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Sökning: WFRF:(Farkas E)

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  • Klionsky, Daniel J., et al. (författare)
  • Guidelines for the use and interpretation of assays for monitoring autophagy
  • 2012
  • Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
  • Forskningsöversikt (refereegranskat)abstract
    • In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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  • Zamora, Juan Carlos, et al. (författare)
  • Considerations and consequences of allowing DNA sequence data as types of fungal taxa
  • 2018
  • Ingår i: IMA Fungus. - : INT MYCOLOGICAL ASSOC. - 2210-6340 .- 2210-6359. ; 9:1, s. 167-185
  • Tidskriftsartikel (refereegranskat)abstract
    • Nomenclatural type definitions are one of the most important concepts in biological nomenclature. Being physical objects that can be re-studied by other researchers, types permanently link taxonomy (an artificial agreement to classify biological diversity) with nomenclature (an artificial agreement to name biological diversity). Two proposals to amend the International Code of Nomenclature for algae, fungi, and plants (ICN), allowing DNA sequences alone (of any region and extent) to serve as types of taxon names for voucherless fungi (mainly putative taxa from environmental DNA sequences), have been submitted to be voted on at the 11th International Mycological Congress (Puerto Rico, July 2018). We consider various genetic processes affecting the distribution of alleles among taxa and find that alleles may not consistently and uniquely represent the species within which they are contained. Should the proposals be accepted, the meaning of nomenclatural types would change in a fundamental way from physical objects as sources of data to the data themselves. Such changes are conducive to irreproducible science, the potential typification on artefactual data, and massive creation of names with low information content, ultimately causing nomenclatural instability and unnecessary work for future researchers that would stall future explorations of fungal diversity. We conclude that the acceptance of DNA sequences alone as types of names of taxa, under the terms used in the current proposals, is unnecessary and would not solve the problem of naming putative taxa known only from DNA sequences in a scientifically defensible way. As an alternative, we highlight the use of formulas for naming putative taxa (candidate taxa) that do not require any modification of the ICN.
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  • Abolhassani, H, et al. (författare)
  • Care of patients with inborn errors of immunity in thirty J Project countries between 2004 and 2021
  • 2022
  • Ingår i: Frontiers in immunology. - : Frontiers Media SA. - 1664-3224. ; 13, s. 1032358-
  • Tidskriftsartikel (refereegranskat)abstract
    • The J Project (JP) physician education and clinical research collaboration program was started in 2004 and includes by now 32 countries mostly in Eastern and Central Europe (ECE). Until the end of 2021, 344 inborn errors of immunity (IEI)-focused meetings were organized by the JP to raise awareness and facilitate the diagnosis and treatment of patients with IEI.ResultsIn this study, meeting profiles and major diagnostic and treatment parameters were studied. JP center leaders reported patients’ data from 30 countries representing a total population of 506 567 565. Two countries reported patients from JP centers (Konya, Turkey and Cairo University, Egypt). Diagnostic criteria were based on the 2020 update of classification by the IUIS Expert Committee on IEI. The number of JP meetings increased from 6 per year in 2004 and 2005 to 44 and 63 in 2020 and 2021, respectively. The cumulative number of meetings per country varied from 1 to 59 in various countries reflecting partly but not entirely the population of the respective countries. Altogether, 24,879 patients were reported giving an average prevalence of 4.9. Most of the patients had predominantly antibody deficiency (46,32%) followed by patients with combined immunodeficiencies (14.3%). The percentages of patients with bone marrow failure and phenocopies of IEI were less than 1 each. The number of patients was remarkably higher that those reported to the ESID Registry in 13 countries. Immunoglobulin (IgG) substitution was provided to 7,572 patients (5,693 intravenously) and 1,480 patients received hematopoietic stem cell therapy (HSCT). Searching for basic diagnostic parameters revealed the availability of immunochemistry and flow cytometry in 27 and 28 countries, respectively, and targeted gene sequencing and new generation sequencing was available in 21 and 18 countries. The number of IEI centers and experts in the field were 260 and 690, respectively. We found high correlation between the number of IEI centers and patients treated with intravenous IgG (IVIG) (correlation coefficient, cc, 0,916) and with those who were treated with HSCT (cc, 0,905). Similar correlation was found when the number of experts was compared with those treated with HSCT. However, the number of patients treated with subcutaneous Ig (SCIG) only slightly correlated with the number of experts (cc, 0,489) and no correlation was found between the number of centers and patients on SCIG (cc, 0,174).Conclusions1) this is the first study describing major diagnostic and treatment parameters of IEI care in countries of the JP; 2) the data suggest that the JP had tremendous impact on the development of IEI care in ECE; 3) our data help to define major future targets of JP activity in various countries; 4) we suggest that the number of IEI centers and IEI experts closely correlate to the most important treatment parameters; 5) we propose that specialist education among medical professionals plays pivotal role in increasing levels of diagnostics and adequate care of this vulnerable and still highly neglected patient population; 6) this study also provides the basis for further analysis of more specific aspects of IEI care including genetic diagnostics, disease specific prevalence, newborn screening and professional collaboration in JP countries.
