15 resultados para Metal-support interaction

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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Objective To compare the effectiveness and safety of three types of stents (sirolimus eluting, paclitaxel eluting, and bare metal) in people with and without diabetes mellitus. Design Collaborative network meta-analysis. Data sources Electronic databases (Medline, Embase, the Cochrane Central Register of Controlled Trials), relevant websites, reference lists, conference abstracts, reviews, book chapters, and proceedings of advisory panels for the US Food and Drug Administration. Manufacturers and trialists provided additional data. Review methods Network meta-analysis with a mixed treatment comparison method to combine direct within trial comparisons between stents with indirect evidence from other trials while maintaining randomisation. Overall mortality was the primary safety end point, target lesion revascularisation the effectiveness end point. Results 35 trials in 3852 people with diabetes and 10 947 people without diabetes contributed to the analyses. Inconsistency of the network was substantial for overall mortality in people with diabetes and seemed to be related to the duration of dual antiplatelet therapy (P value for interaction 0.02). Restricting the analysis to trials with a duration of dual antiplatelet therapy of six months or more, inconsistency was reduced considerably and hazard ratios for overall mortality were near one for all comparisons in people with diabetes: sirolimus eluting stents compared with bare metal stents 0.88 (95% credibility interval 0.55 to 1.30), paclitaxel eluting stents compared with bare metal stents 0.91 (0.60 to 1.38), and sirolimus eluting stents compared with paclitaxel eluting stents 0.95 (0.63 to 1.43). In people without diabetes, hazard ratios were unaffected by the restriction. Both drug eluting stents were associated with a decrease in revascularisation rates compared with bare metal stents in people both with and without diabetes. Conclusion In trials that specified a duration of dual antiplatelet therapy of six months or more after stent implantation, drug eluting stents seemed safe and effective in people both with and without diabetes.

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OBJECTIVES: Aim of the study was to evaluate the patients' sensations during and after laserneedle versus metal needle acupuncture. STUDY DESIGN: The prospective study was performed at the gynaecological outpatient department of a University Teaching Hospital of Bern, Switzerland. Thirty female patients per group were included in the study and randomized into laserneedle or metal needle group. All women visited the acupuncture out patient department because of gynaecological disorders. Age of the patients in the metal needle group was 38 years in median (range 18-73 years); mean age was 41+/-13.3. Age in the laserneedle group was 36 years in median (range 16-60 years) and mean age was 39.1+/-12.2. Interventions were laserneedle acupuncture and metal needle acupuncture. Patients answered a questionnaire before, after the first treatment and prior to the second treatment. The questionnaires asked about the patients' knowledge of the various acupuncture methods and their health condition before treatment, their perception of pain, warmth, tiredness and relaxation during or after application of the needles or during or after the treatment. Statistics were performed by Graph Pad InStat 3 for windows. RESULTS: The common metal needle technique was well known by the patients in comparison to the laserneedle method (p<0.0001***). Laserneedle acupuncture is a method which is painless (p<0.0001***), energy inducing and relaxing (p=0.0257*) which leads to a warming sensation (p=0.0009***) during treatment. CONCLUSION: Both methods laserneedle and metal needle acupuncture are valuable methods in achieving relaxation and improvement of gynaecological symptoms. Laserneedle acupuncture is painless and easy to apply which is a valuable reason to support this technique in the future.

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We prepared and investigated oligonucleotide duplexes of the sequence d(GATGAC(X)(n)GCTAG)d(CTAGC(Y)(n)GTCATC), in which X and Y designate biphenyl- (bph) and pentafluorobiphenyl- ((5F)bph) C-nucleotides, respectively, and n varies from 0-4. These hydrophobic base substitutes are expected to adopt a zipperlike, interstrand stacking motif, in which not only bph/bph or (5F)bph/(5F)bph homo pairs, but also (5F)bph/bph mixed pairs can be formed. By performing UV-melting curve analysis we found that incorporation of a single (5F)bph/(5F)bph pair leads to a duplex that is essentially as stable as the unmodified duplex (n=0), and 2.4 K more stable than the duplex with the nonfluorinated bph/bph pair. The T(m) of the mixed bph/(5F)bph pair was in between the T(m) values of the respective homo pairs. Additional, unnatural aromatic pairs increased the T(m) by +3.0-4.4 K/couple, irrespective of the nature of the aromatic residue. A thermodynamic analysis using isothermal titration calorimetry (ITC) of a series of duplexes with n=3 revealed lower (less negative) duplex formation enthalpies (DeltaH) in the (5F)bph/(5F)bph case than in the bph/bph case, and confirmed the higher thermodynamic stability (DeltaG) of the fluorinated duplex, suggesting it to be of entropic origin. Our data are compatible with a model in which the stacking of (5F)bph versus bph is dominated by dehydration of the aromatic units upon duplex formation. They do not support a model in which van der Waals dispersive forces (induced dipoles) or electrostatic (quadrupole) interactions play a dominant role

