225 research outputs found
The Galactic Cosmic Ray Intensity over the Past 106-109 Years as Recorded by Cosmogenic Nuclides in Meteorites and Terrestrial Samples
Concentrations of stable and radioactive nuclides produced by cosmic ray particles in meteorites allow us to track the long term average of the primary flux of galactic cosmic rays (GCR). During the past ∼10Ma, the average GCR flux remained constant over timescales of hundreds of thousands to millions of years, and, if corrected for known variations in solar modulation, also during the past several years to hundreds of years. Because the cosmic ray concentrations in meteorites represent integral signals, it is difficult to assess the limits of uncertainty of this statement, but they are larger than the often quoted analytical and model uncertainties of some 30%. Time series of concentrations of the radionuclide 10Be in terrestrial samples strengthen the conclusions drawn from meteorite studies, indicating that the GCR intensity on a ∼0.5 million year scale has remained constant within some ±10% during the past ∼10 million years. The very long-lived radioactive nuclide 40K allows to assess the GCR flux over about the past one billion years. The flux over the past few million years has been the same as the longer-term average in the past 0.5-1 billion years within a factor of ∼1.5. However, newer data do not confirm a long-held belief that the flux in the past few million years has been higher by some 30-50% than the very long term average. Neither does our analysis confirm a hypothesis that the iron meteorite data indicate a ∼150 million year periodicity in the cosmic ray flux, possibly related to variations in the long-term terrestrial climat
Recognition and management of potential drug-drug interactions in patients on internal medicine wards
Introduction: Our aim was to study and possibly improve the clinical management of potential drug-drug interactions (pDDIs) in hospitalized patients by specific interventions. Methods: During the initial period, inpatients on three medical wards were screened for major and moderate pDDIs using the interaction screening program Pharmavista. During the second period, patients at discharge were screened similarly. After assessment of the detected pDDIs for clinical relevance, written recommendations and/or information about the pDDIs were sent to the treating physicians. Feedback from the physicians and implementation of the recommendations were analyzed. Results: During the initial period, 502 inpatients were exposed to 567 pDDIs, of which 419 (74%) were judged to be clinically relevant. Three hundred and forty-nine substantiated recommendations and 70 simple information leaflets were handed out to the physicians. Eighty percent (278 of 349) of the recommendations were accepted and implemented. During the second period, 792 patients at hospital discharge were exposed to 392 pDDIs, of which 258 (66%) were judged to be clinically relevant. Two hundred and forty-seven substantiated recommendations and 11 simple information leaflets were sent to the physicians. Seventy-three percent (180 of 247) of the recommendations were accepted. At hospital discharge, 47 of 71 interventions recommending checkable medication changes were implemented. One year after hospital discharge, 11 of 13 checked medication changes were still in place. Conclusions: Clinically relevant pDDIs are common in patients on medical wards, and their management can be influenced by providing substantiated recommendations to physicians. Most changes in medication following such recommendations are still in place 1year after discharg
Targeting the redox system for cardiovascular regeneration in aging
Cardiovascular aging presents a formidable challenge, as the aging process can lead to reduced cardiac function and heightened susceptibility to cardiovascular diseases. Consequently, there is an escalating, unmet medical need for innovative and effective cardiovascular regeneration strategies aimed at restoring and rejuvenating aging cardiovascular tissues. Altered redox homeostasis and the accumulation of oxidative damage play a pivotal role in detrimental changes to stem cell function and cellular senescence, hampering regenerative capacity in aged cardiovascular system. A mounting body of evidence underscores the significance of targeting redox machinery to restore stem cell self-renewal and enhance their differentiation potential into youthful cardiovascular lineages. Hence, the redox machinery holds promise as a target for optimizing cardiovascular regenerative therapies. In this context, we delve into the current understanding of redox homeostasis in regulating stem cell function and reprogramming processes that impact the regenerative potential of the cardiovascular system. Furthermore, we offer insights into the recent translational and clinical implications of redox-targeting compounds aimed at enhancing current regenerative therapies for aging cardiovascular tissues