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  • Gerotziafas, GT, et al. (författare)
  • Guidance for the Management of Patients with Vascular Disease or Cardiovascular Risk Factors and COVID-19: Position Paper from VAS-European Independent Foundation in Angiology/Vascular Medicine
  • 2020
  • Ingår i: Thrombosis and haemostasis. - : Georg Thieme Verlag KG. - 2567-689X .- 0340-6245. ; 120:12, s. 1597-1628
  • Tidskriftsartikel (refereegranskat)abstract
    • COVID-19 is also manifested with hypercoagulability, pulmonary intravascular coagulation, microangiopathy, and venous thromboembolism (VTE) or arterial thrombosis. Predisposing risk factors to severe COVID-19 are male sex, underlying cardiovascular disease, or cardiovascular risk factors including noncontrolled diabetes mellitus or arterial hypertension, obesity, and advanced age. The VAS-European Independent Foundation in Angiology/Vascular Medicine draws attention to patients with vascular disease (VD) and presents an integral strategy for the management of patients with VD or cardiovascular risk factors (VD-CVR) and COVID-19. VAS recommends (1) a COVID-19-oriented primary health care network for patients with VD-CVR for identification of patients with VD-CVR in the community and patients' education for disease symptoms, use of eHealth technology, adherence to the antithrombotic and vascular regulating treatments, and (2) close medical follow-up for efficacious control of VD progression and prompt application of physical and social distancing measures in case of new epidemic waves. For patients with VD-CVR who receive home treatment for COVID-19, VAS recommends assessment for (1) disease worsening risk and prioritized hospitalization of those at high risk and (2) VTE risk assessment and thromboprophylaxis with rivaroxaban, betrixaban, or low-molecular-weight heparin (LMWH) for those at high risk. For hospitalized patients with VD-CVR and COVID-19, VAS recommends (1) routine thromboprophylaxis with weight-adjusted intermediate doses of LMWH (unless contraindication); (2) LMWH as the drug of choice over unfractionated heparin or direct oral anticoagulants for the treatment of VTE or hypercoagulability; (3) careful evaluation of the risk for disease worsening and prompt application of targeted antiviral or convalescence treatments; (4) monitoring of D-dimer for optimization of the antithrombotic treatment; and (5) evaluation of the risk of VTE before hospital discharge using the IMPROVE-D-dimer score and prolonged post-discharge thromboprophylaxis with rivaroxaban, betrixaban, or LMWH.
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  • Agostoni, Angelo, et al. (författare)
  • Hereditary and acquired angioedema: problems and progress: proceedings of the third C1 esterase inhibitor deficiency workshop and beyond
  • 2004
  • Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier BV. - 1097-6825 .- 0091-6749. ; 114:3 Suppl, s. 51-131
  • Tidskriftsartikel (refereegranskat)abstract
    • Hereditary angioedema (HAE), a rare but life-threatening condition, manifests as acute attacks of facial, laryngeal, genital, or peripheral swelling or abdominal pain secondary to intra-abdominal edema. Resulting from mutations affecting C1 esterase inhibitor (C1-INH), inhibitor of the first complement system component, attacks are not histamine-mediated and do not respond to antihistamines or corticosteroids. Low awareness and resemblance to other disorders often delay diagnosis; despite availability of C1-INH replacement in some countries, no approved, safe acute attack therapy exists in the United States. The biennial C1 Esterase Inhibitor Deficiency Workshops resulted from a European initiative for better knowledge and treatment of HAE and related diseases. This supplement contains work presented at the third workshop and expanded content toward a definitive picture of angioedema in the absence of allergy. Most notably, it includes cumulative genetic investigations; multinational laboratory diagnosis recommendations; current pathogenesis hypotheses; suggested prophylaxis and acute attack treatment, including home treatment; future treatment options; and analysis of patient subpopulations, including pediatric patients and patients whose angioedema worsened during pregnancy or hormone administration. Causes and management of acquired angioedema and a new type of angioedema with normal C1-INH are also discussed. Collaborative patient and physician efforts, crucial in rare diseases, are emphasized. This supplement seeks to raise awareness and aid diagnosis of HAE, optimize treatment for all patients, and provide a platform for further research in this rare, partially understood disorder.