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Recent experiments suggest that humans can form and later retrieve new semantic relations unconsciously by way of hippocampus - the key structure thought to support conscious relational (episodic) memory. Given that the hippocampus subserves both conscious and unconscious relational encoding/retrieval, we expected the hippocampus to be place of unconscious-conscious interactions. This hypothesis was tested in an fMRI experiment on the interaction between the unconscious retrieval of face-associated occupations and the subsequent conscious retrieval of celebrities’ occupations. For subliminal encoding, masked combinations of an unfamiliar face and a written occupation (“actor” or “politician”) were subliminally presented. At test, we presented the former subliminal faces again, without occupations and masks, as conscious retrieval cues. We hypothesized that faces would trigger the unconscious reactivation of the associated occupation - actor or politician -, which in turn would facilitate or inhibit the subsequent conscious recollection of a celebrity’s occupation. Following the presentation of a former subliminal face, we presented the portrait of a celebrity that participants were required to sort according to “actor” or “politician”. Depending on whether the triggered unconscious occupation was congruent or incongruent with the celebrity’s occupation, we expected an expedited or retarded conscious retrieval process as reflected in reaction times. Conscious retrieval was expedited in the congruent condition, but there was no effect in the incongruent condition. fMRI data collected during subliminal relational encoding confirmed that the hippocampus was interacting with neocortical semantic storage sites. fMRI data collected at test indicated that the facilitated conscious retrieval of celebrity-associated occupations was related to deactivations in this same network spanning hippocampus and neocortical semantic storage sites. Hence, unconscious retrieval likely preactivated this network, which allowed for a sparing recruitment of additional neural resources to assist conscious retrieval. This finding supports the notion that consciously and unconsciously acquired relational memories are stored in a single, cohesive hippocampal-neocortical memory space.

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Recent evidence suggests that humans can form and later retrieve new semantic relations unconsciously by way of hippocampus-the key structure also recruited for conscious relational (episodic) memory. If the hippocampus subserves both conscious and unconscious relational encoding/retrieval, one would expect the hippocampus to be place of unconscious-conscious interactions during memory retrieval. We tested this hypothesis in an fMRI experiment probing the interaction between the unconscious and conscious retrieval of face-associated information. For the establishment of unconscious relational memories, we presented subliminal (masked) combinations of unfamiliar faces and written occupations ("actor" or "politician"). At test, we presented the former subliminal faces, but now supraliminally, as cues for the reactivation of the unconsciously associated occupations. We hypothesized that unconscious reactivation of the associated occupation-actor or politician-would facilitate or inhibit the subsequent conscious retrieval of a celebrity's occupation, which was also actor or politician. Depending on whether the reactivated unconscious occupation was congruent or incongruent to the celebrity's occupation, we expected either quicker or delayed conscious retrieval process. Conscious retrieval was quicker in the congruent relative to a neutral baseline condition but not delayed in the incongruent condition. fMRI data collected during subliminal face-occupation encoding confirmed previous evidence that the hippocampus was interacting with neocortical storage sites of semantic knowledge to support relational encoding. fMRI data collected at test revealed that the facilitated conscious retrieval was paralleled by deactivations in the hippocampus and neocortical storage sites of semantic knowledge. We assume that the unconscious reactivation has pre-activated overlapping relational representations in the hippocampus reducing the neural effort for conscious retrieval. This finding supports the notion of synergistic interactions between conscious and unconscious relational memories in a common, cohesive hippocampal-neocortical memory space.

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The article proposes granular computing as a theoretical, formal and methodological basis for the newly emerging research field of human–data interaction (HDI). We argue that the ability to represent and reason with information granules is a prerequisite for data legibility. As such, it allows for extending the research agenda of HDI to encompass the topic of collective intelligence amplification, which is seen as an opportunity of today’s increasingly pervasive computing environments. As an example of collective intelligence amplification in HDI, we introduce a collaborative urban planning use case in a cognitive city environment and show how an iterative process of user input and human-oriented automated data processing can support collective decision making. As a basis for automated human-oriented data processing, we use the spatial granular calculus of granular geometry.

