similar long-term clinical outcome with PVI ablation alone when compared with other more extensive persistent AF ablation strategies. Pulmonary vein isolation alone may be an appropriate tactic in this subgroup of persistent AF patients. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.
Uyar, A; Yener, Z; Dogan, A
2016-04-01
The ameliorative potential and antioxidant capacity of an extract of Urtica dioica seeds (UDS) was investigated using histopathological changes in liver and kidney, measuring serum marker enzymes, antioxidant defence systems and lipid peroxidation (malondialdehyde (MDA)) content in various tissues of broilers exposed to aflatoxin (AF). A total of 32 broilers were divided randomly into 4 groups: control, UDS extract-treated, AF-treated and AF+UDS extract-treated. Broilers in control and UDS extract-treated groups were fed on a diet without AF. The AF-treated group and AF+UDS extract-treated groups were treated with an estimated 1 mg total AF/kg feed. The AF+UDS extract groups received in addition 30 ml UDS extract/kg diet for 21 d. The AF-treated group had significantly decreased body weight gain when compared to the other groups. Biochemical analysis showed a small increase in the concentrations of serum aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transpeptidase and lactate dehydrogenase in the AF-treated group compared to that of the control group, whereas concentrations of these enzymes were decreased in the AF+UDS group compared to that of the AF-treated group. Administration of supplementary UDS extract helped restore the AF-induced increase in MDA and reduced the antioxidant system towards normality, particularly in the liver, brain, kidney and heart. Hepatorenal protection by UDS extracts was further supported by the almost normal histology in AF+UDS extract-treated group as compared to the degenerative changes in the AF-treated broilers. It was concluded that UDS extract has a protective hepatorenal effect in broilers affected by aflatoxicosis, probably acting by promoting the antioxidative defence systems.
Guimarães, Patrícia O; Wojdyla, Daniel M; Alexander, John H; Thomas, Laine; Alings, Marco; Flaker, Greg C; Al-Khatib, Sana M; Hanna, Michael; Horowitz, John D; Wallentin, Lars; Granger, Christopher B; Lopes, Renato D
2017-01-15
Evidence supporting use of antithrombotic therapy in atrial fibrillation (AF) is based mainly on data from patients with permanent, persistent, or paroxysmal AF. Less is known about the risk following a new diagnosis of AF and the efficacy and safety of apixaban in these patients. Using data from ARISTOTLE, we assessed the relationship between timing of AF diagnosis and clinical outcomes and the efficacy and safety of apixaban versus warfarin in these patients. Recently diagnosed AF was defined as a new diagnosis of AF within 30days prior to enrollment. Cox proportional hazards models were used to determine the association between recently diagnosed AF and clinical outcomes. We also assessed the efficacy and safety of apixaban versus warfarin according to time since AF diagnosis. In ARISTOTLE, 1899 (10.5%) patients had recently diagnosed AF. After adjustment, patients with recently versus remotely diagnosed AF had a similar risk of stroke/systemic embolism (HR=1.07, 95% CI=0.80-1.42; p=0.67), but higher mortality was seen in patients with recently diagnosed AF (adjusted HR=1.21, 95% CI=1.02-1.43; p=0.03). The beneficial effects of apixaban, compared with warfarin, on clinical outcomes were consistent, irrespective of timing of AF diagnosis (all interaction p-values >0.12). Patients with recently diagnosed AF had a similar risk of stroke but higher mortality than patients with remotely diagnosed AF, suggesting that they are not at "low risk" and warrant stroke prevention strategies. The benefits of apixaban over warfarin were preserved, irrespective of timing of AF diagnosis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Hart, R G; Pearce, L A; Rothbart, R M; McAnulty, J H; Asinger, R W; Halperin, J L
2000-01-01
This study was performed to characterize the risk of stroke in elderly patients with recurrent intermittent atrial fibrillation (AF). Although intermittent AF is common, relatively little is known about the attendant risk of stroke. A longitudinal cohort study was performed comparing 460 participants with intermittent AF with 1,552 with sustained AF treated with aspirin in the Stroke Prevention in Atrial Fibrillation studies and followed for a mean of two years. Independent risk factors for ischemic stroke were identified by multivariate analysis. Patients with intermittent AF were, on average, younger (66 vs. 70 years, p < 0.001), were more often women (37% vs. 26% p < 0.001) and less often had heart failure (11% vs. 21%, p < 0.001) than those with sustained AF. The annualized rate of ischemic stroke was similar for those with intermittent (3.2%) and sustained AF (3.3%). In patients with intermittent AF, independent predictors of ischemic stroke were advancing age (relative risk [RR] = 2.1 per decade, p < 0.001), hypertension (RR = 3.4, p = 0.003) and prior stroke (RR = 4.1, p = 0.01). Of those with intermittent AF predicted to be high risk (24%), the observed stroke rate was 7.8% per year (95% confidence interval 4.5 to 14). In this large cohort of AF patients given aspirin, those with intermittent AF had stroke rates similar to patients with sustained AF and similar stroke risk factors. Many elderly patients with recurrent intermittent AF have substantial rates of stroke and likely benefit from anticoagulation. High-risk patients with intermittent AF can be identified using the same clinical criteria that apply to patients with sustained AF.
Clinical predictors of risk for atrial fibrillation: implications for diagnosis and monitoring.
Brunner, Kyle J; Bunch, T Jared; Mullin, Christopher M; May, Heidi T; Bair, Tami L; Elliot, David W; Anderson, Jeffrey L; Mahapatra, Srijoy
2014-11-01
To create a risk score using clinical factors to determine whom to screen and monitor for atrial fibrillation (AF). The AF risk score was developed based on the summed odds ratios (ORs) for AF development of 7 accepted clinical risk factors. The AF risk score is intended to assess the risk of AF similar to how the CHA2DS2-VASc score assesses stroke risk. Seven validated risk factors for AF were used to develop the AF risk score: age, coronary artery disease, diabetes mellitus, sex, heart failure, hypertension, and valvular disease. The AF risk score was tested within a random population sample of the Intermountain Healthcare outpatient database. Outcomes were stratified by AF risk score for OR and Kaplan-Meier analysis. A total of 100,000 patient records with an index follow-up from January 1, 2002, through December 31, 2007, were selected and followed up for the development of AF through the time of this analysis, May 13, 2013, through September 6, 2013. Mean ± SD follow-up time was 3106±819 days. The ORs of subsequent AF diagnosis of patients with AF risk scores of 1, 2, 3, 4, and 5 or higher were 3.05, 12.9, 22.8, 34.0, and 48.0, respectively. The area under the curve statistic for the AF risk score was 0.812 (95% CI, 0.805-0.820). We developed a simple AF risk score made up of common clinical factors that may be useful to possibly select patients for long-term monitoring for AF detection. Copyright © 2014 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.
Zhao, Fei; Zhang, Shijiang; Shao, Yongfeng; Wu, Yanhu; Qin, Jianwei; Chen, Yijiang; Chen, Liang; Gu, Haitao; Wang, Xiaowei; Huang, Chenjun; Zhang, Wei
2013-10-03
The aim of this study was to determine whether altered calreticulin expression and distribution contribute to the pathogenesis of atrial fibrillation (AF) associated with valvular heart disease (VHD). AF affects electrophysiological and structural changes that exacerbate AF. Atrial remodeling reportedly underlies AF generation, but the precise mechanism of atrial remodeling in AF remains unclear. Right and left atrial specimens were obtained from 68 patients undergoing valve replacement surgery. The patients were divided into sinus rhythm (SR; n=25), paroxysmal AF (PaAF; n=11), and persistent AF (PeAF; AF lasting >6 months; n=32) groups. Calreticulin, integrin-α5, and transforming growth factor-β1 (TGF-β1) mRNA and protein expression were measured. We also performed immunoprecipitation for calreticulin with either calcineurin B or integrin-α5. Calreticulin, integrin-α5, and TGF-β1 mRNA and protein expression were increased in the AF groups, especially in the left atrium in patients with mitral valve disease. Calreticulin interacted with both calcineurin B and integrin-α5. Integrin-α5 expression correlated with TGF-β1 expression, while calreticulin expression correlated with integrin-α5 and TGF-β1 expression. Despite similar cardiac function classifications, calreticulin expression was greater in the PeAF group than in the SR group. Calreticulin, integrin-α5, and TGF-β1 expression was increased in atrial tissue in patients with AF and was related to AF type, suggesting that calreticulin is involved in the pathogenesis of AF in VHD patients. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
Targeting Stable Rotors to Treat Atrial Fibrillation.
Narayan, Sanjiv M; Krummen, David E
2012-09-01
Therapy for atrial fibrillation (AF) remains suboptimal, in large part because its mechanisms are unclear. While pulmonary vein ectopy may trigger AF, it remains uncertain how AF, once triggered, is actually sustained. Recent discoveries show that human AF is maintained by a small number of rotors or focal sources. AF sources are widely distributed in patient-specific locations, often remote from pulmonary veins and in the right atrium and stable for prolonged periods of time. In a multicentre experience, brief targeted ablation at sources (focal impulse and rotor modulation [FIRM]) terminated AF predominantly to sinus rhythm prior to pulmonary vein isolation and eliminated AF on rigorous followup. This review summarises the evidence for stable rotors and focal sources of human AF and their clinical role as ablation targets to eliminate paroxysmal, persistent and long-standing persistent AF.
Obstructive Sleep Apnoea and Atrial Fibrillation
Zhang, Ling; Hou, Yuemei; Po, Sunny S
2015-01-01
Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia and is associated with significant morbidity and mortality. Obstructive sleep apnoea (OSA) is common among patients with AF. Growing evidence suggests that OSA is associated with the initiation and maintenance of AF. This association is independent of obesity, body mass index and hypertension. OSA not only promotes initiation of AF but also has a significant negative impact on the treatment of AF. Patients with untreated OSA have a higher AF recurrence rate with drug therapy, electrical cardioversion and catheter ablation. Treatment with continuous positive airway pressure (CPAP) has been shown to improve AF control in patients with OSA. In this article, we will review and discuss the pathophysiological mechanisms of OSA that may predispose OSA patients to AF as well as the standard and emerging therapies for patients with both OSA and AF. PMID:26835094
Genetic Risk Prediction of Atrial Fibrillation
Lubitz, Steven A.; Yin, Xiaoyan; Lin, Henry J.; Kolek, Matthew; Smith, J. Gustav; Trompet, Stella; Rienstra, Michiel; Rost, Natalia S.; Teixeira, Pedro L.; Almgren, Peter; Anderson, Christopher D.; Chen, Lin Y.; Engström, Gunnar; Ford, Ian; Furie, Karen L.; Guo, Xiuqing; Larson, Martin G.; Lunetta, Kathryn L.; Macfarlane, Peter W.; Psaty, Bruce M.; Soliman, Elsayed Z.; Sotoodehnia, Nona; Stott, David J.; Taylor, Kent D.; Weng, Lu-Chen; Yao, Jie; Geelhoed, Bastiaan; Verweij, Niek; Siland, Joylene E.; Kathiresan, Sekar; Roselli, Carolina; Roden, Dan; van der Harst, Pim; Darbar, Dawood; Jukema, J. Wouter; Melander, Olle; Rosand, Jonathan; Rotter, Jerome I.; Heckbert, Susan R.; Ellinor, Patrick T.; Alonso, Alvaro; Benjamin, Emelia J.
2017-01-01
Background Atrial fibrillation (AF) is common and has a substantial genetic basis. Identification of individuals at greatest AF risk could minimize the incidence of cardioembolic stroke. Methods To determine whether genetic data can stratify risk for development of AF, we examined associations between AF genetic risk scores and incident AF in five prospective studies comprising 18,919 individuals of European ancestry. We examined associations between AF genetic risk scores and ischemic stroke in a separate study of 509 ischemic stroke cases (202 cardioembolic [40%]) and 3,028 controls. Scores were based on 11 to 719 common variants (≥5%) associated with AF at P-values ranging from <1×10−3 to <1×10−8 in a prior independent genetic association study. Results Incident AF occurred in 1,032 (5.5%) individuals. AF genetic risk scores were associated with new-onset AF after adjusting for clinical risk factors. The pooled hazard ratio for incident AF for the highest versus lowest quartile of genetic risk scores ranged from 1.28 (719 variants; 95%CI, 1.13–1.46; P=1.5×10−4) to 1.67 (25 variants; 95%CI, 1.47–1.90; P=9.3×10−15). Discrimination of combined clinical and genetic risk scores varied across studies and scores (maximum C statistic, 0.629–0.811; maximum ΔC statistic from clinical score alone, 0.009–0.017). AF genetic risk was associated with stroke in age- and sex-adjusted models. For example, individuals in the highest quartile of a 127-variant score had a 2.49-fold increased odds of cardioembolic stroke, versus those in the lowest quartile (95%CI, 1.39–4.58; P=2.7×10−3). The effect persisted after excluding individuals (n=70) with known AF (odds ratio, 2.25; 95%CI, 1.20–4.40; P=0.01). Conclusions Comprehensive AF genetic risk scores were associated with incident AF beyond clinical AF risk factors, with magnitudes of risk comparable to other clinical risk factors, though offered small improvements in discrimination. AF genetic risk was also associated with cardioembolic stroke in age- and sex-adjusted analyses. Efforts to determine whether AF genetic risk may improve identification of subclinical AF or distinguish stroke mechanisms are warranted. PMID:27793994
Hengstenberg, Christian; Chandrasekhar, Jaya; Sartori, Samantha; Lefevre, Thierry; Mikhail, Ghada; Meneveau, Nicolas; Tron, Christophe; Jeger, Raban; Kupatt, Christian; Vogel, Birgit; Farhan, Serdar; Sorrentino, Sabato; Sharma, Madhav; Snyder, Clayton; Husser, Oliver; Boekstegers, Peter; Hambrecht, Rainer; Widder, Julian; Hildick-Smith, David; De Carlo, Marco; Wijngaard, Peter; Deliargyris, Efthymios; Bernstein, Debra; Baber, Usman; Mehran, Roxana; Anthopoulos, Prodromos; Dangas, George
2017-11-15
Prior studies have suggested that patients with atrial fibrillation (AF) undergoing transcatheter aortic valve replacement (TAVR) are at higher risk for adverse cardiovascular events. Whether procedural bivalirudin compared with unfractionated heparin (UFH) has a beneficial effect on early outcomes in these patients is unknown. We examined for the effect of baseline or new-onset AF within 30 days of TAVR and explored for the effect of bivalirudin versus UFH by AF status, on 30-day outcomes from the BRAVO 3 trial. The BRAVO-3 trial multicenter randomized trial included 802 patients undergoing transfemoral TAVR randomized to bivalirudin or UFH. We compared AF and no-AF groups and examined for 30-day Bleeding Academic Research Consortium type ≥3b bleeding, major vascular complications and all ischemic endpoints. Adjusted outcomes were analyzed using logistic regression methods. Of the study population, 41.4% (n = 332) patients had baseline or new-onset AF within 30 days of TAVR, whereas 58.6% (n = 470) had no AF. Patients with AF had greater prevalence of renal dysfunction, lower left ventricular ejection fraction, and higher euroSCORE I compared with their counterparts without AF. Among AF and no-AF patients, there were no significant baseline differences between bivalirudin and UFH groups. At 30 days the incidence of death (6.0 vs. 4.5%, P = 0.324) and stroke (3.9 vs. 2.6%, P = 0.274) was similar in AF vs. no-AF patients. However, new-onset AF (n = 38) was associated with significantly greater crude risk of 30-day stroke compared with no AF (HR 4.49, 95% CI 1.37-14.67). Regardless of AF status, there were no differences in 30-day death (P-int = 0.652) or stroke (P-int = 0.066) by anticoagulation type. Prior or new-onset AF is noted in more than one-third of patients undergoing transfemoral TAVR. Despite greater baseline comorbidities than non-AF patients, AF was not associated with significantly higher risk of adjusted 30-day outcomes. In the BRAVO 3 trial, early outcomes were similar regardless of anticoagulant strategy in each group. © 2017 Wiley Periodicals, Inc.
Ablating Atrial Fibrillation: Customizing Lesion Sets Guided by Rotor Mapping
Zaman, Junaid A. B.; Narayan, Sanjiv M.
2015-01-01
Ablation occupies an increasing role in the contemporary management of atrial fibrillation (AF), but results are suboptimal, particularly for persistent AF. While an anatomic approach to ablation is a highly efficacious and safe method to isolate pulmonary vein (PV) triggers, recurrence of AF is not always associated with PV reconnection, and there is compelling evidence that non-PV sites sustain AF after it is triggered. Recent developments in wide-area mapping and signal processing now identify rotors in the vast majority of AF patients that sustain AF and whose elimination improves long-term freedom from AF in multicenter studies. Investigators have now demonstrated rotor and focal sources for AF that show many analogous properties between approaches: they lie in spatially reproducible regions temporally over hours to days, and they are amenable to targeted ablation. This review outlines the rationale and technical developments supporting this mechanistic paradigm for human AF, and discusses how rotor mapping may be implemented for individual patient customization of lesion sets. Mechanistic studies are required to explain why rotor elimination (or other ablation approaches) producing long-term elimination of AF may not always terminate AF acutely, how AF correlates with structural changes on magnetic resonance imaging, and how these findings can be integrated clinically with current ablation strategies to improve patient outcomes. PMID:26306123
Zhao, Xinyu; Xia, Song; Chen, Youxin
2018-06-01
To investigate the characteristic appearances of fundus autofluorescence (FAF) in patients with treatment-naive and active polypoidal choroidal vasculopathy (PCV). Cases with the diagnosis of treatment-naive and active PCV from November 2012 to May 2017 at Peking Union Medical College Hospital were retrospectively reviewed. All patients underwent comprehensive ophthalmologic examination. Autofluorescence (AF) findings were described at the retinal sites of the corresponding lesions identified and diagnosed using indocyanine green angiography and spectral-domain optical coherence tomography. One hundred seventy patients with 192 affected eyes were included. The logMAR BCVA of the patients were 0.53 ± 0.28. The six AF patterns of 243 polypoidal lesions were confluent hypo-AF with hyper-AF ring (49.8%), confluent hypo-AF (22.6%), hyper-AF with hypo-AF ring (3.7%), granular hypo-AF (7.0%), blocked hypo-AF due to hemorrhage (8.6%), and polyps without apparent AF changes (8.2%). For 146 branching vascular networks (BVNs), 97.3% were granular hypo-AF, and others were blocked hypo-AF due to hemorrhage. In eyes with treatment-naive and active PCV, the polypoidal lesions and BVNs induce characteristic FAF changes. FAF images provide reliable adjunct reference for the diagnosis of PCV.
Ablating Atrial Fibrillation: Customizing Lesion Sets Guided by Rotor Mapping.
Zaman, Junaid A B; Narayan, Sanjiv M
2015-01-01
Ablation occupies an increasing role in the contemporary management of atrial fibrillation (AF), but results are suboptimal, particularly for persistent AF. While an anatomic approach to ablation is a highly efficacious and safe method to isolate pulmonary vein (PV) triggers, recurrence of AF is not always associated with PV reconnection, and there is compelling evidence that non-PV sites sustain AF after it is triggered. Recent developments in wide-area mapping and signal processing now identify rotors in the vast majority of AF patients that sustain AF and whose elimination improves long-term freedom from AF in multicenter studies. Investigators have now demonstrated rotor and focal sources for AF that show many analogous properties between approaches: they lie in spatially reproducible regions temporally over hours to days, and they are amenable to targeted ablation. This review outlines the rationale and technical developments supporting this mechanistic paradigm for human AF, and discusses how rotor mapping may be implemented for individual patient customization of lesion sets. Mechanistic studies are required to explain why rotor elimination (or other ablation approaches) producing long-term elimination of AF may not always terminate AF acutely, how AF correlates with structural changes on magnetic resonance imaging, and how these findings can be integrated clinically with current ablation strategies to improve patient outcomes.
Catalina, Purificación; Rodríguez, René; Melen, Gustavo J.; Bueno, Clara; Arriero, Mar; García-Sánchez, Félix; Lassaletta, Alvaro; García-Sanz, Ramón
2009-01-01
MLL-AF4 fusion is a hallmark genetic abnormality in infant B-acute lymphoblastic leukemia (B-ALL) known to arise in utero. The cellular origin of leukemic fusion genes during human development is difficult to ascertain. The bone marrow (BM) microenvironment plays an important role in the pathogenesis of several hematological malignances. BM mesenchymal stem cells (BM-MSC) from 38 children diagnosed with cytogenetically different acute leukemias were screened for leukemic fusion genes. Fusion genes were absent in BM-MSCs of childhood leukemias carrying TEL-AML1, BCR-ABL, AML1-ETO, MLL-AF9, MLL-AF10, MLL-ENL or hyperdiploidy. However, MLL-AF4 was detected and expressed in BM-MSCs from all cases of MLL-AF4+ B-ALL. Unlike leukemic blasts, MLL-AF4+ BM-MSCs did not display monoclonal Ig gene rearrangements. Endogenous or ectopic expression of MLL-AF4 exerted no effect on MSC culture homeostasis. These findings suggest that MSCs may be in part tumor-related, highlighting an unrecognized role of the BM milieu on the pathogenesis of MLL-AF4+ B-ALL. MLL-AF4 itself is not sufficient for MSC transformation and the expression of MLL-AF4 in MSCs is compatible with a mesenchymal phenotype, suggesting a differential impact in the hematopoietic system and mesenchyme. The absence of monoclonal rearrangements in MLL-AF4+ BM-MSCs precludes the possibility of cellular plasticity or de-differentiation of B-ALL blasts and suggests that MLL-AF4 might arise in a population of prehematopoietic precursors. PMID:19995953
Perez, Marco V; Hoffmann, Thomas J; Tang, Hua; Thornton, Timothy; Stefanick, Marcia L; Larson, Joseph C; Kooperberg, Charles; Reiner, Alex P; Caan, Bette; Iribarren, Carlos; Risch, Neil
2013-09-01
Atrial fibrillation (AF) is the most common arrhythmia in women and is associated with higher rates of stroke and death. Rates of AF are lower in African American subjects compared with European Americans, suggesting European ancestry could contribute to AF risk. The Women's Health Initiative (WHI) Observational Study (OS) followed up 93,676 women since the mid 1990s for various cardiovascular outcomes including AF. Multivariate Cox hazard regression analysis was used to measure the association between African American race and incident AF. A total of 8,119 African American women from the WHI randomized clinical trials and OS were genotyped on the Affymetrix Human SNP Array 6.0. Genome-wide ancestry and previously reported single nucleotide polymorphisms associated with AF in European cohorts were tested for association with AF using multivariate logistic regression analyses. Self-reported African American race was associated with lower rates of AF (hazard ratio 0.43, 95% CI 0.32-0.60) in the OS, independent of demographic and clinical risk factors. In the genotyped cohort, there were 558 women with AF. By contrast, genome-wide European ancestry was not associated with AF. None of the single nucleotide polymorphisms previously associated with AF in European populations, including rs2200733, were associated with AF in the WHI African American cohort. African American race is significantly and inversely correlated with AF in postmenopausal women. The etiology of this association remains unclear and may be related to unidentified environmental differences. Larger studies are necessary to identify genetic determinants of AF in African Americans. © 2013.
Depression and Physical Inactivity as Confounding the Effect of Obesity on Atrial Fibrillation.
Garimella, Roja S; Sears, Samuel F; Gehi, Anil K
2016-06-01
Obesity is associated with an increased likelihood for the development of atrial fibrillation (AF) and with worsened AF symptom severity. However, other factors that are correlated with obesity may confound or mediate the relation of obesity with AF symptom severity. The purpose of this study was to determine if depression and physical inactivity may confound the association of obesity and AF symptom severity. Health status and demographic data were captured by questionnaire for 332 outpatients with documented AF. Weight/height was measured and body mass index (kg/m(2)) calculated. Recent depression symptom severity was assessed using the Patient Health Questionnaire-9 questionnaire. Physical activity during the last month was assessed by questionnaire. AF symptom severity was assessed using the University of Toronto AF Severity scale. Multivariate linear regression was used to evaluate which factors were associated with AF symptom severity. Obesity in patients with AF is associated with increased depression severity. In bivariate analysis, increasing body mass index (p = 0.001), lower levels of physical activity (p <0.001), and more severe depression (p <0.001) were associated with worsened AF symptom severity. In multivariate analysis, only physical activity and depression persisted as significant predictors of AF symptom severity. In conclusion, although obesity likely contributes to the substrate predisposing to the development of AF, other factors may contribute to or mediate the worsened AF symptoms associated with obesity. Depression symptoms and physical inactivity, factors closely correlated with obesity, may exacerbate symptoms in patients with AF. Copyright © 2016 Elsevier Inc. All rights reserved.
Incidence, type of atrial fibrillation and risk factors for stroke: a population-based cohort study
Johansson, Cecilia; Dahlqvist, Erik; Andersson, Jonas; Jansson, Jan-Håkan; Johansson, Lars
2017-01-01
Purpose The aims of this study were to estimate the incidence of atrial fibrillation and atrial flutter (AF), to assess the presence of provoking factors and risk factors for stroke and systemic embolism, and to determine the type of AF in patients with first-diagnosed AF. Patients and methods This cohort study was performed in northern Sweden between January 1, 2011 and December 31, 2012. Diagnosis registries were searched for the International Classification of Diseases-10 code for AF (I48) to identify cases of incident AF. All AF diagnoses were electrocardiogram-verified. Data pertaining to provoking factors, type of AF and presence of risk factors for stroke and systemic embolism according to the CHA2DS2-VASc score were obtained from medical records. Results The incidence of AF in the entire population was 4.0 per 1,000 person-years. The incidence was 27.5 per 1,000 person-years in patients aged ≥80 years. A total of 21% of all patients had a provoking factor in association with the first-diagnosed episode of AF. The CHA2DS2-VASc score was 2 or higher in 81% of the patients. Permanent AF was the most common type of AF (29%). Conclusion There was a considerable increase in the incidence of AF with age, and a provoking factor was found in one-fifth. The most common type of AF was permanent AF. Four in five patients had a CHA2DS2-VASc score of 2 or more. PMID:28182159
Refinement of detecting atrial fibrillation in stroke patients: results from the TRACK-AF Study.
Reinke, F; Bettin, M; Ross, L S; Kochhäuser, S; Kleffner, I; Ritter, M; Minnerup, J; Dechering, D; Eckardt, L; Dittrich, R
2018-04-01
Detection of occult atrial fibrillation (AF) is crucial for optimal secondary prevention in stroke patients. The AF detection rate was determined by implantable cardiac monitor (ICM) and compared to the prediction rate of the probability of incident AF by software based analysis of a continuously monitored electrocardiogram at follow-up (stroke risk analysis, SRA); an optimized AF detection algorithm is proposed by combining both tools. In a monocentric prospective study 105 out of 389 patients with cryptogenic stroke despite extensive diagnostic workup were investigated with two additional cardiac monitoring tools: (a) 20 months' monitoring by ICM and (b) SRA during hospitalization at the stroke unit. The detection rate of occult AF was 18% by ICM (n = 19) (range 6-575 days) and 62% (n = 65) had an increased risk for AF predicted by SRA. When comparing the predictive accuracy of SRA to ICM, the sensitivity was 95%, specificity 35%, positive predictive value 27% and negative predictive value 96%. In 18 patients with AF detected by ICM, SRA also showed a medium risk for AF. Only one patient with a very low risk predicted by SRA developed AF revealed by ICM after 417 days. A combination of SRA and ICM is a promising strategy to detect occult AF. SRA is reliable in predicting incident AF with a high negative predictive value. Thus, SRA may serve as a cost-effective pre-selection tool identifying patients at risk for AF who may benefit from further cardiac monitoring by ICM. © 2017 EAN.
