101 research outputs found
ELECTRONIC SPECTRA OF RhH AND RhD
No full text F. Illas, J. Rubio, J. canellas and J.M. Ri***, J. Chem. Phys., 93, 2603(1990) P.B. Ar*** and J.L. Beauchamp, Acc. Chem. Res., 22, 315(1989)Author Institution: Department of Chemistry, University of VictoriaElectronic transitions have been observed with LIF techniques in a supersonic molecular beam of He doped with and and laser-ablated Rh vapor. Bands of RhH have been found near 464.73 and 438.38 nm, which are assigned as (0,0) and (1,0) vibrational bands of a electronic transition. There is a sudden disapperance of the rotational structure in the (1,0) band of RhH above and the spectra associated with higher vibrational levels in the excited states are missing. These observations are attributed to predissociation. Its onset agrees with an ab intio calculation of and the estimate of from The RhH(0,0) band also shows irregular A-doubling. The corresponding (0,0) and (1,0) transitions in RhD appear at 463.40 and 443.02 nm. Analyses of the spectra indicate that the ground state of RhH is an inverted state, which is believed to derive from the electronic configuration and provide the following RhH molecular constants(. The observed ground state symmetry and internuclear distance agree with ab initio Six additional bands have been found for RhD: near and
Microgephyra elegans Hauser & Irwin 2005, sp. n.
No full textMicrogephyra elegans sp. n. Figs 1E, 1F, 2E, 2F, 3E, 3F, 4E, 4F, 5E, 5F, 6C, 7C, 8C, 9B Etymology: L. elegans (fine, graceful). Named in reference to its long antennae and delicate body. Diagnosis: This species is recognised by its red-orange thorax and extremely long antennae, which can be several times the length of the head in the male (Figs 2E, 2F). Description: Male. Head: Ocellar tubercle polished greyish-black, with a few short, black setae. Eyes dichoptic, separated by distance greater than width of ocellar tubercle, ommatidia homogeneous (Fig. 1E). Frons cuticle color greyish-black dorsally, lower frons brown, lacking setae or pubescence (Fig. 1E). Parafacial white pubescent, lacking setae. Genal setae sparse, brownish-black. Lower face dense, white pubescent. Antenna four times longer than head, orange-brown. Scape nearly twice as long as wide with short, black setae overall and some longer setae on ventral apical end. Pedicel nearly square with few black setae. First flagellomere 14 times as long as wide, covered with microsetae bent towards apical tip of antenna. Second flagellomere very small, square with stylus (Fig. 2E). Maxillary palp brown, constricted in middle with long, erect setae on basal half, short, appressed, brown setae in apical half. Proboscis as long as head. Thorax: Mesonotal and pleural cuticle orange-brown, polished without any pubescence, except faint silver pubescence on scutellum, metanepisternum and anatergite. Mesonotum with sparse, short, black setae, and two brown vittae laterally enlarged towards humeral callus, disappearing towards scutellum. Katepisternum and katatergum with sparse, black setae. Wing membrane translucent brownish-grey, covered with microtrichia except the baso-apical part of cell cu-p; two dark bands (Fig. 7C). Pterostigma black. Halter dark brown. Coxae and femora light orange brown, hind coxa with small, brown, apical spot. Fore and hind tibia brown, basally orange, mid tibia orange. Tarsi dark brown, hind basitarsus yellowish. Hind coxa with intense silver pubescence. Coxae with two black macrosetae; hind coxa lacking dorso-lateral macroseta but with hair-like, black setae laterally. Abdomen: Cuticle dark brown, contrasting to orange thorax, polished, with sparse, short, black setae. Gonocoxite with two long black macrosetae laterally (Figs 3E, 4E). Inner margin of gonocoxite with atrium-like cavity. Epandrium with corners folded inwards over nearly a third of width of epandrium and with row of setae on this part; subepandrial sclerite with setae only in most apical part (Fig. 4F). Gonostylus elongate and