An Extreme Solar Event of 20 January 2005: Properties of the Flare and the Origin of Energetic Particles

The extreme solar and SEP event of 20 January 2005 is analyzed from two perspectives. Firstly, we study features of the main phase of the flare, when the strongest emissions from microwaves up to 200 MeV gamma-rays were observed. Secondly, we relate our results to a long-standing controversy on the origin of SEPs arriving at Earth, i.e., acceleration in flares, or shocks ahead of CMEs. All emissions from microwaves up to 2.22 MeV line gamma-rays during the main flare phase originated within a compact structure located just above sunspot umbrae. A huge radio burst with a frequency maximum at 30 GHz was observed, indicating the presence of a large number of energetic electrons in strong magnetic fields. Thus, protons and electrons responsible for flare emissions during its main phase were accelerated within the magnetic field of the active region. The leading, impulsive parts of the GLE, and highest-energy gamma-rays identified with pi^0-decay emission, are similar and correspond in time. The origin of the pi^0-decay gamma-rays is argued to be the same as that of lower energy emissions. We estimate the sky-plane speed of the CME to be 2000-2600 km/s, i.e., high, but of the same order as preceding non-GLE-related CMEs from the same active region. Hence, the flare itself rather than the CME appears to determine the extreme nature of this event. We conclude that the acceleration, at least, to sub-relativistic energies, of electrons and protons, responsible for both the flare emissions and the leading spike of SEP/GLE by 07 UT, are likely to have occurred simultaneously within the flare region. We do not rule out a probable contribution from particles accelerated in the CME-driven shock for the leading GLE spike, which seemed to dominate later on.Comment: 34 pages, 14 Postscript figures. Solar Physics, accepted. A typo corrected. The original publication is available at http://www.springerlink.co

An Observational Overview of Solar Flares

We present an overview of solar flares and associated phenomena, drawing upon a wide range of observational data primarily from the RHESSI era. Following an introductory discussion and overview of the status of observational capabilities, the article is split into topical sections which deal with different areas of flare phenomena (footpoints and ribbons, coronal sources, relationship to coronal mass ejections) and their interconnections. We also discuss flare soft X-ray spectroscopy and the energetics of the process. The emphasis is to describe the observations from multiple points of view, while bearing in mind the models that link them to each other and to theory. The present theoretical and observational understanding of solar flares is far from complete, so we conclude with a brief discussion of models, and a list of missing but important observations.Comment: This is an article for a monograph on the physics of solar flares, inspired by RHESSI observations. The individual articles are to appear in Space Science Reviews (2011

Autoantibodies against type I IFNs in patients with life-threatening COVID-19

Interindividual clinical variability in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is vast. We report that at least 101 of 987 patients with life-threatening coronavirus disease 2019 (COVID-19) pneumonia had neutralizing immunoglobulin G (IgG) autoantibodies (auto-Abs) against interferon-w (IFN-w) (13 patients), against the 13 types of IFN-a (36), or against both (52) at the onset of critical disease; a few also had auto-Abs against the other three type I IFNs. The auto-Abs neutralize the ability of the corresponding type I IFNs to block SARS-CoV-2 infection in vitro. These auto-Abs were not found in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and were present in only 4 of 1227 healthy individuals. Patients with auto-Abs were aged 25 to 87 years and 95 of the 101 were men. A B cell autoimmune phenocopy of inborn errors of type I IFN immunity accounts for life-threatening COVID-19 pneumonia in at least 2.6% of women and 12.5% of men

Determination of SMNI/SMN2 gene dosage by a quantitative genotyping platform combining capillary electrophoresis and MALDI-TOF mass spectrometry

Background: Spinal muscular atrophy (SMA) is a common inherited and fatal neuromuscular disease caused by deletions and/or mutations that lead to altered concentrations of proteins encoded by the survival motor neuron genes SMN1 and SMN2. Because of the high incidence (at least 1 in 10 000 live births and a carrier frequency of 1 in 35 to 1 in 50) and severity of the disease, precise quantification of SMN1 and SMN2 gene copy numbers is essential for diagnosis and genetic counseling. Methods: We developed a genotyping platform combining capillary electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to quantify absolute gene dosage. The absolute gene dosage can be determined by a multiplexed competitive PCR protocol followed by capillary electrophoresis analysis. The relative SMN1/SMN2 ratio can be analyzed by PinPoint assay followed by MALDI-TOF MS analysis. Results: The complementary assays were evaluated in confirmed cases including 9 affected patients, 33 carriers, and 478 healthy individuals from the general population. We were able to determine all genotypes with different SMN1/SMN2 gene copy number ratios, which unambiguously diagnosed carrier status and the severity of SMA with 100% specificity. Conclusions: This quantitative genotyping platform is suitable for detection of SMA. The described approach may serve as a general quantitative genotyping method for molecular diagnosis of other inheritable diseases. (C) 2006 American Association for Clinical Chemistry

