310 research outputs found
Solar-Terrestrial Science Strategy Workshop
The conclusions and recommendations reached at the Solar Terrestrial Science Strategy Workshop are summarized. The charter given to this diverse group was: (1) to establish the level of scientific understanding to be accomplished with the completion of the current and near term worldwide programs; (2) identify the significant scientific questions to be answered by future solar terrestrial programs, and the programs required to answer these questions; and (3) map out a program strategy, taking into consideration currently perceived space capabilities and constraints, to accomplish the identified program
The Organic-Inorganic Polyaniline/V2O5 System. Application as a High-Capacity Hybrid Cathode for Rechargeable Lithium Batteries
The application of a hybrid polyaniline/V2O5 cathode material in reversible lithium electrochemical cells is reported. We have studied the influence of synthesis conditions and subsequent treatments of this hybrid electrode under oxygen in order to optimize its performance as a lithium-insertion cathode. The temperature and duration of this treatment are key parameters in determining the final specific charge of the cathode. The optimal material yielded a specific charge as high as 302 Ah/kg measured at a low discharge rate (C/48) corresponding to the insertion of 2.72 lithium ions per formula unit (C6H4N)0.6V2O5·0.3H2O). Higher scan rates of C/12 lead to specific capacities of 200 Ah/kg. The thermal and electrochemical stability of the hybrid electrode, especially in relation to the decomposition of the organic polymer and its effect on battery performance and cyclability, are also discussed. ©1999 The Electrochemical Society. All rights reserved.This work was partially supported by CICYT (Spain, MAT98-0807-C02-02). We also thank the Ministerio de Educación y Ciencia
(Spain, MEC-AECI) and CONACYT (Mexico) for a predoctoral fellowship
to M.L.C.Peer reviewe
Psychological factors associated with headache frequency, intensity, and headache-related disability in migraine patients
BACKGROUND Several psychological cofactors of migraine have been identified, but relationships to different headache parameters (e.g., headache frequency vs. headache-related disability) are only incompletely understood. METHODS We cross-sectionally assessed 279 migraine patients at their first presentation at our tertiary headache center. We obtained headache and acute medication frequency, pain intensity, the Migraine Disability Assessment Scale (MIDAS), and the Pain Disability Index (PDI) as headache-related outcomes as well as scores of the Hospital Anxiety and Depression Scale (HADS), the Pain Catastrophizing Scale (PCS), Pain-Related Control Scale (PRCS), and Avoidance Endurance Questionnaire (AEQ) as psychological factors. RESULTS Linear regression models revealed the highest associations of the psychological factors with the PDI (adjusted R2 = 0.296, p < 0.001, independent predictors: PCS, AEQ social avoidance, depression) followed by the MIDAS (adjusted R2 = 0.137, p < 0.001, predictors: depression, AEQ social avoidance) and headache frequency (adjusted R2 = 0.083, p < 0.001, predictors: depression, AEQ humor/distraction). Principal component analysis corroborated that psychological factors were preferentially associated with the PDI, while the MIDAS loaded together with headache frequency. CONCLUSION Our results suggest that psychological factors are more strongly associated with the subjective degree of headache-related disability measured by the PDI than with the days with disability (MIDAS) or the more objective parameter of headache frequency. This once again highlights the need for comprehensive assessment of migraine patients with different headache parameters and the need for considering psychological treatment, especially in patients with high disability
Cerebrovascular reactivity during the Valsalva maneuver in migraine, tension-type headache and medication overuse headache
The aim of this study was to investigate, by means of
transcranial Doppler ultrasound (TCD), cerebrovascular
reactivity during the Valsalva maneuver (VM) during
the headache-free interval in patients with migraine (M),
migraine plus tension-type headache (M+TTH), and migraine
plus medication overuse headache (M+MOH). A total of 114 patients (n=60 M, n=38 M+TTH, n=16 M+MOH) and n=60 controls were investigated; diagnoses were made according to the International Headache Society criteria. All subjects underwent TCD monitoring and, simultaneously, non-invasive assessment of arterial blood pressure and end-tidal CO2. Two
indices were determined: the cerebrovascular Valsalva
ratio (CVR) was calculated as the maximum end-diastolic
flow velocity acceleration during the late straining
phase of the VM [cm/s2] and the centroperipheral Valsalva
ratio (CPVR) was defined as the quotient of CVR
to the concomitant arterial blood pressure acceleration
[cm/mmHg x s].
