68 research outputs found
Phases of supersymmetric O(N) theories
We perform a global renormalization group study of O(N) symmetric Wess-Zumino
theories and their phases in three euclidean dimensions. At infinite N the
theory is solved exactly. The phases and phase transitions are worked out for
finite and infinite short-distance cutoffs. A distinctive new feature arises at
strong coupling, where the effective superfield potential becomes multi-valued,
signalled by divergences in the fermion-boson interaction. Our findings resolve
the long-standing puzzle about the occurrence of degenerate O(N) symmetric
phases. At finite N, we find a strongly-coupled fixed point in the local
potential approximation and explain its impact on the phase transition. We also
examine the possibility for a supersymmetric Bardeen-Moshe-Bander phenomenon,
and relate our findings with the spontaneous breaking of supersymmetry in other
models.Comment: 23 pages, 18 figure
On the relevance of polyynyl-substituted PAHs to astrophysics
We report on the absorption spectra of the polycyclic aromatic hydrocarbon
(PAH) molecules anthracene, phenanthrene, and pyrene carrying either an ethynyl
(-C2H) or a butadiynyl (-C4H) group. Measurements were carried out in the mid
infrared at room temperature on grains embedded in CsI pellets and in the near
ultraviolet at cryogenic temperature on molecules isolated in Ne matrices. The
infrared measurements show that interstellar populations of
polyynyl-substituted PAHs would give rise to collective features in the same
way non-substituted PAHs give rise to the aromatic infrared bands. The main
features characteristic of the substituted molecules correspond to the
acetylenic CH stretching mode near 3.05 mum and to the almost isoenergetic
acetylenic CCH in- and out-of-plane bending modes near 15.9 mum.
Sub-populations defined by the length of the polyynyl side group cause
collective features which correspond to the various acetylenic CC stretching
modes. The ultraviolet spectra reveal that the addition of an ethynyl group to
a non-substituted PAH molecule results in all its electronic transitions being
redshifted. Due to fast internal energy conversion, the bands at shorter
wavelengths are significantly broadened. Those at longer wavelengths are only
barely affected in this respect. As a consequence, their relative peak
absorption increases. The substitution with the longer butadiynyl chain causes
the same effects with a larger magnitude, resulting in the spectra to show a
prominent if not dominating pi-pi* transition at long wavelength. After
discussing the relevance of polyynyl-substituted PAHs to astrophysics, we
conclude that this class of highly conjugated, unsaturated molecules are valid
candidates for the carriers of the diffuse interstellar bands.Comment: 29 pages, 9 figures, accepted for publication in ApJ 2 April 201
Effect of iodothyronine hormone status on doxorubicin related cardiotoxicity
The anthracycline anticancer agent doxorubicin has been recognised to induce a dose-dependent cardiotoxicity. The chronic form of such complication is characterized by an irreversible cardiac damage and congestive heart failure. Although the pathogenesis of anthracycline cardiotoxicity seems to be multifactorial, the pivotal role has been attributed to reactive oxygen species formation. Because redox equilibrium in cardiomyocytes may be regulated via iodothyronine hormones, the aim of the study was to appraise the effect of hypothyroidism on heart damages induced by doxorubicin. The rats received methimazole in drinking water (0.001 and 0.025%) after doxorubicin administration (2.0, 5.0 and 15 mg/kg). The cardiac morphology and blood biochemical markers of heart damage were assessed. Decreased levels of iodothyronine hormones had not significant impact on cardiac morphological changes and no effect on the level of B-type natriuretic peptide in rats receiving doxorubicin. Lower hormonal levels had sporadic, diverse effect on blood transaminases, lactate dehydrogenase and creatine kinase levels, but any relation to time, doxorubicin doses and hypothyroid status was found. Hypothyreosis leads to increase in fatty acid binding protein in rats receiving higher dose of doxorubicin. Hypothyreosis had no effect on heart stretching and on necrosis at morphological level, but caused biochemical symptoms of cardiomyocyte necrosis in rats receiving doxorubicin
5-Hydroxymethylfurfural (HMF) formation during subcritical water extraction
The aim of this study was to investigate the
effect of material type (artichoke leave, lemon peel, flaxseed meal), extraction temperature (50, 100, 120, 140, 160,
180, 200 C) and static extraction time (5, 15, 30, 45 min)
on 5-hydroxymethylfurfural (5-HMF) formation during
subcritical water extraction. 5-HMF content of artichoke
leave and lemon peel extracts increased 7.2 and 26.1 times
with the rise of extraction temperature from 160 to 180 C
for 5 min during subcritical water extraction, respectively.