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  • Cicardi, M., et al. (författare)
  • Icatibant, a New Bradykinin-Receptor Antagonist, in Hereditary Angioedema
  • 2010
  • Ingår i: New England Journal of Medicine. - 0028-4793. ; 363:6, s. 532-541
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND Hereditary angioedema is characterized by recurrent attacks of angioedema of the skin, larynx, and gastrointestinal tract. Bradykinin is the key mediator of symptoms. Icatibant is a selective bradykinin B2 receptor antagonist. METHODS In two double-blind, randomized, multicenter trials, we evaluated the effect of icatibant in patients with hereditary angioedema presenting with cutaneous or abdominal attacks. In the For Angioedema Subcutaneous Treatment (FAST) 1 trial, patients received either icatibant or placebo; in FAST-2, patients received either icatibant or oral tranexamic acid, at a dose of 3 g daily for 2 days. Icatibant was given once, subcutaneously, at a dose of 30 mg. The primary end point was the median time to clinically significant relief of symptoms. RESULTS A total of 56 and 74 patients underwent randomization in the FAST-1 and FAST-2 trials, respectively. The primary end point was reached in 2.5 hours with icatibant versus 4.6 hours with placebo in the FAST-1 trial (P=0.14) and in 2.0 hours with icatibant versus 12.0 hours with tranexamic acid in the FAST-2 trial (P<0.001). In the FAST-1 study, 3 recipients of icatibant and 13 recipients of placebo needed treatment with rescue medication. The median time to first improvement of symptoms, as assessed by patients and by investigators, was significantly shorter with icatibant in both trials. No icatibant-related serious adverse events were reported. CONCLUSIONS In patients with hereditary angioedema having acute attacks, we found a significant benefit of icatibant as compared with tranexamic acid in one trial and a nonsignificant benefit of icatibant as compared with placebo in the other trial with regard to the primary end point. The early use of rescue medication may have obscured the benefit of icatibant in the placebo trial. (Funded by Jerini; ClinicalTrials.gov numbers, NCT00097695 and NCT00500656.)
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  • Kohl, S, et al. (författare)
  • CNGB3 mutations account for 50% of all cases with autosomal recessive achromatopsia
  • 2005
  • Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1476-5438 .- 1018-4813. ; 13:3, s. 302-308
  • Tidskriftsartikel (refereegranskat)abstract
    • Achromatopsia is a congenital, autosomal recessively inherited disorder characterized by a lack of color discrimination, low visual acuity (<0.2), photophobia, and nystagmus. Mutations in the genes for CNGA3, CNGB3, and GNAT2 have been associated with this disorder. Here, we analyzed the spectrum and prevalence of CNGB3 gene mutations in a cohort of 341 independent patients with achromatopsia. In 163 patients, CNGB3 mutations could be identified. A total of 105 achromats carried apparent homozygous mutations, 44 were compound (double) heterozygotes, and 14 patients had only a single mutant allele. The derived CNGB3 mutation spectrum comprises 28 different mutations including 12 nonsense mutations, eight insertions and/or deletions, five putative splice site mutations, and three missense mutations. Thus, the majority of mutations in the CNGB3 gene result in significantly altered and/or truncated polypeptides. Several mutations were found recurrently, in particular a 1 bp deletion, c.1148delC, which accounts for over 70% of all CNGB3 mutant alleles. In conclusion, mutations in the CNGB3 gene are responsible for approximately 50% of all patients with achromatopsia. This indicates that the CNGB3/ACHM3 locus on chromosome 8q21 is the major locus for achromatopsia in patients of European origin or descent.
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  • Lima, LE, et al. (författare)
  • A multicenter initial clinical experience with right heart support and beating heart coronary surgery
  • 2001
  • Ingår i: Heart Surgery Forum. - 1098-3511 .- 1522-6662. ; 4:1, s. 61-64
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: During coronary surgery without CPB, exposure of posterior vessel via sternotomy can cause deterioration of cardiac hemodynamics requiring inotrope drugs support. Recent animal experiments demonstrate hemodynamic benefit of right heart support (RHS) with the AMED system. The purpose of this study was to evaluate the hemodynamic effects during cardiac manipulation to expose the posterior coronary arteries, and determine the effect of RHS in restoring hemodynamics, increasing anastomotic exposure and reducing inotropic requirements. Material and Methods: From July 28 to December 29, 32 patients (25 men/ 7 women), mean age of 63.4 (+/- 6.2 years, ages: 49 - 78) received coronary revascularization with the A-Med RHS device. They were divided into two groups of 16 patients, A and B. Group A patients had at least one circumflex branch bypassed. The anterior wall was systematically bypassed off-pump without RHS. The right coronary artery (RCA) and the obtuse coronary artery (OM) were completed utilizing RHS. In group B patients, all vessels including anterior vessels were bypassed with the RHS. Mean arterial pressure (MAP), mean pulmonary arterial pressure (PAP), cardiac output (CO) and the average pump flow (APF) were recorded during the OM and RCA bypass for group A, and for group B LAD data was also recorded. Results: Elective beating heart coronary artery bypass graft (CABG) was successfully accomplished in 32 patients with RHS. Data measurements recorded in Group A showed the improved hemodynamic recovery for OM and RCA bypass with RHS. The MAP increased from 44 to 68mmHg (OM) and from 63 to 81mmHg (RCA), the CO from 2.1 to 4.4 L/min (OM) and from 3.3 to 4.7 L/min (RCA). In group B, the data recorded showed the stability of the MAP in all vessels bypassed (LAD, OM and RCA). No device-related patient incidents ocurred. All 32 patients were discharged to their homes. Conclusons: The AMED system, as RHS support, facilitated coronary bypass without CPB to posterior vessels, restoring hemodynamics, providing better exposure to anastomotic sites and apparently reducing inotropes need. Prospective randomize trials are necessary to confirm this initial experience.
