Determining the state of the corona prior to CMEs is crucial to understanding and ultimately predicting solar eruptions. A common and compelling feature of CMEs is their three-part morphology, as ...seen in white-light observations of a bright expanding loop, followed by a relatively dark cavity, and finally a bright core associated with an erupting prominence/filament. This morphology is an important constraint on CME models. It is also quite common for a three-part structure of loop, cavity, and prominence core to exist quiescently in the corona, and this is equivalently an important constraint on models of CME-precursor magnetic structure. These quiescent structures exist in the low corona, primarily below approximately 1.6 R sub(z), and so are currently observable in white light during solar eclipses, or else by the Mauna Loa Solar Observatory Mk4 coronameter. We present the first comprehensive, quantitative analysis of white-light quiescent cavities as observed by the Mk4 coronameter. We find that such cavities are ubiquitous, as they are the coronal limb counterparts to filament channels observed on the solar disk. We consider examples that range from extremely long-lived, longitudinally extended polar-crown-filament-related cavities to smaller cavities associated with filaments near or within active regions. The former are often visible for days and even weeks at a time and can be identified as long-lived cavities that survive for months. We quantify cavity morphology and intensity contrast properties and consider correlations between these properties. We find multiple cases in which quiescent cavities directly erupt into CMEs and consider how morphological and intensity contrast properties of these cases differ from the general population of cavities. Finally, we discuss the implications that these observations may have for the state of the corona just prior to a CME, and more generally for the nature of coronal MHD equilibria.
The
Coronal Multichannel Polarimeter
(CoMP) measures not only the polarization of coronal emission, but also the full radiance profiles of coronal emission lines. For the first time, CoMP ...observations provide high-cadence image sequences of the coronal line intensity, Doppler shift, and line width simultaneously over a large field of view. By studying the Doppler shift and line width we may explore more of the physical processes of the initiation and propagation of coronal mass ejections (CMEs). Here we identify a list of CMEs observed by CoMP and present the first results of these observations. Our preliminary analysis shows that CMEs are usually associated with greatly increased Doppler shift and enhanced line width. These new observations provide not only valuable information to constrain CME models and probe various processes during the initial propagation of CMEs in the low corona, but also offer a possible cost-effective and low-risk means of space-weather monitoring.
We present the results of the search for large-scale anisotropies in the arrival directions of cosmic rays performed with the KASCADE-Grande experiment at energies higher than eV. To eliminate ...spurious anisotropies due to atmospheric or instrumental effects we apply the east-west method. We show, using the solar time distribution of the number of counts, that this technique allow us to remove correctly the count variations not associated to real anisotropies. By applying the east-west method we obtain the distribution of number of counts in intervals of 20 minutes of sidereal time. This distribution is then analyzed by searching for a dipole component; the significance of the amplitude of the first harmonic is 3.5 , therefore, we derive its upper limit. The phase of the first harmonic is determined with an error of a few hours and is in agreement with the measurements obtained in the 1014 < E < 2 × 1015 eV energy range by the EAS-TOP, IceCube, and IceTop experiments. This supports the hypothesis of a change of the phase of the first harmonic at energies greater than ∼2 × 1014 eV.
The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >1020 eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within ∼50 Mpc through interactions ...with the cosmic microwave background. As there are no sufficiently powerful accelerators within this distance from the Galaxy, explanations for UHECRs range from unusual astrophysical sources to exotic string physics. Also unclear is whether UHECRs consist of protons, heavy nuclei, neutrinos or γ-rays. To resolve these questions, larger detectors with higher duty cycles and which combine multiple detection techniques are needed. Radio emission from UHECRs, on the other hand, is unaffected by attenuation, has a high duty cycle, gives calorimetric measurements and provides high directional accuracy. Here we report the detection of radio flashes from cosmic-ray air showers using low-cost digital radio receivers. We show that the radiation can be understood in terms of the geosynchrotron effect. Our results show that it should be possible to determine the nature and composition of UHECRs with combined radio and particle detectors, and to detect the ultrahigh-energy neutrinos expected from flavour mixing.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Reducing the risk of trocar site hernias Crocetti, D; Sapienza, P; Pedullà, G ...
