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Local sunspot oscillations and umbral dots

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Research in Astronomy and Astrophysics 2018年第9期18卷 1-12页

作者： Yuzef Zhugzhda Robert sych IZMIRAN Institute of Solar-Terrestrial Physics SB RAN Irkutsk Russia

Data analysis of sunspot oscillations based on a 6-hr SDO run of an observation showed that low frequency （0.2 〈ω 〈 1 mHz） oscillations are locally similar to three and five minute oscillations. The oscillations in the sunspot are concentrated in cells of a few arcsec, each of which has its own oscillation spectrum. The analysis of two scenarios for sunspot oscillations leads to a conclusion that local sunspot oscillations occur due to a subphotospheric resonator for slow MHD waves. Empirical models of a sunspot atmosphere and the theory of slow waves in thin magnetic flux tubes are applied to modeling the subphotospheric resonator. The spectrum of local oscillations consists of a great number of lines. This kind of spectrum can occur only if the subphotospheric resonator is a magnetic tube with a rather weak magnetic field. Magnetic tubes of this sort are umbral dots that appear due to the convective tongues in monolithic sunspots. The interrelation of local oscillations with umbral dots and wavefronts of traveling waves in sunspots is discussed.

关键词： Sun sunspot - methods numerical - waves

Magneto-acoustic waves in magnetic twisted flux tubes

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Research in Astronomy and Astrophysics 2021年第5期21卷 247-254页

作者： Wei Wu Robert sych Jie Chen Jiang-Tao Su School of Astronomy and Space Sciences University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Solar Activity National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Institute of Solar-Terrestrial Physics SB RAS Irkutsk 664033Russia

At present,many works about MHD wave diagnostics in magnetic flux tubes are based on some pioneering works not considering the contributions of magnetic *** works considered the effect on MHD waves,but the dispersion relationship they presented only gave the wave modes of m=0,1,2...The kink mode of m=−1 was ***,in this work we present a complete dispersion relationship that includes both magnetic twist and the wave mode of m=−*** to the m=+1 wave mode,the mode of m=−1 also exhibits the mode change at finite kr0,from body to surface *** phase speeds of this mode are usually less than those of m=+1 *** harmonic curves of m=±1 modes in dispersion relationship diagrams are approximately symmetric in respect to a characteristic velocity,*** tube velocity in flux *** on the present dispersion relationship,we revisit the issue of spiral wave patterns in sunspots and find that the magnetic twist has no great influence on their morphology in the frame of linear perturbation analysis.

关键词： Sun:sunspots Sun:oscillations Sun:atmosphere

Tackling the challenge of controlling the spin with electric field

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National Science Review 2021年第2期8卷 8-9页

作者： roberta Sessoli Dipartimento di Chimica ‘Ugo Schiff’ & INSTM RU Università degli Studi di Firenze

Electric(E) fields are commonly employed to control magnetization in some classes of materials such as ***, the extreme confinement of the electric field, for instance under the tip of a scanning tunnel microscope,makes it an ideal tool to manipulate individual spins, generating interest in spins as potential quantum bits. Spins are in fact intrinsic quantum systems that can be manipulated easily by means of pulses of electromagnetic microwaves, as commonly done in magnetic resonance spectroscopies. Although the coupling usually involves the magnetic field of microwaves,

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Antisense therapy:a potential breakthrough in the treatment of neurodegenerative diseases

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Neural Regeneration Research 2024年第5期19卷 1027-1035页

作者： roberta Romano Cecilia Bucci Department of Biological and Environmental Sciences and Technologies(DiSTeBA) University of SalentoLecceItaly

Neurodegenerative diseases are a group of disorders characterized by the progressive degeneration of neurons in the central or peripheral nervous ***,there is no cure for neurodegenerative diseases and this means a heavy burden for patients and the health system ***,it is necessary to find new therapeutic approaches,and antisense therapies offer this possibility,having the great advantage of not modifying cellular genome and potentially being *** preclinical and clinical studies aim to test the safety and effectiveness of antisense therapies in the treatment of neurodegenerative *** objective of this review is to summarize the recent advances in the development of these new technologies to treat the most common neurodegenerative diseases,with a focus on those antisense therapies that have already received the approval of the *** and Drug Administration.