Potpara, Tatjana S; Lip, Gregory Y H
2015-01-01
Ever since the original description of a 'peculiar pulse irregularity', atrial fibrillation (AF) has been studied extensively and has come a long journey from the recognition of its cardiac origins, to the modern concept of AF as a serious public health challenge with profound social and economic implications. This arrhythmia affects around 2% of adult population, and the most common underlying heart diseases accompanying AF in the modern era are hypertension, heart failure and coronary artery disease, as well as valvular heart diseases and numerous other cardiac as well as non-cardiac disorders which have been shown to predispose to AF. On occasions, AF occurs in young otherwise apparently healthy individuals (so called 'lone AF'). For a long time, 'lone' AF has been believed to bear a favourable prognosis as compared to AF with underlying structural heart disease, but increasing evidence suggests that 'lone' AF patients represent a rather heterogeneous cohort, with highly variable individual risk profiles due to the presence of various subclinical cardiovascular risk factors or genetically determined subtle alterations at the cellular or molecular level. For these reasons, the existence of truly 'lone' AF has recently been questioned. In this review article, we present a brief history of the recognition of the public health burden of AF. We discuss some of the misconceptions and breakthroughs on modern knowledge on AF, including the rise (and fall) of the 'lone' AF concept.
Mechanics of oriented electrospun nanofibrous scaffolds for annulus fibrosus tissue engineering.
Nerurkar, Nandan L; Elliott, Dawn M; Mauck, Robert L
2007-08-01
Engineering a functional replacement for the annulus fibrosus (AF) of the intervertebral disc is contingent upon recapitulation of AF structure, composition, and mechanical properties. In this study, we propose a new paradigm for AF tissue engineering that focuses on the reconstitution of anatomic fiber architecture and uses constitutive modeling to evaluate construct function. A modified electrospinning technique was utilized to generate aligned nanofibrous polymer scaffolds for engineering the basic functional unit of the AF, a single lamella. Scaffolds were tested in uniaxial tension at multiple fiber orientations, demonstrating a nonlinear dependence of modulus on fiber angle that mimicked the nonlinearity and anisotropy of native AF. A homogenization model previously applied to native AF successfully described scaffold mechanical response, and parametric studies demonstrated that nonfibrillar matrix, along with fiber connectivity, are key contributors to tensile mechanics for engineered AF. We demonstrated that AF cells orient themselves along the aligned scaffolds and deposit matrix that contributes to construct mechanics under loading conditions relevant to the in vivo environment. The homogenization model was applied to cell-seeded constructs and provided quantitative measures for the evolution of matrix and interfibrillar interactions. Finally, the model demonstrated that at fiber angles of the AF (28 degrees -44 degrees ), engineered material behaved much like native tissue, suggesting that engineered constructs replicate the physiologic behavior of the single AF lamella. Constitutive modeling provides a powerful tool for analysis of engineered AF neo-tissue and native AF tissue alike, highlighting key mechanical design criteria for functional AF tissue engineering.
Omboni, Stefano; Verberk, Willem J
2016-04-12
Timely detection of atrial fibrillation (AF) may effectively prevent cardiovascular consequences. However, traditional diagnostic tools are either poorly reliable (pulse palpation) or not readily accessible (ECG) in general practice. We tested whether an automatic oscillometric blood pressure (BP) monitor embedded with an algorithm for AF detection might be effective for opportunistic screening of asymptomatic AF in the community. A community-based screening campaign in an unselected population to verify the feasibility of AF screening with a Microlife WatchBP Office BP monitor with a patented AFIB algorithm. When possible AF was detected (≥2 of 3 BP measurements reporting AF), a doctor immediately performed a single-lead ECG in order to confirm or exclude the presence of the arrhythmia. The main demographic and clinical data were also collected. 220 consecutive participants from an unselected sample of individuals in a small Italian community. Number of patients detected with AF and diagnosed risk factors for AF. In 12 of 220 participants, the device detected possible AF during the BP measurement: in 4 of them (1.8%), the arrhythmia was confirmed by the ECG. Patients with AF were more likely to be older (77.0±1.2 vs 57.2±15.2 years, p=0.010), obese (50.0 vs 14.4%, p=0.048) and to suffer from a cardiovascular disease (50.0 vs 10.6%, p=0.014) than patients without AF. Participants with a positive BP AF reading and non-AF arrhythmias (n=8) did not differ in their general characteristics from participants with a negative BP AF reading and were younger than patients with AF (mean age 56.4±14.8, p=0.027; 5 of 8 participants aged <65 years). Opportunistic screening of AF by BP measurement is feasible to diagnose this arrhythmia in unaware participants, particularly in those older than 65 years, who are the target patient group recommended by current AF screening guidelines. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Zhong, Wei; Li, Qiong; Sun, Qian; Zhang, Wenliang; Zhang, Jiayang; Sun, Xinguo; Yin, Xinmin; Zhang, Xiang; Zhou, Zhanxiang
2015-01-01
Background: Zinc deficiency has been well documented in alcoholic liver disease. Objective: This study was undertaken to determine whether dietary zinc supplementation provides beneficial effects in treating alcohol-induced gut leakiness and endotoxemia. Methods: Male Sprague Dawley rats were divided into 3 groups and pair-fed (PF) Lieber-DeCarli liquid diet for 8 wk: 1) control (PF); 2) alcohol-fed (AF; 5.00–5.42% wt:vol ethanol); and 3) AF with zinc supplementation (AF/Zn) at 220 ppm zinc sulfate heptahydrate. The PF and AF/Zn groups were pair-fed with the AF group. Hepatic inflammation and endotoxin signaling were determined by immunofluorescence and quantitative polymerase chain reaction (qPCR). Alterations in intestinal tight junctions and aldehyde dehydrogenases were assessed by qPCR and Western blot analysis. Results: The AF rats had greater macrophage activation and cytokine production (P < 0.05) in the liver compared with the PF rats, whereas the AF/Zn rats showed no significant differences (P > 0.05). Plasma endotoxin concentrations of the AF rats were 136% greater than those of the PF rats, whereas the AF/Zn rats did not differ from the PF rats. Ileal permeability was 255% greater in the AF rats and 19% greater in the AF/Zn rats than in the PF rats. The AF group had reduced intestinal claudin-1, occludin, and zona occludens-1 (ZO-1) expression, and the AF/Zn group had upregulated claudin-1 and ZO-1 expression (P < 0.05) compared with the PF group. The intestinal epithelial expression and activity of aldehyde dehydrogenases were elevated (P < 0.05) in the AF/Zn rats compared with those of the AF rats. Furthermore, the ileal expression and function of hepatocyte nuclear factor 4α, which was impaired in the AF group, was significantly elevated in the AF/Zn group compared with the PF group. Conclusions: The results demonstrate that attenuating hepatic endotoxin signaling by preserving the intestinal barrier contributes to the protective effect of zinc on alcohol-induced steatohepatitis in rats. PMID:26468492
Veasey, Rick A; Segal, Oliver R; Large, Janet K; Lewis, Michael E; Trivedi, Uday H; Cohen, Andrew S; Hyde, Jonathan A J; Sulke, A Neil
2011-10-01
Studies assessing radiofrequency ablation (RFA) for atrial fibrillation (AF) performed at the time of concomitant cardiac surgery have reported high success rates. The efficacy of this treatment has primarily been determined by a single electrocardiogram (ECG) or 24-h Holter monitor at follow-up. We sought to assess the true efficacy of this procedure using prolonged cardiac rhythm monitoring. One hundred patients with paroxysmal (n = 47) and persistent AF (n = 53) requiring cardiac surgery were enrolled. Patients were clinically reviewed 6 weeks post-operatively and were monitored with 7-day Holter with full disclosure, 6 months post-surgery. A cohort of 50 patients also underwent 7 day Holter monitoring preoperatively. AF recurrence was defined as >30 s of AF. At 6 months, 75% of patients were in sinus rhythm according to a single ECG. However, only 62% of patients were free from AF on 7-day Holter; all AF episodes in these patients were asymptomatic. The procedure resulted in a significant decrease in AF burden from 56.2% at baseline to 27.5% at 6 months follow-up, (p < 0.001). Predictors of AF recurrence were (1) pre-operative AF duration; (2) persistent compared with paroxysmal AF; (3) increasing left atrial diameter and (4) requirement for mitral valve surgery. Surgical RFA for the treatment of AF, during concomitant cardiac surgery, is a successful procedure and significantly reduces AF burden. However, 13% of patients have asymptomatic AF episodes only identified with continuous monitoring. This has important implications for post-operative anti-arrhythmic and anticoagulant management and for the definition of surgical AF ablation success.
Kanda, Takashi; Masuda, Masaharu; Fujita, Masashi; Iida, Osamu; Okamoto, Shin; Ishihara, Takayuki; Nanto, Kiyonori; Sunaga, Akihiro; Tsujimura, Takuya; Matsuda, Yasuhiro; Ohashi, Takuya; Uematsu, Masaaki
2018-01-01
Differentiation of atrial fibrillation (AF) trigger ectopy from other ectopy is often difficult. The purpose of this study was to compare the origin and coupling intervals (CI) between AF-trigger and non-AF-trigger ectopy. This study consisted of 120 patients with AF who underwent an initial ablation. Isoproterenol was infused up to 20μg/min to provoke ectopy and AF. We measured the CI of all ectopy provoked by an isoproterenol infusion. The %CI was calculated as the CI of the ectopy/P-P interval of the preceding 2 beats. A total of 117 patients had at least one ectopy, and AF was induced in 56 (47%) patients. Of the 276 ectopies observed in this study, 211 (76%) originated from pulmonary veins and 77 (28%) were AF-trigger ectopy. AF-trigger ectopy more frequently originated from pulmonary veins (PVs) (74 vs. 3, p<0.001) and had a significantly shorter CI (201±70ms vs. 365±147ms, p<0.001) and lower %CI (29±11% vs. 55±14%, p<0.001) than that of non-AF-trigger ectopy. A receiver operating characteristics analysis revealed that a %CI of 40% was the best cut-off value for differentiating whether it was an AF-trigger or not. The identified trigger group, including patients with provoked AF-trigger ectopy or ectopy with a low %CI (<40%), had a significantly better AF recurrence-free survival rate than the other group (88% vs. 65%, p=0.004). AF-trigger ectopy predominantly originated from PVs and had a short CI. These findings may be useful for estimating whether ectopies are an AF-trigger or not. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.
Atrial Fibrillation Genetic Risk and Ischemic Stroke Mechanisms.
Lubitz, Steven A; Parsons, Owen E; Anderson, Christopher D; Benjamin, Emelia J; Malik, Rainer; Weng, Lu-Chen; Dichgans, Martin; Sudlow, Cathie L; Rothwell, Peter M; Rosand, Jonathan; Ellinor, Patrick T; Markus, Hugh S; Traylor, Matthew
2017-06-01
Atrial fibrillation (AF) is a leading cause of cardioembolic stroke, but the relationship between AF and noncardioembolic stroke subtypes are unclear. Because AF may be unrecognized, and because AF has a substantial genetic basis, we assessed for predisposition to AF across ischemic stroke subtypes. We examined associations between AF genetic risk and Trial of Org 10172 in Acute Stroke Treatment stroke subtypes in 2374 ambulatory individuals with ischemic stroke and 5175 without from the Wellcome Trust Case-Control Consortium 2 using logistic regression. We calculated AF genetic risk scores using single-nucleotide polymorphisms associated with AF in a previous independent analysis across a range of preselected significance thresholds. There were 460 (19.4%) individuals with cardioembolic stroke, 498 (21.0%) with large vessel, 474 (20.0%) with small vessel, and 814 (32.3%) individuals with strokes of undetermined cause. Most AF genetic risk scores were associated with stroke, with the strongest association ( P =6×10 - 4 ) attributed to scores of 944 single-nucleotide polymorphisms (each associated with AF at P <1×10 - 3 in a previous analysis). Associations between AF genetic risk and stroke were enriched in the cardioembolic stroke subset (strongest P =1.2×10 - 9 , 944 single-nucleotide polymorphism score). In contrast, AF genetic risk was not significantly associated with noncardioembolic stroke subtypes. Comprehensive AF genetic risk scores were specific for cardioembolic stroke. Incomplete workups and subtype misclassification may have limited the power to detect associations with strokes of undetermined pathogenesis. Future studies are warranted to determine whether AF genetic risk is a useful biomarker to enhance clinical discrimination of stroke pathogeneses. © 2017 American Heart Association, Inc.
Bengtson, Lindsay G. S.; Lutsey, Pamela L.; Loehr, Laura R.; Kucharska‐Newton, Anna; Chen, Lin Y.; Chamberlain, Alanna M.; Wruck, Lisa M.; Duval, Sue; Stearns, Sally C.; Alonso, Alvaro
2014-01-01
Background Atrial fibrillation (AF) is associated with increased risk of hospitalization. Little is known about the impact of AF on utilization of noninpatient health care or about sex or race differences in AF‐related utilization. We examined rates of inpatient and outpatient utilization by AF status in the Atherosclerosis Risk in Communities study. Methods and Results Participants with incident AF enrolled in fee‐for‐service Medicare for at least 12 continuous months between 1991 and 2009 (n=932) were matched on age, sex, race and field center with up to 3 participants without AF (n=2729). Healthcare utilization was ascertained from Medicare claims and classified by primary International Classification of Diseases, ninth revision code. The average annual numbers of days hospitalized were 13.2 (95% CI 11.6 to 15.0) and 2.8 (95% CI 2.5 to 3.1) for those with and without AF, respectively. The corresponding numbers of annual outpatient claims were 53.3 (95% CI 50.5 to 56.3) and 22.9 (95% CI 22.1 to 23.8) for those with and without AF, respectively. Most utilization among AF patients was attributable to non‐AF conditions. The adjusted rate ratio for annual days hospitalized for other cardiovascular disease–related reasons was 4.58 (95% CI: 3.41 to 6.16) for those with AF versus those without AF. The association between AF and healthcare utilization was similar among men and women and among white and black participants. Conclusions Participants with AF had considerably greater healthcare utilization, and the difference in utilization for other cardiovascular disease–related reasons was substantial. In addition to rate or rhythm treatment, AF management should focus on the accompanying cardiovascular comorbidities. PMID:25359400
Increasing atrial fibrillation prevalence in acute ischemic stroke and TIA.
Otite, Fadar Oliver; Khandelwal, Priyank; Chaturvedi, Seemant; Romano, Jose G; Sacco, Ralph L; Malik, Amer M
2016-11-08
To evaluate trends in atrial fibrillation (AF) prevalence in acute ischemic stroke (AIS) and TIA in the United States. We used the Nationwide Inpatient Sample to retrospectively compute weighted prevalence of AF in AIS (n = 4,355,140) and TIA (n = 1,816,459) patients admitted to US hospitals from 2004 to 2013. Multivariate-adjusted models were used to evaluate the association of AF with clinical factors, mortality, length of stay, and cost. From 2004 to 2013, AF prevalence increased by 22% in AIS (20%-24%) and by 38% in TIA (12%-17%). AF prevalence varied by age (AIS: 6% in 50-59 vs 37% in ≥80 years; TIA: 4% in 50-59 vs 24% in ≥80 years), sex (AIS: male 19% vs female 25%; TIA: male 15% vs female 14%), race (AIS: white 26% vs black 12%), and region (AIS: Northeast 25% vs South 20%). Advancing age, female sex, white race, high income, and large hospital size were associated with increased odds of AF in AIS. AF in AIS was a risk factor for in-hospital death (odds ratio 1.93, 95% confidence interval 1.89-1.98) but mortality in AIS with AF decreased from 11.6% to 8.3% (p < 0.001). Compared to no AF, AF was associated with increased cost of $2,310 and length of stay 1.1 days in AIS. AF prevalence in AIS and TIA has continued to increase. Disparity in AF prevalence in AIS and TIA exists by patient and hospital factors. AF is associated with increased mortality in AIS. Innovative AIS preventive strategies are needed in patients with AF, especially in the elderly. © 2016 American Academy of Neurology.
Barrett, Tyler W; Self, Wesley H; Wasserman, Brian S; McNaughton, Candace D; Darbar, Dawood
2013-05-01
Atrial fibrillation (AF) is often first detected in the emergency department (ED). Not all AF patients progress to sustained AF (ie, episodes lasting >7 days), which is associated with increased morbidity. The HATCH score stratifies patients with paroxysmal AF according to their risk for progression to sustained AF within 1 year. The HATCH score has previously never been tested in ED patients. We evaluated the accuracy of the HATCH score to predict progression to sustained AF within 1 year of initial AF diagnosis in the ED. We conducted a retrospective cohort study of 253 ED patients with new onset AF and known rhythm status for 1 year following the initial AF detection. The exposure variable was the HATCH score at initial ED evaluation. The primary outcome was rhythm status at 1 year following initial AF diagnosis. We constructed a receiver operating characteristic curve and calculated the area under the curve to estimate the HATCH score's accuracy of predicting progression to sustained AF. Overall, 61 (24%) of 253 of patients progressed to sustained AF within 1 year of initial detection, and the HATCH score receiver operating characteristic area under the curve was 0.62 (95% confidence interval, 0.54-0.70). Among ED patients with new onset AF, the HATCH score was a modest predictor of progression to sustained AF. Because only 2 patients had a HATCH greater than 5, this previously recommended cut-point was not useful in identifying high-risk patients in this cohort. Refinement of this decision aid is needed to improve its prognostic accuracy in the ED population. Copyright © 2013 Elsevier Inc. All rights reserved.
Hruska, Zuzana; Rajasekaran, Kanniah; Yao, Haibo; Kincaid, Russell; Darlington, Dawn; Brown, Robert L.; Bhatnagar, Deepak; Cleveland, Thomas E.
2014-01-01
A currently utilized pre-harvest biocontrol method involves field inoculations with non-aflatoxigenic Aspergillus flavus strains, a tactic shown to strategically suppress native aflatoxin-producing strains and effectively decrease aflatoxin contamination in corn. The present in situ study focuses on tracking the invasion and colonization of an aflatoxigenic A. flavus strain (AF70), labeled with green fluorescent protein (GFP), in the presence of a non-aflatoxigenic A. flavus biocontrol strain (AF36), to better understand the competitive interaction between these two strains in seed tissue of corn (Zea mays). Corn kernels that had been co-inoculated with GFP-labeled AF70 and wild-type AF36 were cross-sectioned and observed under UV and blue light to determine the outcome of competition between these strains. After imaging, all kernels were analyzed for aflatoxin levels. There appeared to be a population difference between the co-inoculated AF70-GFP+AF36 and the individual AF70-GFP tests, both visually and with pixel count analysis. The GFP allowed us to observe that AF70-GFP inside the kernels was suppressed up to 82% when co-inoculated with AF36 indicating that AF36 inhibited progression of AF70-GFP. This was in agreement with images taken of whole kernels where AF36 exhibited a more robust external growth compared to AF70-GFP. The suppressed growth of AF70-GFP was reflected in a corresponding (upto 73%) suppression in aflatoxin levels. Our results indicate that the decrease in aflatoxin production correlated with population depression of the aflatoxigenic fungus by the biocontrol strain supporting the theory of competitive exclusion through robust propagation and fast colonization by the non-aflatoxigenic fungus. PMID:24734028
Hruska, Zuzana; Rajasekaran, Kanniah; Yao, Haibo; Kincaid, Russell; Darlington, Dawn; Brown, Robert L; Bhatnagar, Deepak; Cleveland, Thomas E
2014-01-01
A currently utilized pre-harvest biocontrol method involves field inoculations with non-aflatoxigenic Aspergillus flavus strains, a tactic shown to strategically suppress native aflatoxin-producing strains and effectively decrease aflatoxin contamination in corn. The present in situ study focuses on tracking the invasion and colonization of an aflatoxigenic A. flavus strain (AF70), labeled with green fluorescent protein (GFP), in the presence of a non-aflatoxigenic A. flavus biocontrol strain (AF36), to better understand the competitive interaction between these two strains in seed tissue of corn (Zea mays). Corn kernels that had been co-inoculated with GFP-labeled AF70 and wild-type AF36 were cross-sectioned and observed under UV and blue light to determine the outcome of competition between these strains. After imaging, all kernels were analyzed for aflatoxin levels. There appeared to be a population difference between the co-inoculated AF70-GFP+AF36 and the individual AF70-GFP tests, both visually and with pixel count analysis. The GFP allowed us to observe that AF70-GFP inside the kernels was suppressed up to 82% when co-inoculated with AF36 indicating that AF36 inhibited progression of AF70-GFP. This was in agreement with images taken of whole kernels where AF36 exhibited a more robust external growth compared to AF70-GFP. The suppressed growth of AF70-GFP was reflected in a corresponding (upto 73%) suppression in aflatoxin levels. Our results indicate that the decrease in aflatoxin production correlated with population depression of the aflatoxigenic fungus by the biocontrol strain supporting the theory of competitive exclusion through robust propagation and fast colonization by the non-aflatoxigenic fungus.
Jin, Qi; Pehrson, Steen; Jacobsen, Peter Karl; Chen, Xu
2015-11-01
The objectives of this study were to assess the procedural outcomes of persistent and long-standing persistent atrial fibrillation (PsAF and L-PsAF) ablation guided by remote magnetic navigation (RMN), and to detect factors predicting acute restoration of sinus rhythm (SR) by ablation with RMN. A total of 313 patients (275 male, age 59 ± 9.5 years) with PsAF (187/313) or L-PsAF (126/313) undergoing ablation using RMN were included. Patients' disease history, pulmonary venous anatomy, left atrial (LA) volume, procedure time, mapping plus ablation time, radiofrequency (RF) ablation time, fluoroscopy time, radiation dose, and complications were assessed. Stepwise regression was used to predict which variable could best predict acute restoration from AF to SR by ablation. Compared to PsAF, procedure time and RF ablation time were significantly increased in patients with L-PsAF (P = 0.01 and P < 0.001, respectively). No major complications occurred during the procedures in either PsAF or L-PsAF patients. Fifty five of 313 patients converted directly to SR by ablation. Compared to L-PsAF, the rate of SR restoration was significantly higher in PsAF (21 vs 12%, P = 0.03). Stepwise regression analysis showed LA volume was the primary parameter affecting SR restoration (P = 0.01). The LA volume of patients without direct SR restoration by ablation was 24% greater than that of patients with SR restoration (P < 0.001). Catheter ablation using RMN is a safe and effective method for PsAF and L-PsAF. LA volume could be a predictor of direct restoration of SR from sustaining AF by ablation using RMN.
Benefit of Anticoagulation Therapy in Hyperthyroidism-Related Atrial Fibrillation.
Chan, Pak-Hei; Hai, Jojo; Yeung, Chun-Yip; Lip, Gregory Y H; Lam, Karen Siu-Ling; Tse, Hung-Fat; Siu, Chung-Wah
2015-08-01
Existing data on the risk of ischemic stroke in hyperthyroidism-related atrial fibrillation (AF) and the impact of long-term anticoagulation in these patients, particularly those with self-limiting AF, remain inconclusive. Risk of stroke in hyperthyroidism-related AF is the same as nonhyperthyroid counterparts. This was a single-center observational study of 9727 Chinese patients with nonvalvular AF from July 1997 to December 2011. Patients with AF diagnosed concomitantly with hyperthyroidism were identified. Primary and secondary endpoints were defined as hospitalization with ischemic stroke and intracranial hemorrhage in the first 2 years. Patient characteristics, duration of AF, and choice of antithrombotic therapy were recorded. Self-limiting AF was defined as <7 days' duration. Out of 9727 patients, 642 (6.6%) had concomitant hyperthyroidism and AF at diagnosis. For stroke prevention, 136 and 243 patients (21.1% and 37.9%) were prescribed warfarin and aspirin, respectively, whereas the remaining patients (41.0%) received no therapy. Ischemic stroke occurred in 50 patients (7.8%), and no patient developed hemorrhagic stroke. Patients with CHA2 DS2 -VASc of 0 did not develop stroke. Warfarin effectively reduced the incidence of stroke compared with aspirin or no therapy in patients with CHA2 DS2 -VASc ≥1 and non-self-limiting AF, but not in those with self-limiting AF or CHA2 DS2 -VASc of 0. Presence of hyperthyroidism did not confer additional risk of ischemic stroke compared with nonhyperthyroid AF. Patients with hyperthyroidism-related AF are at high risk of stroke (3.9% per year). Warfarin confers stroke prevention in patients with CHA2 DS2 -VASc ≥1 and non-self-limiting AF. Overall stroke risk was lower in hyperthyroid non-self-limiting AF patients compared with nonhyperthyroid counterparts. © 2015 Wiley Periodicals, Inc.
Franco, Jonathan; Formiga, Francesc; Cepeda, Jose; Llacer, Pau; Arévalo-Lorido, Juan; Cerqueiro, Jose; González-Franco, Alvaro; Epelde, Francesc; Manzano, Luis; Montero Pérez-Barquero, Manuel
2018-05-23
The impact of atrial fibrillation (AF) on the prognosis of heart failure with preserved ejection fraction (HFpEF) is still the subject of debate. We analysed the influence of AF on the prognosis on mortality and readmission in patients with HFpEF. Prospective observational study in 1,971 patients with HFpEF, who were admitted for acute heart failure. Patients were divided into 2 groups according to the presence or absence of AF. We analysed mortality, readmissions and combined mortality/readmissions at one year follow-up. A total of 1,177 (59%) patients had AF, mean age 80.3 (7.8) years and 1,233 (63%) were women. Patients with HFpEF and AF were older, female, greater valvular aetiology and lower comorbidity measured by the Charlson index. At the one year follow-up, 430 (22%) patients had died and 840 (43%) had been readmitted. In the 2 groups analysed, there was no difference in all-cause mortality (22 vs. 21%; P=.739, AF vs. no-AF, respectively) or cardiovascular causes (9.6 vs. 8.2%; P=.739, AF vs. no-AF, respectively). In the multivariable analysis, factors associated with higher mortality were: age, male, valvular aetiology, uric acid, and comorbidity. In the analysis of the subgroup with HFpEF with AF, the presence of chronic AF compared to de novo AF was associated with higher mortality (HR 1,716; 95% CI 1,099-2,681; P=.018). In patients with HFpEF, the presence of AF is frequent. During the one-year follow-up, the presence of AF does not influence mortality or readmissions in patients with HFpEF. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.