Age modeling of young non-varved lake sediments: methods and limits. Examples from two lakes in Central Chile
High-resolution and highly precise age models for recent lake sediments (last 100-150years) are essential for quantitative paleoclimate research. These are particularly important for sedimentological and geochemical proxies, where transfer functions cannot be established and calibration must be based upon the relation of sedimentary records to instrumental data. High-precision dating for the calibration period is most critical as it determines directly the quality of the calibration statistics. Here, as an example, we compare radionuclide age models obtained on two high-elevation glacial lakes in the Central Chilean Andes (Laguna Negra: 33°38′S/70°08′W, 2,680m a.s.l. and Laguna El Ocho: 34°02′S/70°19′W, 3,250m a.s.l.). We show the different numerical models that produce accurate age-depth chronologies based on 210Pb profiles, and we explain how to obtain reduced age-error bars at the bottom part of the profiles, i.e., typically around the end of the 19th century. In order to constrain the age models, we propose a method with five steps: (i) sampling at irregularly-spaced intervals for 226Ra, 210Pb and 137Cs depending on the stratigraphy and microfacies, (ii) a systematic comparison of numerical models for the calculation of 210Pb-based age models: constant flux constant sedimentation (CFCS), constant initial concentration (CIC), constant rate of supply (CRS) and sediment isotope tomography (SIT), (iii) numerical constraining of the CRS and SIT models with the 137Cs chronomarker of AD 1964 and, (iv) step-wise cross-validation with independent diagnostic environmental stratigraphic markers of known age (e.g., volcanic ash layer, historical flood and earthquakes). In both examples, we also use airborne pollutants such as spheroidal carbonaceous particles (reflecting the history of fossil fuel emissions), excess atmospheric Cu deposition (reflecting the production history of a large local Cu mine), and turbidites related to historical earthquakes. Our results show that the SIT model constrained with the 137Cs AD 1964 peak performs best over the entire chronological profile (last 100-150years) and yields the smallest standard deviations for the sediment ages. Such precision is critical for the calibration statistics, and ultimately, for the quality of the quantitative paleoclimate reconstruction. The systematic comparison of CRS and SIT models also helps to validate the robustness of the chronologies in different sections of the profile. Although surprisingly poorly known and under-explored in paleolimnological research, the SIT model has a great potential in paleoclimatological reconstructions based on lake sediment
PI3K/p110α inhibition selectively interferes with arterial thrombosis and neointima formation, but not re-endothelialization: potential implications for drug-eluting stent design
Background Impaired re-endothelialization and stent thrombosis are a safety concern associated with drug-eluting stents (DES). PI3K/p110α controls cellular wound healing pathways, thereby representing an emerging drug target to modulate vascular homoeostasis after injury. Methods and results PI3K/p110α was inhibited by treatment with the small molecule inhibitor PIK75 or a specific siRNA. Arterial thrombosis, neointima formation, and re-endothelialization were studied in a murine carotid artery injury model. Proliferation and migration of human vascular smooth muscle cell (VSMC) and endothelial cell (EC) were assessed by cell number and Boyden chamber, respectively. Endothelial senescence was evaluated by the β-galactosidase assay, endothelial dysfunction by organ chambers for isometric tension. Arterial thrombus formation was delayed in mice treated with PIK75 when compared with controls. PIK75 impaired arterial expression and activity of tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1); in contrast, plasma clotting and platelet aggregation did not differ. In VSMC and EC, PIK75 inhibited expression and activity of TF and PAI-1. These effects occurred at the transcriptional level via the RhoA signalling cascade and the transcription factor NFkB. Furthermore, inhibition of PI3K/p110α with PIK75 or a specific siRNA selectively impaired proliferation and migration of VSMC while sparing EC completely. Treatment with PIK75 did not induce endothelial senescence nor inhibit endothelium-dependent relaxations. In line with this observation, treatment with PIK75 selectively inhibited neointima formation without affecting re-endothelialization following vascular injury. Conclusion Following vascular injury, PI3K/p110α inhibition selectively interferes with arterial thrombosis and neointima formation, but not re-endothelialization. Hence, PI3K/p110α represents an attractive new target in DES desig
Thrombophilia and outcomes of venous thromboembolism in older patients.
BACKGROUND
Limited data exist on thrombophilic risk factors and clinical outcomes in the elderly with venous thromboembolism (VTE).