thin, and curved apically (Figs 3E, 3F, 4E). Hypandrium with about 20 black macrosetae.Aedeagus with apical cap broadly bilobed (Figs 5E, 5F). Ejaculatory apodeme not broadened apically (Fig. 5E). Body length: 6.3 (5.4–6.4) mm. Wing length: 5.4 (4.7–5.4) mm. Female similar to male except as follows: Head: Antenna 2.5 times longer than head, orange-brown (Fig. 2F). First flagellomere 10 times longer than wide, covered with microsetae bent towards apical tip of antenna. Wing membrane generally more infuscate and darker than in males. Abdomen: Sternite 8 dark brown with a row of 10–12 and a row of 10 long, dark brown macrosetae. Furca as in Fig. 6C. Body length: 6.5–8.5 mm. Wing length: 5.1–6.5 mm. Holotype (CASC type number: 18070): MADAGASCAR: Toliara Province: Andohaela National Park, Tsimela, [24.937, 46.627], 175 m, in transitional forest, Parcel II, 19–26.iv.2003, MTr, MI, FDP, RHH, 1ơ, (153174, CASC). Paratypes: MADAGASCAR: Toliara Province: Parc National d’Andohahela, 23.5 km 63 deg ENE Amboasary 7.6 km 99 deg E Hazofotsy, Forêt de Manantalinjo, [24.817, 46.61], 150 m, in spiny forest thicket, 12–16.i.2002, MTr, Fisher, Griswold et al., 1ơ (146490, MEI); Andohaela National Park, Tsimela, Parcelle II, [24.937, 46.627], 175 m, transitional forest, 6–16.i.2003, MTr, MI, FDP, RHH, 1ơ (166265, MEI); 15–26.ii.2003, MTr, MI, FDP, RHH, 1ơ (166264, MEI); 26.ii–8.iii.2003, MTr, MI, FDP, RHH, 1ơ (166267, MNHN); 8–18.iii.2003, MTr, MI, FDP, RHH, 1ơ (166310, MEI); 28.iii–8.iv.2003, MTr, MI, FDP, RHH, 3ơ (166276, 166283, 166303, MEI); 28.i–12.ii.2004, MTr, MI, FDP, RHH, 2ơ (166261, 166301, MEI), 1^ (166274, MNHN); 12–23.ii.2004, MTr, MI, FDP, RHH, 1^ (166275, MEI); Andohaela National Park, 1 km S Ihazofotsy, [24.831, 46.536], 62 m, in spiny forest, Parcel III, 13–20.v.2003, MTr, RHH, MI, 4ơ (146485, 146486, 146488, 146489, MEI), 1^ (146487, MEI); Andohaela National Park, Tsimela, [24.937, 46.627], 175 m, in transitional forest, Parcel II, 19–26.iv.2003, MTr, MI, FDP, RHH, 15ơ (153155, NMSA), (153160, USNM), (153156, 153159, 153162, 153170, 153171, 153172, 153180, 153181, 153182, 153183, 153184, 153185, MEI), (153161, BMNH), 3^ (153186, 153187, 153196, MEI); 1–26.iv.2003, MTr, RHH, MI, 1ơ (146504, MEI), 1^ (146503, MEI); 26.iv–3.v.2003, MTr, MI, RHH, 2ơ (153163, 153167, MEI), 7^ (153189, INHS), (153190, NMSA), (153193, ZMUC), (153191, 153192, 153194, 153195, MEI); 31.v.2003, MTr, RHH, MI, 2ơ (153178, MEI), (153179, SMNS), 1^ (153188, MEI); Berenty Special Reserve, [25.007, 46.303], 36 m, in gallery forest, 23–30.xi.2002, MTr, MI, FDP, RHH, 1ơ (166284, MEI); 30.xi–7.xii.2003, MTr, MI, RHH, 1ơ (166280, MEI); 8–15.xi.2002, MTr, RHH, 1ơ (165114, MEI), 1^ (165105, MEI); 16–23.xi.2002, MTr, MI, RHH, 1ơ (165128, MEI), 1^ (165107, MEI); 23–30.xi.2002, MTr, MI, RHH, 1ơ (165102, MEI); 17–26.i.2003, MTr, MI, RHH,ơ (165112, MEI); Andohaela National Park, Tsimela, Parcelle II, [24.937, 46.627], 176 m, 26.i–5.ii.2003, MTr, MI, RHH, 2ơ (165104, INHS), (166406, MEI); 26.xi–2.xii.2003, MTr, MI, RHH, 1ơ (165103, MEI); 11–21.xii.2003, MTr, MI, RHH, 1ơ (166244, MEI). Biology: This species has been collected from November to May in Malaise traps in spiny forest and in transitional forest.Published as part of Hauser, Martin & Irwin, Michael E., 2005, The subfamily Xestomyzinae (Diptera: Therevidae) new to Madagascar, with the description of four new species, pp. 181-202 in African Invertebrates 46 on pages 189-191, DOI: 10.5281/zenodo.766678
Assessment of channeling bias among initiators of glucose-lowering drugs: A UK cohort study [Corrigendum]
