The 16 EPA PAHs have played an exceptionally large role above all in environmental and analytical sciences in the last 40 years, but now there are good reasons to question their utility in many ...circumstances even though their use is so established and comfortable. Here we review the reasons why the list has been so successful and why sometimes it is seen as less relevant. Three groups of polycyclic aromatic compounds (PAC) are missing: larger and highly relevant PAHs, alkylated PACs, and compounds containing heteroatoms. Attempts to improve the situation for certain matrixes are known and here: (1) an updated list of PAHs (including the 16 EPA PAHs) for the evaluation of the toxicity in the environment (40 EnvPAHs); (2) a list of 23 NSO-heterocyclic compounds and 6 heterocyclic metabolites; and (3) lists of 10 oxy-PAHs and 10 nitro-PAHs are proposed for practical use in the future. A discussion in the scientific community about these lists is invited. Although the state of knowledge has improved dramatically since the introduction of the 16 EPA PAHs in the 1970s, this summary also shows that more research is needed about the toxicity, occurrence in the environment and chemical analysis, particularly of alkylated PAHs, higher molecular weight PAHs and substituted PACs such as amino-PAHs, cyano-PAHs, etc.. We also suggest that a long overdue discussion of an update of regulatory environmental PAH analysis is initiated.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The chemical group of polycyclic aromatic compounds (PAC), including the better-known subgroup of polycyclic aromatic hydrocarbons (PAH) and the heterocyclic aromatic compounds (NSO-PAC, ...heterocycles), comprise several thousand individual compounds. It is hard to find a comprehensive overview in the literature of these PACs that includes a substantial amount of relevant properties. Here an attempt is made to summarize the most studied but also some less well-known PACs. In addition to basic data such as recommended names, abbreviations, CAS numbers, molecular formulas, chemical structures, and exact mono-isotopic molecular weights, physico-chemical properties taken from the literature like boiling points, vapor pressures, water solubilities, Henry's Law constants, n-octanol-water partition coefficients (log K
OW
), and pK
a
are summarized. Selected toxicological data are listed indicating carcinogenic and mutagenic activity or effects on different organisms.
PAC nomenclature is a complex topic, so suggestions for practical use are made. Regarding available data, estimated (instead of measured) values should be used with caution because considerable deviations from experimentally determined values can occur. For an enhanced understanding of the behavior of single PACs in comparison with each other, some of the properties mentioned above are plotted vs. the number of rings or the degree of alkylation. Also, some physico-chemical data are correlated with different functional groups as substituents of the PAHs.
This article reveals that rather little is known about the less common PACs, e.g., higher molecular weight compounds, alkylated or otherwise substituted aromatics, for instance, keto-, oxo-, amino-, nitro-, cyano-PAHs, or some heterocyclic aromatic compounds, including their derivatives. It mirrors the limited state of knowledge about the variety of PACs that do not belong to the 16 EPA PAHs.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Giardia intestinalis is a major cause of diarrheal disease worldwide and two major Giardia genotypes, assemblages A and B, infect humans. The genome of assemblage A parasite WB was recently ...sequenced, and the structurally compact 11.7 Mbp genome contains simplified basic cellular machineries and metabolism. We here performed 454 sequencing to 16x coverage of the assemblage B isolate GS, the only Giardia isolate successfully used to experimentally infect animals and humans. The two genomes show 77% nucleotide and 78% amino-acid identity in protein coding regions. Comparative analysis identified 28 unique GS and 3 unique WB protein coding genes, and the variable surface protein (VSP) repertoires of the two isolates are completely different. The promoters of several enzymes involved in the synthesis of the cyst-wall lack binding sites for encystation-specific transcription factors in GS. Several synteny-breaks were detected and verified. The tetraploid GS genome shows higher levels of overall allelic sequence polymorphism (0.5 versus <0.01% in WB). The genomic differences between WB and GS may explain some of the observed biological and clinical differences between the two isolates, and it suggests that assemblage A and B Giardia can be two different species.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This review outlines the accomplishments and potential developments of targeted alpha (α) particle therapy (TAT). It discusses the therapeutic advantages of the short and highly ionizing path of ...α-particle emissions; the ability of TAT to complement and provide superior efficacy over existing forms of radiotherapy; the physical decay properties and radiochemistry of common α-emitters, including
Ac,
Bi,
Ra,
Pb,
Th,
Ra,
At, and
Tb; the production techniques and proper handling of α-emitters in a radiopharmacy; recent preclinical developments; ongoing and completed clinical trials; and an outlook on the future of TAT.
Giardia intestinalis is a protozoan parasite that causes diarrhea in a wide range of mammalian species. To further understand the genetic diversity between the Giardia intestinalis species, we have ...performed genome sequencing and analysis of a wild-type Giardia intestinalis sample from the assemblage E group, isolated from a pig.
We identified 5012 protein coding genes, the majority of which are conserved compared to the previously sequenced genomes of the WB and GS strains in terms of microsynteny and sequence identity. Despite this, there is an unexpectedly large number of chromosomal rearrangements and several smaller structural changes that are present in all chromosomes. Novel members of the VSP, NEK Kinase and HCMP gene families were identified, which may reveal possible mechanisms for host specificity and new avenues for antigenic variation. We used comparative genomics of the three diverse Giardia intestinalis isolates P15, GS and WB to define a core proteome for this species complex and to identify lineage-specific genes. Extensive analyses of polymorphisms in the core proteome of Giardia revealed differential rates of divergence among cellular processes.