Siontis, Konstantinos C.; Geske, Jeffrey B.; Ong, Kevin; Nishimura, Rick A.; Ommen, Steve R.; Gersh, Bernard J.
2014-01-01
Background Atrial fibrillation (AF) is a common sequela of hypertrophic cardiomyopathy (HCM), but evidence on its prevalence, risk factors, and effect on mortality is sparse. We sought to evaluate the prevalence of AF, identify clinical and echocardiographic correlates, and assess its effect on mortality in a large high‐risk HCM population. Methods and Results We identified HCM patients who underwent evaluation at our institution from 1975 to 2012. AF was defined by known history (either chronic or paroxysmal), electrocardiogram, or Holter monitoring at index visit. We examined clinical and echocardiographic variables in association with AF. The effect of AF on overall and cause‐specific mortality was evaluated with multivariate Cox proportional hazards models. Of 3673 patients with HCM, 650 (18%) had AF. Patients with AF were older and more symptomatic (P<0.001). AF was less common among patients with obstructive HCM phenotype and was associated with larger left atria, higher E/e’ ratios, and worse cardiopulmonary exercise tolerance (all P values<0.001). During median (interquartile range) follow‐up of 4.1 (0.2 to 10) years, 1069 (29%) patients died. Patients with AF had worse survival compared to those without AF (P<0.001). In multivariate analysis adjusted for established risk factors of mortality in HCM, the hazard ratio (95% confidence interval) for the effect of AF on overall mortality was 1.48 (1.27 to 1.71). AF did not have an effect on sudden or nonsudden cardiac death. Conclusions In this large referral HCM population, approximately 1 in 5 patients had AF. AF was a strong predictor of mortality, even after adjustment for established risk factors. PMID:24965028
Liu, Xing-Peng; Xu, Xia; Tian, Ying; Tang, Ri-Bo; Yu, Rong-Hui; Long, De-Yong; Sang, Cai-Hua; Jiang, Chen-Xi; Ning, Man; Dong, Jian-Zeng; Ma, Chang-Sheng
2012-11-01
Atrial Remodeling and Lone Atrial Fibrillation. We sought to investigate the role of anatomic remodeling of the atria and pulmonary veins (PVs) in the progression of lone atrial fibrillation (AF) using dual-source computed tomography (DSCT). From 1,308 consecutive patients referred for an index ablation procedure for AF, we prospectively enrolled 29 consecutive patients with recently developed (<3 months) lone persistent AF (PsAF) and 23 consecutive patients with short-lasting (6-12 months) lone PsAF, all of whom had a history of paroxysmal AF (PAF). The control group consisted of 33 patients with lone PAF. On DSCT, the recently developed PsAF group showed more extensive atrial anatomic remodeling than the PAF group as shown by ∼40% higher spot biatrial volume, even though the mean duration of continuous AF was only 6 weeks. In contrast, the DSCT variables in the recently developed PsAF group and the short-lasting PsAF group were comparable, despite the fact that the mean duration of continuous AF in the latter group was 8 months. Series of cross-sectional areas of the ostial 1.5 cm of PV trunks were comparable in the PAF and PsAF groups in all but 3 ostial planes. A higher spot left atrial volume was the only independent factor associated with the progression of lone PAF to PsAF (OR: 1.06, 95% CI: 1.03-1.09, P<0.0001) on logistic regression. Prominent anatomic remodeling of the atria, rather than the PVs, underlies the mechanism of recent progression of lone paroxysmal AF to the persistent variety. © 2012 Wiley Periodicals, Inc.
Steinberg, Benjamin A.; Hellkamp, Anne S.; Lokhnygina, Yuliya; Patel, Manesh R.; Breithardt, Günter; Hankey, Graeme J.; Becker, Richard C.; Singer, Daniel E.; Halperin, Jonathan L.; Hacke, Werner; Nessel, Christopher C.; Berkowitz, Scott D.; Mahaffey, Kenneth W.; Fox, Keith A.A.; Califf, Robert M.; Piccini, Jonathan P.
2015-01-01
Aim Anticoagulation prophylaxis for stroke is recommended for at-risk patients with either persistent or paroxysmal atrial fibrillation (AF). We compared outcomes in patients with persistent vs. paroxysmal AF receiving oral anticoagulation. Methods and results Patients randomized in the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET-AF) trial (n = 14 264) were grouped by baseline AF category: paroxysmal or persistent. Multivariable adjustment was performed to compare thrombo-embolic events, bleeding, and death between groups, in high-risk subgroups, and across treatment assignment (rivaroxaban or warfarin). Of 14 062 patients, 11 548 (82%) had persistent AF and 2514 (18%) had paroxysmal AF. Patients with persistent AF were marginally older (73 vs. 72, P = 0.03), less likely female (39 vs. 45%, P < 0.0001), and more likely to have previously used vitamin K antagonists (64 vs. 56%, P < 0.0001) compared with patients with paroxysmal AF. In patients randomized to warfarin, time in therapeutic range was similar (58 vs. 57%, P = 0.94). Patients with persistent AF had higher adjusted rates of stroke or systemic embolism (2.18 vs. 1.73 events per 100-patient-years, P = 0.048) and all-cause mortality (4.78 vs. 3.52, P = 0.006). Rates of major bleeding were similar (3.55 vs. 3.31, P = 0.77). Rates of stroke or systemic embolism in both types of AF did not differ by treatment assignment (rivaroxaban vs. warfarin, Pinteraction = 0.6). Conclusion In patients with AF at moderate-to-high risk of stroke receiving anticoagulation, those with persistent AF have a higher risk of thrombo-embolic events and worse survival compared with paroxysmal AF. PMID:25209598
Lichten, Catherine A; Castle-Clarke, Sophie; Manville, Catriona; Horvath, Veronika; Robin, Enora; Krapels, Joachim; Parks, Sarah; Sim, Megan; van Zijverden, Olga; Chataway, Joanna
2015-11-30
Atrial fibrillation (AF) is the most common type of cardiac arrhythmia, affecting approximately 1-2 per cent of the population worldwide. Those who suffer from AF have a five times higher risk of stroke. AF prevalence increases with age and it affects roughly 18 per cent of the population over 85. Consequently, as populations age, AF is becoming an increasingly significant public health issue. Over recent years there have been developments in treatment and management options, both for treating the arrhythmia directly, and assessing and reducing the risk of AF-related stroke, but there is a need to ensure that available knowledge is applied optimally to benefit patients so that opportunities to prevent AF-related stroke are not missed. The aims of this project were to assess the current landscape and explore the direction of future developments in AF management in Europe, with a focus on the use of anticoagulants in the prevention of AF-related stroke. Through rapid evidence assessment, key informant interviews, PESTLE analysis and the development and exploration of future scenarios, we have developed sets of shorter- and longer-term recommendations for improving AF-related patient outcomes. The short-term recommendations are: i) improve AF awareness among the public and policymakers; ii) support education about AF management for healthcare professionals and patients; and iii) maintain engagement in AF-related research across the health services.
Taylor, Elaina C; O'Neill, Mark; Hughes, Lyndsay D; Moss-Morris, Rona
2018-04-01
This study modified the Revised Illness Perception Questionnaire (IPQ-R) in patients with persistent atrial fibrillation (AF). Qualitative interviews and think-aloud techniques informed modification of the IPQ-R to be specific to AF patients. Confirmatory Factor Analysis (CFA) (n = 198) examined the validity of the modified IPQ-R (AF-IPQ-R). Exploratory factor analysis (EFA) examined the new AF-triggers scale. Construct validity examined associations between the AF-IPQ-R, quality of life (QoL) and beliefs about medicines. Test-retest and internal reliability were examined. Interviews indicated that patients viewed triggers of AF rather than initial causes of illness as more applicable. Patients believed specific behaviours such as rest could control AF. Treatment control beliefs related to pharmacological and procedural treatments. These data were used to modify the IPQ-R subscales and to develop a triggers of AF scale. CFA indicated good model fit. EFA of the triggers scale indicated three factors: emotional; health behaviours; and over-exertion triggers. Expected correlations were found between the AF-IPQ-R, QoL and treatment beliefs, evidencing good construct validity. The AF-IPQ-R showed sound psychometric properties. It provides more detailed specification than the IPQ-R of beliefs that may help to understand poor QoL in AF patients, and guidance for future interventions in this area.
Novel pharmacological targets for the rhythm control management of atrial fibrillation.
Burashnikov, Alexander; Antzelevitch, Charles
2011-12-01
Atrial fibrillation (AF) is a growing clinical problem associated with increased morbidity and mortality. Development of safe and effective pharmacological treatments for AF is one of the greatest unmet medical needs facing our society. In spite of significant progress in non-pharmacological AF treatments (largely due to the use of catheter ablation techniques), anti-arrhythmic agents (AADs) remain first line therapy for rhythm control management of AF for most AF patients. When considering efficacy, safety and tolerability, currently available AADs for rhythm control of AF are less than optimal. Ion channel inhibition remains the principal strategy for termination of AF and prevention of its recurrence. Practical clinical experience indicates that multi-ion channel blockers are generally more optimal for rhythm control of AF compared to ion channel-selective blockers. Recent studies suggest that atrial-selective sodium channel block can lead to safe and effective suppression of AF and that concurrent inhibition of potassium ion channels may potentiate this effect. An important limitation of the ion channel block approach for AF treatment is that non-electrical factors (largely structural remodeling) may importantly determine the generation of AF, so that "upstream therapy", aimed at preventing or reversing structural remodeling, may be required for effective rhythm control management. This review focuses on novel pharmacological targets for the rhythm control management of AF. Copyright © 2011 Elsevier Inc. All rights reserved.
Modulated exchange bias in NiFe/CoO/α-Fe2O3 trilayers and NiFe/CoO bilayers
NASA Astrophysics Data System (ADS)
Li, X.; Lin, K.-W.; Yeh, W.-C.; Desautels, R. D.; van Lierop, J.; Pong, Philip W. T.
2017-02-01
While the exchange bias in ferromagnetic/antiferromagnetic (FM/AF) bilayer and FM1/AF/FM2 trilayer configurations has been widely investigated, the role of an AF2 layer in FM/AF1/AF2 trilayer configurations is still not well understood. In this work, the magnetic properties of NiFe/CoO, NiFe/α-Fe2O3 bilayers, and NiFe/CoO/α-Fe2O3 trilayer were studied comparatively. The microstructure and chemical composition were characterized. Temperature dependent magnetometry reveals increased irreversibility temperature in NiFe/CoO/α-Fe2O3 trilayer compared with NiFe/CoO bilayer. The magnetic hysteresis loops show that the exchange bias (Hex) and coercivity (Hc) depend strongly on the anisotropy of AF layer (CoO, α-Fe2O3 and CoO/α-Fe2O3). Our work shows that the AF1/AF2 interfacial interactions can be used effectively for tuning the exchange bias in FM/AF1/AF2 trilayers.
Clinical and Economic Implications of AF Related Stroke.
Ali, Ali N; Abdelhafiz, Ahmed
2016-01-01
A major cause of morbidity and mortality among patients with atrial fibrillation (AF) relates to the increased risk of stroke. The burden of illness that AF imparts on stroke is likely to increase with our aging populations and increasingly sophisticated cardiac monitoring techniques. Understanding the clinical and economic differences between AF related ischaemic stroke and non-AF related stroke is important if we are to improve future cost effectiveness analyses of potential preventative treatments, but also to help educate clinical and policy decision makers on use or availability of treatments to prevent AF related stroke. In this article we review the existing evidence that highlights differences in the clinical characteristics and outcomes between AF and non-AF stroke, as well as differences in their economic impact and discuss ways to improve future economic analyses.
1984-06-01
recep- tors at leas" in NG-108-15 cells. When cells were treated with chloroquine which intarfeceswith lyzosoimai enzyme function by changing the pil...but not by its quaternary analogue . Further, when the peripheral component of morphine’s net effect on feeding is blocked by co-administration of
ERIC Educational Resources Information Center
Head, Alison J.
2016-01-01
This paper identifies approaches, challenges, and best practices related to planning and designing today's academic library learning spaces. As part of the Project Information Literacy (PIL) Practitioner Series, qualitative data is presented from 49 interviews conducted with a sample of academic librarians, architects, and library consultants.…
Schwarz, Simon; Ravens, Ursula; Knaut, Michael
2016-01-01
Abstract Background and Purpose 5‐HT increases force and L‐type Ca2 + current (ICa,L) and causes arrhythmias through 5‐HT4 receptors in human atrium. In permanent atrial fibrillation (peAF), atrial force responses to 5‐HT are blunted, arrhythmias abolished but ICa,L responses only moderately attenuated. We investigated whether, in peAF, this could be due to an increased function of PDE3 and/or PDE4, using the inhibitors cilostamide (300 nM) and rolipram (1 μM) respectively. Experimental Approach Contractile force, arrhythmic contractions and ICa,L were assessed in right atrial trabeculae and myocytes, obtained from patients with sinus rhythm (SR), paroxysmal atrial fibrillation (pAF) and peAF. Key Results Maximum force responses to 5‐HT were reduced to 15% in peAF, but not in pAF. Cilostamide, but not rolipram, increased both the blunted force responses to 5‐HT in peAF and the inotropic potency of 5‐HT fourfold to sevenfold in trabeculae of patients with SR, pAF and peAF. Lusitropic responses to 5‐HT were not decreased in peAF. Responses of ICa,L to 5‐HT did not differ and were unaffected by cilostamide or rolipram in myocytes from patients with SR or peAF. Concurrent cilostamide and rolipram increased 5‐HT's propensity to elicit arrhythmias in trabeculae from patients with SR, but not with peAF. Conclusions and Implications PDE3, but not PDE4, reduced inotropic responses to 5‐HT in peAF, independently of lusitropy and ICa,L, but PDE3 activity was the same as that in patients with SR and pAF. Atrial remodelling in peAF abolished the facilitation of 5‐HT to induce arrhythmias by inhibition of PDE3 plus PDE4. PMID:27238373
Effect of Omega-3 Polyunsaturated Fatty Acid Supplementation in Patients with Atrial Fibrillation.
Kumar, Sanjay; Qu, Sarah; Kassotis, John T
2012-01-01
Atrial fibrillation (AF) is the most common sustained atrial arrhythmia conferring a higher morbidity and mortality. Despite the increasing incidence of AF; available therapies are far from perfect. Dietary fish oils, containing omega 3 fatty acids, also called polyunsaturated fatty acid [PUFA] have demonstrated beneficial electrophysiological, autonomic and anti-inflammatory effects on both atrial and ventricular tissue. Multiple clinical trials, focusing on various subsets of patients with AF, have studied the role of PUFA and their potential role in reducing the incidence of this common arrhythmia. While PUFA appears to have a beneficial effect in the primary prevention of AF in the elderly with structural heart disease, this benefit has not been universally observed. In the secondary prevention of AF, PUFA seems to have a greater impact in the reducing AF in patients with paroxysmal or persistent AF, stages of AF associated with less atrial fibrosis and negative structural remodeling. However, AF suppression has not been consistently demonstrated in clinical trials. In patients undergoing heart surgery, increasing PUFA intake has yielded mixed results in terms of AF prevention post-operatively; however, increased PUFA has been associated with a reduction in hospital stay. Therefore recommending the use of PUFA for the purpose of AF reduction remains controversial. This is in part attributable to the complexity of AF. Other conflicting variables include: heterogeneous patient populations studied; variable dosing; duration of follow-up; comorbidities; and, concomitant pharmacotherapy. This review article reviews in detail available basic and clinical research studies of fish oil in the treatment of AF, and its role in the treatment of this common disorder. AF=Atrial fibrillation, CHS=Cardiovascular Health Study,CABG=Coronary artery bypass surgery, d=Day, DHA=Docosahexaenoic acid, EPA=Eicosapentaenoic acid, ERP= Effective refractory period, g=Gram, PAF= Paroxysmal atrial fibrillation, PeAF= Persistent atrial fibrillation PUFA= Polyunsaturated fatty acid.
Novel Insights into the Organization of Laticifer Cells: A Cell Comprising a Unified Whole System1
Castelblanque, Lourdes; Balaguer, Begoña; Rodríguez, Juan José; Orozco, Marianela; Vera, Pablo
2016-01-01
Laticifer cells are specialized plant cells that synthesize and accumulate latex. Studies on laticifers have lagged behind in recent years, and data regarding the functional role of laticifers and their fitness benefit still remain elusive. Laticifer differentiation and its impact on plant growth and development also remain to be investigated. Here, cellular, molecular, and genetic tools were developed to examine the distribution, differentiation, ontogeny, and other characteristic features, as well as the potential developmental role of laticifer cells in the latex-bearing plant Euphorbia lathyris. The organization of the laticiferous system within the E. lathyris plant body is reported, emerging as a single elongated and branched coenocytic cell, constituting the largest cell type existing in plants. We also report the ontogeny and organization of laticifer cells in the embryo and the identification of a laticifer-associated gene expression pattern. Moreover, the identification of laticifer- and latex-deficient mutants (pil mutants) allowed for the identification of distinct loci regulating laticifer differentiation, growth, and metabolic activity. Additionally, pil mutants revealed that laticifer cells appear nonessential for plant growth and development, thus pointing toward their importance, instead, for specific ecophysiological adaptations of latex-bearing plants in natural environments. PMID:27468995
Type IV pili mechanochemically regulate virulence factors in Pseudomonas aeruginosa.
Persat, Alexandre; Inclan, Yuki F; Engel, Joanne N; Stone, Howard A; Gitai, Zemer
2015-06-16
Bacteria have evolved a wide range of sensing systems to appropriately respond to environmental signals. Here we demonstrate that the opportunistic pathogen Pseudomonas aeruginosa detects contact with surfaces on short timescales using the mechanical activity of its type IV pili, a major surface adhesin. This signal transduction mechanism requires attachment of type IV pili to a solid surface, followed by pilus retraction and signal transduction through the Chp chemosensory system, a chemotaxis-like sensory system that regulates cAMP production and transcription of hundreds of genes, including key virulence factors. Like other chemotaxis pathways, pili-mediated surface sensing results in a transient response amplified by a positive feedback that increases type IV pili activity, thereby promoting long-term surface attachment that can stimulate additional virulence and biofilm-inducing pathways. The methyl-accepting chemotaxis protein-like chemosensor PilJ directly interacts with the major pilin subunit PilA. Our results thus support a mechanochemical model where a chemosensory system measures the mechanically induced conformational changes in stretched type IV pili. These findings demonstrate that P. aeruginosa not only uses type IV pili for surface-specific twitching motility, but also as a sensor regulating surface-induced gene expression and pathogenicity.
Poly(Ionic Liquid) Semi-Interpenetrating Network Multi-Responsive Hydrogels
Tudor, Alexandru; Florea, Larisa; Gallagher, Simon; Burns, John; Diamond, Dermot
2016-01-01
Herein we describe poly(ionic liquid) hydrogel actuators that are capable of responding to multiple stimuli, namely temperature, ionic strength and white light irradiation. Using two starting materials, a crosslinked poly ionic liquid (PIL) and a linear poly(N-isopropylacrylamide-co-spiropyran-co-acrylic acid), several semi-interpenetrating (sIPN) hydrogels were synthesised. The dimensions of hydrogels discs were measured before and after applying the stimuli, to quantify their response. Samples composed of 100% crosslinked PIL alone showed an average area reduction value of ~53% when the temperature was raised from 20 °C to 70 °C, ~24% when immersed in 1% w/w NaF salt solution and no observable photo-response. In comparison, sIPNs containing 300% w/w linear polymer showed an average area reduction of ~45% when the temperature was raised from 20 °C to 70 °C, ~36% when immersed in 1% NaF w/w salt solution and ~10% after 30 min exposure to white light irradiation, respectively. Moreover, by varying the content of the linear component, fine-control over the photo-, thermo- and salt response, swelling-deswelling rate and mechanical properties of the resulting sIPN was achieved. PMID:26861339
Gurung, Ishwori; Berry, Jamie-Lee; Hall, Alexander M J; Pelicic, Vladimir
2017-04-07
Streptococcus sanguinis, a naturally competent opportunistic human pathogen, is a Gram-positive workhorse for genomics. It has recently emerged as a model for the study of type IV pili (Tfp)-exceptionally widespread and important prokaryotic filaments. To enhance genetic manipulation of Streptococcus sanguinis, we have developed a cloning-independent methodology, which uses a counterselectable marker and allows sophisticated markerless gene editing in situ. We illustrate the utility of this methodology by answering several questions regarding Tfp biology by (i) deleting single or mutiple genes, (ii) altering specific bases in genes of interest, and (iii) engineering genes to encode proteins with appended affinity tags. We show that (i) the last six genes in the pil locus harbouring all the genes dedicated to Tfp biology play no role in piliation or Tfp-mediated motility, (ii) two highly conserved Asp residues are crucial for enzymatic activity of the prepilin peptidase PilD and (iii) that pilin subunits with a C-terminally appended hexa-histidine (6His) tag are still assembled into functional Tfp. The methodology for genetic manipulation we describe here should be broadly applicable. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.
DOE Office of Scientific and Technical Information (OSTI.GOV)
LEE,Y.N.; SONG,Z.; LIU,Y.
2001-01-13
Knowledge of aerosol chemical composition is key to understanding a number of properties of ambient aerosol particles including sources, size/number distribution, chemical evolution, optical properties and human health effects. Although filter based techniques have been widely used to determine aerosol chemical constituents, they generally cannot provide sufficiently fast time resolution needed to investigate sources and chemical evolution that effect aerosol chemical, size and number changes. In order to gain an ability to describe and predict the life cycles of ambient aerosols as a basis for ambient air quality control, fast and sensitive determination of the aerosol chemical composition must bemore » made available. To help to achieve this goal, we deployed a newly developed technique, referred to as PILS (particle-into-liquid-sampler), on the DOE G1 aircraft during the 2000 Texas Air Quality Study (TexAQS 2000) to characterize the major ionic species of aerosol particles with aerodynamic size smaller than 2.5 {micro}m (PM 2.5). The results obtained are examined in the context of other simultaneously collected data for insights into the measurement capability of the PILS system.« less
Expression of Xylella fastidiosa Fimbrial and Afimbrial Proteins during Biofilm Formation▿
Caserta, R.; Takita, M. A.; Targon, M. L.; Rosselli-Murai, L. K.; de Souza, A. P.; Peroni, L.; Stach-Machado, D. R.; Andrade, A.; Labate, C. A.; Kitajima, E. W.; Machado, M. A.; de Souza, A. A.
2010-01-01
Complete sequencing of the Xylella fastidiosa genome revealed characteristics that have not been described previously for a phytopathogen. One characteristic of this genome was the abundance of genes encoding proteins with adhesion functions related to biofilm formation, an essential step for colonization of a plant host or an insect vector. We examined four of the proteins belonging to this class encoded by genes in the genome of X. fastidiosa: the PilA2 and PilC fimbrial proteins, which are components of the type IV pili, and XadA1 and XadA2, which are afimbrial adhesins. Polyclonal antibodies were raised against these four proteins, and their behavior during biofilm development was assessed by Western blotting and immunofluorescence assays. In addition, immunogold electron microscopy was used to detect these proteins in bacteria present in xylem vessels of three different hosts (citrus, periwinkle, and hibiscus). We verified that these proteins are present in X. fastidiosa biofilms but have differential regulation since the amounts varied temporally during biofilm formation, as well as spatially within the biofilms. The proteins were also detected in bacteria colonizing the xylem vessels of infected plants. PMID:20472735
Studies of Global Solar Magnetic Field Patterns Using a Newly Digitized Archive
NASA Astrophysics Data System (ADS)
Hewins, I.; Webb, D. F.; Gibson, S. E.; McFadden, R.; Emery, B. A.; Malanushenko, A. V.
2017-12-01
The McIntosh Archive consists of a set of hand-drawn solar Carrington maps created by Patrick McIntosh from 1964 to 2009. McIntosh used mainly Ha, He 10830Å and photospheric magnetic measurements from both ground-based and NASA satellite observations. With these he traced polarity inversion lines (PILs), filaments, sunspots and plage and, later, coronal holes, yielding a unique 45-year record of features associated with the large-scale organization of the solar magnetic field. We discuss our efforts to preserve and digitize this archive; the original hand-drawn maps have been scanned, a method for processing these scans into digital, searchable format has been developed, and a website and an archival repository at NOAA's National Centers for Environmental Information (NCEI) has been created. The archive is complete for SC 23 and partially complete for SCs 21 and 22. In this paper we show examples of how the data base can be utilized for scientific applications. We compare the evolution of the areas and boundaries of CHs with other recent results, and we use the maps to track the global, SC-evolution of filaments, large-scale positive and negative polarity regions, PILs and sunspots.
Gurung, Ishwori; Berry, Jamie-Lee; Hall, Alexander M. J.
2017-01-01
Abstract Streptococcus sanguinis, a naturally competent opportunistic human pathogen, is a Gram-positive workhorse for genomics. It has recently emerged as a model for the study of type IV pili (Tfp)—exceptionally widespread and important prokaryotic filaments. To enhance genetic manipulation of Streptococcus sanguinis, we have developed a cloning-independent methodology, which uses a counterselectable marker and allows sophisticated markerless gene editing in situ. We illustrate the utility of this methodology by answering several questions regarding Tfp biology by (i) deleting single or mutiple genes, (ii) altering specific bases in genes of interest, and (iii) engineering genes to encode proteins with appended affinity tags. We show that (i) the last six genes in the pil locus harbouring all the genes dedicated to Tfp biology play no role in piliation or Tfp-mediated motility, (ii) two highly conserved Asp residues are crucial for enzymatic activity of the prepilin peptidase PilD and (iii) that pilin subunits with a C-terminally appended hexa-histidine (6His) tag are still assembled into functional Tfp. The methodology for genetic manipulation we describe here should be broadly applicable. PMID:27903891
Simulations of Flare Reconnection in Breakout Coronal Mass Ejections
NASA Astrophysics Data System (ADS)
DeVore, C. Richard; Karpen, J. T.; Antiochos, S. K.
2009-05-01
We report 3D MHD simulations of the flare reconnection in the corona below breakout coronal mass ejections (CMEs). The initial setup is a single bipolar active region imbedded in the global-scale background dipolar field of the Sun, forming a quadrupolar magnetic configuration with a coronal null point. Rotational motions applied to the active-region polarities at the base of the atmosphere introduce shear across the polarity inversion line (PIL). Eventually, the magnetic stress and energy reach the critical threshold for runaway breakout reconnection, at which point the sheared core field erupts outward at high speed. The vertical current sheet formed by the stretching of the departing sheared field suffers reconnection that reforms the initial low-lying arcade across the PIL, i.e., creates the flare loops. Our simulation model, the Adaptively Refined MHD Solver, exploits local grid refinement to resolve the detailed structure and evolution of the highly dynamic current sheet. We are analyzing the numerical experiments to identify and interpret observable signatures of the flare reconnection associated with CMEs, e.g., the flare loops and ribbons, coronal jets and shock waves, and possible origins of solar energetic particles. This research was supported by NASA and ONR.
