scholarly journals Nanoplasmonic methods in angular spectroscopy of nanoscale biological objects

2021 ◽  
Vol 23 (4) ◽  
pp. 111-115
Author(s):  
Valeriy V. Yatsishen

The paper presents the results of calculating the angular spectra of light reflection under the condition of excitation of surface plasmons in the Kretschman scheme. The silver layer in this scheme plays the role of a reference material, the minimum in the angular spectrum of which serves as a reference point for the shift of the minimum of the angular spectrum when a layer of the studied biological material is added to the considered layered system, which were melanin and biological tissue. As a result of the work, specific pronounced minima in the angular spectra were obtained, which make it possible to identify these materials with a high degree of accuracy due to the narrow resonance peaks in the angular reflection spectra, which are spaced from the peak in the reflection from the silver film by certain angles. The method contains all the characteristic features of the resonance spectroscopy method; the conditions for the excitation of a surface plasmon at the metal boundary act as resonance conditions.

2017 ◽  
Vol 11 (1) ◽  
pp. 4
Author(s):  
Martin Kristiansson

I artikeln diskuteras en lärarstudie om vad som utmärker samhällskunskaps-ämnet på svenskt mellanstadium. Det sker mot bakgrund av en skandinavisk ämnesdidaktisk diskussion om ämnets tydlighet med fokus riktad mot svenska förhållanden. Här har ämnet beskrivits som otydligt i läroplans- och läroboks-forskning medan det framträder som mer tydligt i lärarforskning. Denna lärarforskning har dock oftast studerat grundskolans högstadium och gymnasium. Studier på mellanstadiet saknas och min studie visar, till skillnad från dessa studier, att ämnet är otydligt när lärarna talar om det. Det är ett stadie som också skiljer sig från högstadiets och gymnasiets ämnescentrerade ämneslärarkultur genom att det är mer elevcentrerat och klasslärarbundet med högre grad av ämnesintegration. Artikeln fokuserar därför samhällskunskapsämnets relationer till övriga samhällsorienterande (SO) ämnen – geografi, historia och religionskunskap – och vad det innebär för ämnets otydlighet. Genom intervjuer med lärare om deras SO-undervisning och samhällskunskapsämnets del i den, illustrerat med hjälp av begreppen ”ämnesmarkörer”, ”ämnesväxlingar” och ”ämnesöverlappningar”, framträder ämnet som underordnat och undanskymt i relation till särskilt geografi och historia. De har en dominerande position inom gruppen och bidrar till att samhällskunskapsämnet förblir otydligt. I artikelns konklusion och diskussion argumenteras för betydelsen av en rekonstruktion av relationerna inom gruppen, inte endast för att göra samhällskunskapsämnet tydligare, utan för att också övriga ämnen skall ge ett starkare bidrag till elevers lärande om samhället och dess frågor både som enskilda ämnen och tillsammans.Nyckelord: samhällskunskap, samhällsorienterande ämnen, ämnesmarkörer, ämnesväxlingar, ämnesöverlappningarAbstractThis article reports on a practice-related study of the characteristic features of the civics subject in Swedish upper primary education. The discussion takes place against the background of a Scandinavian subject-specific pedagogical debate on the lack of clarity in the civics subject in relation to the other social studies subjects. In Sweden, curriculum and textbook research has pointed out that civics seems to have a vague and unspecified role in primary education, while it seems to have a more prominent role in practice-related research. However, the latter research has often focused on lower and upper secondary education, and so far there have been no studies of the role of civics in primary education. In contrast to the studies of civics in secondary education, my study shows that civics in primary education emerges as very obscure in teachers’ talk about it. At this stage of education, civics is not as subject-centred as it is in the subject-teaching culture of secondary education, but rather a pupil-centred subject with a high degree of integration with other subjects. The article has a focus on civics in relation to the other social studies subjects (SO), namely geography, history and religious studies, and on how the interrelations affect the perception of civics. The study is based on interviews with teachers on their SO teaching and the role of civics with the help of the concepts of ”subject marker”, ”subject-switching”, and ”subject-overlapping”. The result of the analysis is that civics emerges as a subordinated and inconspicuous subject in relation to geography and history, in particular. These two subjects have a dominant position in the subject cluster and contribute to relegating civics to a vague and unclear backseat. In conclusion, the article argues for the need of reconstructing the interrelations in the subject cluster, not only for the sake of clarifying the role and content of civics, but also to ensure that the other subjects can also contribute more to pupils’ learning about community and citizenship issues, as separate subjects and together.Keywords: civics, social studies subjects, subjects, subject marker, subject-switching, subject-overlapping