OBJECTIVES
To describe the prevalence of laboratory thrombophilic risk factors and their association with VTE recurrence or death in a cohort of elderly people with VTE.
METHODS
In 240 patients aged ≥65 years with acute VTE without active cancer or an indication for extended anticoagulation, we performed laboratory thrombophilia testing 1 year after the index VTE. Recurrence or death was assessed during the 2-year follow-up.
RESULTS
A total of 78% of patients had ≥1 laboratory thrombophilic risk factor(s). Elevated levels of von Willebrand factor, homocysteine, coagulant activity of factor VIII (FVIII:C), fibrinogen, FIX:C, and low antithrombin activity were the most prevalent risk factors (43%, 30%, 15%, 14%, 13%, and 11%, respectively). Additionally, 16.2% of patients experienced VTE recurrence and 5.8% of patients died. Patients with a von Willebrand factor of >182%, FVIII:C level >200%, homocysteine level >15μmol/L, or lupus anticoagulant had a significantly higher rate of recurrence than those without these risk factors (15.0 vs. 6.1 [P = .006], 23.5 vs. 8.2 [P = .01], 17.0 vs. 6.8 [P = .006], and 89.5 vs. 9.2 [P = .02] events per 100 patient-years, respectively). Furthermore, patients with a high fibrinogen level or hyperhomocysteinemia with a homocysteine level ≥30 μmol/L had significantly higher mortality than patients with normal levels (18.5 vs. 2.8 [P = .049] and 13.6 vs. 2 [P = .002] deaths per 100 patient-years, respectively). After adjustments for relevant confounders, these associations remained unchanged.
CONCLUSION
Laboratory thrombophilic risk factors are common in elderly people with VTE and allow for the identification of a population at the risk of worse clinical outcomes
Differences in duration of anticoagulation after pulmonary embolism and deep vein thrombosis: Findings from the SWIss Venous ThromboEmbolism Registry (SWIVTER).
BACKGROUND
Although the two manifestations of venous thromboembolism (VTE), deep vein thrombosis (DVT) and pulmonary embolism (PE), vary considerably, the consensus guidelines recommend similar algorithms for therapeutic anticoagulation in both conditions. Real-world data assessing contemporary management strategies in PE and DVT alone may help tailoring future recommendations towards more individualized patient care.
METHODS
In the present analysis, we compared demographics, comorbidities, treatment patterns, and clinical outcomes of PE versus DVT only among 2062 consecutive patients with confirmed VTE enrolled by 11 acute care hospitals between November 2012 and February 2015 in the SWIss Venous ThromboEmbolism Registry (SWIVTER).
RESULTS
Overall, 1246 (60 %) patients were diagnosed with PE. In comparison to DVT alone, PE patients were older (66 vs. 59 years; p < 0.001), more frequently had acute and chronic comorbidities, less frequently had prior VTE and hormone replacement, and were less often pregnant. VTE was considered similarly often provoked in patients with PE and DVT alone (33.8 % vs. 33.5 %; p = 0.88). Anticoagulation for an indefinite duration was more often prescribed to patients with PE than those with DVT alone (45.7 vs. 19.6 %; p < 0.001), and PE diagnosis was the strongest independent predictor of indefinite anticoagulation (OR 3.21; 95 % CI 2.55-4.06; p < 0.001). Diagnosis of PE was associated with both increased risk of 90-day mortality (HR 2.31, 95 % CI 1.44-3.71; p = 0.001) and major bleeding (HR 3.88, 95 % CI 1.63-9.22; p = 0.002).