Duke, Stephen O.; Kenyon, William H.
1986-01-01
The possible role of photosynthesis in the mechanism of action of the herbicide acifluorfen (2-chloro-4-(trifluoromethyl)phenoxy-2-nitrobenzoate; AF) was examined. The sensitivity to AF of cotyledons of cucumber (Cucumis sativus L.) which had been grown under far red light (FR) and white light were compared. FR grown tissues which were photosynthetically imcompetent were hypersensitive to AF under white light and had approximately the same relative response to AF under blue and red light as green, white-light-grown tissues. Ultrastructural damage was apparent in FR-grown, AF-treated tissues within an hour after exposure to white light, with cytoplasmic and plastidic disorganization occurring simultaneously. In cucumber cotyledon tissue which had been greening for various time periods, there was no correlation between photosynthetic capacity and herbicidal efficacy of AF. PSII inhibitors (atrazine and DCMU) and the photophosphorylation inhibitor, tentoxin, had no effect on AF activity. Atrazine did not reduce AF activity at any concentration or light intensity tested, indicating that there is no second, photosynthetic-dependent mechanism of action operating at low AF concentrations or low fluence rates. Carbon dioxide-dependent O2 evolution of intact chloroplasts of spinach (Spinacia oleracea L.) had an AF I50 of 125 micromolar compared to 1000 micromolar for cucumber, whereas AF was much more herbicidally active in tissues of cucumber than of spinach. Differences in activity could not be accounted for by differences in uptake of AF. Our results indicate that there is no photosynthetic involvement in the mechanism of action of AF in cucumber. Images Fig. 2 PMID:16664919
Porter, Michael; Spear, William; Akar, Joseph G; Helms, Ray; Brysiewicz, Neil; Santucci, Peter; Wilber, David J
2008-06-01
Complex fractionated atrial electrograms (CFAE) may identify critical sites for perpetuation of atrial fibrillation (AF) and provide useful targets for ablation. Current assessment of CFAE is subjective; automated detection algorithms may improve reproducibility, but their utility in guiding ablation has not been tested. In 67 patients presenting for initial AF ablation (42 paroxysmal, 25 persistent), LA and CS mapping were performed during induced or spontaneous AF. CFAE were identified by an online automated computer algorithm and displayed on electroanatomical maps. A mean of 28 +/- 18 sites/patient were identified (20 +/- 13% of mapped sites), and were more frequent during persistent AF. CFAE occurred most commonly within the CS, on the atrial septum, and around the pulmonary veins. Ablation initially targeting CFAE terminated AF in 88% of paroxysmal AF, but only 20% of persistent AF (P < 0.001). Subsequently, additional ablation was performed in all patients (PV isolation for paroxysmal AF, PV isolation + mitral and roof lines for persistent AF). Minimum follow-up was 1 year. One-year freedom from recurrent atrial arrhythmias without antiarrhythmic drug therapy after a single procedure was 90% for paroxysmal AF, and 68% for persistent AF. Ablation guided by automated detection of CFAE proved feasible, and was associated with a high AF termination rate in paroxysmal, but not persistent AF. As an adjunct to conventional techniques, it was associated with excellent long-term single procedure outcomes in both groups. Criteria for identifying optimal CFAE sites for ablation, and selection of patients most likely to benefit, require additional study.
Vora, A; Kapoor, A; Nair, M; Lokhandwala, Y; Narsimhan, C; Ravikishore, A G; Dwivedi, S K; Namboodiri, N; Hygriv, R; Saxena, A; Nabar, A; Garg, S; Bardoloi, N; Yadav, R; Nambiar, A; Pandurangi, U; Jhala, D; Naik, A; Nagmallesh; Rajagopal, S; Selvaraj, R; Arora, V; Thachil, A; Thomas, J; Panicker, G
A national atrial fibrillation (AF) registry was conducted under the aegis of the Indian Heart Rhythm Society (IHRS), to capture epidemiological data-type of AF, clinical presentation and comorbidities, current treatment practices, and 1-year follow-up outcomes. A total of 1537 patients were enrolled from 24 sites in India in the IHRS-AF registry from July 2011 to August 2012. Their baseline characteristics and follow-up data were recorded in case report forms and subsequently analyzed. The average age of Indian AF patients was 54.7 years. There was a marginal female preponderance - 51.5% females and 48.5% males. At baseline, 20.4% had paroxysmal AF; 33% had persistent AF; 35.1% had permanent AF and 11% had first AF episode. At one-year follow-up, 45.6% patients had permanent AF. Rheumatic valvular heart disease (RHD) was present in 47.6% of patients. Hypertension, heart failure, coronary artery disease, and diabetes were seen in 31.4%, 18.7%, 16.2%, and 16.1%, respectively. Rate control was the strategy used in 75.2% patients, digoxin and beta-blockers being the most frequently prescribed rate-control drugs. Oral anticoagulation (OAC) drugs were used in 70% of patients. The annual mortality was 6.5%, hospitalization 8%, and incidence of stroke 1%. In India, AF patients are younger and RHD is still the most frequent etiology. Almost two-third of the patients have persistent/permanent AF. At one-year follow-up, there is a significant mortality and morbidity in AF patients in India. Copyright © 2016. Published by Elsevier B.V.
Sommer, Philipp; Kircher, Simon; Rolf, Sascha; John, Silke; Arya, Arash; Dinov, Borislav; Richter, Sergio; Bollmann, Andreas; Hindricks, Gerhard
2016-03-01
There remains a lack of consensus regarding the ideal ablation strategy for atrial fibrillation (AF), particularly in patients with persistent or longstanding persistent AF. Given increasing evidence from clinical imaging studies that rotors sustain AF, rotor elimination may be a desirable procedural endpoint. However, there is no description to date of the clinical outcomes using rotor elimination during ablation as the procedural endpoint. Moreover, a series of studies question whether procedural AF termination is a desirable endpoint for ablation after many forms of AF ablation. We report a single-center experience of rotor elimination during AF ablation using Focal Impulse and Rotor Mapping (FIRM), describing 20 consecutive patients with case descriptions of 3 patients with recurrent longstanding persistent AF after prior ablation. In all cases, endocardial mapping using a 64-electrode basket catheter was performed to identify rotors, which were eliminated using radiofrequency catheter ablation. After it was verified that all identified rotors were eliminated, standard ablation consisting of PV isolation was performed. Notably, persistent AF terminated in only 1/20 (5%) patients. However, after a follow-up of 6 months, single-procedure freedom from AF was 80% (16/20 patients) with only 1 patient on antiarrhythmic drugs. All three patients in the highlighted series are AF free despite the lack of acute procedural AF termination. Patients with persistent AF including those with unsuccessful prior ablation can be treated successfully by rotor targeted ablation, using the elimination of all rotors rather than acute AF termination as the procedural endpoint. © 2015 Wiley Periodicals, Inc.
Suissa, Laurent; Lachaud, Sylvain; Mahagne, Marie-Hélène
2014-01-01
Tracking down atrial fibrillation (AF) in the stroke unit is a relevant challenge for the prevention of recurrent AF-related stroke. The optimal terms of use of continuous ECG monitoring (CEM) are unknown. We compared 24-hour routine Holter ECG with two different CEM analysis strategies for AF detection. We prospectively enrolled consecutive ischemic stroke patients. All AF-naïve patients received CEM during hospitalization. Two methods for reading CEM data were compared: manual analysis using the Holter function (hCEM) and semiautomated analysis using software (aCEM). The McNemar test was used to compare AF detection rates. Of the 362 patients included, 58 (16.0%) were non-AF-naïve patients and 304 were AF-naïve patients. AF-Naïve patients underwent CEM with a median duration of 5.3 days (3.4-9.7). We detected 22 new AF cases (7.2%) with first-24-hour hCEM, 31 (10.2%) with aCEM, and 42 (13.8%) with hCEM. hCEM and aCEM both significantly increased the AF detection rate compared to first-24-hour hCEM. hCEM detected more new AF cases than aCEM (+3.6%, p = 0.003). In stroke patients, early and prolonged aCEM and hCEM both increase the AF detection rate compared to first-24-hour hCEM. hCEM gives the best AF detection rate. We suggest that in aCEM, detection based only on the ventricular rhythm analysis explains its lower specificity and sensitivity. © 2014 S. Karger AG, Basel.
Kallmünzer, Bernd; Breuer, Lorenz; Hering, Christiane; Raaz-Schrauder, Dorette; Kollmar, Rainer; Huttner, Hagen B; Schwab, Stefan; Köhrmann, Martin
2012-04-01
Anticoagulation is a highly effective secondary prevention in patients with cardioembolic stroke and atrial fibrillation/flutter (AF). However, the condition remains underdiagnosed, because paroxysmal AF may be missed by diagnostic tests in the acute phase. In this study, the sensitivity of AF detection was assessed for serial electrocardiographic recordings and continuous stroke unit telemetric monitoring with or without a structured algorithm to analyze telemetric data (SEA-AF). Three hundred forty-six consecutive patients with acute ischemic stroke were prospectively included and subjected to standard telemetric monitoring. In addition, telemetric data were separately analyzed following SEA-AF, consisting of a structured evaluation of episodes with high risk for AF and a chronological beat-to-beat screening of the full registration. Serial electrocardiograms were conducted in 24-hour intervals. Median effective telemetry monitoring time was 75.5 hours (interquartile range 64-86 hours). Overall, AF was diagnosed in 119 of 346 patients (34.4%). The structured reading algorithm was the most sensitive method to detected AF. Conventional telemetry and serial electrocardiographic assessments were less effective. However, only 35% of patients with previously documented paroxysmal AF and negative baseline electrocardiogram demonstrated AF episodes during monitoring. Continuous stroke unit telemetry using SEA-AF shows a significantly higher detection rate for AF compared with daily electrocardiographic assessments and standard telemetry without structured reading. The low overall probability to detect paroxysmal AF with either method during the first days after stroke demonstrates the urgent need for complementary diagnostic strategies such as long-term monitoring and frequent follow-up assessments. Clinical Trial Registration- URL: www.clinicaltrials.gov. Unique identifier: NCT01177748.
Giacomantonio, Nicholas B; Bredin, Shannon S D; Foulds, Heather J A; Warburton, Darren E R
2013-04-01
This systematic review sought to evaluate critically the health benefits of physical activity among persons with atrial fibrillation (AF). AF is increasing in Western society. While health benefits of physical activity are well established, benefits of physical activity among individuals with AF are not clearly identified. Literature was retrieved systematically through searching electronic databases (MEDLINE, EMBASE, Cochrane), cross-referencing, and drawing on the authors' knowledge. Identified original research articles evaluated health benefits of physical activity among persons with AF or effects of physical activity on AF incidence. From 1056 individual citations, 36 eligible articles were identified. Moderate-intensity physical activity was found to improve exercise capacity, quality of life, and the ability to carry out activities of daily living among persons with AF (n = 6). Increased incidence of AF was not associated with physical activity among the general population (n = 2), although long-term vigorous endurance exercise may be associated with increased incidence of AF (n = 7), and greater risks may be associated with high-intensity physical activity among those with AF (n = 2). Moderate-intensity physical activity among individuals with AF does not adversely alter training outcomes, functional capacity, morbidity, or mortality compared with those in sinus rhythm (n = 12). Physical activity may improve management and treatment of AF (n = 6) and, among at-risk populations, may reduce incidence of AF (n = 3). In conclusion, moderate-intensity physical activity should be encouraged among persons with or at risk of AF. Further research is needed. Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
Atrial Fibrillation: Mechanisms, Therapeutics, and Future Directions
Pellman, Jason; Sheikh, Farah
2017-01-01
Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia, affecting 1% to 2% of the general population. It is characterized by rapid and disorganized atrial activation leading to impaired atrial function, which can be diagnosed on an EKG by lack of a P-wave and irregular QRS complexes. AF is associated with increased morbidity and mortality and is a risk factor for embolic stroke and worsening heart failure. Current research on AF support and explore the hypothesis that initiation and maintenance of AF require pathophysiological remodeling of the atria, either specifically as in lone AF or secondary to other heart disease as in heart failure-associated AF. Remodeling in AF can be grouped into three categories that include: (i) electrical remodeling, which includes modulation of L-type Ca2+ current, various K+ currents and gap junction function; (ii) structural remodeling, which includes changes in tissues properties, size, and ultrastructure; and (iii) autonomic remodeling, including altered sympathovagal activity and hyperinnervation. Electrical, structural, and autonomic remodeling all contribute to creating an AF-prone substrate which is able to produce AF-associated electrical phenomena including a rapidly firing focus, complex multiple reentrant circuit or rotors. Although various remodeling events occur in AF, current AF therapies focus on ventricular rate and rhythm control strategies using pharmacotherapy and surgical interventions. Recent progress in the field has started to focus on the underlying substrate that drives and maintains AF (termed upstream therapies); however, much work is needed in this area. Here, we review current knowledge of AF mechanisms, therapies, and new areas of investigation. PMID:25880508
Immune Regulatory Properties of CD117pos Amniotic Fluid Stem Cells Vary According to Gestational Age
Di Trapani, Mariano; Bassi, Giulio; Fontana, Emanuela; Giacomello, Luca; Pozzobon, Michela; Guillot, Pascale V.; De Coppi, Paolo
2015-01-01
Amniotic Fluid Stem (AFS) cells are broadly multipotent fetal stem cells derived from the positive selection and ex vivo expansion of amniotic fluid CD117/c-kitpos cells. Considering the differentiation potential in vitro toward cell lineages belonging to the three germ layers, AFS cells have raised great interest as a new therapeutic tool, but their immune properties still need to be assessed. We analyzed the in vitro immunological properties of AFS cells from different gestational age in coculture with T, B, and natural killer (NK) cells. Nonactivated (resting) first trimester-AFS cells showed lower expression of HLA class-I molecules and NK-activating ligands than second and third trimester-AFS cells, whose features were associated with lower sensitivity to NK cell-mediated lysis. Nevertheless, inflammatory priming with interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) enhanced resistance of all AFS cell types to NK cytotoxicity. AFS cells modulated lymphocyte proliferation in a different manner according to gestational age: first trimester-AFS cells significantly inhibited T and NK cell proliferation, while second and third trimester-AFS cells were less efficient. In addition, only inflammatory-primed second trimester-AFS cells could suppress B cell proliferation, which was not affected by the first and third trimester-AFS cells. Indolamine 2,3 dioxygenase pathway was significantly involved only in T cell suppression mediated by second and third trimester-AFS cells. Overall, this study shows a number of significant quantitative differences among AFS cells of different gestational age that have to be considered in view of their clinical application. PMID:25072397
Lone atrial fibrillation: where are we now?
Potpara, Tatjana S; Lip, Gregory Y
2011-10-01
There is a growing pandemic of atrial fibrillation (AF), affecting nearly 2% of the general adult population. Atrial fibrillation is commonly associated with structural heart disease, and AF itself causes a sequence of complex processes of electrical, contractile, and structural remodeling of the atrial myocardium, which facilitate further AF progression. Nonetheless, AF may also affect individuals aged ≤ 65 years who have no evidence of associated cardiopulmonary or other disease, including hypertension; this is otherwise referred to as "lone" AF and is considered to have a generally favorable prognosis. The true prevalence of lone AF is unknown. Growing insights into the diversity of numerous mechanisms involved in the pathogenesis of AF, including acute atrial stretch, structural and electrophysiological alterations, systemic inflammation, oxidative stress, autonomic imbalance, genetic predisposition, and many others, and increasing recognition of novel risk factors for AF, including obesity, metabolic syndrome, subclinical atherosclerosis, sleep apnea, alcohol consumption, and endurance sports, suggest that apparently lone AF might not be so "lone" in many patients, which could have important prognostic and therapeutic implications. In this article, we summarize the current knowledge of epidemiology, etiopathogenesis, and pathophysiology of so-called lone AF and discuss the issues of long-term prognosis and management of patients who have an apparently lone AF.
AF-6 is a positive modulator of the PINK1/parkin pathway and is deficient in Parkinson's disease
Haskin, Joseph; Szargel, Raymonde; Shani, Vered; Mekies, Lucy N.; Rott, Ruth; Lim, Grace G. Y.; Lim, Kah-Leong; Bandopadhyay, Rina; Wolosker, Herman; Engelender, Simone
2013-01-01
Parkin E3 ubiquitin-ligase activity and its role in mitochondria homeostasis are thought to play a role in Parkinson's disease (PD). We now report that AF-6 is a novel parkin interacting protein that modulates parkin ubiquitin-ligase activity and mitochondrial roles. Parkin interacts with the AF-6 PDZ region through its C-terminus. This leads to ubiquitination of cytosolic AF-6 and its degradation by the proteasome. On the other hand, endogenous AF-6 robustly increases parkin translocation and ubiquitin-ligase activity at the mitochondria. Mitochondrial AF-6 is not a parkin substrate, but rather co-localizes with parkin and enhances mitochondria degradation through PINK1/parkin-mediated mitophagy. On the other hand, several parkin and PINK1 juvenile disease-mutants are insensitive to AF-6 effects. AF-6 is present in Lewy bodies and its soluble levels are strikingly decreased in the caudate/putamen and substantia nigra of sporadic PD patients, suggesting that decreased AF-6 levels may contribute to the accumulation of dysfunctional mitochondria in the disease. The identification of AF-6 as a positive modulator of parkin translocation to the mitochondria sheds light on the mechanisms involved in PD and underscores AF-6 as a novel target for future therapeutics. PMID:23393160
The Bcr Kinase Downregulates Ras Signaling by Phosphorylating AF-6 and Binding to Its PDZ Domain
Radziwill, G.; Erdmann, R. A.; Margelisch, U.; Moelling, K.
2003-01-01
The protein kinase Bcr is a negative regulator of cell proliferation and oncogenic transformation. We identified Bcr as a ligand for the PDZ domain of the cell junction and Ras-interacting protein AF-6. The Bcr kinase phosphorylates AF-6, which subsequently allows efficient binding of Bcr to AF-6, showing that the Bcr kinase is a regulator of the PDZ domain-ligand interaction. Bcr and AF-6 colocalize in epithelial cells at the plasma membrane. In addition, Bcr, AF-6, and Ras form a trimeric complex. Bcr increases the affinity of AF-6 to Ras, and a mutant of AF-6 that lacks a specific phosphorylation site for Bcr shows a reduced binding to Ras. Wild-type Bcr, but not Bcr mutants defective in binding to AF-6, interferes with the Ras-dependent stimulation of the Raf/MEK/ERK pathway. Since AF-6 binds to Bcr via its PDZ domain and to Ras via its Ras-binding domain, we propose that AF-6 functions as a scaffold-like protein that links Bcr and Ras to cellular junctions. We suggest that this trimeric complex is involved in downregulation of Ras-mediated signaling at sites of cell-cell contact to maintain cells in a nonproliferating state. PMID:12808105
Rhythm-based heartbeat duration normalization for atrial fibrillation detection.
Islam, Md Saiful; Ammour, Nassim; Alajlan, Naif; Aboalsamh, Hatim
2016-05-01
Screening of atrial fibrillation (AF) for high-risk patients including all patients aged 65 years and older is important for prevention of risk of stroke. Different technologies such as modified blood pressure monitor, single lead ECG-based finger-probe, and smart phone using plethysmogram signal have been emerging for this purpose. All these technologies use irregularity of heartbeat duration as a feature for AF detection. We have investigated a normalization method of heartbeat duration for improved AF detection. AF is an arrhythmia in which heartbeat duration generally becomes irregularly irregular. From a window of heartbeat duration, we estimate the possible rhythm of the majority of heartbeats and normalize duration of all heartbeats in the window based on the rhythm so that we can measure the irregularity of heartbeats for both AF and non-AF rhythms in the same scale. Irregularity is measured by the entropy of distribution of the normalized duration. Then we classify a window of heartbeats as AF or non-AF by thresholding the measured irregularity. The effect of this normalization is evaluated by comparing AF detection performances using duration with the normalization, without normalization, and with other existing normalizations. Sensitivity and specificity of AF detection using normalized heartbeat duration were tested on two landmark databases available online and compared with results of other methods (with/without normalization) by receiver operating characteristic (ROC) curves. ROC analysis showed that the normalization was able to improve the performance of AF detection and it was consistent for a wide range of sensitivity and specificity for use of different thresholds. Detection accuracy was also computed for equal rates of sensitivity and specificity for different methods. Using normalized heartbeat duration, we obtained 96.38% accuracy which is more than 4% improvement compared to AF detection without normalization. The proposed normalization method was found useful for improving performance and robustness of AF detection. Incorporation of this method in a screening device could be crucial to reduce the risk of AF-related stroke. In general, the incorporation of the rhythm-based normalization in an AF detection method seems important for developing a robust AF screening device. Copyright © 2016 Elsevier Ltd. All rights reserved.
Colquhoun, Heather L; Carroll, Kelly; Eva, Kevin W; Grimshaw, Jeremy M; Ivers, Noah; Michie, Susan; Sales, Anne; Brehaut, Jamie C
2017-09-29
Audit and feedback (A&F) is a common strategy for helping health providers to implement evidence into practice. Despite being extensively studied, health care A&F interventions remain variably effective, with overall effect sizes that have not improved since 2003. Contributing to this stagnation is the fact that most health care A&F interventions have largely been designed without being informed by theoretical understanding from the behavioral and social sciences. To determine if the trend can be improved, the objective of this study was to develop a list of testable, theory-informed hypotheses about how to design more effective A&F interventions. Using purposive sampling, semi-structured 60-90-min telephone interviews were conducted with experts in theories related to A&F from a range of fields (e.g., cognitive, health and organizational psychology, medical decision-making, economics). Guided by detailed descriptions of A&F interventions from the health care literature, interviewees described how they would approach the problem of designing improved A&F interventions. Specific, theory-informed hypotheses about the conditions for effective design and delivery of A&F interventions were elicited from the interviews. The resulting hypotheses were assigned by three coders working independently into themes, and categories of themes, in an iterative process. We conducted 28 interviews and identified 313 theory-informed hypotheses, which were placed into 30 themes. The 30 themes included hypotheses related to the following five categories: A&F recipient (seven themes), content of the A&F (ten themes), process of delivery of the A&F (six themes), behavior that was the focus of the A&F (three themes), and other (four themes). We have identified a set of testable, theory-informed hypotheses from a broad range of behavioral and social science that suggest conditions for more effective A&F interventions. This work demonstrates the breadth of perspectives about A&F from non-healthcare-specific disciplines in a way that yields testable hypotheses for healthcare A&F interventions. These results will serve as the foundation for further work seeking to set research priorities among the A&F research community.
Kim, Joo Han; Moon, Hong Joo; Lee, Jin Hoon; Kim, Jong Hyun; Kwon, Taek Hyun; Park, Youn Kwan
2012-10-15
We evaluated the influence of rabbit notochordal cells on the expression of inflammatory mediators by human annulus fibrosus (AF) cells cocultured with macrophage-like cells. To identify the protective effect of rabbit notochordal cells on AF during in vitro inflammation. Discogenic pain, which is an important cause of intractable lower back pain, is associated with macrophage-mediated inflammation in the AF. Although rabbit notochordal cells prevent intervertebral disc degeneration, their effects on human AF inflammation remain unknown. Human AF pellets were cocultured for 48 hours with notochordal cell clusters from adult New Zealand White rabbits and phorbol myristate acetate (PMA)-stimulated human macrophage-like THP-1 cells. Conditioned media (CM) from the cocultures were assayed by enzyme-linked immunosorbent assay. The expression of inflammatory mediators in the AF pellets was evaluated by real-time reverse-transcription polymerase chain reaction. The levels of mRNA for interleukin (IL)-6, IL-8, and inducible nitric oxide synthase (iNOS) in the AF pellets cocultured with notochordal cells and macrophages (hAF[rNC-M]) were significantly lower than those in the AF pellets cultured with macrophages alone (hAF[M]) (P < 0.05). The levels of IL-6 and IL-8 proteins in the CM of hAF(rNC-M) were significantly lower than those in the CM of hAF(M) (P < 0.05). Coculturing with notochordal cells significantly decreased the levels of mRNA for IL-6, IL-8, and iNOS in the macrophage-exposed AF pellets (P < 0.05). After 1 ng/mL IL-1β stimulation, the levels of IL-6 and IL-8 mRNA and the level of IL-8 protein production were significantly decreased in the AF pellets with notochordal cells compared with naïve AF pellets (P < 0.05). In an in vitro coculture system, rabbit notochordal cells reduced the levels of main inflammatory mediators and gene expression in the human AF during inflammation. Therefore, rabbit notochordal cells may constitute an important protective tool against symptomatic disc development.
Chemistry of 1,1,2,2,9,9,10,10-octafluoro-[2,2]-paracyclophane: Its synthesis and reactions
NASA Astrophysics Data System (ADS)
Duan, Jian-Xin
This dissertation describes the first example of the synthesis of 1,1,2,2,9,9,10,10-octafluoro[2.2]paracyclophane (AF4) under non-high-dilution conditions. Under very mild reaction conditions, bis-p-(chlorodifluoromethyl)benzene (TFPX dichloride) and its derivatives reacted with Zn dust in N,N-dimethyl acetamide (DMA) (Zinc method) affording the corresponding AF4 and its derivatives in moderate to good yields. Purification of products was also studied and an efficient purification process was developed. A new and very cheap method for preparation of TFPX dichloride is also disclosed. Using the very cheap fluorinating reagent, anhydrous hydrogen fluoride (AHF), 1,4-bis(trichloromethyl)benezene or its derivatives were converted to TFPX and its derivatives in high yields (F/Cl exchange reaction). With the success of the Zinc method and F/Cl exchange reaction, highly pure AF4 thus can be provided to the semiconductor industry and academy research scientists in large quantity and at a very low price. Starting from AF4, numerous AF4 derivatives were synthesized using convenient reaction conditions. Reaction of AF4 with fuming nitric acid at room temperature gave mono-nitroAF4 in almost quantitative yield. Reduction of the mono-nitroAF4 with iron powder in the presence of HCl in alcoholic solvent gave the aminoAF4 in 90% yield. Via the diazonium salt intermediate, iodoAF4 was also obtained in good yield. Under similar reaction conditions, disubstituted AF4 derivatives were also prepared in good yields. Heating a mixture of AF4, trifluoroacetyl peroxide and dichloromethane gave the trifluoromethylated dimeric AF4 as a mixture of diastereomers. When these products were heated to 170--180°C in the presence of I 2, 4-trifluoromethyl-AF4 was obtained in almost 87% yield. X-ray structural analysis showed that the C-C bond connecting the two cyclophane moieties to be longer than the normal C-C bond. Kinetic studies, conducted in the presence of excess amount of hydrogen donor, showed this bond to be quite weak. Oxidation of AF4 with HIO3 in the presence of catalytic amount of H2SO4 in trifluoroacetic acid gave AF4 quinone in one step. AF4 quinone can be easily reduced to the hydroquinone by Na 2S2O4 aqueous solution.