No full textAnkarfeldt MZ, Thorsted BL, Groenwold RHH, et al. Clin Epidemiol. 2017;9:19–30. On page 23, Figure 1 Notes section was marked incorrectly. The correct Notes should read as follows:Figure 1 Propensity score over time for GLP-1 versus basal insulin initiators.Notes: Blue: insulin, red: GLP-1.Abbreviation: GLP-1, glucagon-like peptide-1 analogs. On page 24, Figure 2 Notes section was marked incorrectly. The correct Notes should read as follows:Figure 2 Propensity score over time for DPP-4i versus sulfonylurea initiators.Notes: Blue: sulfonylurea, red: DPP-4i.Abbreviation: DPP-4i, dipeptidyl peptidase-4 inhibitors. On Page 3 of Supplementary materials, Figure S2 caption was shown incorrectly. The correct caption should read as follows:Figure S2 Histograms of propensity score over time. Intention-to-treat and perprotocol cohorts of all identified initiators of GLP-1 and insulin, and DPP-4i and sulfonylurea, respectively. Blue: insulin and sulfonylurea initiators, respectively. Red: GLP-1 and DPP-4i initiators, respectively. Despite the above corrections, the interpretation of these figures in the published proof and the Supplementary materials was correct. Read the original articl
Combinatorial targeting of ribbon-helix-helix artificial transcription factors to chimeric recognition sites
No full textArtificial transcription factors (ATFs) are potent synthetic biology tools for modulating endogenous gene expression and precision genome editing. The ribbon-helix-helix (RHH) superfamily of transcription factors are widespread in bacteria and archaea. The principal DNA binding determinant in this family comprises a two-stranded antiparallel β-sheet (ribbons) in which a pair of eight-residue motifs insert into the major groove. Here, we demonstrate that ribbons of divergent RHH proteins are compact and portable elements that can be grafted into a common α-helical scaffold producing active ATFs. Hybrid proteins cooperatively recognize DNA sites possessing core tetramer boxes whose functional spacing is dictated by interactions between the α-helical backbones. These interactions also promote combinatorial binding of chimeras with different transplanted ribbons, but identical backbones, to synthetic sites bearing cognate boxes for each protein either in vitro or in vivo. The composite assembly of interacting hybrid proteins offers potential advantages associated with combinatorial approaches to DNA recognition compared with ATFs that involve binding of a single protein. Moreover, the new class of RHH ATFs may be utilized to re-engineer transcriptional circuits, or may be enhanced with affinity tags, fluorescent moieties or other elements for targeted genome marking and manipulation in bacteria and archaea. © The Author(s) 2012
La historia como concepto y como práctica: conocimiento histórico en el Rio de la Plata (1780-1840)
No full textEl artículo se propone analizar las formas de conocimiento histórico desarrolladas en el Río de la Plata entre 1780 y 1840 teniendo en cuenta sus condiciones de producción y su sentido. Para ello se examinan los marcos conceptuales referidos a la historia, su conocimiento y representación; la progresiva toma de distancia frente a la literatura para poder constituirse en una forma de conocimiento crítico y pragmático; los usos sociales que se le daba al pasado; y algunas prácticas vinculadas al saber histórico como la edición de colecciones documentales. A lo largo de esta indagación se consideran tanto las condiciones intelectuales como políticas que afectaron laproducción de conocimiento y representaciones históricas. En ese sentido se presta especial atención a las innovaciones promovidas por los escritores ilustrados y al impacto provocado por el proceso revolucionario en la relación que se establecía con el pasado, el presente y el futuro
Modeling of the structure and interactions of the B. anthracis antitoxin, MoxX: deletion mutant studies highlight its modular structure and repressor function