关键词： Alzheimer’s disease amyotrophic lateral sclerosis antisense oligonucleotide Huntington’s disease neurodegenerative disorders Parkinson’s disease siRNA

α-Synuclein oligomers and fibrils:partners in crime in synucleinopathies

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Neural Regeneration Research 2023年第11期18卷 2332-2342页

作者： Alessandra Bigi roberta Cascella Cristina Cecchi Department of Experimental and Clinical Biomedical Sciences Section of BiochemistryUniversity of FlorenceFlorenceItaly

The misfolding and aggregation of a-synuclein is the general hallmark of a group of devastating neurodegenerative pathologies referred to as synucleinopathies,such as Parkinson’s disease,dementia with Lewy bodies,and multiple system *** such conditions,a range of different misfolded aggregates,including oligomers,protofibrils,and fibrils,are present both in neurons and glial *** expe rimental evidence supports the proposition that solu ble oligomeric assemblies,formed during the early phases of the aggregation process,are the major culprits of neuronal toxicity;at the same time,fibrillar confo rmers appear to be the most efficient at propagating among interconnected neurons,thus contributing to the spreading ofα-synuclein ***,α-synuclein fibrils have been recently repo rted to release soluble and highly toxic oligomeric species,responsible for an immediate dysfunction in the recipient *** this review,we discuss the current knowledge about the plethora of mechanisms of cellular dysfunction caused byα-synuclein oligome rs and fibrils,both contributing to neurodegeneration in synucleinopathies.

关键词： amyloid aggregation neurodegeneration Parkinson’s disease protein aggregation protein misfolding

TIME-TEMPERATURE-MISCIBILITY AND MORPHOLOGY OF POLYOLEFIN BLENDS

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Chinese Journal of Polymer Science 2000年第3期18卷 263-270页

作者： roberta.Shanks GandaraAmarasinghe CRC for Polymers Applied Chemistry RMIT University GPO Box 2476V Melbourne AustraliaCRC for Polymers Applied Chemistry RMIT University GPO Box 2476V Melbourne Australia

Miscibility and crystallization have been studied for polypropylene-polyethylene and polyethylene-polyethyleneblends. In the case of the polypropylene blends the composition of interest is 20% polypropylene. At this composition thepolypropylene has been found to be soluble in linear low density polyethylene but insoluble in high, low and very lowdensity polyethylenes. The miscibility has been concluded from the crystallization kinetics and polarised optical microscopywith a hot stage. Polyethylene-polyethylene blends have been formed from polymers with similar average branching contentbut where they have different melting temperatures. Important consequences are to introduce long branches into apolyethylene that only has short branches, and to modify the morphology of a polyethylenes so that haze, gloss and strainhardening are improved. Polyethylene blends must be developed after careful consideration of the branch content anddistribution within each of the constituents. It is not sufficient to simply blend polyethylenes, with the desired range ofproperties, without regard to the miscibility of the blend composition.

关键词： Polypropylene Polyethylene Blend Miscibility Thermal analysis Morphology Crystallization Melting

An Encyclopedic Approach to the Conservation of 20^(th)-Century Architecture

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Built Heritage 2018年第2期2卷 93-102页

作者： roberta Grignolo Academy of Architecture Universitàdella Svizzera ItalianaMendrisioSwitzerland

The built heritage of the 20^(th) century concerns society in general: it is the background to everyday life and the stage of ‘past experience’. Therefore, recent past buildings should not be considered merely for their aesthetic features;they also have to do with physical well-being, social rituals and representations, as well as with associated concepts such as values and emotions. But conservation of 20^(th)-century heritage is not straightforward. It requires specific strategies as well as critical and operational tools, which are not part of the cultural background of the actors of the transformation of our cities (architects, engineers, heritage officials, etc.) and do not yet feature in current design teaching curricula in most universities. To fill these gaps, in 2008 four Swiss architectural schools (USI, EPFL, ETHZ, SUPSI) launched a research project titled ‘Critical Encyclopaedia for reuse and restoration of 20^(th)-century architecture’ (2009-2013). The article presents one of the outcomes of this research: the work developed by the section titled ‘Historical and Critical Tools for Conservation’, which will be published shortly. It provides readers with the cultural, theoretical and critical frame of reference required to understand recent architectural heritage in its widest sense: as a historical, symbolic and aesthetic resource, but also as being endowed with social, economic and ecological value. By examining theories and doctrines which have developed over time and thanks to the exemplary nature and variety of the selected cases, it provides a historical appraisal of how intervention in the field of recent heritage has evolved over the past 60 years. Furthermore the oeuvre presents intervention tools in action: by analysing a vast array of case studies which address the main areas of conservation practice (historical and critical research, analysis of materials and technical features, identification of compatible new uses, regulatory compliance), i