Porous silicon photoluminescence biosensor for rapid and sensitive detection of toxins
NASA Astrophysics Data System (ADS)
Melnyk, Yulia; Pavlova, Karyna; Myndrul, Valerii; Viter, Roman; Smyntyna, Valentyn; Iatsunskyi, Igor
2017-08-01
A rapid and low cost photoluminescence (PL) immunosensor for the determination of low concentrations of Ochratoxin A(OTA) and Aflatoxine B1 (AfB1) has been developed. This biosensor was based on porous silicon (PSi) fabricated by metal-assisted chemical etching (MACE) and modified by antibodies against OTA/AfB1 (anti-OTA/anti-AfB1). Biofunctionalization method of the PSi surface by anti-OTA/ anti-AfB1 was developed. The changes of the PL intensity after interaction of the immobilized anti-OTA/anti-AfB1with OTA/AfB1 antigens were used as biosensor signal, allowing sensitive and selective detection of OTA/AfB1 antigens in BSA solution. The sensitivity of the reported optical biosensor towards OTA/AfB1 antigens is in the range from 10-3 to 102 ng/ml.
Left atrial structure and function in atrial fibrillation: ENGAGE AF-TIMI 48
Gupta, Deepak K.; Shah, Amil M.; Giugliano, Robert P.; Ruff, Christian T.; Antman, Elliott M.; Grip, Laura T.; Deenadayalu, Naveen; Hoffman, Elaine; Patel, Indravadan; Shi, Minggao; Mercuri, Michele; Mitrovic, Veselin; Braunwald, Eugene; Solomon, Scott D.
2014-01-01
Aims The complex relationship between left atrial (LA) structure and function, electrical burden of atrial fibrillation (AF) and stroke risk is not well understood. We aimed to describe LA structure and function in AF. Methods and results Left atrial structure and function was assessed in 971 subjects enrolled in the echocardiographic substudy of ENGAGE AF-TIMI 48. Left atrial size, emptying fraction (LAEF), and contractile function were compared across AF types (paroxysmal, persistent, or permanent) and CHADS2 scores as an estimate of stroke risk. The majority of AF patients (55%) had both LA enlargement and reduced LAEF, with an inverse relationship between LA size and LAEF (R = −0.57, P < 0.001). With an increasing electrical burden of AF and higher CHADS2 scores, LA size increased and LAEF declined. Moreover, 19% of AF subjects had impaired LAEF despite normal LA size, and LA contractile dysfunction was present even among the subset of AF subjects in sinus rhythm at the time of echocardiography. Conclusions In a contemporary AF population, LA structure and function were increasingly abnormal with a greater electrical burden of AF and higher stroke risk estimated by the CHADS2 score. Moreover, LA dysfunction was present despite normal LA size and sinus rhythm, suggesting that the assessment of LA function may add important incremental information in the evaluation of AF patients. Clinical Trial Registration: http://www.clinicaltrials.gov; ID = NCT00781391. PMID:24302269
The why, when and how to test for obstructive sleep apnea in patients with atrial fibrillation.
Desteghe, Lien; Hendriks, Jeroen M L; McEvoy, R Doug; Chai-Coetzer, Ching Li; Dendale, Paul; Sanders, Prashanthan; Heidbuchel, Hein; Linz, Dominik
2018-04-12
Sleep apnea is associated with increased cardiovascular risk and may be important in atrial fibrillation (AF) management. It is present in up to 62% of the AF population and is highly under-recognized and underdiagnosed. Obstructive sleep apnea (OSA) is strongly associated with AF and non-randomized trials have shown that its treatment can help to reduce AF recurrences and maintain sinus rhythm. The 2016 European Society of Cardiology guidelines for the management of AF recommend that AF patients should be questioned regarding the symptoms of OSA and that OSA-treatment should be optimized to improve AF treatment results. However, strategies on how to implement OSA testing in the standard work-up of AF patients are not provided in the guidelines. Additionally, overnight OSA monitoring rather than interrogation for OSA-related clinical signs alone may be necessary to reliably identify OSA in the majority of AF patients. This review summarizes the available clinical data on OSA in AF patients, and discusses the following key questions: Why and When is testing for OSA needed in AF patients? How and Where should it be performed and coordinated? and Who should test for OSA? To implement OSA testing in a cardiology or electrophysiology clinic, we propose a multidisciplinary integrated care approach based on a chronic care model. We describe the tools, infrastructure and coordination needed to test for OSA in the standard workup of patients with symptomatic AF prior to the initiation of directed invasive or pharmacological rhythm control management.
Atrial fibrillation in the Middle East: unmapped, underdiagnosed, undertreated.
Al-Shamkhani, Warkaa; Ayetey, Harold; Lip, Gregory Y H
2018-05-01
Atrial fibrillation (AF) is the commonest persistent cardiac arrhythmia with an estimated incidence rate of between 1.5-2% and an important cause of strokes. Few epidemiological studies and clinical trials on the management of AF have been conducted outside Europe and North America. These gaps in our understanding of AF likely lead to sub-optimal management of patients with AF in the rest of the world. Areas covered: We discuss the epidemiology, treatment and clinical outcomes for AF in the Middle East after systematic review of published work for AF from the Middle East. We also discuss important clinical trials on AF conducted in the West in the same period to help contextualize our findings. Expert commentary: The few available Middle East studies suggest important epidemiological differences between Middle Eastern and Western AF populations. In particular, the Middle Eastern AF population is younger and have more co-morbidities than patients in the West. We find that significant numbers of moderate to high risk patients with AF are either undertreated or untreated placing them at increased risk of complications such as stroke. More studies in the Middle Eastern population are required to aid the development of region-specific clinical guidelines to improve patient care.
Persistent atrial fibrillation vs paroxysmal atrial fibrillation: differences in management.
Margulescu, Andrei D; Mont, Lluis
2017-08-01
Atrial fibrillation (AF) is the most common human arrhythmia. AF is a progressive disease, initially being nonsustained and induced by trigger activity, and progressing towards persistent AF through alteration of the atrial myocardial substrate. Treatment of AF aims to decrease the risk of stroke and improve the quality of life, by preventing recurrences (rhythm control) or controlling the heart rate during AF (rate control). In the last 20 years, catheter-based and, less frequently, surgical and hybrid ablation techniques have proven more successful compared with drug therapy in achieving rhythm control in patients with AF. However, the efficiency of ablation techniques varies greatly, being highest in paroxysmal and lowest in long-term persistent AF. Areas covered: In this review, we discuss the fundamental differences between paroxysmal and persistent AF and the potential impact of those differences on patient management, emphasizing the available therapeutic strategies to achieve rhythm control. Expert commentary: Treatment to prevent AF recurrences is suboptimal, particularly in patients with persistent AF. Emerging technologies, such as documentation of atrial fibrosis using magnetic resonance imaging and documentation of electrical substrate using advanced electrocardiographic imaging techniques are likely to provide valuable insights about patient-specific tailoring of treatments.
Lau, Dennis H; Kalman, Jonathan; Sanders, Prashanthan
2014-09-01
Recent studies have highlighted significant variations in the management of recent-onset sustained atrial fibrillation (AF). We aim to provide a succinct and clear management algorithm for physicians treating patients with recent-onset sustained AF. We performed a comprehensive search of the literature on the management of recent-onset sustained AF with focus on studies reporting cardioversion of AF, antiarrhythmic agents, and anticoagulation. We also reviewed recent practice guidelines on AF management. This review provides a guide on a tailored management approach of patients with recent-onset sustained AF. After initial detailed clinical assessment, optimal rate and rhythm control options can be provided, depending on hemodynamic stability, duration of AF episode, and AF stroke risk. Issues surrounding electrical and pharmacologic cardioversion are discussed in detail. We emphasize the importance of thromboembolic risk assessment and appropriate anticoagulation surrounding the point of cardioversion. Last, we highlighted the need for appropriate specialized follow-up care after acute AF management. Despite the highly heterogeneous clinical presentations, management of recent-onset sustained AF must include stroke risk assessment, appropriate anticoagulation, and follow-up care in all patients beyond optimum rate and rhythm control strategies. Copyright © 2014. Published by Elsevier Inc.
Fei, Dennis Liang; Motowski, Hayley; Chatrikhi, Rakesh; Gao, Shaojian; Kielkopf, Clara L.; Varmus, Harold
2016-01-01
We have asked how the common S34F mutation in the splicing factor U2AF1 regulates alternative splicing in lung cancer, and why wild-type U2AF1 is retained in cancers with this mutation. A human lung epithelial cell line was genetically modified so that U2AF1S34F is expressed from one of the two endogenous U2AF1 loci. By altering levels of mutant or wild-type U2AF1 in this cell line and by analyzing published data on human lung adenocarcinomas, we show that S34F-associated changes in alternative splicing are proportional to the ratio of S34F:wild-type gene products and not to absolute levels of either the mutant or wild-type factor. Preferential recognition of specific 3′ splice sites in S34F-expressing cells is largely explained by differential in vitro RNA-binding affinities of mutant versus wild-type U2AF1 for those same 3′ splice sites. Finally, we show that lung adenocarcinoma cell lines bearing U2AF1 mutations do not require the mutant protein for growth in vitro or in vivo. In contrast, wild-type U2AF1 is required for survival, regardless of whether cells carry the U2AF1S34F allele. Our results provide mechanistic explanations of the magnitude of splicing changes observed in U2AF1-mutant cells and why tumors harboring U2AF1 mutations always retain an expressed copy of the wild-type allele. PMID:27776121
Kim, Daehoon; Yang, Pil-Sung; Jang, Eunsun; Yu, Hee Tae; Kim, Tae-Hoon; Uhm, Jae-Sun; Kim, Jong-Youn; Pak, Hui-Nam; Lee, Moon-Hyoung; Joung, Boyoung; Lip, Gregory Yh
2018-05-01
Most data on the clinical epidemiology of atrial fibrillation (AF) are reported from Western populations, and data for Asians are limited. We aimed to investigate the 10-year trends of the prevalence and incidence of non-valvular AF and provide prevalence projections till 2060 in Korea. We also investigated the annual risks of adverse outcomes among patients with AF. Using the Korean National Health Insurance Service database involving the entire Korean population, a total of 679,416 adults with newly diagnosed AF were identified from 2006 to 2015. The incidence and prevalence of AF and risk of adverse outcomes following AF onset were assessed. The prevalence of AF progressively increased by 2.10-fold from 0.73% in 2006 to 1.53% in 2015. The trend of its incidence was flat with a 10-year overall incidence of 1.77 per 1,000 person-years. The prevalence of AF is expected to reach 5.81% (2,290,591 patients with AF) in 2060. For a decade, the risk of all-cause mortality following AF declined by 30% (adjusted hazard ratio [HR]: 0.70, 95% confidence interval [CI]: 0.68-0.72), heart failure by 52% (adjusted HR: 0.48, 95% CI: 0.44-0.51), and ischemic stroke by 9% (adjusted HR: 0.91, 95% CI: 0.88-0.93). The burden of AF among Asian patients is increasing. Although the overall risks of cardiovascular events and death following AF onset have decreased over a decade, the event rates are still high. Optimized management of any associated comorbidities should be part of the holistic management approach for patients with AF. Copyright © 2018. Published by Elsevier Inc.
Sozzi, Gabriel O.; Greve, L. Carl; Prody, Gerry A.; Labavitch, John M.
2002-01-01
α-l-Arabinofuranosidases (α-Afs) are plant enzymes capable of releasing terminal arabinofuranosyl residues from cell wall matrix polymers, as well as from different glycoconjugates. Three different α-Af isoforms were distinguished by size exclusion chromatography of protein extracts from control tomatoes (Lycopersicon esculentum) and an ethylene synthesis-suppressed (ESS) line expressing an antisense 1-aminocyclopropane-1-carboxylic synthase transgene. α-Af I and II are active throughout fruit ontogeny. α-Af I is the first Zn-dependent cell wall enzyme isolated from tomato pericarp tissues, thus suggesting the involvement of zinc in fruit cell wall metabolism. This isoform is inhibited by 1,10-phenanthroline, but remains stable in the presence of NaCl and sucrose. α-Af II activity accounts for over 80% of the total α-Af activity in 10-d-old fruit, but activity drops during ripening. In contrast, α-Af III is ethylene dependent and specifically active during ripening. α-Af I released monosaccharide arabinose from KOH-soluble polysaccharides from tomato cell walls, whereas α-Af II and III acted on Na2CO3-soluble pectins. Different α-Af isoform responses to gibberellic acid, synthetic auxins, and ethylene were followed by using a novel ESS mature-green tomato pericarp disc system. α-Af I and II activity increased when gibberellic acid or 2,4-dichlorophenoxyacetic acid was applied, whereas ethylene treatment enhanced only α-Af III activity. Results suggest that tomato α-Afs are encoded by a gene family under differential hormonal controls, and probably have different in vivo functions. The ESS pericarp explant system allows comprehensive studies involving effects of physiological levels of different growth regulators on gene expression and enzyme activity with negligible wound-induced ethylene production. PMID:12114586
Alonso, Alvaro; Agarwal, Sunil K; Soliman, Elsayed Z; Ambrose, Marietta; Chamberlain, Alanna M; Prineas, Ronald J; Folsom, Aaron R
2009-07-01
To define the incidence and cumulative risk of atrial fibrillation (AF) in a population-based cohort of whites and African Americans. African-Americans reportedly have a lower risk of AF than whites despite their higher exposure to AF risk factors. However, precise estimates of AF incidence in African Americans have not been previously published. We studied the incidence of AF in the Atherosclerosis Risk in Communities (ARIC) study, which has followed up 15,792 men and women 45 to 65 years of age at baseline from 4 communities in the United States since 1987. Atrial fibrillation cases were identified from electrocardiograms conducted at baseline and 3 follow-up visits, and from hospitalizations and death certificates through the end of 2004. During follow-up, 1,085 new cases of AF were identified (196 in African Americans, 889 in whites). Crude incidence rates of AF were 6.7, 4.0, 3.9, and 3.0 per 1,000 persons per year in white men, white women, African-American men, and African-American women, respectively. Increasing age was exponentially associated with an elevated risk of AF. Compared to whites, African-Americans had a 41% (95% CI: 8%-62%) lower age- and sex-adjusted risk of being diagnosed with AF. The cumulative risk of AF at 80 years of age was 21% in white men, 17% in white women, and 11% in African-American men and women. In this population-based cohort, African Americans presented a lower risk of AF than whites. Still, the burden of AF among the former is substantial, with 1 in 9 receiving a diagnosis of AF before 80 years of age.
Zhou, Ziqiang; Hu, Dayi
2008-01-01
Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. Since only limited data on the Chinese population, which is the largest in the world, is available, we conducted an epidemiological study on the prevalence and risk factors of AF in mainland China. This population-based study conducted by cluster sampling comprised 29079 participants forming 14 cohorts from 13 provinces across China, where the population was nearly 1 billion. Every participant underwent electrocardiogram and physical examinations and responded to the interviewer-led questionnaire(s). Univariate and multiple statistical analyses were conducted to explore the relationship between AF prevalence and risk factors. The age-standardized prevalence of AF in China (>or=30 y) was 0.65%, and it increased with age. Men showed a higher prevalence of AF than women (0.91% [age-standardized, 0.66%] vs. 0.65% [0.63%], P = 0.013); several significant risk factors (age, hyperthyroidism, coronary heart disease, and rheumatic heart disease) were identified for AF in the general population. Stroke prevalence was much higher in AF patients than in non-AF people (12.95% vs. 2.28%, P < 0.001). AF was confirmed to be a significant independent risk factor for stroke prevalence in the studied population (OR = 2.776, [1.814, 4.248], P < 0.001). We found that AF patients received poor treatment (2.7%, warfarin; 39.7%, aspirin). This study conducted on a large sample size demonstrates that AF prevalence in mainland China is slightly lower than that in Western countries and similar to that in Asian areas, and confirms that AF is a serious public health problem in China. We identified several potential risk factors, but their associations with AF still need to be further studied.
Aspergillus sensitization or carriage in cystic fibrosis patients.
Fillaux, Judith; Brémont, François; Murris, Marlène; Cassaing, Sophie; Tétu, Laurent; Segonds, Christine; Pipy, Bernard; Magnaval, Jean-François
2014-07-01
Aspergillus fumigatus (Af) sensitization and persistent carriage are deleterious to lung function, but no consensus has been reached defining these medical entities. This work aimed to identify possible predictive factors for patients who become sensitized to Af, compared with a control group of non-sensitized Af carriers. Between 1995 and 2007, 117 pediatric patients were evaluated. Demographic data, CFTR gene mutations, body mass index and FEV1 were recorded. The presence of Af in sputum, the levels of Af-precipitin, total IgE (t-IgE) and specific IgE to Af (Af-IgE) were determined. Patients were divided into 2 groups: (1) "sensitization": level of Af-IgE > 0.35 IU/mL with t-IgE level < 500 IU/mL and (2) "persistent or transient carriage": Af-IgE level ≤ 0.35 IU/mL with either an Af transient or persistent positive culture. A survival analysis was performed with the appearance of Af-IgE in serum as an outcome variable. Severe mutation (hazard ratio = 3.2), FEV1 baseline over 70% of theoretical value (hazard ratio = 4.9), absence of Pa colonization, catalase activity and previous azithromycin administration (hazard ratio = 9.8, 4.1 and 1.9, respectively) were predictive factors for sensitization. We propose a timeline of the biological events and a tree diagram for risk calculation. Two profiles of cystic fibrosis patients can be envisaged: (1) patients with nonsevere mutation but low FEV1 baselines are becoming colonized with Af or (2) patients with high FEV1 baselines who present with severe mutation are more susceptible to the Af sensitization and then to the presentation of an allergic bronchopulmonary aspergillosis event.
Predictors of Long-term Success After Concomitant Surgical Ablation for Atrial Fibrillation.
Pecha, Simon; Ghandili, Susanne; Hakmi, Samer; Willems, Stephan; Reichenspurner, Hermann; Wagner, Florian Mathias
2017-01-01
According to guidelines, atrial fibrillation (AF) ablation success should be measured by 24-hour Holter electrocardiogram (ECG). However, information on long-term success, especially obtained by 24-hour Holter ECG, is rare. We therefore analyzed rhythm course and long-term outcomes of our patients undergoing concomitant surgical AF ablation. Between January 2003 and April 2011, 486 patients underwent concomitant surgical AF ablation in our institution. Patients with 24-hour Holter ECG rhythm status available between 5 and 10 years postoperatively were included in this retrospective data analysis (n = 155). Ablation lesions were limited to either a pulmonary vein isolation (n = 31, 20%), a more complex left atrial lesion set (n = 89, 57%), or biatrial lesions (n = 35, 23%). Primary end point of the study was freedom from AF during long-term follow-up. Mean patient age was 68.1 ± 8.4 years; 57.4% were male. Mean follow-up time was 5.9 years. Surgical AF ablation provided freedom from AF rate of 56.6% during long-term follow-up, with significantly better results in patients with paroxysmal than in those with persistent AF (67.2% vs 51.8% P = 0.03). A stable rhythm course was observed during follow-up, without statistically significant differences between 12 months and latest follow-up (63.2% vs 56.6%; P = 0.25). In multivariate analysis, preoperative paroxysmal AF, duration of AF, and left atrial diameter were predictors of long-term ablation success. Surgical AF ablation provided freedom from AF rate of 56.6% during long-term follow-up. Statistically significant predictors of ablation success at latest follow-up were preoperative paroxysmal AF, duration of AF, and a preoperative smaller left atrial diameter. Copyright © 2017. Published by Elsevier Inc.
Jan, Matevž; Žižek, David; Geršak, Živa Miriam; Geršak, Borut
2018-05-03
While catheter ablation (CA) is an established treatment for symptomatic paroxysmal atrial fibrillation (AF), convergent epicardial and endocardial ablation procedure (CVP) has been primarily used to treat persistent AF. The aim of this single-center, prospective, randomized study was to compare treatment efficacy of CA and CVP in paroxysmal AF patients by monitoring AF, atrial tachycardia (AT), and atrial flutter (AFL) recurrence with Implantable Loop Recorder (ILR). Fifty patients (74% male) with history of paroxysmal AF were randomized between CA and CVP. Outcomes were determined by ILRs; every episode of AF/AT/AFL lasting 6 minutes or more was defined as a recurrence. AF burden (AFB) and required AF reinterventions (cardioversions and repeat ablations) were quantified after a 3-month blanking period. Total procedural (266 ± 44 vs. 242 ± 39 minutes) and ablation duration (52 ± 10 vs. 48 ± 12 minutes) was similar in both groups. Recurrence of AF/AT/AFL was more likely in the CA group compared to the CVP group (OR 3.78 (95% CI (1.17, 12.19), P = 0.048)). During the follow-up period (mean 30.5 ± 6.9 months), higher AF burden and more reinterventions for recurrent AF were recorded in the CA group. There were more periprocedural complications in the CVP group (12.5%) compared to the CA group (0%). Treatment of paroxysmal AF with CVP showed less arrhythmia recurrence compared to CA. In addition, patients after CVP had fewer reinterventions and lower AF burden, but more periprocedural complications. © 2018 Wiley Periodicals, Inc.
Atrial Fibrillation and Colonic Neoplasia in African Americans.
Nouraie, Mehdi; Kansal, Vandana; Belfonte, Cassius; Ghazvini, Mohammad; Haidari, Tahmineh; Shahnazi, Anahita; Brim, Hassan; Soliman, Elsayed Z; Ashktorab, Hassan
2015-01-01
Colorectal cancer (CRC) and atrial fibrillation/flutter (AF) share several risk factors including increasing age and obesity. However, the association between CRC and AF has not been thoroughly examined, especially in African Americans. In this study we aimed to assess the prevalence of AF and its risk factors in colorectal neoplasia in an African American. We reviewed records of 527 African American patients diagnosed with CRC and 1008 patients diagnosed with benign colonic lesions at Howard University Hospital from January 2000 to December 2012. A control group of 731 hospitalized patients without any cancer or colonic lesion were randomly selected from the same time and age range, excluding patients who had diagnosis of both CRC and/or adenoma. The presence or absence of AF was based upon ICD-9 code documentation. The prevalence of AF in these three groups was compared by multivariate logistic regression. The prevalence of AF was highest among CRC patients (10%) followed by adenoma patients (7.2%) then the control group (5.4%, P for trend = 0.002). In the three groups of participants, older age (P<0.008) and heart failure (P<0.001) were significantly associated with higher risk of AF. After adjusting for these risk factors, CRC (OR: 1.4(95%CI):0.9-2.2, P = 0.2) and adenoma (OR: 1.1(95%CI):0.7-1.6, P = 0.7) were not significantly associated AF compared to control group. AF is highly prevalent among CRC patients; 1 in 10 patients had AF in our study. The predictors of AF in CRC was similar to that in adenoma and other patients after adjustment for potential confounders suggesting that the increased AF risk in CRC is explained by higher prevalence of AF risk factors.
Atrioventricular node functional remodeling induced by atrial fibrillation.
Zhang, Youhua; Mazgalev, Todor N
2012-09-01
The atrioventricular node (AVN) plays a vital role in determining the ventricular rate during atrial fibrillation (AF). AF results in profound electrophysiological and structural remodeling in the atria as well as the sinus node. However, it is unknown whether AVN undergoes remodeling during AF. To determine whether AVN undergoes functional remodeling during AF. AVN conduction properties were studied in vitro in 9 rabbits with AF and 10 normal controls. A previously validated index of AVN dual-pathway electrophysiology, His-electrogram alternans, was used to monitor fast-pathway or slow-pathway (SP) AVN conduction in these experiments. AVN conduction properties were further studied in vivo in 7 dogs with chronic AF and 8 controls. Compared with the control rabbits, the rabbits with AF had a longer AVN conduction time (83 ± 16 ms vs 68 ± 7 ms; P <.01), longer AVN effective refractory period (141 ± 27 ms vs 100 ± 9 ms; P <.01), an earlier transition from fast-pathway to SP conduction (at a longer prematurity, 249 ± 60 ms vs 171 ± 24 ms; P <.01), and a slower ventricular rate during simulated AF (RR interval 249 ± 42 ms vs 202 ± 12 ms; P <.01). Notably, a larger proportion of conducted beats utilized the SP in AF preparations (92% ± 12% vs 63% ± 32%; P <.05). Long-term AF in dogs resulted in a longer atrioventricular conduction time and AVN effective refractory period and a slower ventricular rate during AF compared with the controls. Pronounced AVN functional electrophysiological remodeling occurs after long-term AF, which could lead to a spontaneous slowing of the ventricular rate. Furthermore, the SP dominance during AF underscores the effectiveness of its modification by ablation for ventricular rate control during AF. Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
Nam, Ki Tae; Yun, Cheol Min; Kim, Jee Taek; Yang, Kyung-Sook; Kim, Hyun Joo; Kim, Seong-Woo; Oh, Jaeryung; Huh, Kuhl
2015-12-01
To compare the lesion characteristics of two different types of confocal scanning laser ophthalmoscopy (cSLO) autofluorescence (AF) images in central serous chorioretinopathy (CSC). The study included 63 eyes of 61 patients; 63 pairs of fundus autofluorescence (FAF) images were compared before CSC resolution in 63 eyes, FAF images of 31 eyes were also compared after CSC resolution. The lesion characteristics (brightness and composite pattern) were compared between Heidelberg Retina Angiograph 2 (HRA2; Heidelberg Engineering, Germany) and Optomap Tx (Optomap; Optos, Scotland) FAF images. The lesion composite pattern was categorized as diffuse or granular. Diffuse AF was defined as homogenously increased or decreased AF, and granular AF was defined as dot-like, coarse changes in AF. The mean disease duration and subretinal fluid (SRF) height in the spectral domain optical coherence tomography were compared according to the FAF image characteristics. Lesion brightness before CSC resolution was hypo-AF in 48 eyes (76.2 %), hyper-AF in three (4.8 %), and mixed-AF in 12 (19.0 %) in HRA2 FAF images. In comparison, nine (14.3 %) images were hypo-AF, 44 (69.8 %) were hyper-AF, and 10 (15.9 %) were mixed-AF in Optomap FAF images (P < 0.0001). There was no significant difference in lesion composite pattern between the two FAF image wavelengths. Patients with lesions that were hyper-AF in Optomap FAF and hypo-AF in HRA2 FAF had a shorter disease duration and greater SRF height (1 month, 281 um) than those who were hyper-AF in both Optomap and HRA2 images (26 months, 153 um; P = 0.004, 0.001). The two types of FAF images of CSC showed different lesion brightness before and after CSC resolution but demonstrated similar lesion composite patterns.