No full textOur previous report on Bacillus anthracis toxin-antitoxin module (MoxXT) identified it to be a two component system wherein, PemK-like toxin (MoxT) functions as a ribonuclease (Agarwal S et al. JBC 285:7254-7270, 2010). The labile antitoxin (MoxX) can bind to/neutralize the action of the toxin and is also a DNA-binding protein mediating autoregulation. In this study, molecular modeling of MoxX in its biologically active dimeric form was done. It was found that it contains a conserved Ribbon-Helix-Helix (RHH) motif, consistent with its DNA-binding function. The modeled MoxX monomers dimerize to form a two-stranded antiparallel ribbon, while the C-terminal region adopts an extended conformation. Knowledge guided protein-protein docking, molecular dynamics simulation, and energy minimization was performed to obtain the structure of the MoxXT complex, which was exploited for the de novo design of a peptide capable of binding to MoxT. It was found that the designed peptide caused a decrease in MoxX binding to MoxT by 42% at a concentration of 2 μM in vitro. We also show that MoxX mediates negative transcriptional autoregulation by binding to its own upstream DNA. The interacting regions of both MoxX and DNA were identified in order to model their complex. The repressor activity of MoxX was found to be mediated by the 16 N-terminal residues that contains the ribbon of the RHH motif. Based on homology with other RHH proteins and deletion mutant studies, we propose a model of the MoxX-DNA interaction, with the antiparallel β-sheet of the MoxX dimer inserted into the major groove of its cognate DNA. The structure of the complex of MoxX with MoxT and its own upstream regulatory region will facilitate design of molecules that can disrupt these interactions, a strategy for development of novel antibacterials
Implementation and evaluation of tailored intervention strategies to influence antibiotic prescribing for community-acquired pneumonia
No full textAdherence to guidelines for the management of community-acquired pneumonia (CAP) has been shown to improve patients' clinical outcomes. However, several studies have indicated that the chosen antibiotic regimen is frequently not consistent with guideline recommendations. This might lead to suboptimal treatment, either by exposing patients to a greater risk of treatment failure or by unnecessary use of broad-spectrum antibiotics, which contributes to the emergence of antibiotic-resistant pathogens or consequent development of Clostridium difficile-associated diarrhoea. It has been demonstrated that active implementation of CAP guidelines can significantly improve adherence to recommendations, which consequently, might improve patients' clinical outcomes. The present research developed, implemented and evaluated tailored intervention strategies to improve physicians' concordance with CAP guidelines. A number of inter-related studies were conducted as a part of this research project. Firstly, baseline data was collected to measure the level of physicians' adherence to national CAP guidelines in two Tasmanian hospitals, the Royal Hobart Hospital (RHH) and North Western Regional Hospital (NWRH). It was evident in that study that adherence to CAP management guidelines was poor at both study sites (16.1% and 7.5% for RHH and NWRH, respectively). This was followed by a study to identify and quantify potential barriers to the adherence to CAP guideline recommendations. A questionnaire was distributed to RHH doctors in non-surgical areas of practice. Of the study population, 43.1% doctors responded to the survey; of those who responded, 46.4% thought the influence of senior doctors on their juniors could be a factor affecting adherence to the guidelines. Other barriers noted were a lack of guideline awareness (39.3%), the requirement to calculate the severity of CAP (35.7%), and the existence of other guidelines that conflict with Therapeutic Guidelines: antibiotic, version 14 (TG14; 28.6%). A qualitative study was then designed to determine factors that influence doctors working within the emergency department (ED) to prescribe ceftriaxone outside the TG14 recommendations. Eight face-to-face interviews were performed with ED doctors. Five main themes emerged as influencing decisions regarding the selection of ceftriaxone for patients with CAP: (i) clinical intuition compared to a structured evaluation of severity, (ii) clinical uncertainty, (iii) prior