Annals of the Royal College of Surgeons of England,
10/2014, Letnik:
96, Številka:
7
Journal Article
OBJECTIVE:To assess the control of hypertensive patients assisted in an outpatient service and identify associated variables.
DESIGN AND METHOD:Cross-sectional study with analysis of the electronic ...medical forms of 614 patients in a high-complexity hypertension outpatient service. Inclusion criteria were being at least 18 years old and being in treatment for at least six months. The sample excluded 104 patients for having secondary hypertension and 64 for presenting incomplete data. The dependent variable was blood pressure control (less than que140/90 mmHg). Independent variables were demographic and clinical characteristics. Logistic regression analysis was carried out with a significance level of p < 0.05
RESULTS:The characteristics of hypertensive patients were63.2 ± 15.5 years old, 64.4% were men, 74.1% had white skin, 50.8% were married, body mass index of 29.3 ± 6.2 (38.8% were obese), and blood pressure of 141.8 ± 22.3/78.4 ± 14.6 mmHg. Laboratory tests showed the following Resultsglycemia = 109.9 ± 33.5 mg/dL, glycated hemoglobin = 6.1% ± 1.3%, total cholesterol = 179.4 ± 40.1 mg/dL, LDL = 101.2 ± 32.6 mg/dL, urea = 43.0 ± 23.3 mg/dL, and creatinine = 1.20 ± 0.96 mg/dL. The glomerular filtration rate evaluated by the MDRD equation was 67.7 ± 25.2 mL/minute and 30.7% of the patients had proteinuria. Exams revealed the occurrence of dyslipidemia (46.3%), diabetes (34.8%), chronic kidney disease (27.9%), left ventricular hypertrophy (12.5%), stroke (9.6%), and coronary insufficiency (8.4%). Hypertensive patients had 8.6 ± 4.5 medications prescribed and the main hypertensive drugs were diuretics (68.7%), calcium channel blockers (59.7%), angiotensin AT1 receptor blockers (47.8%), beta-blockers (47.6%), and ACE inhibitors (27.4%). In addition, 23.3% of the patients had resistant hypertension and 48.9% were uncontrolled hypertensive patients. The associated variables are shown in Table 1.(Figure is included in full-text article.)
CONCLUSIONS:Nearly half of the examined hypertensive patients did not have their blood pressure controlled. Clinical variables and target organs damage were associated with uncontrolled hypertension.
OBJECTIVE:Adrenal incidentalomas (AIs) are often discovered after an imaging-work up that is unrelated to specific adrenal gland disease. Up to 30% of AIs show endogenous cortisol excess, without ...signs or symptoms of clinically evident Cushingʼs syndrome. According to literature, subclinical hypercortisolism (SH) is more frequently associated to hypertension as well as obesity and metabolic disorders. Previous studies have established in SH higher cardiovascular (CV) risk, and increased incidence of CV events. Aim of the study was to confirm the existence of a linear relationship between augmented level of cortisol obtained by 24h-urinary free cortisol and overnight 1-mg dexamethason suppression test, and worsening clinical outcomes.(Figure is included in full-text article.)
DESIGN AND METHOD:We retrospectively analyzed data from 543 patients (224 F, 319 M; mean age 59.6+12.4 yrs) with AIs, referred to our Unit between January 2000 to December 2017. After follow-up duration of at least 36 months, we have registered main comorbidities, such as cardiovascular events (pulmonary embolism, deep vein thrombosis, myocardial infarction), metabolic disorders, neoplasms and autoimmune disorders.