Karna, Sunil; Patel, Harshil; Fahey, Nisha; Raithatha, Shyamsundar; Handorf, Anna; Bostrom, John; Bashar, Syed; Talati, Kandarp; Shah, Ravi; Goldberg, Robert J; Thanvi, Sunil; Allison, Jeroan J; Chon, Ki; Nimbalkar, Somashekhar Marutirao; McManus, David D
2017-01-01
Introduction Atrial fibrillation (AF), the world’s most common arrhythmia, often goes undetected and untreated in low-resource communities, including India, where AF epidemiology is undefined. AF is an important risk factor for stroke, which plagues an estimated 1.6 million Indians annually. As such, early detection of AF and management of high-risk patients is critically important to decrease stroke burden in individuals with AF. This study aims to describe the epidemiology of AF in Anand District, Gujarat, India, characterise the clinical profile of individuals who are diagnosed with AF and determine the performance of two mobile technologies for community-based AF screening. Methods This observational study builds on findings from a previous feasibility study and leverages two novel technologies as well as an existing community health programme to perform door-to-door AF screening for 2000 people from 60 villages of Anand District, Gujarat, India using local health workers. A single-lead ECG and a pulse-based application is used to screen each individual for AF three times over a period of 5 days. Participants with suspected arrhythmias are followed up by study cardiologist who makes final diagnoses. Participants diagnosed with AF are initiated on treatment based on current anticoagulation guidelines and clinical reasoning. Analytical plan Age-stratified and sex-stratified prevalence of AF in the Anand District will be calculated for sample and estimated for Anand distribution using survey design weights. Sociodemographic and clinical factors associated with AF will be evaluated using multivariable regression methods. Performance of each mobile technology in detecting AF will be evaluated using a 12-lead ECG interpretation as the gold standard. Ethics and dissemination This protocol was approved separately by the Institutional Review Board of University of Massachusetts Medical School and the Human Research Ethics Committee at Charutar Arogya Mandal. The findings of this study will be disseminated through peer-reviewed journals and scientific conferences. PMID:29247089
Treatment of Atrial Fibrillation By The Ablation Of Localized Sources
Narayan, Sanjiv M.; Krummen, David E.; Shivkumar, Kalyanam; Clopton, Paul; Rappel, Wouter-Jan; Miller, John M.
2012-01-01
Objectives We hypothesized that human atrial fibrillation (AF) may be sustained by localized sources (electrical rotors and focal impulses), whose elimination (Focal Impulse and Rotor Modulation, FIRM) may improve outcome from AF ablation. Background Catheter ablation for AF is a promising therapy, whose success is limited in part by uncertainty in the mechanisms that sustain AF. We developed a computational approach to map whether AF is sustained by several meandering waves (the prevailing hypothesis) or localized sources, then prospectively tested whether targeting patient-specific mechanisms revealed by mapping would improve AF ablation outcome. Methods We recruited 92 individuals during 107 consecutive ablation procedures for paroxysmal or persistent (72%) AF. Cases were prospectively treated, in a 2-arm 1:2 design, by ablation at sources (FIRM-Guided) followed by conventional ablation (n=36), or conventional ablation alone (n=71; FIRM-Blinded). Results Localized rotors or focal impulses were detected in 98 (97%) of 101 cases with sustained AF, each exhibiting 2.1±1.0 sources. The acute endpoint (AF termination or consistent slowing) was achieved in 86% of FIRM-guided versus 20% of FIRM-Blinded cases (p<0.001). FIRM ablation alone at the primary source terminated AF in 2.5 minutes (median; IQR 1.0–3.1). Total ablation time did not differ between groups (57.8±22.8 versus 52.1±17.8 minutes, p=0.16). During 273 days (median; IQR 132–681 days) after a single procedure, FIRM-Guided cases had higher freedom from AF (82.4% versus 44.9%; p<0.001) after a single procedure than FIRM-blinded cases with rigorous, often implanted, ECG monitoring. Adverse events did not differ between groups. CONCLUSIONS Localized electrical rotors and focal impulse sources are prevalent sustaining-mechanisms for human AF. FIRM ablation at patient-specific sources acutely terminated or slowed AF, and improved outcome. These results offer a novel mechanistic framework and treatment paradigm for AF. (ClinicalTrials.gov number, NCT01008722) PMID:22818076
Recognition of the 3′ splice site RNA by the U2AF heterodimer involves a dynamic population shift
Voith von Voithenberg, Lena; Sánchez-Rico, Carolina; Kang, Hyun-Seo; Madl, Tobias; Zanier, Katia; Barth, Anders; Warner, Lisa R.; Sattler, Michael; Lamb, Don C.
2016-01-01
An essential early step in the assembly of human spliceosomes onto pre-mRNA involves the recognition of regulatory RNA cis elements in the 3′ splice site by the U2 auxiliary factor (U2AF). The large (U2AF65) and small (U2AF35) subunits of the U2AF heterodimer contact the polypyrimidine tract (Py-tract) and the AG-dinucleotide, respectively. The tandem RNA recognition motif domains (RRM1,2) of U2AF65 adopt closed/inactive and open/active conformations in the free form and when bound to bona fide Py-tract RNA ligands. To investigate the molecular mechanism and dynamics of 3′ splice site recognition by U2AF65 and the role of U2AF35 in the U2AF heterodimer, we have combined single-pair FRET and NMR experiments. In the absence of RNA, the RRM1,2 domain arrangement is highly dynamic on a submillisecond time scale, switching between closed and open conformations. The addition of Py-tract RNA ligands with increasing binding affinity (strength) gradually shifts the equilibrium toward an open conformation. Notably, the protein–RNA complex is rigid in the presence of a strong Py-tract but exhibits internal motion with weak Py-tracts. Surprisingly, the presence of U2AF35, whose UHM domain interacts with U2AF65 RRM1, increases the population of the open arrangement of U2AF65 RRM1,2 in the absence and presence of a weak Py-tract. These data indicate that the U2AF heterodimer promotes spliceosome assembly by a dynamic population shift toward the open conformation of U2AF65 to facilitate the recognition of weak Py-tracts at the 3′ splice site. The structure and RNA binding of the heterodimer was unaffected by cancer-linked myelodysplastic syndrome mutants. PMID:27799531
Lim, Byounghyun; Hwang, Minki; Song, Jun-Seop; Ryu, Ah-Jin; Joung, Boyoung; Shim, Eun Bo; Ryu, Hyungon
2017-01-01
Background We previously reported that stable rotors are observed in in-silico human atrial fibrillation (AF) models, and are well represented by a dominant frequency (DF). In the current study, we hypothesized that the outcome of DF ablation is affected by conduction velocity (CV) conditions and examined this hypothesis using in-silico 3D-AF modeling. Methods We integrated 3D CT images of left atrium obtained from 10 patients with persistent AF (80% male, 61.8±13.5 years old) into in-silico AF model. We compared AF maintenance durations (max 300s), spatiotemporal stabilities of DF, phase singularity (PS) number, life-span of PS, and AF termination or defragmentation rates after virtual DF ablation with 5 different CV conditions (0.2, 0.3, 0.4, 0.5, and 0.6m/s). Results 1. AF maintenance duration (p<0.001), spatiotemporal mean variance of DF (p<0.001), and the number of PS (p = 0.023) showed CV dependent bimodal patterns (highest at CV0.4m/s and lowest at CV0.6m/s) consistently. 2. After 10% highest DF ablation, AF defragmentation rates were the lowest at CV0.4m/s (37.8%), but highest at CV0.5 and 0.6m/s (all 100%, p<0.001). 3. In the episodes with AF termination or defragmentation followed by 10% highest DF ablation, baseline AF maintenance duration was shorter (p<0.001), spatiotemporal mean variance of DF was lower (p = 0.014), and the number of PS was lower (p = 0.004) than those with failed AF defragmentation after DF ablation. Conclusion Virtual ablation of DF, which may indicate AF driver, was more likely to terminate or defragment AF with spatiotemporally stable DF, but not likely to do so in long-lasting and sustained AF conditions, depending on CV. PMID:29287119
Circulating miRNAs in acute new-onset atrial fibrillation and their target mRNA network.
da Silva, Ananília Medeiros Gomes; de Araújo, Jéssica Nayara Góes; de Oliveira, Katiene Macêdo; Novaes, Ana Eloísa Melo; Lopes, Mariana Borges; de Sousa, Júlio César Vieira; Filho, Antônio Amorim de Araújo; Luchessi, André Ducati; de Rezende, Adriana Augusto; Hirata, Mário Hiroyuki; Silbiger, Vivian Nogueira
2018-04-20
MicroRNAs (miRNAs) are involved in the pathogenesis of atrial fibrillation (AF), acting on development and progression. Our pilot study investigated the expression of six miRNAs and their miRNA-mRNA interactions in patients with acute new-onset AF, well-controlled AF, and normal sinus rhythm (controls). Plasma of acute new-onset AF patients (n = 5) was collected in the emergency room when patients presented with irregular and fast-atrial fibrillation rhythm. Samples from well-controlled AF (n = 16) and control (n = 15) patients were collected during medical appointments following an ECG. Expression of miR-21, miR-133a, miR-133b, miR-150, miR-328, and miR-499 was analyzed by real-time PCR. Ingenuity Pathway Analysis and the TargetScan database identified the top 30 mRNA targets of these miRNA, seeking the miRNA-mRNA interactions in cardiovascular process. Increased expression of miR-133b (1.4-fold), miR-328 (2.0-fold), and miR-499 (2.3-fold) was observed in patients with acute new-onset AF, compared with well-controlled AF and control patients. Decreased expression of miR-21 was seen in patients with well-controlled AF compared to those with acute new-onset AF and controls (0.6-fold). The miRNA-mRNA interaction demonstrated that SMAD7 and FASLG genes were the targets of miR-21, miR-133b, and miR-499 and were directly related to AF, being involved in apoptosis and fibrosis. The miRNAs had different expression profiles dependent on the AF condition, with higher expression in the acute new-onset AF than well-controlled AF. Clinically, this may contribute to an effective assessment for patients, leading to early detection of AF and monitoring to reduce the risk of other serious cardiovascular events. © 2018 Wiley Periodicals, Inc.
Steinberg, Benjamin A; Hellkamp, Anne S; Lokhnygina, Yuliya; Patel, Manesh R; Breithardt, Günter; Hankey, Graeme J; Becker, Richard C; Singer, Daniel E; Halperin, Jonathan L; Hacke, Werner; Nessel, Christopher C; Berkowitz, Scott D; Mahaffey, Kenneth W; Fox, Keith A A; Califf, Robert M; Piccini, Jonathan P
2015-02-01
Anticoagulation prophylaxis for stroke is recommended for at-risk patients with either persistent or paroxysmal atrial fibrillation (AF). We compared outcomes in patients with persistent vs. paroxysmal AF receiving oral anticoagulation. Patients randomized in the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET-AF) trial (n = 14 264) were grouped by baseline AF category: paroxysmal or persistent. Multivariable adjustment was performed to compare thrombo-embolic events, bleeding, and death between groups, in high-risk subgroups, and across treatment assignment (rivaroxaban or warfarin). Of 14 062 patients, 11 548 (82%) had persistent AF and 2514 (18%) had paroxysmal AF. Patients with persistent AF were marginally older (73 vs. 72, P = 0.03), less likely female (39 vs. 45%, P < 0.0001), and more likely to have previously used vitamin K antagonists (64 vs. 56%, P < 0.0001) compared with patients with paroxysmal AF. In patients randomized to warfarin, time in therapeutic range was similar (58 vs. 57%, P = 0.94). Patients with persistent AF had higher adjusted rates of stroke or systemic embolism (2.18 vs. 1.73 events per 100-patient-years, P = 0.048) and all-cause mortality (4.78 vs. 3.52, P = 0.006). Rates of major bleeding were similar (3.55 vs. 3.31, P = 0.77). Rates of stroke or systemic embolism in both types of AF did not differ by treatment assignment (rivaroxaban vs. warfarin, Pinteraction = 0.6). In patients with AF at moderate-to-high risk of stroke receiving anticoagulation, those with persistent AF have a higher risk of thrombo-embolic events and worse survival compared with paroxysmal AF. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Cardiology.
Multimodal Imaging of Disease-Associated Pigmentary Changes in Retinitis Pigmentosa
Schuerch, Kaspar; Marsiglia, Marcela; Lee, Winston; Tsang, Stephen H.; Sparrow, Janet R.
2016-01-01
Purpose Using multiple imaging modalities we evaluated the changes in photoreceptor cells and RPE that are associated with bone spicule-shaped melanin pigmentation in retinitis pigmentosa (RP). Methods In a cohort of 60 RP patients, short-wavelength autofluorescence (SW-AF), near-infrared (NIR)-AF, NIR-reflectance (NIR-R), spectral domain optical coherence tomography (SD-OCT) and color fundus images were studied. Results Central AF rings were visible in both SW-AF and NIR-AF images. Bone spicule pigmentation was non-reflective in NIR-R, hypoautofluorescent with SW-AF and NIR-AF imaging and presented as intraretinal hyperreflective foci in SD-OCT images. In areas beyond the AF ring outer border, the photoreceptor ellipsoid zone (EZ) band was absent in SD-OCT scans and the visibility of choroidal vessels in SW-AF, NIR-AF and NIR-R images was indicative of reduced RPE pigmentation. Choroidal visibility was most pronounced in the zone approaching peripheral areas of bone spicule pigmentation; here RPE/Bruch’s membrane thinning became apparent in SD-OCT scans. Conclusions These findings are consistent with a process by which RPE cells vacate their monolayer and migrate into inner retina in response to photoreceptor cell degeneration. The remaining RPE spread, undergo thinning and consequently become less pigmented. An explanation for the absence of NIR-AF melanin signal in relation to bone spicule pigmentation is not forthcoming. PMID:28005673
Wiesel, Joseph; Salomone, Thomas J
2017-10-15
Early detection of asymptomatic atrial fibrillation (AF) provides an opportunity to treat patients to reduce their risk of stroke. Long-term residents of skilled nursing facilities frequently have multiple risk factors for strokes due to AF and may benefit from screening for AF. Patients in a skilled nursing facility 65 years and older, without a history of AF and without a pacemaker or defibrillator, were evaluated using a Microlife WatchBP Home A automatic blood pressure monitor that can detect AF when set to a triple reading mode. Those with readings positive for AF were evaluated with a standard 12-lead electrocardiogram (ECG) or a 30-second single-channel ECG to confirm the presence of AF. A total of 101 patients were screened with an average age of 78 years, and 48 (48%) were female. Nine automatic blood pressure monitor readings were positive for possible AF. Of those, 7 (6.9%, 95% confidence intervals 3.0% to 14.2%) had AF confirmed with ECG. Only 2 (2%, 95% confidence interval 0.3% to 7.7%) were false-positive readings. One-time screening for AF using an automatic blood pressure monitor in a skilled nursing facility resulted in a high number of patients with newly diagnosed AF. Copyright © 2017 Elsevier Inc. All rights reserved.
Kindem, Ingvild A; Reindal, Eva K; Wester, Astrid L; Blaasaas, Karl G; Atar, Dan
2008-01-01
Several studies have associated elevated C-reactive protein (CRP) levels to the occurrence of atrial fibrillation (AF). We sought to estimate the frequency and prognostic impact of AF in patients with bacteremia, and to study the possible association between AF and CRP as well as between AF and mortality in this population. We retrospectively evaluated patient charts of patients with bacteremia with Escherichia coli or Streptococcus pneumoniae admitted to the Aker University Hospital in Oslo between 1994 and 2004. Known cardiac risk factors for AF, signs and mode of conversion of AF, and, if applicable, date of death were registered, as were characteristics of infection, such as systemic inflammatory response syndrome and white blood cell count. Initial CRP values were categorized into 4 strata. Odds ratios of the 3 highest CRP categories compared with the lowest were obtained from logistic models adjusting for known cardiac risk factors for AF as well as possible factors that may have had an impact on the odds ratios for the different CRP levels. Cox regression analysis was used to compare new-onset AF and death during the first 2 weeks after hospitalization. A total of 672 patient charts were studied; 104 patients (15.4%) had new-onset AF. Peak incidence of new-onset AF occurred on the day of admission. Peak CRP values were reached during the following 2 days. High CRP level at admission did not predict the occurrence of AF. The observed mortality was higher among patients with new-onset AF (p = 0.001) during the first 2 weeks after hospitalization, but this effect disappears when adjusted for relevant factors. The frequency of new-onset AF in bacteremia is substantial. Initial CRP levels or white blood cell count do not seem to predict new-onset AF, as opposed to systemic inflammatory response syndrome. On the other hand, in patients with bacteremia, new-onset AF should be viewed as an indicator of increased mortality and morbidity. Copyright 2008 S. Karger AG, Basel.
Vadmann, Henrik; Pedersen, Susanne S; Nielsen, Jens Cosedis; Rodrigo-Domingo, Maria; Pehrson, Steen; Johannessen, Arne; Hansen, Peter Steen; Johansen, Jens Brock; Riahi, Sam
2015-10-01
Catheter ablation for atrial fibrillation (AF) is an important but expensive procedure that is the subject of some debate. Physicians' attitudes toward catheter ablation may influence promotion and patient acceptance. This is the first study to examine the attitudes of Danish cardiologists toward catheter ablation for AF, using a nationwide survey. We developed a purpose-designed questionnaire to evaluate attitudes toward catheter ablation for AF that was sent to all Danish cardiologists (n = 401; response n = 272 (67.8%)). There was no association between attitudes toward ablation and the experience or age of the cardiologist with respect to patients with recurrent AF episodes with a duration of <48 hours or >7 days and/or need for cardioversion. The majority (69%) expected a recurrence of AF after catheter ablation in more than 30% of the cases. For patients with persistent longstanding AF with a duration of >1 year, the attitude toward ablation for longstanding AF was more likely to be positive with increasing age (P < 0.01) and years of experience of the cardiologist (P = 0.002). Danish cardiologists generally have a positive attitude toward catheter ablation for AF, maintain up-to-date knowledge of the procedure, and are aware what information on ablation treatment should be given to patients with AF. The cardiologists had a positive attitude toward ablation for AF in patients with AF episodes <48 hours and patients with episodes >7 days, or those who needed medical/electrical conversion, but a more negative attitude toward treating longstanding AF patients. © 2015 Wiley Periodicals, Inc.
Frota, Myrna Maria Arcanjo; Bernardes, Ricardo Affonso; Vivan, Rodrigo Ricci; Vivacqua-Gomes, Nilton; Duarte, Marco Antonio Hungaro; Vasconcelos, Bruno Carvalho de
2018-01-18
To evaluate the amount of apically extruded debris, percentage of foraminal enlargement and apical foramen (AF) deformation that occurred during root canal preparation with different reciprocation systems: Reciproc, WaveOne (M-Wire), and ProDesign R (Shape Memory Technology Wire) at two different working lengths (WLs): 0.0 and 1.0 mm beyond the AF. The AF of 120 root canals in 60 mesial roots of mandibular molars were photographed with stereomicroscope and randomly assigned into four groups: manual, Reciproc (REC), WaveOne (WO), and ProDesign R (PDR); subsequently, they were further subdivided according to the WL (n=15). Teeth were instrumented, coupled to a dual collecting chamber, and then another photograph of each AF was captured. Extrusion was analysed by determining the weight of extruded debris. Each AF diameter was measured in pre- and post-instrumentation images to determine deformation, which was analysed, and afterwards the final format of AFs was classified (circular/oval/deformed). We found no significant differences when analysing each system at different WLs. When considering each WL, REC and WO showed highest extrusion values (P<.05); for AF enlargement, differences were observed only for WO, when it was used beyond the AF; differences were observed among M-Wire groups beyond the AF (P<.05). AF deformation was observed in all groups; PDR showed the lowest AF deformation values at both WLs; M-Wire groups showed 50% strain beyond the AF. Authors concluded that beyond the apical limit, the alloy and taper are important aspects when considering extrusion and deformation.
Yang, Hua; Cao, Tingting; Gao, Li; Wang, Lili; Zhu, Chengying; Xu, Yuanyuan; Jing, Yu; Zhu, Haiyan; Lv, Na; Yu, Li
2017-07-20
Occurrence of MLL (Mixed Lineage Leukemia) gene rearrangements indicates poor prognosis in acute myeloid leukemia (AML) patients. This is the first study to report the positive rate and distribution characteristics of MLL rearrangements in AML patients in north China. We used multiplex nested real time PCR (RT-PCR) to screen for incidence of 11 MLL rearrangements in 433 AML patients. Eleven MLL rearrangements included (MLL-PTD, MLL-AF9, MLL-ELL, MLL-AF10, MLL-AF17, MLL-AF6, MLL-ENL, MLL-AF1Q, MLL-CBP, MLL-AF1P, MLL-AFX1). There were 68 AML patients with MLL rearrangements, and the positive rate was 15.7%. MLL-PTD (4.84%) was detected in 21 patients, MLL-AF9 in 15, (3.46%), MLL-ELL in 10 (2.31%), MLL-AF10 in 8 (1.85%), MLL-AF1Q in 2 (0.46%), 3 cases each of MLL-AF17, MLL-AF6, MLL-ENL (0.69% each), a and single case each of MLL-CBP, MLL-AF1P, and MLL-AFX1 (0.23% each). The highest rate of MLL rearrangements was found in 24 patients with M5 subtype AML, occurring in 24 cases (35.3%). MLL rearrangements occurred in 21 patients with M2 subtype AML (30.9%), and in 10 patients with M4 subtype AML (14.7%). Screening fusion genes by multiplex nested RT-PCR is a convenient, fast, economical, and accurate method for diagnosis and predicting prognosis of AML.
Sorigue, Marc; Gual-Capllonch, Francisco; Garcia, Olga; Sarrate, Edurne; Franch-Sarto, Mireia; Ibarra, Gladys; Grau, Javier; Orna, Elisa; Ribera, Josep-Maria; Sancho, Juan-Manuel
2018-05-04
Atrial fibrillation (AF) and cancer are common disorders in the general population but there are few studies in patients with both diseases. More specifically, there are scarce data on AF in patients with non-Hodgkin lymphoma (NHL). We assessed the incidence, predictive factors, management, and survival impact of AF in a cohort of patients with NHL from a single institution between 2002 and 2016 (n = 747). Twenty-three patients were diagnosed with AF before and 40 after the diagnosis of NHL (of the later, 16 were secondary to an extracardiac comorbidity and 24 unrelated to any triggering event [primary AF]). The 5-year cumulative incidence of new-onset AF was 4% (95% confidence interval [CI] 3-6%). Age and hypertension were the only predictive factors for the development of AF. Management of AF was heterogeneous, primarily with anti-vitamin K agents but also antiplatelet therapy in a significant proportion of patients. Among the 63 patients, there were six episodes of ischemic stroke/transient ischemic attack and four venous thromboembolic events, with four major bleeding episodes. Overall survival (OS) was inferior in patients with AF (HR 0.1, 95% CI 0.01-0.7, p = 0.02), largely due to secondary AF. We conclude that the incidence of new-onset AF in NHL patients seemed somewhat higher than in the general population, although with similar predictive factors. The management was heterogeneous, and the risk of ischemic and hemorrhagic events did not seem higher than in cancer-free patients. Survival was particularly poor for patients with secondary AF.
Zeemering, Stef; Bonizzi, Pietro; Maesen, Bart; Peeters, Ralf; Schotten, Ulrich
2015-01-01
Spatiotemporal complexity of atrial fibrillation (AF) patterns is often quantified by annotated intracardiac contact mapping. We introduce a new approach that applies recurrence plot (RP) construction followed by recurrence quantification analysis (RQA) to epicardial atrial electrograms, recorded with a high-density grid of electrodes. In 32 patients with no history of AF (aAF, n=11), paroxysmal AF (PAF, n=12) and persistent AF (persAF, n=9), RPs were constructed using a phase space electrogram embedding dimension equal to the estimated AF cycle length. Spatial information was incorporated by 1) averaging the recurrence over all electrodes, and 2) by applying principal component analysis (PCA) to the matrix of embedded electrograms and selecting the first principal component as a representation of spatial diversity. Standard RQA parameters were computed on the constructed RPs and correlated to the number of fibrillation waves per AF cycle (NW). Averaged RP RQA parameters showed no correlation with NW. Correlations improved when applying PCA, with maximum correlation achieved between RP threshold and NW (RR1%, r=0.68, p <; 0.001) and RP determinism (DET, r=-0.64, p <; 0.001). All studied RQA parameters based on the PCA RP were able to discriminate between persAF and aAF/PAF (DET persAF 0.40 ± 0.11 vs. 0.59 ± 0.14/0.62 ± 0.16, p <; 0.01). RP construction and RQA combined with PCA provide a quick and reliable tool to visualize dynamical behaviour and to assess the complexity of contact mapping patterns in AF.
Influence of atrial substrate on local capture induced by rapid pacing of atrial fibrillation.
Rusu, Alexandru; Jacquemet, Vincent; Vesin, Jean-Marc; Virag, Nathalie
2014-05-01
Preliminary studies showed that the septum area was the only location allowing local capture of both the atria during rapid pacing of atrial fibrillation (AF) from a single site. The present model-based study investigated the influence of atrial substrate on the ability to capture AF when pacing the septum. Three biophysical models of AF with an identical anatomy from human atria but with different AF substrates were used: (i) AF based on multiple wavelets, (ii) AF based on heterogeneities in vagal activation, (iii) AF based on heterogeneities in repolarization. A fourth anatomical model without Bachmann's bundle (BB) was also implemented. Rapid pacing was applied from the septum at pacing cycle lengths in the range of 50-100% of AF cycle length. Local capture was automatically assessed with 24 pairs of electrodes evenly distributed on the atrial surface. The results were averaged over 16 AF simulations. In the homogeneous substrate, AF capture could reach 80% of the atrial surface. Heterogeneities degraded the ability to capture during AF. In the vagal substrate, the capture tended to be more regular and the degradation of the capture was not directly related to the spatial extent of the heterogeneities. In the third substrate, heterogeneities induced wave anchorings and wavebreaks even in areas close to the pacing site, with a more dramatic effect on AF capture. Finally, BB did not significantly affect the ability to capture. Atrial fibrillation substrate had a significant effect on rapid pacing outcomes. The response to therapeutic pacing may therefore be specific to each patient.
Remodeling of Kv1.5 channel in right atria from Han Chinese patients with atrial fibrillation.
Ou, Xian-hong; Li, Miao-ling; Liu, Rui; Fan, Xin-rong; Mao, Liang; Fan, Xue-hui; Yang, Yan; Zeng, Xiao-rong
2015-04-28
The incidence of atrial fibrillation (AF) in rheumatic heart diseases (RHD) is very high and increases with age. Occurrence and maintenance of AF are very complicated process accompanied by many different mechanisms. Ion-channel remodeling, including the voltage-gated potassium channel Kv1.5, plays an important role in the pathophysiology of AF. However, the changes of Kv1.5 channel expression in Han Chinese patients with RHD and AF remain poorly understood. The aim of the present study was to investigate whether the Kv1.5 channels of the right atria may be altered with RHD, age, and sex to contribute to AF. Right atrial appendages were obtained from 20 patients with normal cardiac functions who had undergone surgery, and 26 patients with AF. Subjects were picked from 4 groups: adult and aged patients in normal sinus rhythm (SR) and AF. Patients were divided into non-RHD and RHD groups or men and women groups in normal SR and AF, respectively. The expression of Kv1.5 protein and messenger RNA (mRNA) were measured using Western blotting and polymerase chain reaction (PCR) method, respectively. Compared with the SR group, the expression of Kv1.5 protein decreased significantly in the AF group. However, neither Kv1.5 protein nor KCNA5 mRNA had significant differences in adult and aged groups, non-RHD and RHD group, and men and women group of AF. The expression of Kv1.5 channel protein changes with AF but not with age, RHD, and sex in AF.
