The dinuclear Pt–Au complex (CNC)(PPh3)Pt Au(PPh3)(ClO4) (2) (CNC=2,6‐diphenylpyridinate) was prepared. Its crystal structure shows a rare metal–metal bonding situation, with very short Pt–Au and ...Au–Cipso(CNC) distances and dissimilar Pt–Cipso(CNC) bonds. Multinuclear NMR spectra of 2 show the persistence of the Pt–Au bond in solution and the occurrence of unusual fluxional behavior involving the PtII and AuI metal fragments. The PtII⋅⋅⋅ AuI interaction has been thoroughly studied by means of DFT calculations. The observed bonding situation in 2 can be regarded as a model for an intermediate in a transmetalation process.
The swing of a rare metronome: A bimetallic Pt–Au complex was synthesized and its electronic structure studied by DFT methods. In solution, it showed unusual fluxional behavior involving the formation and cleavage of Au−C bonds (see picture). The complex can be viewed as a model for an intermediate in a transmetalation process promoted by cooperative metal catalysts, whereby the Pt−Au bond anchors the two metallic fragments.
Bimetallic single–atom catalysts (b–SACs) have recently gained prominence by virtue of the unique catalytic cooperative interactions they can exhibit, intertwining electronic and geometric effects. ...To date, research efforts have exclusively focused on direct mechanisms such as electron density transfer or sequential reactivity. Herein, the first study on indirect, coordination–induced catalytic synergies in carbon‐supported RuPt SACs is conducted. To this end, a holistic approach is developed, combining i) precision synthesis, ii) advanced characterization, iii) exploration of single–site adsorption properties via the hydrogen evolution reaction, and iv) modeling through density functional theory. Despite the lack of both intermetallic coordination in the first or second shell and charge redistribution effects, the RuPt SACs exhibit a H2 formation rate enhanced up to 15–fold compared with their monometallic counterparts. To unfold the origin of the intermetallic cooperativity, modifications of the structural and catalytic properties induced by the integration of a second metal species are investigated. Thus, Pt atoms are found to selectively occupy the most energeticallyfavorable cavities in the support, prompting Ru atoms to assume a distinct, more active, configuration. This contribution unveils a novel principle of bimetallic cooperativity, demonstrating the key role of integrative experimental and computational analyses in studying b–SACs.
Coordination–induced cooperativity effects between isolated Ru and Pt atoms are investigated via the hydrogen evolution reaction, selected as a probe for single–site H–adsorption properties. Pt atoms are found to selectively occupy the most energetically favorable cavities in the carbon host, prompting Ru atoms to adopt a distinct and more active configuration.
Erectile dysfunction (ED) is the most frequently treated male sexual dysfunction worldwide. ED is a chronic condition that exerts a negative impact on male self-esteem and nearly all life domains ...including interpersonal, family, and business relationships.
The aim of this study is to provide an updated overview on currently used and available conservative treatment options for ED with a special focus on their efficacy, tolerability, safety, merits, and limitations including the role of combination therapies for monotherapy failures.
The methods used were PubMed and MEDLINE searches using the following keywords: ED, phosphodiesterase type 5 (PDE5) inhibitors, oral drug therapy, intracavernosal injection therapy, transurethral therapy, topical therapy, and vacuum-erection therapy/constriction devices. Additionally, expert opinions by the authors of this article are included.
Level 1 evidence exists that changes in sedentary lifestyle with weight loss and optimal treatment of concomitant diseases/risk factors (e.g., diabetes, hypertension, and dyslipidemia) can either improve ED or add to the efficacy of ED-specific therapies, e.g., PDE5 inhibitors. Level 1 evidence also exists that treatment of hypogonadism with total testosterone < 300 ng/dL (10.4 nmol/L) can either improve ED or add to the efficacy of PDE5 inhibitors. There is level 1 evidence regarding the efficacy and safety of the following monotherapies in a spectrum-wide range of ED populations: PDE5 inhibitors, intracavernosal injection therapy with prostaglandin E1 (PGE1, synonymous alprostadil) or vasoactive intestinal peptide (VIP)/phentolamine, and transurethral PGE1 therapy. There is level 2 evidence regarding the efficacy and safety of the following ED treatments: vacuum-erection therapy in a wide range of ED populations, oral L-arginine (3–5 g), topical PGE1 in special ED populations, intracavernosal injection therapy with papaverine/phentolamine (bimix), or papaverine/phentolamine/PGE1 (trimix) combination mixtures. There is level 3 evidence regarding the efficacy and safety of oral yohimbine in nonorganic ED. There is level 3 evidence that combination therapies of PDE5 inhibitors + either transurethral or intracavernosal injection therapy generate better efficacy rates than either monotherapy alone. There is level 4 evidence showing enhanced efficacy with the combination of vacuum-erection therapy + either PDE5 inhibitor or transurethral PGE1 or intracavernosal injection therapy. There is level 5 evidence (expert opinion) that combination therapy of PDE5 inhibitors + L-arginine or daily dosing of tadalafil + short-acting PDE5 inhibitors pro re nata may rescue PDE5 inhibitor monotherapy failures. There is level 5 evidence (expert opinion) that adding either PDE5 inhibitors or transurethral PGE1 may improve outcome of penile prosthetic surgery regarding soft (cold) glans syndrome. There is level 5 evidence (expert opinion) that the combination of PDE5 inhibitors and dapoxetine is effective and safe in patients suffering from both ED and premature ejaculation. Porst H, Burnett A, Brock G, Ghanem H, Giuliano F, Glina S, Hellstrom W, Martin-Morales A, Salonia A, Sharlip I, and the ISSM Standards Committee for Sexual Medicine. SOP conservative (medical and mechanical) treatment of erectile dysfunction. J Sex Med 2013;10:130–171.