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  • Nava, Porfirio, et al. (författare)
  • JAM-A regulates epithelial proliferation through Akt/beta-catenin signalling
  • 2011
  • Ingår i: EMBO Reports. - : Wiley-Blackwell Publishing Inc.. - 1469-221X .- 1469-3178. ; 12:4, s. 314-20
  • Tidskriftsartikel (refereegranskat)abstract
    • Expression of the tight junction protein junctional adhesion molecule-A (JAM-A) has been linked to proliferation and tumour progression. However, a direct role for JAM-A in regulating proliferative processes has not been shown. By using complementary in vivo and in vitro approaches, we demonstrate that JAM-A restricts intestinal epithelial cell (IEC) proliferation in a dimerization-dependent manner, by inhibiting Akt-dependent beta-catenin activation. Furthermore, IECs from transgenic JAM-A(-/-)/beta-catenin/T-cell factor reporter mice showed enhanced beta-catenin-dependent transcription. Finally, inhibition of Akt reversed colonic crypt hyperproliferation in JAM-A-deficient mice. These data establish a new link between JAM-A and IEC homeostasis.
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  • Veer, IM, et al. (författare)
  • Psycho-social factors associated with mental resilience in the Corona lockdown
  • 2021
  • Ingår i: Translational psychiatry. - : Springer Science and Business Media LLC. - 2158-3188. ; 11:1, s. 67-
  • Tidskriftsartikel (refereegranskat)abstract
    • The SARS-CoV-2 pandemic is not only a threat to physical health but is also having severe impacts on mental health. Although increases in stress-related symptomatology and other adverse psycho-social outcomes, as well as their most important risk factors have been described, hardly anything is known about potential protective factors. Resilience refers to the maintenance of mental health despite adversity. To gain mechanistic insights about the relationship between described psycho-social resilience factors and resilience specifically in the current crisis, we assessed resilience factors, exposure to Corona crisis-specific and general stressors, as well as internalizing symptoms in a cross-sectional online survey conducted in 24 languages during the most intense phase of the lockdown in Europe (22 March to 19 April) in a convenience sample of N = 15,970 adults. Resilience, as an outcome, was conceptualized as good mental health despite stressor exposure and measured as the inverse residual between actual and predicted symptom total score. Preregistered hypotheses (osf.io/r6btn) were tested with multiple regression models and mediation analyses. Results confirmed our primary hypothesis that positive appraisal style (PAS) is positively associated with resilience (p < 0.0001). The resilience factor PAS also partly mediated the positive association between perceived social support and resilience, and its association with resilience was in turn partly mediated by the ability to easily recover from stress (both p < 0.0001). In comparison with other resilience factors, good stress response recovery and positive appraisal specifically of the consequences of the Corona crisis were the strongest factors. Preregistered exploratory subgroup analyses (osf.io/thka9) showed that all tested resilience factors generalize across major socio-demographic categories. This research identifies modifiable protective factors that can be targeted by public mental health efforts in this and in future pandemics.
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  • Alvarez-Crespo, Mayte, 1980, et al. (författare)
  • The Amygdala as a Neurobiological Target for Ghrelin in Rats: Neuroanatomical, Electrophysiological and Behavioral Evidence
  • 2012
  • Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 7:10
  • Tidskriftsartikel (refereegranskat)abstract
    • Here, we sought to demonstrate that the orexigenic circulating hormone, ghrelin, is able to exert neurobiological effects (including those linked to feeding control) at the level of the amygdala, involving neuroanatomical, electrophysiological and behavioural studies. We found that ghrelin receptors (GHS-R) are densely expressed in several subnuclei of the amygdala, notably in ventrolateral (LaVL) and ventromedial (LaVM) parts of the lateral amygdaloid nucleus. Using whole-cell patch clamp electrophysiology to record from cells in the lateral amygdaloid nucleus, we found that ghrelin reduced the frequency of mEPSCs recorded from large pyramidal-like neurons, an effect that could be blocked by co-application of a ghrelin receptor antagonist. In ad libitum fed rats, intra-amygdala administration of ghrelin produced a large orexigenic response that lasted throughout the 4 hr of testing. Conversely, in hungry, fasted rats ghrelin receptor blockade in the amygdala significantly reduced food intake. Finally, we investigated a possible interaction between ghrelin's effects on feeding control and emotional reactivity exerted at the level of the amygdala. In rats allowed to feed during a 1-hour period between ghrelin injection and anxiety testing (elevated plus maze and open field), intra-amygdala ghrelin had no effect on anxiety-like behavior. By contrast, if the rats were not given access to food during this 1-hour period, a decrease in anxiety-like behavior was observed in both tests. Collectively, these data indicate that the amygdala is a valid target brain area for ghrelin where its neurobiological effects are important for food intake and for the suppression of emotional (anxiety-like) behaviors if food is not available.