2006 ◽  
pp. 87-96
Author(s):  
Yu. Shvetsov

The article considers the problem of bureaucratisation of the state and the most important social and economic consequences of this phenomenon. The essence of bureaucracy has been revealed, characteristic features of its functioning in Russia have been analyzed; the material base of bureaucracy and its dominating status in the society have been substantiated. The conclusion has been made that the process of changing the role of the budget to serve the interests of bureaucracy is being accomplished.


2020 ◽  
Vol 19 (7) ◽  
pp. 509-526
Author(s):  
Qin Huang ◽  
Fang Yu ◽  
Di Liao ◽  
Jian Xia

: Recent studies implicate microbiota-brain communication as an essential factor for physiology and pathophysiology in brain function and neurodevelopment. One of the pivotal mechanisms about gut to brain communication is through the regulation and interaction of gut microbiota on the host immune system. In this review, we will discuss the role of microbiota-immune systeminteractions in human neurological disorders. The characteristic features in the development of neurological diseases include gut dysbiosis, the disturbed intestinal/Blood-Brain Barrier (BBB) permeability, the activated inflammatory response, and the changed microbial metabolites. Neurological disorders contribute to gut dysbiosis and some relevant metabolites in a top-down way. In turn, the activated immune system induced by the change of gut microbiota may deteriorate the development of neurological diseases through the disturbed gut/BBB barrier in a down-top way. Understanding the characterization and identification of microbiome-immune- brain signaling pathways will help us to yield novel therapeutic strategies by targeting the gut microbiome in neurological disease.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Monica del C. Gomez-Alonso ◽  
Anja Kretschmer ◽  
Rory Wilson ◽  
Liliane Pfeiffer ◽  
Ville Karhunen ◽  
...  

Abstract Background The discovery of robust and trans-ethnically replicated DNA methylation markers of metabolic phenotypes, has hinted at a potential role of epigenetic mechanisms in lipid metabolism. However, DNA methylation and the lipid compositions and lipid concentrations of lipoprotein sizes have been scarcely studied. Here, we present an epigenome-wide association study (EWAS) (N = 5414 total) of mostly lipid-related metabolic measures, including a fine profiling of lipoproteins. As lipoproteins are the main players in the different stages of lipid metabolism, examination of epigenetic markers of detailed lipoprotein features might improve the diagnosis, prognosis, and treatment of metabolic disturbances. Results We conducted an EWAS of leukocyte DNA methylation and 226 metabolic measurements determined by nuclear magnetic resonance spectroscopy in the population-based KORA F4 study (N = 1662) and replicated the results in the LOLIPOP, NFBC1966, and YFS cohorts (N = 3752). Follow-up analyses in the discovery cohort included investigations into gene transcripts, metabolic-measure ratios for pathway analysis, and disease endpoints. We identified 161 associations (p value < 4.7 × 10−10), covering 16 CpG sites at 11 loci and 57 metabolic measures. Identified metabolic measures were primarily medium and small lipoproteins, and fatty acids. For apolipoprotein B-containing lipoproteins, the associations mainly involved triglyceride composition and concentrations of cholesterol esters, triglycerides, free cholesterol, and phospholipids. All associations for HDL lipoproteins involved triglyceride measures only. Associated metabolic measure ratios, proxies of enzymatic activity, highlight amino acid, glucose, and lipid pathways as being potentially epigenetically implicated. Five CpG sites in four genes were associated with differential expression of transcripts in blood or adipose tissue. CpG sites in ABCG1 and PHGDH showed associations with metabolic measures, gene transcription, and metabolic measure ratios and were additionally linked to obesity or previous myocardial infarction, extending previously reported observations. Conclusion Our study provides evidence of a link between DNA methylation and the lipid compositions and lipid concentrations of different lipoprotein size subclasses, thus offering in-depth insights into well-known associations of DNA methylation with total serum lipids. The results support detailed profiling of lipid metabolism to improve the molecular understanding of dyslipidemia and related disease mechanisms.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Gabriel Sigmund ◽  
Cristina Santín ◽  
Marc Pignitter ◽  
Nathalie Tepe ◽  
Stefan H. Doerr ◽  
...  