clinical experience, (iv) source of guidance and (v) prescribing etiquette. A questionnaire survey was then sent to infectious disease pharmacists nationally in order to identify the strategies that have been used and perceived as successful for the management of CAP in their institutions. Of the study population, 41 pharmacists (27.3%) responded to the questionnaire. Of these, 90.2% pharmacists reported their hospitals having an antimicrobial stewardship (AMS) program. Multifaceted strategies to enhance antibiotic prescribing in ED for CAP, were mentioned as being in place in all responses. However, the largest number of the respondents (34.1%) considered use of CAP clinical pathways to be the most effective strategy. Intervention strategies were subsequently developed and implemented based on the findings from the above studies. Two interventions were implemented over two time periods: one with general strategies across medical units and a second focused on the ED. During the general intervention period, local CAP guidelines (based on TG14) were released. The guidelines were developed and approved by the hospital's medical and emergency departments. The release of the CAP guidelines was accompanied by a multifaceted educational package to increase awareness of the guidelines. Medical and ED teams were targeted in the educational package, which included group sessions, wall posters and laminated lanyard cards summarising the local guidelines. During the second time period, two further strategies were introduced (a CAP clinical management pathway and monthly auditing with feedback) and targeted specifically at ED staff. We evaluated the impact of the interventions on guideline adherence rates and clinical outcomes (mortality rates and hospital length of stay, LOS). To evaluate the impact of the intervention, two hospital sites were selected, one (RHH) acted as an intervention site and the other (NWRH) as a control site where no intervention was made. The study found the intervention had an overall impact on guideline adherence rates at the intervention site, and it reduced overall mortality rates and LOS for patients with non-severe CAP. Compared to the baseline data, the adherence rate increased significantly at the RHH during the intervention period (16.1% vs 50%; p 0.05). The in-patient mortality was significantly lower in the intervention group when compared to the non-intervention groups (all baseline data plus the data from the NWRH during the intervention period) (3.4% vs 7.3%; p < 0.05). Sub-group analysis revealed patients with non-severe CAP in the intervention group had an average LOS 0.8 days shorter than the non-intervention groups (p < 0.05). Results from the previous study indicated a positive impact of the intervention in the overall adherence to CAP recommendations. However, two main strategies were conducted in two consecutive times during the intervention periods, a general intervention and an ED-focused intervention. Therefore, a time-series analysis was conducted to determine the impact of strategies over time at the intervention site. The rates of adherence to the CAP guidelines during the pre-intervention (5 months) and general intervention periods (5 months) were 28.1% and 31.2%, respectively. The difference was not statistically significant. During the ED-focused intervention period (7 months), the level of adherence with guidelines was significantly higher at 61.5% (p < 0.05). Finally, we evaluated the use of ceftriaxone in all indications in two time periods, before and after the initiation of the intervention. The aim of this study was to determine if our intervention in CAP management could affect the use of ceftriaxone in other indications. Concordance to the TG14 for all indications, with the exception of respiratory tract infection (RTI), was similar between the two study periods. For the RTI, concordant use of ceftriaxone significantly increased from 50% during the first period to 64.5% during the second study period (p < 0.05). Among community-acquired lower respiratory tract infections, our findings indicated a significant decrease in the unnecessary use of ceftriaxone for patients with mild CAP and acute exacerbation of chronic obstructive pulmonary disease in the intervention group (both 19% vs 3.2%; p < 0.05). However, there were no significant changes in the appropriate prescribing of ceftriaxone for other indications. In conclusion, this research project identified, with in-depth analysis, potential factors that lead to the prescription of discordant antibiotic regimens for empirical management of CAP. It was subsequently demonstrated that a tailored multifaceted intervention significantly improved adherence to CAP guidelines, which consequently reduced the inappropriate prescribing of ceftriaxone for this indication. This was associated with a decrease in mortality rate and length of hospital stay among patients in the intervention group
Proceso de configuración del campo historiográfico uruguayo
No full textLa configuración del campo historiográfico uruguayo fue lenta. Comenzó a definirse a mediados del siglo XX cuando se establecieron centros de formación y profesionalización como la Facultad de Humanidades y Ciencias de la Universidad de la República (1945) y el Instituto de Profesores Artigas (1949). Sus antecedentes se remontan al período de la modernización y estuvieron articulados en un difuso espacio transnacional, rioplatense, pautado por una intensa interacción de autores y corrientes que generaron relatos fundantes y mitemas identitarios de carácter nacional ista. Los objet ivos de este ar t ículo son analizar sus antecedentes, su proceso de consolidación e identificar sus características particulares
Fluoroarene Complexes with Small Bite Angle Bisphosphines: Routes to Amine–Borane and Aminoborylene Complexes
No full textFluoroarene complexes of the small bite angle bisphosphine Cy2PCH2PCy2 (dcpm) have been prepared: [Rh(dcpm)(η6-1,2-F2C6H4)][Al{OC(CF3)3}4] and [Rh(dcpm)(η6-1,2,3-F3C6H3)][Al{OC(CF3)3}4]. These complexes act as precursors to a previously inaccessible σ-amine–borane complex [Rh(dcpm)(η2-H3B·NMe3)][Al{OC(CF3)3}4] of a small bite-angle phosphine. This complex is a poor catalyst for the dehydrocoupling of H3B·NMe2H. Instead, formation of the bridging borylene complex [{RhH(µ-dcpm)}2(µ-H)(µ-BNMe2)][Al{OC(CF3)3}4] occurs, which has been studied by NMR, mass spectrometry, crystallographic and DFT techniques. This represents a new route to bridging borylene complexes
Interactions of rhodium carbonyl compounds supported on inorganic oxides with CO, H2 and propylene
No full textRhCl(CO)(PPh3)2, RhH(CO)(PPh3)3, and [RhClfCO)2]2 were supported on silica gel, γ-alumina, titania.and magensia in 3 to 5 wt % to study the interactions of rhodium carbonyl with the surface of inorganic oxides When trans-RhCI(CO)(PPh3)2 was supported on the surface of silica gel, cis-RhCl(CO) (PPh3)2 species was detected via the splitting of the CO infra red stretching band of trans-RhCI (CO)(PPh3)2. With other supports, same phenomenon was observed but with the different pattern of intensities of the splitted CO stretching bands. RhH(CO)(PPh3)3 was easily decarbonylated, after interacting with the surface of silica gel, γ-alumina, and titania. However, [RhCl(CO)2]2 was decarbonylated on the surface of inorganic oxides mentioned above and most of supported [RhCl(CO)2]2 converted to a stable surface carbonyl species [M-OH-RhCI(CO)2; M = Si, Al, Ti]. Diffuse reflectance infrared spectroscopy (DRS) was used to study the interactions of 5 wt % RhCl(CO)(PPh3)2 supported on silica gel with H2, CO and/or propylene at various temperatures. The result indicated that the surface intermediates formed from the interaction of RhCl(CO)(PPh3)2 with CO, H2 and C3H6 were not identical to the corresponding liquid-phase intermediates of RhCl(CO)(PPh3)2 in the presence of solvent. © 1987 Korean Institute of Chemical Engineering
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