The dynamic cerebrovascular autoregulatory response
to the VM, measured as CVR, was increased in patients
with M and M+TTH compared to age-matched healthy
subjects. By contrast, CPVR (i.e. the quotient of the
cerebrovascular to the peripheral autonomic response),
was increased in M patients compared to
healthy subjects and all other headache conditions
tested.
Cerebrovascular autoregulatory response during the
VM was increased in M patients compared to agematched
normal healthy subjects, indicating a disturbed
autonomic control of cerebral vasoreactivity.
The CPVR seems to be a sensitive parameter for distinguishing between M patients and M+TTH or M+MOH patients
Viral enhancer mimicry of host innate-immune promoters
The inflammatory milieu is the natural habitat for a pathogenic infection, characterised by activity of pro-inflammatory signalling pathways and inflammatory cytokines. Viral entry rapidly activates a range of innate-immune signalling events such as the activation of Pattern Recognition Receptors (PRRs) [1]-[5]. A virus must therefore counteract intrinsic cellular and innate-immune responses to successfully complete the replication cycle. Frequently this is accomplished by encoding viral effector molecules that block these cellular responses by working as either structural or functional mimics of host target proteins [6]-[11]. Nuclear DNA viruses are dependent on the host transcriptional machinery to express the first viral genes; for example the immediate-early (IE) control elements of DNA viruses are by definition absolutely dependent on host transcription factors (TF) [12]. Therefore, these viruses are particularly hostage to their host transcriptional environment [13], [14]. Here we propose that mimicry of regulatory DNA sequences by viral regulatory regions may also provide an additional strategy to counteract at IE times of infection the innate-immune response. In this context, viral IE control elements might functionally mimic innate-immune enhancers, taking advantage of the activated immune signalling TFs for promoting viral IE gene expression
Recommended from our members
Reducing deforestation and improving livestock productivity: greenhouse gas mitigation potential of silvopastoral systems in Caquetá
Colombia's agriculture, forestry and other land use sector accounts for nearly half of its total greenhouse gas (GHG) emissions. The importance of smallholder deforestation is comparatively high in relation to its regional counterparts, and livestock agriculture represents the largest driver of primary forest depletion. Silvopastoral systems (SPSs) are presented as agroecological solutions that synergistically enhance livestock productivity, improve local farmers' livelihoods and hold the potential to reduce pressure on forest conversion. The department of Caquetá represents Colombia's most important deforestation hotspot. Targeting smallholder livestock farms through survey data, in this work we investigate the GHG mitigation potential of implementing SPSs for smallholder farms in this region. Specifically, we assess whether the carbon sequestration taking place in the soil and biomass of SPSs is sufficient to offset the per-hectare increase in livestock GHG emissions resulting from higher stocking rates. To address these questions we use data on livestock population characteristics and historic land cover changes reported from a survey covering 158 farms and model the carbon sequestration occurring in three different scenarios of progressively-increased SPS complexity using the CO2 fix model. We find that, even with moderate tree planting densities, the implementation of SPSs can reduce GHG emissions by 2.6 Mg CO2e ha−1 yr−1 in relation to current practices, while increasing agriculture productivity and contributing to the restoration of severely degraded landscapes
More Attacks and Analgesic Use in Old Age: Self-Reported Headache Across the Lifespan in a German Sample
Background: Reliable population-based data on the prevalence and characteristics of primary headache across the lifespan are essential. However, robust data are lacking. Methods: We utilized questionnaire data from a random general population sample in Germany, that comprised 2,478 participants aged ≥14 years. A standardized questionnaire addressing headache and headache treatment was filled in during the face-to-face survey. Results: The 6-month prevalence of self-reported headache in the total sample amounted to 39.0% (known diagnosis of migraine 7.2%; tension-type headache 12.4%; another diagnosis or unknown diagnosis 23.4%). Age-specific prevalence rates were 37.9% (14-34 years), 44.6% (35-54 years), 38.5% (55-74 years), and 26.9% (≥75 years). Compared to age group 14-34, participants aged 35-54 were more (OR = 1.29, 95%-CI 1.05-1.60, p = 0.018) and those aged ≥75 were less (OR = 0.55, 95%-CI 