AbstractGlobally landscape fires produce about 256 Tg of pyrogenic carbon or charcoal each year. The role of charcoal as a source of environmentally persistent free radicals, which are precursors of potentially harmful reactive oxygen species, is poorly constrained. Here, we analyse 60 charcoal samples collected from 10 wildfires, that include crown as well as surface fires in forest, shrubland and grassland spanning different boreal, temperate, subtropical and tropical climate. Using electron spin resonance spectroscopy, we measure high concentrations of environmentally persistent free radicals in charcoal samples, much higher than those found in soils. Concentrations increased with degree of carbonization and woody fuels favoured higher concentrations. Moreover, environmentally persistent free radicals remained stable for an unexpectedly long time of at least 5 years. We suggest that wildfire charcoal is an important global source of environmentally persistent free radicals, and therefore potentially of harmful reactive oxygen species.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii159-ii160
Author(s):  
Roberta Rudà ◽  
Riccardo Pascuzzo ◽  
Francesca Mo ◽  
Alessia Pellerino ◽  
Peter B Barker ◽  
...  

Abstract BACKGROUND There is lack of information on the role of excitatory and inhibitory neurotransmitters in the development of seizures in patients with lower grade gliomas. Increase of glutamate and downregulation of GABA have been suggested in preclinical models and human surgical samples to be associated with brain tumor-related epilepsy. MATERIAL AND METHODS We prospectively investigated with the use of magnetic resonance spectroscopy (MRS) the differences in the ratio of metabolites (glutamate/GABA, glutamate/creatine and GABA/creatine) in the peritumoral areas between patients with or without seizures in a series of lower grade gliomas. Tumors were classified according to WHO Classification of 2016 as follows:11 grade II IDH mutated and 1p/19q codeleted; 3 grade III IDH mutated and 1p/19q codeleted; 6 grade II IDH mutated and 1p/19q intact; 1 grade III IDH mutated and 1p/19q intact; 1 grade II IDH wild-type. Patients received surgery alone or followed by temozolomide chemotherapy according to the presence of risk factors. RESULTS At baseline evaluation, maximum glutamate/GABA values were significantly higher (p=0.023) in the peritumoral area of patients with seizures (1.008 ± 0.368) with respect to those without seizures (0.691 ± 0.170). No other metabolites ratio showed significant differences between the two groups. Similar results were obtained when analyzing the metabolites ratio in the examinations during the follow-up. In the cohort of patients with seizures (n.14) variations of metabolite ratios were not associated with tumor location, 1p/19q codeletion, use of AEDs, concomitant chemotherapy or seizure characteristics (type, duration, frequency). CONCLUSIONS The study is ongoing with the aim of analyzing further the correlations between ratio of metabolites and status of the tumor (stable vs progressive).


