1,721,086 research outputs found
Protein self-entanglement modulates successful folding to the native state: A multi-scale modeling study
Full text linkThe computer-aided investigation of protein folding has greatly benefited from coarse-grained models, that is, simplified representations at a resolution level lower than atomistic, providing access to qualitative and quantitative details of the folding process that would be hardly attainable, via all-atom descriptions, for medium to long molecules. Nonetheless, the effectiveness of low-resolution models is itself hampered by the presence, in a small but significant number of proteins, of nontrivial topological self-entanglements. Features such as native state knots or slipknots introduce conformational bottlenecks, affecting the probability to fold into the correct conformation; this limitation is particularly severe in the context of coarse-grained models. In this work, we tackle the relationship between folding probability, protein folding pathway, and protein topology in a set of proteins with a nontrivial degree of topological complexity. To avoid or mitigate the risk of incurring in kinetic traps, we make use of the elastic folder model, a coarse-grained model based on angular potentials optimized toward successful folding via a genetic procedure. This light-weight representation allows us to estimate in silico folding probabilities, which we find to anti-correlate with a measure of topological complexity as well as to correlate remarkably well with experimental measurements of the folding rate. These results strengthen the hypothesis that the topological complexity of the native state decreases the folding probability and that the force-field optimization mimics the evolutionary process these proteins have undergone to avoid kinetic traps
The challenge of early glomerular filtration rate decline in response to antihypertensive treatment and chronic kidney disease outcomes
No full textHypertension and chronic kidney disease (CKD) are closely linked pathological processes. Combating high blood pressure (BP) is an essential part of preventing CKD progression and reducing cardiovascular (CV) risk. Data from recent randomized controlled trials on patients at high CV risk showed the beneficial effects of intensive action to meet BP targets on mortality related to CV disease. The impact of meeting such targets on renal function is still unclear, however, particularly for patients with CKD. This issue has been the object of several post hoc analyses because lowering BP definitely has a nephroprotective role, but the early decline in glomerular filtration rate (GFR) associated with antihypertensive therapies and strict BP targets is still a concern in nephrology clinical practice. The present review discusses the results of studies on this topic, focusing specifically on the clinical significance of early GFR decline in response to treatment with angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, or to different BP targets, in terms of renal and CV outcomes, and how this tips the balance towards continuing or discontinuing antihypertensive therapy
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Primaquine tolerant P. vivax in an italian traveller from Guatemala
No full textPlasmodium vivax infections caused by strains with low sensitivity to primaquine are widespread in the Western Pacific and Southeast Asia, and have been recently reported from Central America as well. We report a case of primaquine failure in a P. vivax infection acquired in Guatemala. A 28-year-old Italian woman developed two months after returning from Guatemala a vivax malaria attack that was treated with a standard chloroquine course (1,500 mg over three days) combined with primaquine (15 mg/day for 14 days). Two months later, she had a relapse that was again treated with chloroquine and primaquine at the same doses. After two more months, a second relapse occurred: this time primaquine (30 mg/day for 14 days was administered; the patient remained well during a follow-up period of six months and all parasitologic examination results were negative. Doses of primaquine as high as 6 mg/kg total dose may be indicated in the treatment of vivax malaria cases from Central Americ
Do environmental factors influence the occurrence of acute meningitis in industrialized countries? An epidemic of varying aetiology in Northern Italy.
No full textEffects of Antirejection Drugs on Innate Immune Cells After Kidney Transplantation
No full textOver the last decades, our understanding of adaptive immune responses to solid organ transplantation increased considerably and allowed development of immunosuppressive drugs targeting key alloreactive T cells mechanism. As a result, rates of acute rejection dropped and short-term graft survival improved significantly. However, long-term outcomes are still disappointing. Recently, increasing evidence supports that innate immune responses plays roles in allograft rejection and represents a valuable target to further improve long-term allograft survival. Innate immune cells are activated by molecules with stereotypical motifs produced during injury (i.e., damage-associated molecular patterns, DAMPS) or infection (i.e., pathogen-associated molecular patterns, PAMPs). Activated innate immune cells can exert direct pro- and anti-inflammatory effects, while also priming adaptive immune responses. These cells are activated after transplantation by multiple stimuli, including ischemia-reperfusion injury, rejection, and infections. Data from animal models of graft rejection, show that inhibition of innate immunity promotes development of tolerance. Therefore, understanding mechanisms of innate immunity is important to improve graft outcomes. This review discusses effects of currently used immunosuppressive agents on innate immune responses in kidney transplantation
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