CONCLUSIONS
Our analysis affirms differences in demographics, risk factors, and clinical outcomes of PE versus DVT alone. In routine clinical practice, duration of anticoagulation is being managed differently between the two manifestations of VTE, in contrast to recommendations of the current consensus guidelines
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Inferring the structure of the solar corona and inner heliosphere during the Maunder minimum using global thermodynamic magnetohydrodynamic simulations
Observations of the Sun’s corona during the space era have led to a picture of relatively constant, but cyclically varying solar output and structure. Longer-term, more indirect measurements, such as from 10Be, coupled by other albeit less reliable contemporaneous reports, however, suggest periods of significant departure from this standard. The Maunder Minimum was one such epoch where: (1) sunspots effectively disappeared for long intervals during a 70 yr period; (2) eclipse observations suggested the distinct lack of a visible K-corona but possible appearance of the F-corona; (3) reports of aurora were notably reduced; and (4) cosmic ray intensities at Earth were inferred to be substantially higher. Using a global thermodynamic MHD model, we have constructed a range of possible coronal configurations for the Maunder Minimum period and compared their predictions with these limited observational constraints. We conclude that the most likely state of the corona during—at least—the later portion of the Maunder Minimum was not merely that of the 2008/2009 solar minimum, as has been suggested recently, but rather a state devoid of any large-scale structure, driven by a photospheric field composed of only ephemeral regions, and likely substantially reduced in strength. Moreover, we suggest that the Sun evolved from a 2008/2009-like configuration at the start of the Maunder Minimum toward an ephemeral-only configuration by the end of it, supporting a prediction that we may be on the cusp of a new grand solar minimum
Long-Term Mortality after New-Onset Atrial Fibrillation in COVID-19
Background: Atrial fibrillation (AF) has been described as a common cardiovascular manifestation in patients suffering from coronavirus disease 2019 (COVID-19) and has been suggested to be a potential risk factor for a poor clinical outcome. Methods: In this observational study, all patients hospitalized due to COVID-19 in 2020 in the Cantonal Hospital of Baden were included. We assessed clinical characteristics, in-hospital outcomes as well as long-term outcomes with a mean follow-up time of 278 (±90) days. Results: Amongst 646 patients diagnosed with COVID-19 (59% male, median age: 70 (IQR: 59-80)) in 2020, a total of 177 (27.4%) patients were transferred to the intermediate/intensive care unit (IMC/ICU), and 76 (11.8%) were invasively ventilated during their hospitalization. Ninety patients (13.9%) died. A total of 116 patients (18%) showed AF on admission of which 34 (29%) had new-onset AF. Patients with COVID-19 and newly diagnosed AF were more likely to require invasive ventilation (OR: 3.5; p = 0.01) but did not encounter an increased in-hospital mortality. Moreover, AF neither increased long-term mortality nor the number of rehospitalizations during follow-up after adjusting for confounders. Conclusions: In patients suffering from COVID-19, the new-onset of AF on admission was associated with an increased risk of invasive ventilation and transfer to the IMC/ICU but did not affect in-hospital or long-term mortality
Long-term dietary n3 fatty acid prevents aging-related cardiac diastolic and vascular dysfunction
Aims: The prevalence of left ventricular (LV) diastolic and vascular dysfunction increases with age, eventually leading to heart failure with preserved ejection fraction (HFpEF). A preventive strategy is an unmet medical need. We and others reported previously on the beneficial effects of omega-3 fatty acid alpha linolenic acid (ALA) on cardiovascular disorders in animal models and translational studies. We now investigate whether long-term dietary ALA could prevent LV diastolic dysfunction and vascular aging in a murine model.
Methods and results: Wild-type C57BL/6 J mice were fed a chow or ALA diet for 12 months, starting at 6 months of age. Here, we show that aged (~18 months) mice recapitulate major hallmarks of HFpEF, including LV diastolic dysfunction with preserved ejection fraction, impaired vascular function, cardiac fibrosis, arterial stiffening and inflammation, as well as elevated B-type natriuretic peptide (BNP). Long-term ALA supplementation upregulated the mitochondrial tricarboxylic acid enzyme Idh2 and the antioxidant enzymes SOD1 and Gpx1. It also has been associated with reduced inflammation and ECM remodeling, accompanied by a significant downregulation of fibrosis biomarkers MMP-2 and TGF-β in both cardiac and vascular tissues obtained from aged mice. Our data exhibited the preventive effects of dietary ALA against LV diastolic dysfunction, impaired vasorelaxation, cardiac fibrosis, inflammation and arterial stiffening in aged mice.
Conclusions: We provide evidence and a simplified mechanistic insight on how long-term ALA supplementation is a successful strategy to prevent the development of age-related diastolic and vascular dysfunction
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