Impact of atrial fibrillation on stroke-related healthcare costs.
Sussman, Matthew; Menzin, Joseph; Lin, Iris; Kwong, Winghan J; Munsell, Michael; Friedman, Mark; Selim, Magdy
2013-11-25
Limited data exist on the economic implications of stroke among patients with atrial fibrillation (AF). This study assesses the impact of AF on healthcare costs associated with ischemic stroke (IS), hemorrhagic stroke (HS), or transient ischemic attack (TIA). A retrospective analysis of MarketScan claims data (2005-2011) for AF patients ≥18 years old with ≥1 inpatient claim for stroke, or ≥1 ED or inpatient claim for TIA as identified by ICD-9-CM codes who had ≥12 months continuous enrollment prior to initial stroke. Initial event- and stroke-related costs 12 months post-index were compared among patients with AF and without AF. Adjusted costs were estimated, controlling for demographics, comorbidities, anticoagulant use, and baseline resource use. Data from 23,807 AF patients and 136,649 patients without AF were analyzed. Unadjusted mean cost of the index event was $20,933 for IS, $59,054 for HS, $8616 for TIA hospitalization, and $3395 for TIA ED visit. After controlling for potential confounders, adjusted mean incremental costs (index plus 12-month post-index) for AF patients were higher than those for non-AF patients by: $4726, $7824, and $1890 for index IS, HS, TIA (identified by hospitalization), respectively, and $1700 for TIA (identified by ED) (all P<0.01). In multivariate regression analysis, AF was associated with a 20% (IS), 13% (HS), and 18% (TIA) increase in total stroke-related costs. Stroke-related care for IS, HS, and TIA is costly, especially among individuals with AF. Reducing the risk of AF-related stroke is important from both clinical and economic standpoints.
Catheter ablation in patients with persistent atrial fibrillation
Kirchhof, Paulus; Calkins, Hugh
2017-01-01
Catheter ablation is increasingly offered to patients who suffer from symptoms due to atrial fibrillation (AF), based on a growing body of evidence illustrating its efficacy compared with antiarrhythmic drug therapy. Approximately one-third of AF ablation procedures are currently performed in patients with persistent or long-standing persistent AF. Here, we review the available information to guide catheter ablation in these more chronic forms of AF. We identify the following principles: Our clinical ability to discriminate paroxysmal and persistent AF is limited. Pulmonary vein isolation is a reasonable and effective first approach for catheter ablation of persistent AF. Other ablation strategies are being developed and need to be properly evaluated in controlled, multicentre trials. Treatment of concomitant conditions promoting recurrent AF by life style interventions and medical therapy should be a routine adjunct to catheter ablation of persistent AF. Early rhythm control therapy has a biological rationale and trials evaluating its value are underway. There is a clear need to generate more evidence for the best approach to ablation of persistent AF beyond pulmonary vein isolation in the form of adequately powered controlled multi-centre trials. PMID:27389907
Khomaziuk, I M; Habulavichene, Zh M; Khomaziuk, V A
2011-01-01
Particularities and clinical importance of the structural and functional changes of myocardium were estimated in Chernobyl disaster clean-up workers with atrial fibrillation (AF). We examined 122 men with AF, which was associated with ischemic heart disease and arterial hypertension. Paroxysmal AF was diagnosed in 42 patients, 80 patients had permanent AE Control group comprised 80 men without AF. Echocardiography and Doppler studies were performed using ultrasound scanner Aloka SSD-630 (Japan). Significant structural and functional changes of the heart were revealed already in paroxysmal AF and became more pronounced in permanent AF. Increased left atrial size, its ratio to left ventricular end diastolic diameter, diastolic dysfunction were important echocardiographic predictors of AF. Heart walls thickening was accompanied by disorders of myocardial relaxation, increase in myocardial mass led to ischemia, and together they promoted overload, dysfunction of atrium and development of AF. Obligatory echocardiographic examination of the Chernobyl disaster clean-up workers with ischemic heart disease and arterial hypertension is necessary for predicting AF early, ordering adequate therapy in proper time and improving prognosis.
2009-01-01
Initiative EIJ Egyptian Islamic Jihad EIJM Eritrean Islamic Jihad Movement EPLF Eritrean People’s Liberation Front FPENS Formal Private Education Network in...ceremonies, the siyaaro or pilgrimages to the tombs of saints (practiced in particular by Sufis), and the celebration of Mawliid (the Prophet... tombs become pil- grimage centers.17 An important Sufi-linked organization is Ahlu Sunna wal-Jama’a (ASWJ), which seeks to unify the Sufi community
Case study of water-soluble metal containing organic constituents of biomass burning aerosol
Alexandra L. Chang-Graham; Luisa T. M. Profeta; Timothy J. Johnson; Robert J. Yokelson; Alexander Laskin; Julia Laskin
2011-01-01
Natural and prescribed biomass fires are a major source of aerosols that may persist in the atmosphere for several weeks. Biomass burning aerosols (BBA) can be associated with long-range transport of water-soluble N-, S-, P-, and metal-containing species. In this study, BBA samples were collected using a particle-into-liquid sampler (PILS) from laboratory burns of...
ERIC Educational Resources Information Center
Head, Alison J.; Eisenberg, Michael B.
2011-01-01
The paper presents findings from 560 interviews with undergraduates on 10 campuses distributed across the US, as part of Project Information Literacy (PIL). Overall, the findings suggest that students use a "less is more" approach to manage and control all of the IT devices and information systems available to them while they are in the…
Shannahoff-Khalsa, D S; Ray, L E; Levine, S; Gallen, C C; Schwartz, B J; Sidorowich, J J
1999-12-01
The objective of this study was to compare efficacy of two meditation protocols for treating patients with obsessive-compulsive disorder (OCD). Patients were randomized to two groups-matched for sex, age, and medication status-and blinded to the comparison protocol. They were told the trial would last for 12 months, unless one protocol proved to be more efficacious. If so, groups would merge, and the group that received the less efficacious treatment would also be afforded 12 months of the more effective one. The study was conducted at Children's Hospital, San Diego, Calif. Patients were selected according to Diagnostic and Statistical Manual of Mental Disorders, Third Edition-Revised (DSM-III-R) criteria and recruited by advertisements and referral. At baseline, Group 1 included 11 adults and 1 adolescent, and Group 2 included 10 adults. Group 1 employed a kundalini yoga meditation protocol and Group 2 employed the Relaxation Response plus Mindfulness Meditation technique. Baseline and 3-month interval testing was conducted using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Symptoms Checklist-90-Revised Obsessive Compulsive (SCL-90-R OC) and Global Severity Index (SCL-90-R GSI) scales, Profile of Moods scale (POMS), Perceived Stress Scale (PSS), and Purpose in Life (PIL) test. Seven adults in each group completed 3 months of therapy. At 3 months, Group 1 demonstrated greater improvements (Student's independent groups t-test) on the Y-BOCS, SCL-90-R OC and GSI scales, and POMS, and greater but nonsignificant improvements on the PSS and PIL test. An intent-to-treat analysis (Y-BOCS) for the baseline and 3-month tests showed that only Group 1 improved. Within-group statistics (Student's paired t-tests) showed that Group 1 significantly improved on all six scales, but Group 2 had no improvements. Groups were merged for an additional year using Group 1 techniques. At 15 months, the final group (N=11) improved 71%, 62%, 66%, 74%, 39%, and 23%, respectively, on the Y-BOCS, SCL-90-R OC, SCL-90-R GSI, POMS, PSS, and PIL; P<0.003 (analysis of variance). This study demonstrates that kundalini yoga techniques are effective in the treatment of OCD.
Richter, Lubna V; Franks, Ashley E; Weis, Robert M; Sandler, Steven J
2017-04-15
Geobacter sulfurreducens , an anaerobic metal-reducing bacterium, possesses type IV pili. These pili are intrinsic structural elements in biofilm formation and, together with a number of c -type cytochromes, are thought to serve as conductive nanowires enabling long-range electron transfer (ET) to metal oxides and graphite anodes. Here, we report that a posttranslational modification of a nonconserved amino acid residue within the PilA protein, the structural subunit of the type IV pili, is crucial for growth on insoluble extracellular electron acceptors. Matrix-assisted laser desorption ionization (MALDI) mass spectrometry of the secreted PilA protein revealed a posttranslational modification of tyrosine-32 with a moiety of a mass consistent with a glycerophosphate group. Mutating this tyrosine into a phenylalanine inhibited cell growth with Fe(III) oxides as the sole electron acceptor. In addition, this amino acid substitution severely diminished biofilm formation on graphite surfaces and impaired current output in microbial fuel cells. These results demonstrate that the capability to attach to insoluble electron acceptors plays a crucial role for the cells' ability to utilize them. The work suggests that glycerophosphate modification of Y32 is a key factor contributing to the surface charge of type IV pili, influencing the adhesion of Geobacter to specific surfaces. IMPORTANCE Type IV pili are bacterial appendages that function in cell adhesion, virulence, twitching motility, and long-range electron transfer (ET) from bacterial cells to insoluble extracellular electron acceptors. The mechanism and role of type IV pili for ET in Geobacter sulfurreducens is still a subject of research. In this study, we identified a posttranslational modification of the major G. sulfurreducens type IV pilin, suggested to be a glycerophosphate moiety. We show that a mutant in which the glycerophosphate-modified tyrosine-32 is replaced with a phenylalanine has reduced abilities for ET and biofilm formation compared with those of the wild type. The results show the importance of the glycerophosphate-modified tyrosine for surface attachment and electron transfer in electrode- or Fe(III)-respiring G. sulfurreducens cells. Copyright © 2017 American Society for Microbiology.
Franks, Ashley E.; Weis, Robert M.; Sandler, Steven J.
2017-01-01
ABSTRACT Geobacter sulfurreducens, an anaerobic metal-reducing bacterium, possesses type IV pili. These pili are intrinsic structural elements in biofilm formation and, together with a number of c-type cytochromes, are thought to serve as conductive nanowires enabling long-range electron transfer (ET) to metal oxides and graphite anodes. Here, we report that a posttranslational modification of a nonconserved amino acid residue within the PilA protein, the structural subunit of the type IV pili, is crucial for growth on insoluble extracellular electron acceptors. Matrix-assisted laser desorption ionization (MALDI) mass spectrometry of the secreted PilA protein revealed a posttranslational modification of tyrosine-32 with a moiety of a mass consistent with a glycerophosphate group. Mutating this tyrosine into a phenylalanine inhibited cell growth with Fe(III) oxides as the sole electron acceptor. In addition, this amino acid substitution severely diminished biofilm formation on graphite surfaces and impaired current output in microbial fuel cells. These results demonstrate that the capability to attach to insoluble electron acceptors plays a crucial role for the cells' ability to utilize them. The work suggests that glycerophosphate modification of Y32 is a key factor contributing to the surface charge of type IV pili, influencing the adhesion of Geobacter to specific surfaces. IMPORTANCE Type IV pili are bacterial appendages that function in cell adhesion, virulence, twitching motility, and long-range electron transfer (ET) from bacterial cells to insoluble extracellular electron acceptors. The mechanism and role of type IV pili for ET in Geobacter sulfurreducens is still a subject of research. In this study, we identified a posttranslational modification of the major G. sulfurreducens type IV pilin, suggested to be a glycerophosphate moiety. We show that a mutant in which the glycerophosphate-modified tyrosine-32 is replaced with a phenylalanine has reduced abilities for ET and biofilm formation compared with those of the wild type. The results show the importance of the glycerophosphate-modified tyrosine for surface attachment and electron transfer in electrode- or Fe(III)-respiring G. sulfurreducens cells. PMID:28138101
Predisposing factors for atrial fibrillation in the elderly
Wasmer, Kristina; Eckardt, Lars; Breithardt, Günter
2017-01-01
Atrial fibrillation (AF) in the elderly occurs as a consequence of cardiovascular aging and an age related increase of comorbidity. Several predisposing factors for AF have been identified for the overall AF population. Most of them, cardiovascular disease in particular, play a role in younger and older patients. The longer time period during which these risk factors can cause structural changes that ultimately lead to AF may, at least in part, explain the association between age and AF. In addition, less well defined age-related changes in cellular electrophysiologic properties and structure predispose to AF in the elderly. PMID:28592961
Characterization of a novel antibacterial glycopeptide produced by Penicillium sp. M03.
Yang, W H; Zhang, W C; Lu, X M; Jiang, G S; Gao, P J
2009-04-01
To isolate a novel antibiotic termed AF from fermentation broth of Penicillium sp. M03 and to examine its antimicrobial activity, biological properties and structure characteristics. Sephadex LH-20 and HPLC were used to purify AF from fermentation broth of Penicillium sp. M03. The antimicrobial activity of AF was evaluated with the agar diffusion test. Amino acid and monosaccharide composition of AF was analysed by a HITACHI 835 detector and HPLC assay, respectively. Matrix-assisted laser desorption time of flight mass spectrometry, FT-IR and (1)H nuclear magnetic resonance spectra analyses were performed to examine the initial structure of AF. Eighty milligrams of AF was isolated as white powder from 1-l Penicillium sp. M03 fermentation broth. It consists of five amino acid and two monosaccharide residues and the molecular weight of it was 1017, and it was stable to beta-lactamase, heat, acid and alkali. AF showed inhibitory activity to a wide range of bacteria, particularly to multidrug-resistant Staphylococcus aureus. AF was a novel antibacterial glycopeptide with a broad inhibitory spectrum to pathogenic bacteria including multidrug-resistant agents. Furthermore, it is difficult to generate bacteria resistant to AF. Characterization of AF made it a potential antibiotic to fight against antibiotic-resistant bacterial pathogens.
A new predictor of atrial fibrillation after coronary artery bypass graft surgery: HATCH score.
Selvi, Mithat; Gungor, Hasan; Zencir, Cemil; Gulasti, Sevil; Eryilmaz, Ufuk; Akgullu, Cagdas; Durmaz, Selim
2018-03-01
The aim of this study was to investigate the association between HATCH score and atrial fibrillation (AF) after coronary artery bypass graft (CABG) surgery. 369 patients (103 patients with AF and 266 patients without AF) undergoing isolated CABG surgery were analyzed. Complete medical records were retrospectively collected to investigate HATCH score. The median age of patients with AF was significantly higher than the median age of non-AF group (60.8±10.0 years vs 67.8±9.5 years, P<0.001). HATCH score was significantly higher in patients who developed AF after CABG surgery than the non-AF group (P=0.017). Multivariate logistic regression analysis showed that HATCH score (OR 1.334; 95% CI 1.022 to 1.741, P=0.034) was an independent predictor of AF after CABG surgery. Receiver operating characteristic curve analysis showed that the cut-off point of HATCH score related to predict AF was >1 (two or more), with a sensitivity of 42% and specificity of 70%. Patients with elevated preoperative HATCH score may have higher risk for AF after CABG surgery. © American Federation for Medical Research (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
A Critical Role for CRM1 in Regulating HOXA Gene Transcription in CALM-AF10 Leukemias
Conway, Amanda E.; Haldeman, Jonathan M.; Wechsler, Daniel S.; Lavau, Catherine P.
2014-01-01
The leukemogenic CALM-AF10 fusion protein is found in patients with immature acute myeloid and T-lymphoid malignancies. CALM-AF10 leukemias display abnormal H3K79 methylation and increased HOXA cluster gene transcription. Elevated expression of HOXA genes is critical for leukemia maintenance and progression; however, the precise mechanism by which CALM-AF10 alters HOXA gene expression is unclear. We previously determined that CALM contains a CRM1-dependent nuclear export signal (NES), which is both necessary and sufficient for CALM-AF10-mediated leukemogenesis. Here, we find that interaction of CALM-AF10 with the nuclear export receptor CRM1 is necessary for activating HOXA gene expression. We show that CRM1 localizes to HOXA loci where it recruits CALM-AF10, leading to transcriptional and epigenetic activation of HOXA genes. Genetic and pharmacological inhibition of the CALM-CRM1 interaction prevents CALM-AF10 enrichment at HOXA chromatin, resulting in immediate loss of transcription. These results provide a comprehensive mechanism by which the CALM-AF10 translocation activates the critical HOXA cluster genes. Furthermore, this report identifies a novel function of CRM1: the ability to bind chromatin and recruit the NES-containing CALM-AF10 transcription factor. PMID:25027513
Atrial Fibrillation in Eight New World Camelids.
Bozorgmanesh, R; Magdesian, K G; Estell, K E; Stern, J A; Swain, E A; Griffiths, L G
2016-01-01
There is limited information on the incidence of clinical signs, concurrent illness and treatment options for atrial fibrillation (AF) in New World Camelids (NWC). Describe clinical signs and outcome of AF in NWC. Eight New World Camelids admitted with AF. A retrospective observational study of camelids diagnosed with AF based on characteristic findings on electrocardiogram (ECG). All animals had an irregularly irregular heart rhythm detected on physical examination and 4 cases had obtunded mentation on admission. Three camelids were diagnosed with AF secondary to oleander intoxication, 3 animals had underlying cardiovascular disease, 1 was diagnosed with lone AF and 1 had AF diagnosed on examination for a urethral obstruction. Five of eight animals survived to discharge and nonsurvivors consisted of animals which died or were euthanized as a result of cardiovascular disease (2/8) or extra-cardiac disease unrelated to the AF (1/8). Atrial fibrillation occurs in NWC in association with cardiovascular disease, extra-cardiac disease or as lone AF. Amiodarone and transthoracic cardioversion were attempted in one llama with lone AF, but were unsuccessful. Atrial fibrillation was recorded in 0.1% of admissions. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.
Quantitative fundus autofluorescence in healthy eyes.
Greenberg, Jonathan P; Duncker, Tobias; Woods, Russell L; Smith, R Theodore; Sparrow, Janet R; Delori, François C
2013-08-21
Fundus autofluorescence was quantified (qAF) in subjects with healthy retinae using a standardized approach. The objective was to establish normative data and identify factors that influence the accumulation of RPE lipofuscin and/or modulate the observed AF signal in fundus images. AF images were acquired from 277 healthy subjects (age range: 5-60 years) by employing a Spectralis confocal scanning laser ophthalmoscope (cSLO; 488-nm excitation; 30°) equipped with an internal fluorescent reference. For each image, mean gray level was calculated as the average of eight preset regions, and was calibrated to the reference, zero-laser light, magnification, and optical media density from normative data on lens transmission spectra. Relationships between qAF and age, sex, race/ethnicity, eye color, refraction/axial length, and smoking status were evaluated as was measurement repeatability and the qAF spatial distribution. qAF levels exhibited a significant increase with age. qAF increased with increasing eccentricity up to 10° to 15° from the fovea and was highest superotemporally. qAF values were significantly greater in females, and, compared with Hispanics, qAF was significantly higher in whites and lower in blacks and Asians. No associations with axial length and smoking were observed. For two operators, between-session repeatability was ± 9% and ± 12%. Agreement between the operators was ± 13%. Normative qAF data are a reference tool essential to the interpretation of qAF measurements in ocular disease.
Soeki, Takeshi; Matsuura, Tomomi; Tobiume, Takeshi; Bando, Sachiko; Matsumoto, Kazuhisa; Nagano, Hiromi; Uematsu, Etsuko; Kusunose, Kenya; Ise, Takayuki; Yamaguchi, Koji; Yagi, Shusuke; Fukuda, Daiju; Yamada, Hirotsugu; Wakatsuki, Tetsuzo; Shimabukuro, Michio; Sata, Masataka
2018-05-30
The ability to identify risk markers for new-onset atrial fibrillation (AF) is critical to the development of preventive strategies, but it remains unknown whether a combination of clinical, electrocardiographic, and echocardiographic parameters predicts the onset of AF. In the present study, we evaluated the predictive value of a combined score that includes these parameters.Methods and Results:We retrospectively studied 1,040 patients without AF who underwent both echocardiography and 24-h Holter electrocardiography between May 2005 and December 2010. During a median follow-up period of 68.4 months (IQR, 49.9-93.3 months), we investigated the incidence of new-onset AF. Of the 1,040 patients, 103 (9.9%) developed AF. Patients who developed AF were older than patients who did not. Total heart beats, premature atrial contraction (PAC) count, maximum RR interval, and frequency of sinus pause quantified on 24-h electrocardiography were associated with new-onset AF. LA diameter (LAD) on echocardiography was also associated with the development of AF. On multivariate Cox analysis, age ≥58 years, PAC count ≥80 beats/day, maximum RR interval ≥1.64 s, and LAD ≥4.5 cm were independently associated with the development of AF. The incidence rate of new-onset AF significantly increased as the combined score (i.e., the sum of the risk score determined using hazard ratios) increased. A combined score that includes age, PAC count, maximum RR interval, and LAD could help characterize the risk of new-onset AF.
Statin and Atrial Fibrilation: When does it work?
Fauchier, Laurent; Clementy, Nicolas; Pierre, Bertrand; Babuty, Dominique
2012-01-01
In the recent years, some clinical and experimental studies have suggested that the use of statins may protect against atrial fibrillation (AF). A relation between inflammation and the development of AF has been described, and the potent anti-inflammatory and antioxidant properties of statins may make them effective in preventing the development of AF. A global analysis of the literature suggests that the use of statins is associated with a decreased risk of incidence or recurrence of AF in some cases. However, this beneficial effect is not seen for all types of AF in all the patients. The use of statins seems associated 1) with a lack of benefit in primary prevention of AF, 2) with a significant but heterogeneous decreased risk of recurrence of AF in secondary prevention, and 3) with a very significant and homogeneous reduction for the risk of post operative AF. An intensive lipid lowering statin regimen does not provide greater protection against AF. Patients with coronary heart disease are curr ently treated with statins in most cases, and this may not have an impact on their treatment. In contrast, it remains to determine more accurately if statins may bring a significant benefit for some AF patients without any type of established atherosclerotic disease or with a low risk of atherogenesis. Since it remains uncertain whether the suppression of AF in these patients is beyond doubt beneficial, prescribing statins for this purpose alone should not be recommended at the present time.
Kishima, Hideyuki; Mine, Takanao; Takahashi, Satoshi; Ashida, Kenki; Ishihara, Masaharu; Masuyama, Tohru
2017-04-01
Transforming growth factor-β 1 (TGF-β 1 ) is an important factor that induces atrial fibrosis and atrial fibrillation (AF). The purpose of this study was to evaluate the association between TGF-β 1 level and clinical factors before catheter ablation (CA), and to investigate the impact of TGF-β 1 level on the outcome after CA for AF. This prospective study included 151 patients (persistent AF group: n = 59, paroxysmal AF [PAF] group: n = 54, and control group: n = 38). All patients who underwent CA for AF were followed up for 12 months. The PAF group had the highest TGF-β 1 levels in all patients. An early recurrence of AF (ERAF: defined as episodes of atrial tachyarrhythmia within a 3-month blanking period) was detected in 60 patients (53%). Recurrent AF after the blanking period was detected in 36 patients (32%). On multivariate analysis, low TGF-β 1 level was the only independent factor associated with recurrent AF. Moreover, the AF recurrence ratio was higher in the low TGF-β 1 group (< 12.56 ng/mL) than in the high TGF-β 1 group (16 of 29 patients, 55% vs. 20 of 84 patients, 24%, P = 0.002 by log-rank test). PAF was associated with a higher TGF-β 1 level. Moreover, lower TGF-β 1 level in AF patients could be a cause of recurrent AF after CA. © 2017 Wiley Periodicals, Inc.
Scholz, Bastian; Kowarz, Eric; Rössler, Tanja; Ahmad, Khalil; Steinhilber, Dieter; Marschalek, Rolf
2015-01-01
AF4/AFF1 and AF5/AFF4 are the molecular backbone to assemble “super-elongation complexes” (SECs) that have two main functions: (1) control of transcriptional elongation by recruiting the positive transcription elongation factor b (P-TEFb = CyclinT1/CDK9) that is usually stored in inhibitory 7SK RNPs; (2) binding of different histone methyltransferases, like DOT1L, NSD1 and CARM1. This way, transcribed genes obtain specific histone signatures (e.g. H3K79me2/3, H3K36me2) to generate a transcriptional memory system. Here we addressed several questions: how is P-TEFb recruited into SEC, how is the AF4 interactome composed, and what is the function of the naturally occuring AF4N protein variant which exhibits only the first 360 amino acids of the AF4 full-length protein. Noteworthy, shorter protein variants are a specific feature of all AFF protein family members. Here, we demonstrate that full-length AF4 and AF4N are both catalyzing the transition of P-TEFb from 7SK RNP to their N-terminal domain. We have also mapped the protein-protein interaction network within both complexes. In addition, we have first evidence that the AF4N protein also recruits TFIIH and the tumor suppressor MEN1. This indicate that AF4N may have additional functions in transcriptional initiation and in MEN1-dependend transcriptional processes. PMID:26171280
Chen, Xizhuo; Zhao, Yanxin; Zhong, Suyu; Cui, Zaixu; Li, Jiaqi; Gong, Gaolang; Dong, Qi; Nan, Yun
2018-05-01
The arcuate fasciculus (AF) is a neural fiber tract that is critical to speech and music development. Although the predominant role of the left AF in speech development is relatively clear, how the AF engages in music development is not understood. Congenital amusia is a special neurodevelopmental condition, which not only affects musical pitch but also speech tone processing. Using diffusion tensor tractography, we aimed at understanding the role of AF in music and speech processing by examining the neural connectivity characteristics of the bilateral AF among thirty Mandarin amusics. Compared to age- and intelligence quotient (IQ)-matched controls, amusics demonstrated increased connectivity as reflected by the increased fractional anisotropy in the right posterior AF but decreased connectivity as reflected by the decreased volume in the right anterior AF. Moreover, greater fractional anisotropy in the left direct AF was correlated with worse performance in speech tone perception among amusics. This study is the first to examine the neural connectivity of AF in the neurodevelopmental condition of amusia as a result of disrupted music pitch and speech tone processing. We found abnormal white matter structural connectivity in the right AF for the amusic individuals. Moreover, we demonstrated that the white matter microstructural properties of the left direct AF is modulated by lexical tone deficits among the amusic individuals. These data support the notion of distinctive pitch processing systems between music and speech.