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In this article, we present a new microscopic theoretical approach to the description of spin crossover in molecular crystals. The spin crossover crystals under consideration are composed of molecular fragments formed by the spin-crossover metal ion and its nearest ligand surrounding and exhibiting well defined localized (molecular) vibrations. As distinguished from the previous models of this phenomenon, the developed approach takes into account the interaction of spin-crossover ions not only with the phonons but also a strong coupling of the electronic shells with molecular modes. This leads to an effective coupling of the local modes with phonons which is shown to be responsible for the cooperative spin transition accompanied by the structural reorganization. The transition is characterized by the two order parameters representing the mean values of the products of electronic diagonal matrices and the coordinates of the local modes for the high- and low-spin states of the spin crossover complex. Finally, we demonstrate that the approach provides a reasonable explanation of the observed spin transition in the [Fe(ptz)6](BF4)2 crystal. The theory well reproduces the observed abrupt low-spin → high-spin transition and the temperature dependence of the high-spin fraction in a wide temperature range as well as the pronounced hysteresis loop. At the same time within the limiting approximations adopted in the developed model, the evaluated high-spin fraction vs. T shows that the cooperative spin-lattice transition proves to be incomplete in the sense that the high-spin fraction does not reach its maximum value at high temperature.

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Background: There is evidence that drinking during residential treatment is related to various factors, such as patients’ general control beliefs and self-efficacy, as well as to external control of alcohol use by program’s staff and situations where there is temptation to drink. As alcohol use during treatment has been shown to be associated with the resumption of alcohol use after discharge from residential treatment, we aimed to investigate how these variables are related to alcohol use during abstinenceoriented residential treatment programs for alcohol use disorders (AUD). Methods: In total, 509 patients who entered 1 of 2 residential abstinence-oriented treatment programs for AUD were included in the study. After detoxification, patients completed a standardized diagnostic procedure including interviews and questionnaires. Drinking was assessed by patients’ selfreport of at least 1 standard drink or by positive breathalyzer testing. The 2 residential programs were categorized as high or low control according to the average number of tests per patient. Results: Regression analysis revealed a significant interaction effect between internal and external control suggesting that patients with high internal locus of control and high frequency of control by staff demonstrated the least alcohol use during treatment (16.7%) while patients with low internal locus of control in programs with low external control were more likely to use alcohol during Treatment (45.9%). No effects were found for self-efficacy and temptation. Conclusions: As alcohol use during treatment is most likely associated with poor treatment outcomes, external control may improve treatment outcomes and particularly support patients with low internal locus of control, who show the highest risk for alcohol use during treatment. High external control may complement high internal control to improve alcohol use prevention while in treatment. Key Words: Alcohol Dependence, Alcohol Use, Locus of Control, Alcohol Testing.

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In any physicochemical process in liquids, the dynamical response of the solvent to the solutes out of equilibrium plays a crucial role in the rates and products: the solvent molecules react to the changes in volume and electron density of the solutes to minimize the free energy of the solution, thus modulating the activation barriers and stabilizing (or destabilizing) intermediate states. In charge transfer (CT) processes in polar solvents, the response of the solvent always assists the formation of charge separation states by stabilizing the energy of the localized charges. A deep understanding of the solvation mechanisms and time scales is therefore essential for a correct description of any photochemical process in dense phase and for designing molecular devices based on photosensitizers with CT excited states. In the last two decades, with the advent of ultrafast time-resolved spectroscopies, microscopic models describing the relevant case of polar solvation (where both the solvent and the solute molecules have a permanent electric dipole and the mutual interaction is mainly dipole−dipole) have dramatically progressed. Regardless of the details of each model, they all assume that the effect of the electrostatic fields of the solvent molecules on the internal electronic dynamics of the solute are perturbative and that the solvent−solute coupling is mainly an electrostatic interaction between the constant permanent dipoles of the solute and the solvent molecules. This well-established picture has proven to quantitatively rationalize spectroscopic effects of environmental and electric dynamics (time-resolved Stokes shifts, inhomogeneous broadening, etc.). However, recent computational and experimental studies, including ours, have shown that further improvement is required. Indeed, in the last years we investigated several molecular complexes exhibiting photoexcited CT states, and we found that the current description of the formation and stabilization of CT states in an important group of molecules such as transition metal complexes is inaccurate. In particular, we proved that the solvent molecules are not just spectators of intramolecular electron density redistribution but significantly modulate it. Our results solicit further development of quantum mechanics computational methods to treat the solute and (at least) the closest solvent molecules including the nonperturbative treatment of the effects of local electrostatics and direct solvent−solute interactions to describe the dynamical changes of the solute excited states during the solvent response.