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  • Anesten, Fredrik, et al. (författare)
  • Interleukin-6 in the central amygdala is bioactive and co-localised with glucagon-like peptide-1 receptor
  • 2019
  • Ingår i: Journal of Neuroendocrinology. - : Wiley. - 0953-8194 .- 1365-2826. ; 31:6
  • Tidskriftsartikel (refereegranskat)abstract
    • Neuronal circuits involving the central amygdala (CeA) are gaining prominence as important centres for regulation of metabolic functions. As a part of the subcortical food motivation circuitry, CeA is associated with food motivation and hunger. We have previously shown that interleukin (IL)-6 can act as a downstream mediator of the metabolic effects of glucagon-like peptide-1 (GLP-1) receptor (R) stimulation in the brain, although the sites of these effects are largely unknown. In the present study, we used the newly generated and validated RedIL6 reporter mouse strain to investigate the presence of IL-6 in the CeA, as well as possible interactions between IL-6 and GLP-1 in this nucleus. IL-6 was present in the CeA, mostly in cells in the medial and lateral parts of this structure, and a majority of IL-6-containing cells also co-expressed GLP-1R. Triple staining showed GLP-1 containing fibres co-staining with synaptophysin close to or overlapping with IL-6 containing cells. GLP-1R stimulation enhanced IL-6 mRNA levels. IL-6 receptor-alpha (IL-6Rα) was found to a large part in neuronal CeA cells. Using electrophysiology, we determined that cells with neuronal properties in the CeA could be rapidly stimulated by IL-6 administration in vitro. Moreover, microinjections of IL-6 into the CeA could slightly reduce food intake in vivo in overnight fasted rats. In conclusion, IL-6 containing cells in the CeA express GLP-1R, are close to GLP-1-containing synapses, and demonstrate increased IL-6 mRNA in response to GLP-1R agonist treatment. IL-6, in turn, exerts biological effects in the CeA, possibly via IL-6Rα present in this nucleus. 2019 The Authors. Journal of Neuroendocrinology published by John Wiley & Sons Ltd on behalf of British Society for Neuroendocrinology
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  • Appi, E., et al. (författare)
  • Two phase-matching regimes in high-order harmonic generation
  • 2023
  • Ingår i: Optics Express. - 1094-4087. ; 31:20, s. 31687-31697
  • Tidskriftsartikel (refereegranskat)abstract
    • High-order harmonic generation (HHG) provides scalable sources of coherent extreme ultraviolet radiation with pulse duration down to the attosecond time scale. Efficient HHG requires the constructive interplay between microscopic and macroscopic effects in the generation volume, which can be achieved over a large range of experimental parameters from the driving field properties to those of the generating medium. Here, we present a systematic study of the harmonic yield as a function of gas pressure and medium length. Two regimes for optimum yield are identified, supporting the predictions of a recently proposed analytical model. Our observations are independent on the focusing geometry and, to a large extent, on the pulse duration and laser intensity, providing a versatile approach to HHG optimization.
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  • Baldermann, A., et al. (författare)
  • Impact of green clay authigenesis on element sequestration in marine settings
  • 2022
  • Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Retrograde clay mineral reactions (reverse weathering), including glauconite formation, are first-order controls on element sequestration in marine sediments. Here, we report substantial element sequestration by glauconite formation in shallow marine settings from the Triassic to the Holocene, averaging 3 +/- 2 mmol.cm(-2).kyr(-1) for K, Mg and Al, 16 +/- 9 mmol.cm(-2).kyr(-1) for Si and 6 +/- 3 mmol.cm(-2).kyr(-1) for Fe, which is similar to 2 orders of magnitude higher than estimates for deep-sea settings. Upscaling of glauconite abundances in shallow-water (0-200 m) environments predicts a present-day global uptake of similar to <= 0.1 Tmol.yr(-1) of K, Mg and Al, and similar to 0.1-0.4 Tmol.yr(-1) of Fe and Si, which is similar to half of the estimated Mesozoic elemental flux. Clay mineral authigenesis had a large impact on the global marine element cycles throughout Earth's history, in particular during 'greenhouse' periods with sea level highstand, and is key for better understanding past and present geochemical cycling in marine sediments.
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25.