RESULTS:In Table 1 we reported anthropometric and laboratory data baseline in patients with non-producing - AIs and SH patients. 33 patients with SH (13 M, 20 F; mean age 58.44+10,76 yrs) underwent unilateral laparoscopic adrenalectomy; 48 patients (23 M, 25 F; mean age 57.21+8 yrs) performed a conservative pharmacological treatment. Surgery group showed a minor prevalence of cardiovascular events than conservative group, especially acute myocardial infarction and related therapeutic procedures (percutaneous stenting and surgical bypass) (0.03 % and 0.03 % vs 11 % and 8.9 %, respectively).
CONCLUSIONS:In SH patients higher levels of 24h-urinary free cortisol and higher levels of plasma cortisol after overnight 1-mg dexamethason suppression test are strictly linked to higher levels of total cholesterol, LDL cholesterol and uric acid, as well as worsen clinical outcomes. Our results confirm that hormonal activity and autonomous production of cortisol is related to higher prevalence of cardiovascular diseases, i.e. arterial hypertension, and CV complications, as myocardial infarction.
Primary aldosteronism (PA) is associated with increased cardiovascular risk and left ventricle (LV) changes. Given its peculiar biomolecular and anatomic properties, excessive epicardial fat, the ...heart-specific visceral fat depot, can affect LV morphology. Whether epicardial fat can be associated with aldosterone and LV mass (LVM) in patients with PA is unknown. We performed ultrasound measurement of the epicardial fat thickness (EAT) in 79 consecutive newly diagnosed patients with PA, 59 affected by bilateral adrenal hyperplasia (IHA), 20 aldosterone-producing adenoma (APA), and 30 patients with essential hypertension (low renin hypertension) (EH). The 3 groups did not differ by age, sex distribution, body mass index (BMI), waist circumference (WC), or blood pressure values. EAT showed a trend of increase in both APA and IHA groups when compared to patients with EH (8.3±1.8 vs. 7.9±1.3 vs. 7.8±2 mm, respectively). EAT was significantly correlated with indexed LVM in the IHA group (r=0.35, p<005), better than BMI or WC were. Interestingly, EAT was highly associated with plasma aldosterone concentrations (PAC) and PAC/plasma renin activity (PRA) (PAC/PRA) in the APA group (p=0.58, p=0.37, p<0.01, for both), whereas BMI and WC were not. EAT was also correlated with PRA in the IHA group (p=-0.28, p<0.05). Our study indicates a novel and interesting interaction of EAT with PA, independent of obesity, abdominal fat and blood pressure control. EAT can locally affect LVM, at least in patients with IHA. Further studies in larger population will be required to confirm these findings.
A fundamental question in stem cell research is whether cultured multipotent adult stem cells represent endogenous multipotent precursor cells. Here we address this question, focusing on SKPs, a ...cultured adult stem cell from the dermis that generates both neural and mesodermal progeny. We show that SKPs derive from endogenous adult dermal precursors that exhibit properties similar to embryonic neural-crest stem cells. We demonstrate that these endogenous SKPs can first be isolated from skin during embryogenesis and that they persist into adulthood, with a niche in the papillae of hair and whisker follicles. Furthermore, lineage analysis indicates that both hair and whisker follicle dermal papillae contain neural-crest-derived cells, and that SKPs from the whisker pad are of neural-crest origin. We propose that SKPs represent an endogenous embryonic precursor cell that arises in peripheral tissues such as skin during development and maintains multipotency into adulthood.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
We report the first direct measurement of the overall characteristics of microwave radio emission from extensive air showers. Using a trigger provided by the KASCADE-Grande air shower array, the ...signals of the microwave antennas of the Cosmic-Ray Observation via Microwave Emission experiment have been read out and searched for signatures of radio emission by high-energy air showers in the GHz frequency range. Microwave signals have been detected for more than 30 showers with energies above 3×10^{16} eV. The observations presented in this Letter are consistent with a mainly forward-directed and polarized emission process in the GHz frequency range. The measurements show that microwave radiation offers a new means of studying air showers at E≥10^{17} eV.
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