Studies of Gamma-Ray Burst (GRB) properties, such as duration and spectral hardness, have found evidence for additional classes, beyond the short/hard and long/soft prototypes, using model-dependent ...methods. In this paper, a model-independent approach was used to analyse the gamma-ray light curves of large samples of GRBs detected by BATSE, Swift/BAT and Fermi/GBM. All the features were extracted from the GRB time profiles in four energy bands using the Stationary Wavelet Transform and Principal Component Analysis. t-distributed Stochastic Neighbourhood Embedding (t-SNE) visualisation of the features revealed two distinct groups of Swift/BAT bursts using the T100 interval with 64 ms resolution data. When the same analysis was applied to 4 ms resolution data, two groups were seen to emerge within the first second (T1) post-trigger. These two groups primarily consisted of short/hard (Group 1) and long/soft (Group 2) bursts, and were 95% consistent with the groups identified using the T100 64 ms resolution data. Kilonova candidates, arising from compact object mergers, were found to belong to Group 1, while those events with associated supernovae fell into Group 2. Differences in cumulative counts between the two groups in the first second, and in the minimum variability timescale, identifiable only with the 4 ms resolution data, may account for this result. Short GRBs have particular significance for multi-messenger science as a distinctive EM signature of a binary merger, which may be discovered by its gravitational wave emissions. Incorporating the T1 interval into classification algorithms may support the rapid classification of GRBs, allowing for an improved prioritisation of targets for follow-up observations.
M. africanum West African 2 constitutes an ancient lineage of the M. tuberculosis complex that commonly causes human tuberculosis in West Africa and has an attenuated phenotype relative to M. ...tuberculosis.
In search of candidate genes underlying these differences, the genome of M. africanum West African 2 was sequenced using classical capillary sequencing techniques. Our findings reveal a unique sequence, RD900, that was independently lost during the evolution of two important lineages within the complex: the "modern" M. tuberculosis group and the lineage leading to M. bovis. Closely related to M. bovis and other animal strains within the M. tuberculosis complex, M. africanum West African 2 shares an abundance of pseudogenes with M. bovis but also with M. africanum West African clade 1. Comparison with other strains of the M. tuberculosis complex revealed pseudogenes events in all the known lineages pointing toward ongoing genome erosion likely due to increased genetic drift and relaxed selection linked to serial transmission-bottlenecks and an intracellular lifestyle.
The genomic differences identified between M. africanum West African 2 and the other strains of the Mycobacterium tuberculosis complex may explain its attenuated phenotype, and pave the way for targeted experiments to elucidate the phenotypic characteristic of M. africanum. Moreover, availability of the whole genome data allows for verification of conservation of targets used for the next generation of diagnostics and vaccines, in order to ensure similar efficacy in West Africa.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We explore the notion that consciousness may be more of a belief than an empirically verifiable fact, shaped by the subjective nature of our experiences and the inherent limitations of reporting ...them. Contemporary science has yet to provide definitive proof of subjective experience beyond self-reports, which even sophisticated machines could mimic under specific conditions. Philosophical concepts such as phenomenological zombies—creatures identical to us but lacking consciousness—highlight the difficulty of distinguishing between actual conscious experience and mere behavioral reports. Current experimental designs often conflate metacognition (beliefs about perception) with consciousness, as seen in Higher-Order Thought theories and the Perceptual Reality Monitoring theory. These frameworks suggest that our sense of being conscious arises from metacognitive processes, potentially leading to cognitive biases. Studies involving disruptions to brain regions responsible for metacognitive accuracy further complicate our understanding of consciousness. Additionally, phenomena like delusional misidentification syndromes challenge the assumption of a coherent self that reliably perceives and reports reality. By questioning these assumptions, we propose that consciousness might be an elaborate belief system, a convenient construct for survival rather than an intrinsic quality of our being. This perspective urges a reconsideration of the fundamental nature of consciousness and our approach to studying it.
Enterococci are common constituents of dairy products such as cheese, in which it is believed that they contribute to the development of some of their organoleptic properties. This is particularly ...true in the Mediterranean region, where farmhouse cheeses are generally made from raw milk, which tends to harbour enterococci. In recent years, however, enterococci have emerged as serious pathogens in hospital environments, where vancomycin-resistant strains are on the increase. In this study we have characterized 95 enterococci isolated from 3 different goats' milk cheeses, belonging to the species
Enterococcus devriesei,
Enterococcus faecalis and
E. malodoratus, among others. Genomic typification by RAPD and ERIC-PCR showed that the genotypes tended to be specific to particular cheeses; only two of the different cheeses contained two genotypes.
E. malodoratus showed the highest intraspecific diversity. No more than 13% of the isolates demonstrated any antimicrobial activity, most of these belonging to
E. devriesei. Screening for the most important enterocin structural genes by dot-blot hybridization proved negative for enterocins A, B and P. All the isolates belonging to
E. faecalis,
E. hirae and
E. avium, on the other hand, hybridized with the enterocin EJ97 gene probe and all the
E. faecalis strains hybridized with the AS-48 and MR10A structural gene probes. The genes
gelE,
esp,
asa1,
efaA and
ace, all associated to virulence factors in enterococci, were detected at different levels in
E. faecalis whilst they were not detected in the remaining species studied. No resistance to vancomycin was detected by PCR screening. The gene for tyrosine decarboxylase (
tdc) was detected in all the
E. faecalis and
E. hirae isolates but in none of the others.
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![[Commentary] Reporting and ...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/2632-3834/small "[Commentary] Reporting and Subjectivity Traps: A Brief Opinion Article on Consciousness as Belief")