  • Bathen, M. E., et al. (författare)
  • Anisotropic and plane-selective migration of the carbon vacancy in SiC : Theory and experiment
  • 2019
  • Ingår i: Physical Review B. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 100:1
  • Tidskriftsartikel (refereegranskat)abstract
    • We investigate the migration mechanism of the carbon vacancy (VC) in silicon carbide (SiC) using a combination of theoretical and experimental methodologies. The VC, commonly present even in state-of-the-art epitaxial SiC material, is known to be a carrier lifetime killer and therefore strongly detrimental to device performance. The desire for VC removal has prompted extensive investigations involving its stability and reactivity. Despite suggestions from theory that VC migrates exclusively on the C sublattice via vacancy-atom exchange, experimental support for such a picture is still unavailable. Moreover, the existence of two inequivalent locations for the vacancy in 4H-SiC [hexagonal, VC(h), and pseudocubic, VC(k)] and their consequences for VC migration have not been considered so far. The first part of the paper presents a theoretical study of VC migration in 3C- and 4H-SiC. We employ a combination of nudged elastic band (NEB) and dimer methods to identify the migration mechanisms, transition state geometries, and respective energy barriers for VC migration. In 3C-SiC, VC is found to migrate with an activation energy of EA=4.0 eV. In 4H-SiC, on the other hand, we anticipate that VC migration is both anisotropic and basal-plane selective. The consequence of these effects is a slower diffusivity along the axial direction, with a predicted activation energy of EA=4.2 eV, and a striking preference for basal migration within the h plane with a barrier of EA=3.7 eV, to the detriment of the k-basal plane. Both effects are rationalized in terms of coordination and bond angle changes near the transition state. In the second part, we provide experimental data that corroborates the above theoretical picture. Anisotropic migration of VC in 4H-SiC is demonstrated by deep level transient spectroscopy (DLTS) depth profiling of the Z1/2 electron trap in annealed samples that were subject to ion implantation. Activation energies of EA=(4.4±0.3) eV and EA=(3.6±0.3) eV were found for VC migration along the c and a directions, respectively, in excellent agreement with the analogous theoretical values. The corresponding prefactors of D0=0.54cm2/s and 0.017cm2/s are in line with a simple jump process, as expected for a primary vacancy point defect.
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  • Biurrun, Idoia, et al. (författare)
  • Benchmarking plant diversity of Palaearctic grasslands and other open habitats
  • 2021
  • Ingår i: Journal of Vegetation Science. - Oxford : John Wiley & Sons. - 1100-9233 .- 1654-1103. ; 32:4
  • Tidskriftsartikel (refereegranskat)abstract
    • Journal of Vegetation Science published by John Wiley & Sons Ltd on behalf of International Association for Vegetation Science.Aims: Understanding fine-grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine-grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups). Location: Palaearctic biogeographic realm. Methods: We used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001, 0.001, 0.01, 0.1, 1, 10, 100 and 1,000 m2 and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class. Results: Patterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi-natural) grasslands and natural grasslands are the richest vegetation type. The open-access file ”GrassPlot Diversity Benchmarks” and the web tool “GrassPlot Diversity Explorer” are now available online (https://edgg.org/databases/GrasslandDiversityExplorer) and provide more insights into species richness patterns in the Palaearctic open habitats. Conclusions: The GrassPlot Diversity Benchmarks provide high-quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation-plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology. © 2021 The Authors.
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  • Gambadauro, Pietro, et al. (författare)
  • Correlates of sexual initiation among European adolescents
  • 2018
  • Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:2
  • Tidskriftsartikel (refereegranskat)abstract
    • BackgroundSexuality is a physiological component of adolescent development, though early initiation is associated with reproductive health risk. This study aimed at identifying correlates and predictors of sexual initiation in a large multinational cohort of European adolescents.MethodsA questionnaire addressing socio-demographics, behaviours, mental health and sexual activity, was delivered to 11,110 adolescents recruited from 168 randomly selected schools in 10 European countries between 2009 and 2011. A follow-up questionnaire was delivered after 12 months. The longitudinal association of baseline risk behaviors, psychological attributes and contextual vulnerabilities, with sexual initiation during follow-up was evaluated through simple and multivariable age/sex stratified logistic regression. Multinomial logistic regression measured the association between predictors and sexual initiation with or without coexisting reproductive risk factors, such as multiple partners or infrequent condom use.ResultsBaseline sexual experience was reported by 19.2% of 10,757 respondents (median age 15; IQR 14–15; females 59.6%). This was significantly more frequent among pupils older than 15 (41%) and males (20.8%). Of 7,111 pupils without previous experience who were available at follow-up (response rate 81.8%), 17% reported sexual initiation, without differences between females and males. Baseline smoking (age/sex adjusted odds ratio [aOR] 3.63), alcohol use (aOR 2.95), illegal drugs use (aOR 2.72), and poor sleep (aOR 1.71) predicted sexual initiation. Stratified analyses showed a particularly strong association in case of younger and female pupils, and, among girls, when initiation was reported together with multiple partners and/or infrequent condom use. Externalizing (i.e. conduct and hyperactivity) symptoms independently predicted sexual initiation. Internalizing difficulties (i.e. emotional and peer problems) were negatively associated with early and risky sexual initiation among boys. Significant predictors included also being bullied, fighting, truancy, and low parental involvement.ConclusionsAdolescent sexual behaviours are related to non-sexual risk behaviours, psychological difficulties and contextual vulnerabilities. While gateway effects explain some associations, a comprehensive model is needed to understand adolescent sexual behaviours, their physical, mental, and social health outcomes, and their potential positive effects on wellbeing. Tailored interventions may need to consider younger girls as a particularly vulnerable group in view of a strong association between non-sexual and sexual behaviors.