Genes ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 1036
Author(s):  
Junhong Ye ◽  
Jifu Li ◽  
Ping Zhao

Although ignored in the past, with the recent deepening of research, significant progress has been made in the field of non-coding RNAs (ncRNAs). Accumulating evidence has revealed that microRNA (miRNA) response elements regulate RNA. Long ncRNAs, circular RNAs, pseudogenes, miRNAs, and messenger RNAs (mRNAs) form a competitive endogenous RNA (ceRNA) network that plays an essential role in cancer and cardiovascular, neurodegenerative, and autoimmune diseases. Gastric cancer (GC) is one of the most common cancers, with a high degree of malignancy. Considerable progress has been made in understanding the molecular mechanism and treatment of GC, but GC’s mortality rate is still high. Studies have shown a complex ceRNA crosstalk mechanism in GC. lncRNAs, circRNAs, and pseudogenes can interact with miRNAs to affect mRNA transcription. The study of the involvement of ceRNA in GC could improve our understanding of GC and lead to the identification of potential effective therapeutic targets. The research strategy for ceRNA is mainly to screen the different miRNAs, lncRNAs, circRNAs, pseudogenes, and mRNAs in each sample through microarray or sequencing technology, predict the ceRNA regulatory network, and, finally, conduct functional research on ceRNA. In this review, we briefly discuss the proposal and development of the ceRNA hypothesis and the biological function and principle of ceRNAs in GC, and briefly introduce the role of ncRNAs in the GC’s ceRNA network.


2013 ◽  
Vol 79 (7) ◽  
pp. 681-685 ◽  
Author(s):  
Worthington G. Schenk ◽  
John B. Hanks ◽  
Philip W. Smith

The role of preoperative parathyroid imaging continues to evolve. This study evaluated whether surgeon-performed ultrasound (U/S) obviates the need for other imaging studies and leads to a focused exploration with a high degree of surgical success. From July 2010 to February 2012, 200 patients presenting with nonfamilial primary hyperparathyroidism underwent neck U/S in the surgeon's office. The U/S interpretation was classified as Class 1 if an adenoma was identified with high confidence, Class 2 if a possible but not definite enlarged gland was imaged, and Class 0 (zero) if no adenoma was identified. The findings were correlated with subsequent intra-operative findings. There were 144 Class 1 U/Ss (72%); of 132 patients coming to surgery, 96.2 per cent had surgical findings concordant with preoperative U/S and all had apparent surgical cure. Twenty-nine patients (14.5%) had Class 2 U/S; the 31 per cent confirmed false-positives in this group were usually colloid nodules. Fourteen of 27 with Class 0 U/S underwent surgery after being offered dynamically enhanced computed tomography scan. All 200 patients were apparent surgical cures. Surgeon-performed U/S is expedient, convenient, inexpensive, and accurate. A clearly identified adenoma can safely lead to a focused limited exploration and avoid additional imaging 93 per cent of the time.


2017 ◽  
Vol 16 (5) ◽  
pp. 626-644 ◽  
Author(s):  
Elizaveta Sivak ◽  
Maria Yudkevich

This paper studies the dynamics of key characteristics of the academic profession in Russia based on the analysis of university faculty in the two largest cities in Russia – Moscow and St Petersburg. We use data on Russian university faculty from two large-scale comparative studies of the academic profession (‘The Carnegie Study’ carried out in 1992 in 14 countries, including Russia, and ‘The Changing Academic Profession Study’, 2007–2012, with 19 participating countries and which Russia joined in 2012) to look at how faculty’s characteristics and attitudes toward different aspects of their academic life changed over 20 years (1992–2011) such as faculty’s views on reasons to leave or to stay at a university, on university’s management and the role of faculty in decision making. Using the example of universities in the two largest Russian cities, we demonstrate that the high degree of overall centralization of governance in Russian universities barely changed in 20 years. Our paper provides comparisons of teaching/research preferences and views on statements concerning personal strain associated with work, academic career perspectives, etc., not only in Russian universities between the years 1992 and 2012, but also in Russia and other ‘Changing Academic Profession’ countries.


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