Poly(N-isopropylacrylamide)-Tethered Silicate Platelets for Colloidal Dispersion of Conjugated Polymers with Thermoresponsive and Photoluminescence Properties

Poly(N-isopropylacrylamide)-tethered nanosilicate platelets (NSP-PNiPAAm) have been synthesized by covalently bonding the polymer onto the surfaces of silicate platelets of nanometer dimension, and this class of nanohybrids has proved to be effective for dispersing water-insoluble conjugated polymers (CPs). Simple pulverization of poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) with NSP-PNiPAAm rendered the powder material dispersible in water, whereupon it displayed thermoresponsive properties at 37.5 degrees C and CP particle size variation between ea, 50 and 100 nm by SEM observation. The same dispersion had a maximum UV-vis absorption at 524 mu and PL emission at 605 nm. The PL emission was significantly higher at 4 degrees C than at 45 degrees C. Being coated as a film, it showed an orange emission under an ultraviolet lamp, consistent with the PL measurement. The water-borne process of dispersing the CP in aqueous media by the presence of NSP-PNiPAAm and followed by film formation to demonstrate a unique method of manipulating hydrophobic conjugated polymers in a facile manner

Control and detection of organosilane polarization on nanowire field-effect transistors

We demonstrated control and detection of UV-induced 3-aminopropyltriethoxysilane (APTES) polarization using silicon nanowire field-effect transistors made by top-down lithograph technology. The electric dipole moment in APTES films induced by UV-illumination was shown to produce negative effective charges. When individual dipoles were aligned with an externally applied electric field, the collective polarization can prevail over the UV-induced charges in the wires and give rise to an abnormal resistance enhancement in n-type wires. Real-time detection of hybridization of 15-mer poly-T/poly-A DNA molecules was performed, and the amount of hybridization-induced charges in the silicon wire was estimated. Based on these results, detection sensitivity of the wire sensors was discussed

The association between multimorbidity and poor adherence with cardiovascular medications

Multimorbidity, defined as the presence of two or more chronic conditions, leads to a substantial public health burden. This study evaluated its association with adherence with cardiovascular medications in a Chinese population. A proportional stratified sampling was adopted to draw a representative sample of residents living in Henan Province, China. Interviewer-administered surveys were conducted by trained researchers. The outcomes included the number of chronic medical conditions, adherence with long-term medications (MMAS-8), and depressive symptoms (CESD-20). Binary logistic regression analysis was conducted to evaluate if medication adherence was associated with the presence of multimorbidity. From a total of 3866 completed surveys, the proportion of subjects having 0, 1 and ≥ 2 chronic conditions was 62.6%, 23.8% and 13.5%, respectively. Among 27.6% who were taking chronic medications, 66.6% had poor medication adherence (MMAS-8 score ≤ 6). From binary logistic regression analysis, subjects with poor medication adherence were significantly associated with multimorbidity (adjusted odds ratio [AOR]: 1.35, 95% C.I. 1.02–1.78, p = 0.037). Other associated factors included older age (AOR = 1.04, 95% C.I. 1.03–1.05, p < 0.001), smoking (AOR = 1.63, 95% C.I. 1.16–2.30, p = 0.005), family history of hypertension (AOR = 1.51, 95% C.I. 1.19–1.93, p = 0.001), and fair to poor self-perceived health status (AOR = 2.15, 95% C.I. 1.69–2.74, p < 0.001). Using medication adherence as the outcome variable, multimorbidity was significantly associated with poor drug adherence (AOR = 1.34, 95% C.I. 1.02–1.77, p = 0.037). Multimorbidity was associated with poorer medication adherence. This implies the need for closer monitoring of the medication taking behavior among those with multiple chronic conditions