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  • Holm, Jonas, et al. (författare)
  • EuroSCORE II and N-terminal pro-B-type natriuretic peptide for risk evaluation : an observational longitudinal study in patients undergoing coronary artery bypass graft surgery
  • 2014
  • Ingår i: British Journal of Anaesthesia. - : Oxford University Press. - 0007-0912 .- 1471-6771. ; 113:1, s. 75-82
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Postoperative heart failure remains the major cause of death after cardiac surgery. As N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a predictor for postoperative heart failure, the aim was to evaluate if preoperative NT-proBNP could provide additional prognostic information to the recently launched EuroSCORE II.Methods: A total of 365 patients with acute coronary syndrome (ACS) undergoing isolated coronary artery bypass graft (CABG) surgery were studied prospectively. Preoperative NT-proBNP and EuroSCORE II were evaluated with regard to severe circulatory failure after operation according to prespecified criteria. To assess what clinical outcomes are indicated by NT-proBNP levels in different risk categories, the patients were stratified according to EuroSCORE II. Based on receiver operating characteristics analysis, these cohorts were assessed with regard to preoperative NT-proBNP below or above 1028 ng litre(-1). The follow-up time averaged 4.4 (0.7) yr.Results: Preoperative NT-proBNP >= 1028 ng litre(-1) [odds ratio (OR) 9.9,95% confidence interval (CI) 1.01-98.9; P=0.049] and EuroSCORE II (OR 1.24, 95% CI 1.06-1.46; P=0.008) independently predicted severe circulatory failure after operation. In intermediate-risk patients (EuroSCORE II 2.0-10.0), NT-proBNP >= 1028 ng litre(-1) was associated with a higher incidence of severe circulatory failure (6.6% vs 0%; P=0.007), renal failure (14.8% vs 5.4%; P=0.03), stroke (6.6% vs 0.7%; P=0.03), longer intensive care unit stay [37 (35) vs 27 (38) h; P=0.002], and worse long-term survival.Conclusions: Combining EuroSCORE II and preoperative NT-proBNP appears to improve risk prediction with regard to severe circulatory failure after isolated CABG for ACS. NT-proBNP may be particularly useful in patients at intermediate risk according to EuroSCORE II.
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37.
  • Major, B., et al. (författare)
  • Macroscopic Optimization of High Harmonic Generation for High Power Laser Pulses
  • 2016
  • Ingår i: High Intensity Lasers and High Field Phenomena, HILAS 2016. - 9781943580095 ; Part F15-HILAS 2016
  • Konferensbidrag (refereegranskat)abstract
    • We study upscaling of gas high harmonic generation, to make efficient use of the ever increasing laser pulse powers. Loose focusing geometries optimizing phasematching are investigated and compared in HHG efficiency to shorter focusing arrangements.
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38.
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39.
  • McIlwain, Sean, et al. (författare)
  • Crux : Rapid Open Source Protein Tandem Mass Spectrometry Analysis
  • 2014
  • Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 13:10, s. 4488-4491
  • Tidskriftsartikel (refereegranskat)abstract
    • Efficiently and accurately analyzing big protein tandem mass spectrometry data sets requires robust software that incorporates state-of-the-art computational, machine learning, and statistical methods. The Crux mass spectrometry analysis software toolkit (http://cruxtoolkit.sourceforge.net) is an open source project that aims to provide users with a cross-platform suite of analysis tools for interpreting protein mass spectrometry data.
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41.