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NH···π hydrogen bonds occur frequently between the amino acid side groups in proteins and peptides. Data-mining studies of protein crystals find that ~80% of the T-shaped histidine···aromatic contacts are CH···π, and only ~20% are NH···π interactions. We investigated the infrared (IR) and ultraviolet (UV) spectra of the supersonic-jet-cooled imidazole·benzene (Im·Bz) complex as a model for the NH···π interaction between histidine and phenylalanine. Ground- and excited-state dispersion-corrected density functional calculations and correlated methods (SCS-MP2 and SCS-CC2) predict that Im·Bz has a Cs-symmetric T-shaped minimum-energy structure with an NH···π hydrogen bond to the Bz ring; the NH bond is tilted 12° away from the Bz C₆ axis. IR depletion spectra support the T-shaped geometry: The NH stretch vibrational fundamental is red shifted by −73 cm⁻¹ relative to that of bare imidazole at 3518 cm⁻¹, indicating a moderately strong NH···π interaction. While the Sₒ(A1g) → S₁(B₂u) origin of benzene at 38 086 cm⁻¹ is forbidden in the gas phase, Im·Bz exhibits a moderately intense Sₒ → S₁ origin, which appears via the D₆h → Cs symmetry lowering of Bz by its interaction with imidazole. The NH···π ground-state hydrogen bond is strong, De=22.7 kJ/mol (1899 cm⁻¹). The combination of gas-phase UV and IR spectra confirms the theoretical predictions that the optimum Im·Bz geometry is T shaped and NH···π hydrogen bonded. We find no experimental evidence for a CH···π hydrogen-bonded ground-state isomer of Im·Bz. The optimum NH···π geometry of the Im·Bz complex is very different from the majority of the histidine·aromatic contact geometries found in protein database analyses, implying that the CH···π contacts observed in these searches do not arise from favorable binding interactions but merely from protein side-chain folding and crystal-packing constraints. The UV and IR spectra of the imidazole·(benzene)₂ cluster are observed via fragmentation into the Im·Bz+ mass channel. The spectra of Im·Bz and Im·Bz₂ are cleanly separable by IR hole burning. The UV spectrum of Im·Bz₂ exhibits two 000 bands corresponding to the Sₒ → S₁ excitations of the two inequivalent benzenes, which are symmetrically shifted by −86/+88 cm⁻¹ relative to the 000 band of benzene.

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The article proposes granular computing as a theoretical, formal and methodological basis for the newly emerging research field of human–data interaction (HDI). We argue that the ability to represent and reason with information granules is a prerequisite for data legibility. As such, it allows for extending the research agenda of HDI to encompass the topic of collective intelligence amplification, which is seen as an opportunity of today’s increasingly pervasive computing environments. As an example of collective intelligence amplification in HDI, we introduce a collaborative urban planning use case in a cognitive city environment and show how an iterative process of user input and human-oriented automated data processing can support collective decision making. As a basis for automated human-oriented data processing, we use the spatial granular calculus of granular geometry.

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IRT1 and IRT2 are members of the Arabidopsis ZIP metal transporter family that are specifically induced by iron deprivation in roots and act as heterologous suppressors of yeast mutations inhibiting iron and zinc uptake. Although IRT1 and IRT2 are thought to perform redundant functions as root-specific metal transporters, insertional inactivation of the IRT1 gene alone results in typical symptoms of iron deficiency causing severe leaf chlorosis and lethality in soil. The irt1 mutation is characterized by specific developmental defects, including a drastic reduction of chloroplast thylakoid stacking into grana and lack of palisade parenchyma differentiation in leaves, reduced number of vascular bundles in stems, and irregular patterns of enlarged endodermal and cortex cells in roots. Pulse labeling with 59Fe through the root system shows that the irt1 mutation reduces iron accumulation in the shoots. Short-term labeling with 65Zn reveals no alteration in spatial distribution of zinc, but indicates a lower level of zinc accumulation. In comparison to wild-type, the irt1 mutant responds to iron and zinc deprivation by altered expression of certain zinc and iron transporter genes, which results in the activation of ZIP1 in shoots, reduction of ZIP2 transcript levels in roots, and enhanced expression of IRT2 in roots. These data support the conclusion that IRT1 is an essential metal transporter required for proper development and regulation of iron and zinc homeostasis in Arabidopsis.