Besides, 5-HMF content of artichoke leave, lemon peel and
flaxseed meal extracts increased 1.4, 2.0 and 4.5 times as
static extraction time increased from 15 to 45 min at
180 C during subcritical water extraction, respectively.
The highest 5-HMF content of artichoke leave and lemon
peel extracts were obtained as 58.83 and 231.21 mg/L at
180 C and 45 min, respectively. However, for flaxseed
meal, the highest 5-HMF content (222.94 mg/L) was
obtained at 200 C and 15 min during subcritical water
extraction.Project Nos. 2014.M80.02.03, 2014.M80.02.04 by Artvin Coruh University Scientific Research Project Uni
Influence of quorum sensing signal molecules on biofilm formation in Proteus mirabilis O18
The influence of basis of quorum sensing molecules on Proteus strains is much less known as compared to Pseudomonas or Escherichia. We have previously shown that a series of acylated homoserine lactones (acyl-HSL) does not influence the ureolytic, proteolytic, or hemolytic abilities, and that the swarming motility of Proteus mirabilis rods is strain specific. The aim of the presented study was to find out if the presence of a series of acyl-HSL influences biofilm formation of P. mirabilis laboratory strain belonging to O18 serogroup. This serogroup is characterized by the presence of a unique non-carbohydrate component, namely phosphocholine. Escherichia coli and P. mirabilis O18 strains used in this work contains cloned plasmids encoding fluorescent protein genes with constitutive gene expression. In mixed biofilms in stationary and continuous flow conditions, P. mirabilis O18 overgrow whole culture. P. mirabilis O18 strain has genetically proved a presence of AIâ2 quorum sensing system. Differences in biofilm structure were observed depending on the biofilm type and culture methods. From tested acylated homoserine lactones (BHL, HHL, OHL, DHL, dDHL, tDHL), a significant influence had BHL on thickness, structure, and the amount of exopolysaccharides produced by biofilms formed by P. mirabilis O18 pDsRed2
Taqman Real-Time PCR Detects Avipoxvirus DNA in Blood of HawaĂŹi `Amakihi (Hemignathus virens)
Margaret E. M. Farias et al...Background
Avipoxvirus sp. is a significant threat to endemic bird populations on several groups of islands worldwide, including HawaĂŹi, the Galapagos Islands, and the Canary Islands. Accurate identification and genotyping of Avipoxvirus is critical to the study of this disease and how it interacts with other pathogens, but currently available methods rely on invasive sampling of pox-like lesions and may be especially harmful in smaller birds.
Methodology/Principal Findings
Here, we present a nested TaqMan Real-Time PCR for the detection of the Avipoxvirus 4b core protein gene in archived blood samples from Hawaiian birds. The method was successful in amplifying Avipoxvirus DNA from packed blood cells of one of seven Hawaiian honeycreepers with confirmed Avipoxvirus infections and 13 of 28 HawaĂŹi `amakihi (Hemignathus virens) with suspected Avipoxvirus infections based on the presence of pox-like lesions. Mixed genotype infections have not previously been documented in HawaĂŹi but were observed in two individuals in this study.
Conclusions/Significance
We anticipate that this method will be applicable to other closely related strains of Avipoxvirus and will become an important and useful tool in global studies of the epidemiology of Avipoxvirus.Funding for this study was provided by: U.S. Geological Survey, Pacific Island Ecosystems Research Center (biology.usgs.gov/pierc/); U.S. Geological Survey Wildlife (biology.usgs.gov/wter/) and Invasive Species (biology.usgs.gov/invasive/) Programs; National Science Foundation (DEB0083944, www.nsf.gov); NIH/NCRR IDeA Networks of Biomedical Research Excellence (INBRE), P20RR016467 (http://www.ncrr.nih.gov/research_infrastâructure/institutional_development_award/âidea_networks_of_biomedical_research_excâellence/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe
Tracing potential soil contamination in the historical Solvay soda ash plant area, Jaworzno, Southern Poland
This study of soil conditions was carried out on 30 meadow soil (podzol) samples from the vicinity of the soda ash heap in Jaworzno, supplemented by analyses of 18 samples of waste deposited on the heap. In all samples, the total content of macroelements (Ca and Na) and heavy metals (Cd, Cr, Ni, Pb and Zn) as well as pH were analysed. The element concentrations were measured using inductively coupled plasma optical emission spectrometry (ICP-OES). The materials examined were neutral to ultra-alkaline. Total accumulations (mg kg(â1)) of chemical elements in the soil vary from 130.24 to 14076.67 for Ca, 41.40â926.23 for Na, 0.03â3.34 for Cd, 0.94â103.62 for Cr, 0.94â35.89 for Ni, 3.51â76.47 for Pb and 12.05â279.13 for Zn, whereas quantities of the same elements in the waste samples vary from 171705.13 to 360487.94 for Ca, 517.64â3152.82 for Na, 0.2â9.89 for Cd, 1.16â20.40 for Cr, 1.08â9.79 for Ni, 0.1â146.05 for Pb and 10.26â552.35 for Zn. The vertical distribution of the metals was determined in each soil profile. Despite enrichment of heavy metals in the uppermost horizon on the top of the heap, the results lead to the conclusion that the relation of historical production of soda ash in Jaworzno to current contamination of the local soil environment is insignificant
Factors influencing physical activity and rehabilitation in survivors of critical illness: a systematic review of quantitative and qualitative studies
PURPOSE: To identify, evaluate and synthesise studies examining the barriers and enablers for survivors of critical illness to participate in physical activity in the ICU and post-ICU settings from the perspective of patients, caregivers and healthcare providers. METHODS: Systematic review of articles using five electronic databases: MEDLINE, CINAHL, EMBASE, Cochrane Library, Scopus. Quantitative and qualitative studies that were published in English in a peer-reviewed journal and assessed barriers or enablers for survivors of critical illness to perform physical activity were included. Prospero ID: CRD42016035454. RESULTS: Eighty-nine papers were included. Five major themes and 28 sub-themes were identified, encompassing: (1) patient physical and psychological capability to perform physical activity, including delirium, sedation, illness severity, comorbidities, weakness, anxiety, confidence and motivation; (2) safety influences, including physiological stability and concern for lines, e.g. risk of dislodgement; (3) culture and team influences, including leadership, interprofessional communication, administrative buy-in, clinician expertise and knowledge; (4) motivation and beliefs regarding the benefits/risks; and (5) environmental influences, including funding, access to rehabilitation programs, staffing and equipment. CONCLUSIONS: The main barriers identified were patient physical and psychological capability to perform physical activity, safety concerns, lack of leadership and ICU culture of mobility, lack of interprofessional communication, expertise and knowledge, and lack of staffing/equipment and funding to provide rehabilitation programs. Barriers and enablers are multidimensional and span diverse factors. The majority of these barriers are modifiable and can be targeted in future clinical practice
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