  • Richard, Jennifer E., et al. (författare)
  • GLP-1 Receptor Stimulation of the Lateral Parabrachial Nucleus Reduces Food Intake: Neuroanatomical, Electrophysiological, and Behavioral Evidence
  • 2014
  • Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 155:11, s. 4356-4367
  • Tidskriftsartikel (refereegranskat)abstract
    • The parabrachial nucleus (PBN) is a key nucleus for the regulation of feeding behavior. Inhibitory inputs from the hypothalamus to the PBN play a crucial role in the normal maintenance of feeding behavior, because their loss leads to starvation. Viscerosensory stimuli result in neuronal activation of the PBN. However, the origin and neurochemical identity of the excitatory neuronal input to the PBN remain largely unexplored. Here, we hypothesize that hindbrain glucagon-like peptide 1 (GLP-1) neurons provide excitatory inputs to the PBN, activation of which may lead to a reduction in feeding behavior. Our data, obtained from mice expressing the yellow fluorescent protein in GLP-1-producing neurons, revealed that hindbrain GLP-1-producing neurons project to the lateral PBN (lPBN). Stimulation of lPBN GLP-1 receptors (GLP-1Rs) reduced the intake of chow and palatable food and decreased body weight in rats. It also activated lPBN neurons, reflected by an increase in the number of c-Fos-positive cells in this region. Further support for an excitatory role of GLP-1 in the PBN is provided by electrophysiological studies showing a remarkable increase in firing of lPBN neurons after Exendin-4 application. We show that within the PBN, GLP-1R activation increased gene expression of 2 energy balance regulating peptides, calcitonin gene-related peptide (CGRP) and IL-6. Moreover, nearly 70% of the lPBN GLP-1 fibers innervated lPBN CGRP neurons. Direct intra-lPBN CGRP application resulted in anorexia. Collectively, our molecular, anatomical, electrophysiological, pharmacological, and behavioral data provide evidence for a functional role of the GLP-1R for feeding control in the PBN.
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42.
  • Scheiblhofer, E., et al. (författare)
  • Revisiting Glauconite Geochronology: Lessons Learned from In Situ Radiometric Dating of a Glauconite-Rich Cretaceous Shelfal Sequence
  • 2022
  • Ingår i: Minerals. - : MDPI AG. - 2075-163X. ; 12:7
  • Tidskriftsartikel (refereegranskat)abstract
    • The scarcity of well-preserved and directly dateable sedimentary sequences is a major impediment to inferring the Earth's paleo-environmental evolution. The authigenic mineral glauconite can potentially provide absolute stratigraphic ages for sedimentary sequences and constraints on paleo-depositional conditions. This requires improved approaches for measuring and interpreting glauconite formation ages. Here, glauconite from a Cretaceous shelfal sequence (Langenstein, northern Germany) was characterized using petrographical, geochemical (EMP), andmineralogical (XRD) screening methods before in situ Rb-Sr dating via LA-ICP-MS/MS. The obtained glauconite ages (similar to 101 to 97 Ma) partly overlap with the depositional age of the Langenstein sequence (+/- 3 Ma), but without the expected stratigraphic age progression, which we attribute to detrital and diagenetic illitic phase impurities inside the glauconites. Using a novel age deconvolution approach, which combines the new Rb-Sr dataset with published K-Ar ages, we recalculate the glauconite bulk ages to obtain stratigraphically significant 'pure' glauconite ages (similar to 100 to 96 Ma). Thus, our results show that pristine ages can be preserved in mineralogically complex glauconite grains even under burial diagenetic conditions (T < 65 degrees C; <1500 m depth), confirming that glauconite could be a suitable archive for paleo-environmental reconstructions and direct sediment dating.
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43.
  • Subarkah, D., et al. (författare)
  • Unraveling the histories of Proterozoic shales through in situ Rb-Sr dating and trace element laser ablation analysis
  • 2022
  • Ingår i: Geology. - : Geological Society of America. - 0091-7613 .- 1943-2682. ; 50:1, s. 66-70
  • Tidskriftsartikel (refereegranskat)abstract
    • Authigenic components in marine sediments are important archives for past environment reconstructions. However, defining reliable age constraints and assessing the effects of post depositional overprints in Precambrian sequences are challenging. We demonstrate a new laser-based analytical approach that has the potential to rapidly and accurately evaluate the depositional and alteration histories of Proterozoic shales. Our study employs a novel application of in situ Rb-Sr dating coupled with simultaneous trace-element analysis using reaction-cell laser ablation-inductively coupled plasma-tandem mass spectrometry (LA-ICPMS/MS). We present results from shales sourced from two wells in the Proterozoic McArthur Basin, northern Australia. These rocks have been widely used by previous studies as a key section for ancient biogeochemical and paleo-redox reconstructions. Shales from well UR5 yielded initial Sr-87/Sr-86 ratios, Rb-Sr ages, and rare earth element plus yttrium (REEY) patterns similar to those of a dolerite sampled from the same core. We propose that the UR5 samples chronicle hydrothermal alteration instigated by the dolerite intrusion. In contrast, a correlative shale from well UR6 yielded an age consistent with the expected depositional age (1577 +/- 56 Ma) with REEY and initial Sr-87/Sr-86 ratios similar to ca. 1.5 Ga seawater. We suggest that this sample records the minimum depositional age and early marine diagenetic history for this unit. This new technique can date Proterozoic shales quickly, cheaply, and with minimum sample preparation. Importantly, ages are triaged to differentiate between those recording primary marine versus secondary processes. This novel approach provides a potentially powerful tool for dating and fingerprinting the vast array of ancient marine shales for further studies of Earth systems through deep time.
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