Li, Shufeng; Li, Hongli; Mingyan, E; Yu, Bo
2009-02-01
The development of pulmonary vein stenosis has recently been described after radiofrequency ablation (RF) to treat atrial fibrillation (AF). The purpose of this study was to examine expression of TGFbeta1 in pulmonary vein stenosis after radiofrequency ablation in chronic atrial fibrillation of dogs. About 28 mongrel dogs were randomly assigned to the sham-operated group (n = 7), the AF group (n = 7), AF + RF group (n = 7), and RF group (n = 7). In AF or AF + RF groups, dogs underwent chronic pulmonary vein (PV) pacing to induce sustained AF. RF application was applied around the PVs until electrical activity was eliminated. Histological assessment of pulmonary veins was performed using hematoxylin and eosin staining; TGFbeta1 gene expression in pulmonary veins was examined by RT-PCR analysis; expression of TGFbeta1 protein in pulmonary veins was assessed by Western blot analysis. Rapid pacing from the left superior pulmonary vein (LSPV) induced sustained AF in AF group and AF + RF group. Pulmonary vein ablation terminated the chronic atrial fibrillation in dogs. Histological examination revealed necrotic tissues in various stages of collagen replacement, intimal thickening, and cartilaginous metaplasia with chondroblasts and chondroclasts. Compared with sham-operated and AF group, TGFbeta1 gene and protein expressions was increased in AF + RF or RF groups. It was concluded that TGFbeta1 might be associated with pulmonary vein stenosis after radiofrequency ablation in chronic atrial fibrillation of dogs.
NASA Astrophysics Data System (ADS)
Pahlevaninezhad, H.; Lee, A. M. D.; Hyun, C.; Lam, S.; MacAulay, C.; Lane, P. M.
2013-03-01
In this paper, we conduct a phantom study for modeling the autofluorescence (AF) properties of tissue. A combined optical coherence tomography (OCT) and AF imaging system is proposed to measure the strength of the AF signal in terms of the scattering layer thickness and concentration. The combined AF-OCT system is capable of estimating the AF loss due to scattering in the epithelium using the thickness and scattering concentration calculated from the co-registered OCT images. We define a correction factor to account for scattering losses in the epithelium and calculate a scatteringcorrected AF signal. We believe the scattering-corrected AF will reduce the diagnostic false-positives rate in the early detection of airway lesions due to confounding factors such as increased epithelial thickness and inflammations.
Davies, Christopher J.; Regouski, Misha; Hall, Justin; Olsen, Aaron L.; Meng, Qinggang; Rutigliano, Heloisa M.; Dosdall, Derek J.; Angel, Nathan A.; Sachse, Frank B.; Seidel, Thomas; Thomas, Aaron J.; Stott, Rusty; Panter, Kip E.; Lee, Pamela M.; Van Wettere, Arnaud J.; Stevens, John R.; Wang, Zhongde; MacLeod, Rob S.; Marrouche, Nassir F.; White, Kenneth L.
2016-01-01
Introduction Large animal models of progressive atrial fibrosis would provide an attractive platform to study relationship between structural and electrical remodeling in atrial fibrillation (AF). Here we established a new transgenic goat model of AF with cardiac specific overexpression of TGF-β1 and investigated the changes in the cardiac structure and function leading to AF. Methods and Results Transgenic goats with cardiac specific overexpression of constitutively active TGF-β1 were generated by somatic cell nuclear transfer. We examined myocardial tissue, ECGs, echocardiographic data, and AF susceptibility in transgenic and wild-type control goats. Transgenic goats exhibited significant increase in fibrosis and myocyte diameters in the atria compared to controls, but not in the ventricles. P-wave duration was significantly greater in transgenic animals starting at 12-month of age, but no significant chamber enlargement was detected, suggesting conduction slowing in the atria. Furthermore, this transgenic goat model exhibited a significant increase in AF vulnerability. Six of 8 transgenic goats (75%) were susceptible to AF induction and exhibited sustained AF (>2 minutes), whereas, none of 6 controls displayed sustained AF (P<0.01). Length of induced AF episodes was also significantly greater in the transgenic group compared to controls (687±212.02 vs. 2.50±0.88 seconds, P<0.0001), but no persistent or permanent AF was observed. Conclusion A novel transgenic goat model with a substrate for AF was generated. In this model, cardiac overexpression of TGF-β1 led to an increase in fibrosis and myocyte size in the atria, and to progressive P-wave prolongation. We suggest that these factors underlie increased AF susceptibility. PMID:27447370
Maan, Abhishek; Jorgensen, Neal W; Mansour, Moussa; Dudley, Samuel; Jenny, Nancy S; Defilippi, Christopher; Szklo, Moyses; Alonso, Alvaro; Refaat, Marwan M; Ruskin, Jeremy; Heckbert, Susan R; Heist, E Kevin
2016-12-01
During atrial fibrillation (AF), a high rate of myocyte activation causes cellular stress and initiates the process of atrial remodeling, which further promotes persistence of AF. Although heat shock proteins (HSPs) have been shown to prevent atrial remodeling and suppress the occurrence of AF in cellular and animal experimental models, increased levels of HSP-60 have been observed in patients with postoperative AF, likely reflecting a response to cellular stress. To better understand the role of HSP-60 in relation to AF, we examined the association of HSP-60 levels in relation to the future development of AF in the Multi-Ethnic Study of Atherosclerosis (MESA). MESA is a cohort study that recruited 6,814 participants aged 45-84 years and free of known cardiovascular disease at baseline (2000-2002) from six field centers. We investigated 983 participants, selected at random from the total cohort, who had HSP-60 measured and were free of AF at baseline. We tested the association of HSP-60 levels with the incidence of AF using multivariate Cox models after adjustment for demographics, clinical characteristics, and biomarkers. During an average of 10.6 years of follow-up, 77 participants developed AF. We did not observe a significant association between the log-transformed HSP-60 levels and development of AF on either unadjusted or multivariate analysis (adjusted hazard ratio: 1.02 per unit difference on natural log scale, 95% confidence interval: 0.77-1.34 ln (ng/mL). Contrary to the findings from the preclinical studies, which demonstrated an important role of HSP-60 in the pathogenesis of AF, we did not observe a significant association between HSP-60 and occurrence of AF. © 2016 Wiley Periodicals, Inc.
Goren, Amir; Liu, Xianchen; Gupta, Shaloo; Simon, Teresa A; Phatak, Hemant
2013-01-01
This study builds upon current studies of atrial fibrillation (AF) and health outcomes by examining more comprehensively the humanistic burden of illness (quality of life, activity impairment, and healthcare resource utilization) among adult patients with AF, using a large, nationally representative sample and matched controls. Data were analyzed from the Internet-based 2009 US National Health and Wellness Survey. Outcomes were Mental and Physical Component Summary (MCS and PCS) and health utility scores from the SF-12, activity impairment, hospitalizations, and healthcare provider and emergency room (ER) visits. Patients with self-reported diagnosis of AF were matched randomly on age and gender with an equal number of respondents without AF. Generalized linear models examined outcomes as a function of AF vs. non-AF status, controlling for CHADS2 score, comorbidity counts, demographics, and clinical variables. Exploratory structural equation modeling assessed the above in an integrated model of humanistic burden. Mean age of AF patients (1,296 from a total sample of 75,000) was 64.9 years and 65.1% were male. Adjusting for covariates, compared with non-AF patients, AF patients had lower MCS, PCS, and utility scores, greater activity impairment (rate ratio = 1.26), more traditional provider visits (rate ratio = 1.43), and increased odds of ER visits (OR = 2.53) and hospitalizations (OR = 2.71). Exploratory structural equation modeling analyses revealed that persons with AF experienced a significantly higher overall humanistic burden. This study highlights and clarifies the substantial burden of AF and its implications for preparing efficacious AF management plans to address the imminent rise in prevalence.
Yu, Hee Tae; Shim, Jaemin; Park, Junbeom; Kim, In-Soo; Kim, Tae-Hoon; Uhm, Jae-Sun; Joung, Boyoung; Lee, Moon-Hyoung; Kim, Young-Hoon; Pak, Hui-Nam
2017-06-01
Atrial fibrillation (AF) type can vary depending on condition and timing, and some patients who initially present with persistent AF may be changed to paroxysmal AF after antiarrhythmic drug medication and cardioversion. We investigated whether circumferential pulmonary vein isolation (CPVI) alone is an effective rhythm control strategy in patients with persistent AF to paroxysmal AF. We enrolled 113 patients with persistent AF to paroxysmal AF (male 75%, 60.4±10.1 years old) who underwent catheter ablation for nonvalvular AF at 3 tertiary hospitals. The participants were randomly assigned to 2 groups: CPVI alone (n=59) or CPVI plus linear ablation (CPVI+Line; posterior box+anterior line, n=54). Compared with the CPVI+Line, CPVI alone required shorter procedure (187.2±58.0 versus 211.2±63.9 min; P =0.043) and ablation times (4922.1±1110.5 versus 6205.7±1425.2 s; P <0.001) without difference in procedure-related major complication (3% versus 2%; P =0.611). Antiarrhythmic drug utility rates after ablation were not different between the 2 groups (22% versus 30%; P =0.356). Overall, AF-free survival (log-rank; P =0.206) and AF and antiarrhythmic drug-free survival (log-rank; P =0.321) were not different between groups. CPVI alone is an effective rhythm control strategy with a shorter procedure time in persistent AF patients converted to paroxysmal AF compared with CPVI with linear ablation. URL: https://www.clinicaltrials.gov. Unique identifier: NCT02176616. © 2017 American Heart Association, Inc.
Molnar, Amber O; Eddeen, Anan Bader; Ducharme, Robin; Garg, Amit X; Harel, Ziv; McCallum, Megan K; Perl, Jeffrey; Wald, Ron; Zimmerman, Deborah; Sood, Manish M
2017-07-06
Early evidence suggests proteinuria is independently associated with incident atrial fibrillation (AF). We sought to investigate whether the association of proteinuria with incident AF is altered by kidney function. Retrospective cohort study using administrative healthcare databases in Ontario, Canada (2002-2015). A total of 736 666 patients aged ≥40 years not receiving dialysis and with no previous history of AF were included. Proteinuria was defined using the urine albumin-to-creatinine ratio (ACR) and kidney function by the estimated glomerular filtration rate (eGFR). The primary outcome was time to AF. Cox proportional models were used to determine the hazard ratio for AF censored for death, dialysis, kidney transplant, or end of follow-up. Fine and Grey models were used to determine the subdistribution hazard ratio for AF, with death as a competing event. Median follow-up was 6 years and 44 809 patients developed AF. In adjusted models, ACR and eGFR were associated with AF ( P <0.0001). The association of proteinuria with AF differed based on kidney function (ACR × eGFR interaction, P <0.0001). Overt proteinuria (ACR, 120 mg/mmol) was associated with greater AF risk in patients with intact (eGFR, 120) versus reduced (eGFR, 30) kidney function (adjusted hazard ratios, 4.5 [95% CI, 4.0-5.1] and 2.6 [95% CI, 2.4-2.8], respectively; referent ACR 0 and eGFR 120). Results were similar in competing risk analyses. Proteinuria increases the risk of incident AF markedly in patients with intact kidney function compared with those with decreased kidney function. Screening and preventative strategies should consider proteinuria as an independent risk factor for AF. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.
Yoshiga, Yasuhiro; Shimizu, Akihiko; Ueyama, Takeshi; Ono, Makoto; Fukuda, Masakazu; Fumimoto, Tomoko; Ishiguchi, Hironori; Omuro, Takuya; Kobayashi, Shigeki; Yano, Masafumi
2018-08-01
An effective catheter ablation strategy, beyond pulmonary vein isolation (PVI), for persistent atrial fibrillation (AF) is necessary. Pulmonary vein (PV)-reconduction also causes recurrent atrial tachyarrhythmias. The effect of the PVI and additional effect of a superior vena cava (SVC) isolation (SVCI) was strictly evaluated. Seventy consecutive patients with persistent AF who underwent a strict sequential ablation strategy targeting the PVs and SVC were included in this study. The initial ablation strategy was a circumferential PVI. A segmental SVCI was only applied as a repeat procedure when patients demonstrated no PV-reconduction. After the initial procedure, persistent AF was suppressed in 39 of 70 (55.7%) patients during a median follow-up of 32 months. After multiple procedures, persistent AF was suppressed in 46 (65.7%) and 52 (74.3%) patients after receiving the PVI alone and PVI plus SVCI strategies, respectively. In 6 of 15 (40.0%) patients with persistent AF resistant to PVI, persistent AF was suppressed. The persistent AF duration independently predicted persistent AF recurrences after multiple PVI alone procedures [HR: 1.012 (95% confidence interval: 1.006-1.018); p<0.001] and PVI plus SVCI strategies [HR: 1.018 (95% confidence interval: 1.011-1.025); p<0.001]. A receiver-operating-characteristic analysis for recurrent persistent AF indicated an optimal cut-off value of 20 and 32 months for the persistent AF duration using the PVI alone and PVI plus SVCI strategies, respectively. The outcomes of the PVI plus SVCI strategy were favorable for patients with shorter persistent AF durations. The initial SVCI had the additional effect of maintaining sinus rhythm in some patients with persistent AF resistant to PVI. Copyright © 2018 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.
Movérare-Skrtic, Sofia; Börjesson, Anna E.; Farman, Helen H.; Sjögren, Klara; Windahl, Sara H.; Lagerquist, Marie K.; Andersson, Annica; Stubelius, Alexandra; Carlsten, Hans; Gustafsson, Jan-Åke; Ohlsson, Claes
2014-01-01
The bone-sparing effect of estrogen is primarily mediated via estrogen receptor (ER) α, which stimulates target gene transcription through two activation functions (AFs), AF-1 in the N-terminal and AF-2 in the ligand-binding domain. It was recently demonstrated that the ER antagonist ICI 182,780 (ICI) acts as an ER agonist in uterus of mice with mutations in the ERα AF-2. To evaluate the estrogen-like effects of ICI in different tissues, ovariectomized wild-type mice and mice with mutations in the ERα AF-2 (ERαAF-20) were treated with ICI, estradiol, or vehicle for 3 wk. Estradiol increased the trabecular and cortical bone mass as well as the uterine weight, whereas it reduced fat mass, thymus weight, and the growth plate height in wild-type but not in ERαAF-20 mice. Although ICI had no effect in wild-type mice, it exerted tissue-specific effects in ERαAF-20 mice. It acted as an ERα agonist on trabecular bone mass and uterine weight, whereas no effect was seen on cortical bone mass, fat mass, or thymus weight. Surprisingly, a pronounced inverse agonistic activity was seen on the growth plate height, resulting in enhanced longitudinal bone growth. In conclusion, ICI uses ERα AF-1 in a tissue-dependent manner in mice lacking ERαAF-2, resulting in no effect, agonistic activity, or inverse agonistic activity. We propose that ERα lacking AF-2 is constitutively active in the absence of ligand in the growth plate, enabling ICI to act as an inverse agonist. PMID:24395795
Movérare-Skrtic, Sofia; Börjesson, Anna E; Farman, Helen H; Sjögren, Klara; Windahl, Sara H; Lagerquist, Marie K; Andersson, Annica; Stubelius, Alexandra; Carlsten, Hans; Gustafsson, Jan-Åke; Ohlsson, Claes
2014-01-21
The bone-sparing effect of estrogen is primarily mediated via estrogen receptor (ER) α, which stimulates target gene transcription through two activation functions (AFs), AF-1 in the N-terminal and AF-2 in the ligand-binding domain. It was recently demonstrated that the ER antagonist ICI 182,780 (ICI) acts as an ER agonist in uterus of mice with mutations in the ERα AF-2. To evaluate the estrogen-like effects of ICI in different tissues, ovariectomized wild-type mice and mice with mutations in the ERα AF-2 (ERαAF-2(0)) were treated with ICI, estradiol, or vehicle for 3 wk. Estradiol increased the trabecular and cortical bone mass as well as the uterine weight, whereas it reduced fat mass, thymus weight, and the growth plate height in wild-type but not in ERαAF-2(0) mice. Although ICI had no effect in wild-type mice, it exerted tissue-specific effects in ERαAF-2(0) mice. It acted as an ERα agonist on trabecular bone mass and uterine weight, whereas no effect was seen on cortical bone mass, fat mass, or thymus weight. Surprisingly, a pronounced inverse agonistic activity was seen on the growth plate height, resulting in enhanced longitudinal bone growth. In conclusion, ICI uses ERα AF-1 in a tissue-dependent manner in mice lacking ERαAF-2, resulting in no effect, agonistic activity, or inverse agonistic activity. We propose that ERα lacking AF-2 is constitutively active in the absence of ligand in the growth plate, enabling ICI to act as an inverse agonist.
Frota, Myrna Maria Arcanjo; Bernardes, Ricardo Affonso; Vivan, Rodrigo Ricci; Vivacqua-Gomes, Nilton; Duarte, Marco Antonio Hungaro; de Vasconcelos, Bruno Carvalho
2018-01-01
Abstract Objective To evaluate the amount of apically extruded debris, percentage of foraminal enlargement and apical foramen (AF) deformation that occurred during root canal preparation with different reciprocation systems: Reciproc, WaveOne (M-Wire), and ProDesign R (Shape Memory Technology Wire) at two different working lengths (WLs): 0.0 and 1.0 mm beyond the AF. Material and methods The AF of 120 root canals in 60 mesial roots of mandibular molars were photographed with stereomicroscope and randomly assigned into four groups: manual, Reciproc (REC), WaveOne (WO), and ProDesign R (PDR); subsequently, they were further subdivided according to the WL (n=15). Teeth were instrumented, coupled to a dual collecting chamber, and then another photograph of each AF was captured. Extrusion was analysed by determining the weight of extruded debris. Each AF diameter was measured in pre- and post-instrumentation images to determine deformation, which was analysed, and afterwards the final format of AFs was classified (circular/oval/deformed). Results We found no significant differences when analysing each system at different WLs. When considering each WL, REC and WO showed highest extrusion values (P<.05); for AF enlargement, differences were observed only for WO, when it was used beyond the AF; differences were observed among M-Wire groups beyond the AF (P<.05). AF deformation was observed in all groups; PDR showed the lowest AF deformation values at both WLs; M-Wire groups showed 50% strain beyond the AF. Conclusion Authors concluded that beyond the apical limit, the alloy and taper are important aspects when considering extrusion and deformation. PMID:29364346
Bansal, Nisha; Fan, Dongjie; Hsu, Chi-yuan; Ordonez, Juan D.; Marcus, Gregory M.; Go, Alan S.
2013-01-01
Background Atrial fibrillation (AF) frequently occurs in patients with chronic kidney disease (CKD). However, the long-term impact of development of AF on the risk of adverse renal outcomes in patients with CKD is unknown. In this study, we determined the association between incident AF and risk of end-stage renal disease (ESRD) among adults with CKD. Methods and Results We studied adults with CKD (defined as persistent glomerular filtration rate [eGFR] <60 ml/min/1.73 m2 by the CKD-EPI equation) enrolled in Kaiser Permanente Northern California who were identified between 2002–2010 and who did not have prior ESRD or previously documented AF. Incident AF was identified using primary hospital discharge diagnoses and/or two or more outpatient visits for AF. Incident ESRD was ascertained from a comprehensive health plan registry for dialysis and renal transplant. Among 206,229 adults with CKD, 16,463 developed incident AF. During a mean follow-up of 5.1± 2.5 years, there were 345 cases of ESRD that occurred after development of incident AF (74 per 1000 person-years) compared with 6505 cases of ESRD during periods without AF (64 per 1000 person-years, P<0.001). After adjustment for potential confounders, incident AF was associated with a 67% increase in rate of ESRD (hazard ratio 1.67, 95% confidence interval: 1.46–1.91). Conclusions Incident AF is independently associated with increased risk of developing ESRD in adults with CKD. Further study is needed to identify potentially modifiable pathways through which AF leads to a higher risk of progression to ESRD. PMID:23275377
Bengtson, Lindsay G S; Chen, Lin Y; Chamberlain, Alanna M; Michos, Erin D; Whitsel, Eric A; Lutsey, Pamela L; Duval, Sue; Rosamond, Wayne D; Alonso, Alvaro
2014-09-01
Atrial fibrillation (AF) frequently coexists in the setting of myocardial infarction (MI), being associated with increased mortality. Nonetheless, temporal trends in the occurrence of AF complicating MI and in the prognosis of these patients are not well described. We examined temporal trends in prevalence of AF in the setting of MI and the effect of AF on prognosis in the community. We studied a population-based sample of 20,049 validated first-incident nonfatal hospitalized MIs among 35- to 74-year old residents of 4 communities in the Atherosclerosis Risk in Communities (ARIC) Study from 1987 through 2009. Prevalence of AF in the setting of MI increased from 11% to 15% during the 23-year study period. The multivariable adjusted odds ratio for prevalent AF, per 5-year increment, was 1.11 (95% confidence interval 1.04 to 1.19). Overall, in patients with MI, AF was associated with increased 1-year case fatality (odds ratio 1.47, 95% confidence interval 1.07 to 2.01) compared with those without AF. However, there was no evidence that the impact of AF on MI survival changed over time or differed over time by sex, race, or MI classification (all p values >0.10). In conclusion, co-occurrence of AF in MI slightly increased between 1987 and 2009. The adverse impact of AF on survival in the setting of MI was consistent throughout. In the setting of MI, co-occurrence of AF should be viewed as a critical clinical event, and treatment needs unique to this population should be explored further. Copyright © 2014 Elsevier Inc. All rights reserved.
Martins, Raphael P; Kaur, Kuljeet; Hwang, Elliot; Ramirez, Rafael J; Willis, B Cicero; Filgueiras-Rama, David; Ennis, Steven R; Takemoto, Yoshio; Ponce-Balbuena, Daniela; Zarzoso, Manuel; O'Connell, Ryan P; Musa, Hassan; Guerrero-Serna, Guadalupe; Avula, Uma Mahesh R; Swartz, Michael F; Bhushal, Sandesh; Deo, Makarand; Pandit, Sandeep V; Berenfeld, Omer; Jalife, José
2014-04-08
Little is known about the mechanisms underlying the transition from paroxysmal to persistent atrial fibrillation (AF). In an ovine model of long-standing persistent AF we tested the hypothesis that the rate of electric and structural remodeling, assessed by dominant frequency (DF) changes, determines the time at which AF becomes persistent. Self-sustained AF was induced by atrial tachypacing. Seven sheep were euthanized 11.5±2.3 days after the transition to persistent AF and without reversal to sinus rhythm; 7 sheep were euthanized after 341.3±16.7 days of long-standing persistent AF. Seven sham-operated animals were in sinus rhythm for 1 year. DF was monitored continuously in each group. Real-time polymerase chain reaction, Western blotting, patch clamping, and histological analyses were used to determine the changes in functional ion channel expression and structural remodeling. Atrial dilatation, mitral valve regurgitation, myocyte hypertrophy, and atrial fibrosis occurred progressively and became statistically significant after the transition to persistent AF, with no evidence for left ventricular dysfunction. DF increased progressively during the paroxysmal-to-persistent AF transition and stabilized when AF became persistent. Importantly, the rate of DF increase correlated strongly with the time to persistent AF. Significant action potential duration abbreviation, secondary to functional ion channel protein expression changes (CaV1.2, NaV1.5, and KV4.2 decrease; Kir2.3 increase), was already present at the transition and persisted for 1 year of follow up. In the sheep model of long-standing persistent AF, the rate of DF increase predicts the time at which AF stabilizes and becomes persistent, reflecting changes in action potential duration and densities of sodium, L-type calcium, and inward rectifier currents.
Shulman, Eric; Kargoli, Faraj; Aagaard, Philip; Hoch, Ethan; Di Biase, Luigi; Fisher, John; Gross, Jay; Kim, Soo; Ferrick, Kevin J; Krumerman, Andrew
2017-09-01
Atrial fibrillation (AF) is the most common arrhythmia and is associated with significant morbidity and mortality. Despite having a higher burden of traditional AF risk factors, African American and Hispanic minorities have a lower incidence of AF when compared to non-Hispanic whites, referred to as the "racial paradox." Lower SES among Hispanics and African Americans may help to explain the lower incidence rates of AF compared to non-Hispanic whites. An electrocardiogram/electronic medical records database in New York State was interrogated for individuals free of AF for development of subsequent AF from 2000 to 2013. SES was assessed per zip code via a composite of 6 measures Z-scored to the New York State average. SES was reclassified into decile groups. Cox regression analysis controlling for all baseline differences was used to estimate the independent predictive ability of SES for AF. We identified 48 631 persons (43% Hispanic, 37% African Americans, and 20% non-Hispanic white; mean age 59 years; mean follow-up of 3.2 years) of which 4556 AF cases occurred. Hispanics and African Americans had lower AF risk than whites in all SES deciles (P < 0.001 by log-rank test). Higher SES was borderline associated with lower AF risk (hazard ratio: 0.990, 95% confidence interval: 0.980-1.001, P = 0.061). P trend analysis was not significant by any race/ethnic group by SES deciles for AF. Our study suggests that non-Hispanic whites were at higher risk for AF compared to nonwhites, and this was independent of SES. © 2017 Wiley Periodicals, Inc.
Polejaeva, Irina A; Ranjan, Ravi; Davies, Christopher J; Regouski, Misha; Hall, Justin; Olsen, Aaron L; Meng, Qinggang; Rutigliano, Heloisa M; Dosdall, Derek J; Angel, Nathan A; Sachse, Frank B; Seidel, Thomas; Thomas, Aaron J; Stott, Rusty; Panter, Kip E; Lee, Pamela M; Van Wettere, Arnaud J; Stevens, John R; Wang, Zhongde; MacLeod, Rob S; Marrouche, Nassir F; White, Kenneth L
2016-10-01
Large animal models of progressive atrial fibrosis would provide an attractive platform to study relationship between structural and electrical remodeling in atrial fibrillation (AF). Here we established a new transgenic goat model of AF with cardiac specific overexpression of TGF-β1 and investigated the changes in the cardiac structure and function leading to AF. Transgenic goats with cardiac specific overexpression of constitutively active TGF-β1 were generated by somatic cell nuclear transfer. We examined myocardial tissue, ECGs, echocardiographic data, and AF susceptibility in transgenic and wild-type control goats. Transgenic goats exhibited significant increase in fibrosis and myocyte diameters in the atria compared to controls, but not in the ventricles. P-wave duration was significantly greater in transgenic animals starting at 12 months of age, but no significant chamber enlargement was detected, suggesting conduction slowing in the atria. Furthermore, this transgenic goat model exhibited a significant increase in AF vulnerability. Six of 8 transgenic goats (75%) were susceptible to AF induction and exhibited sustained AF (>2 minutes), whereas none of 6 controls displayed sustained AF (P < 0.01). Length of induced AF episodes was also significantly greater in the transgenic group compared to controls (687 ± 212.02 seconds vs. 2.50 ± 0.88 seconds, P < 0.0001), but no persistent or permanent AF was observed. A novel transgenic goat model with a substrate for AF was generated. In this model, cardiac overexpression of TGF-β1 led to an increase in fibrosis and myocyte size in the atria, and to progressive P-wave prolongation. We suggest that these factors underlie increased AF susceptibility. © 2016 Wiley Periodicals, Inc.