0.40-0.76, p 14 days per month. The frequency of headache did not differ significantly between age groups in men [χ2(3, N = 384) = 1.45, p > 0.05], but in women [χ2(3, N = 651) = 21.57, p 14 days per month: 1.8 (14-34 years), 2.5 (35-54 years), 3.2 (55-74 years), and 3.4 (≥75 years), respectively 7.9 (14-34 years), 11.4 (35-54 years), 18.4 (55-74 years), and 22.8 (≥75 years). Conclusions: In general, the prevalence of headache decreases with age. However, older women suffer from more frequent attacks and older participants take analgesics on more days per month than younger participants. This might put them at risk of medication overuse which may lead to medication overuse headache. More research is needed to understand these specifics in headache frequency and treatment behavior in older people
Use of outpatient medical care by headache patients in Germany: a population-based cross-sectional study
Background: Headache sufferers in need of professional health care often do not utilize the care available, and factors influencing headache-specific physician consultation are not yet understood. Objectives of this study are (1) to assess self-reported headache-specific physician consultations and (2) to identify headache-related and sociodemographic predictors. Methods: Data of a random sample of the general population in Germany aged ≥14 years were analyzed (N = 2461). A multivariate binary logistic regression was conducted to identify a parsimonious model to predict physician consultation. Results: 50.7% of the participants with headache reported at least one headache-specific physician consultation during lifetime. Of these, 53.6% had seen one, 26.1% two, and 20.3% more than two physicians because of their headaches. The odds of physician consultation increased with the number of headache days per month (HDM) (reference HDM 1) HDM 1–3 (OR = 2.29), HDM 4–14 (OR = 2.41), and HDM ≥15 (OR = 4.83) and increasing Headache Impact Test score (HIT-6) (reference “no or little impact”) moderate impact (OR = 1.74), substantial impact (OR = 3.01), and severe impact (OR = 5.08). Middle-aged participants were more likely to have consulted than younger and older ones (reference 14–34 years) 35–54 years (OR = 1.90), 55–74 years (OR = 1.96), ≥75 years (OR = 1.02). The odds of physician consultation among self-employed subjects were lower than among employed manual workers (OR = 0.48). The living environment (rural versus urban) did not have an influence on the consultation frequency. Conclusion: The results indicate that apart from burden-related factors (headache frequency; headache impact), health care utilization patterns are also influenced by patients’ occupational status and age. Further research is needed to analyze whether the lower consultation rate means that the self-employed have a higher risk of chronification or that they have more effective self-management strategies regarding headache
Management of medication overuse (MO) and medication overuse headache (MOH) S1 guideline.
INTRODUCTION
Chronic headache due to the overuse of medication for the treatment of migraine attacks has a prevalence of 0.5-2.0%. This guideline provides guidance for the management of medication overuse (MO) and medication overuse headache (MOH).
RECOMMENDATIONS
Treatment of headache due to overuse of analgesics or specific migraine medications involves several stages. Patients with medication overuse (MO) or medication overuse headache (MOH) should be educated about the relationship between frequent use of symptomatic headache medication and the transition from episodic to chronic migraine (chronification), with the aim of reducing and limiting the use of acute medication. In a second step, migraine prophylaxis should be initiated in patients with migraine and overuse of analgesics or specific migraine drugs. Topiramate, onabotulinumtoxinA and the monoclonal antibodies against CGRP or the CGRP-receptor are effective in patients with chronic migraine and medication overuse. In patients with tension-type headache, prophylaxis is performed with amitriptyline. Drug prophylaxis should be supplemented by non-drug interventions. For patients in whom education and prophylactic medication are not effective, pausing acute medication is recommended. This treatment can be performed in an outpatient, day hospital or inpatient setting. Patients with headache due to overuse of opioids should undergo inpatient withdrawal. The success rate of the stepped treatment approach is 50-70% after 6 to 12 months. A high relapse rate is observed in patients with opioid overuse. Tricyclic antidepressants, neuroleptics (antiemetics) and the administration of steroids are recommended for the treatment of withdrawal symptoms or headaches during the medication pause. Consistent patient education and further close monitoring reduce the risk of relapse
- …