Our results indicate that despite a well conserved core of genes there is significant genome variation between Giardia isolates, both in terms of gene content, gene polymorphisms, structural chromosomal variations and surface molecule repertoires. This study improves the annotation of the Giardia genomes and enables the identification of functionally important variation.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
High resolution MALDI MS in combination with solvent free sample preparation was employed to characterize a petroleum pitch and a coal tar pitch. The elemental formulas of thousands of mass ...spectrometric peaks were assigned according to the accurate masses. Large polycyclic aromatic hydrocarbons (LPAHs) were found to be the major components in the complex mixtures. Iso-abundance plots were introduced to sort and visualize the molecular constituents into different types based on the carbon and double bond equivalence (DBE) numbers. The differences between the petroleum pitch and the coal tar pitch could be easily observed by comparing their iso-abundance plots. LPAHs in the investigated petroleum pitch possess broad carbon number and DBE number distributions and there is no significant change in the signal intensity between even and odd carbon numbered LPAH species. On the contrary, a smaller variety of carbon number and DBE number distribution of LPAH species is found in the investigated coal tar pitch and LPAHs with even carbon numbers are present in a significantly higher amount in comparison to the odd numbered species. Ion mobility mass spectrometry was used to differentiate the petroleum pitch from coal tar pitch and provides additional molecular size information of complex pitch samples.
Objective
Among patients assessed by the emergency medical service (EMS) and hospitalized with a final diagnosis of stroke, to describe delays, patient characteristics, actions taken and outcome in ...relation to the early recognition of stroke by the EMS clinician.
Methods
Patients admitted to any of six stroke units in Region Västra Götaland, Sweden, with a final diagnosis of stroke from 1 January 2013 to 31 December 2015 were included. Data on follow‐up were retrieved from the Swedish Stroke Register.
Results
In all, 5467 patients were included. Stroke was recognized by the EMS clinician in 4396 cases (80.4%). The mean difference in the time from dialling 112 until arrival at the stroke unit was 556 min shorter when stroke was recognized, while the mean difference in the time from dialling 112 until a preliminary report from a computed tomography (CT) scan was 219 min shorter as compared with the patients in whom stroke was not recognized. After adjustment for age, sex, neurological deficits and coma, a lack of suspicion of stroke on EMS arrival was associated with an increased risk of death during three months of follow‐up (odds ratio 1.66; 95% confidence interval 1.19–2.32; p = .003).
Conclusion
Among patients with a stroke, more than 80% were recognized by the EMS clinician. Early recognition of stroke was associated with a markedly shorter time until arrival at the stroke unit and until the preliminary report of a CT scan. A lack of early stroke recognition was associated with an increased risk of death.
Through different windows: One major obstacle in energy research is the complexity and variety of compounds present in crude oil. A study of different ionization methods for mass spectrometry shows ...that the mass spectrum very strongly depends on which method is used.
The importance of lateral gene transfer in genome evolution of microbial eukaryotes is slowly being appreciated. Acquisitions of genes have led to metabolic adaptation in diverse eukaryotic lineages. ...In most cases the metabolic genes have originated from prokaryotes, often followed by sequential transfers between eukaryotes. However, the knowledge of gene transfer in eukaryotes is still mainly based on anecdotal evidence. Some of the observed patterns may be biases in experimental approaches and sequence databases rather than evolutionary trends. Rigorous systematic studies of gene acquisitions that allow for the possibility of exchanges of all categories of genes from all sources are needed to get a more objective view of gene transfer in eukaryote evolution. It may be that the role of gene transfer in the diversification process of microbial eukaryotes currently is underestimated.
Abstract
This study reports the high-yield production of a novel
133/135
La theranostic pair at a 22 MeV proton beam energy as an attractive alternative to the recently introduced
132/135
La pair, ...demonstrating over an order of magnitude production increase of
133/135
La (231 ± 8 MBq
133
La and 166 ± 5 MBq
135
La at End of Bombardment (EOB)) compared to 11.9 MeV production of
132/135
La (0.82 ± 0.06 MBq
132
La and 19.0 ± 1.2 MBq
135
La) for 500 µA·min irradiations. A new sealed solid cyclotron target is introduced, which is fast to assemble, easy to handle, storable, and contains reusable components. Radiolabeling with macrocyclic chelators DOTA and macropa achieved full incorporation, with respective apparent
133
La molar activites of 33 ± 5 GBq/µmol and 30 ± 4 GBq/µmol. PET centers with access to a 22 MeV capable cyclotron could produce clinically-relevant doses of
133/135
La, via
nat
Ba irradiation, as a standalone theranostic agent for PET imaging and Auger electron therapy. With lower positron energies and less energetic and abundant gamma rays than
68
Ga,
44
Sc and
132
La,
133
La appears to be an attractive radiometal candidate for PET applications requiring a higher scanning resolution, a relatively long isotopic half-life, ease of handling, and a low patient dose.
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