关键词： 20^(th)-century architecture conservation historical-critical tools conservation design strategies conservation case studies

Concerning spikes in emission and absorption in the microwave range

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Research in Astronomy and Astrophysics 2013年第1期13卷 115-128页

作者： Gennady P.Chernov Robert A.sych Guang-Li Huang Hai-Sheng Ji Yi-Hua Yan Cheng-Ming Tan Key Laboratory of Solar Activity National Astronomical ObservatoryChinese Academy of Sciences Pushkov Institute of Terrestrial Magnetism Ionosphere and Radio Wave PropagationRussian Academy of Sciences (IZMIRAN) Institute of Solar-Terrestrial Physics Purple Mountain Observatory Chinese Academy of Sciences

In some events, weak fast solar bursts （near the level of the quiet Sun） were observed in the background of numerous spikes in emission and absorption. In such a case, the background contains the noise signals of the receiver. In events on 2005 September 16 and 2002 April 14, the solar origin of fast bursts was confirmed by simultaneous recording of the bursts at several remote observatories. The noisy background pixels in emission and absorption can be excluded by subtracting a higher level of continuum when constructing the spectra. The wavelet spectrum, noisy pro- files in different polarization channels and a spectrum with continuum level greater than zero demonstrates the noisy character of pixels with the lowest levels of emission and absorption. Thus, in each case, in order to judge the solar origin of all spikes, it is necessary to determine the level of continuum against the background of which the solar bursts are observed. Several models of microwave spikes are discussed. The electron cyclotron maser emission mechanism runs into serious problems with the in- terpretation of microwave millisecond spikes： the main obstacles are too high values of the magnetic field strength in the source （Pe 〈 uB）. The probable mechanism is the interaction of plasma Langmuir waves with ion-sound waves （l ＋ s → t） in a source related to shock fronts in the reconnection region.

关键词： solar flare -- radio emission -- spike-bursts

Role of Smad7 in inflammatory bowel diseases

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World Journal of Gastroenterology 2012年第40期18卷 5664-5668页

作者： Giovanni Monteleone roberta Caruso Francesco Pallone Department of Internal Medicine University Tor Vergata of Rome

Crohn's disease and ulcerative colitis,the major forms of inflammatory bowel diseases(IBD) in man,are complex diseases in which genetic and environmental factors interact to promote an excessive mucosal immune response directed against normal components of the bacterial *** is also evidence that the pathologic process is due to defects in counterregulatory mechanisms,such as those involving the immunosuppressive cytokine transforming growth factor(TGF)-***,studies in human IBD tissues and murine models of colitis have documented a disruption of TGF-1 signalling marked by a block in the phosphorylation of Smad3,a signalling molecule associated with the activated TGF-receptor,due to up-regulation of Smad7,an intracellular inhibitor of Smad3 ***-down of Smad7 with a specific antisense oligonucleotide restores TGF-1/Smad3 signalling,thus resulting in a marked suppression of inflammatory cytokine production and attenuation of murine *** findings together with the demonstration that Smad7 antisense oligonucleotide is not toxic when administered in mice have paved the way for the development of a Smad7 antisense oligonucleotidebased pharmaceutical compound that is now ready to enter the *** this article we review the available data supporting the pathogenic role of Smad7 in IBD and discuss whether and how Smad7 antisense therapy could help dampen the ongoing inflammation in IBD.

关键词： Inflammatory bowel diseases Gut inflam-mation Transforming growth factor-β1 Smad7 Anti-sense oligonucleotides