A rapid, non-sacrificial chromosome preparation technique for freshwater teleosts

The use of fin epithelium from the tilapia, Oreochromis mossambicus, and the grass carp, Ctenopharyngodon idella, was investigated to provide a rapid, non-sacrificial procedure for determining ploidy. A combination of colchicine, prolonged hypotonic treatment, dissociation of cells followed by Giemsa staining makes it possible to achieve good quality metaphase chromosome spreads using small fish without the use of sterile conditions, centrifuges or sacrificing the specimen. In situations such as the induction of triploidy or tetraploidy, it is necessary to have a quick, reliable method of assessing the results of experimental design. The technique presented in this report provides numerous, well-spread metaphase chromosomes with a tissue handling time of less than 2 h

Assessment of Cement Durability in Repository Environment

Portland cement paste is proposed as the material to filling in the annulus between the casing of a borehole and the geological formation in a deep repository for spent sealed radiation sources in Brazil. The cement paste is intended to function as structural material, an additional barrier against the migration of radionuclides outside the repository, and as a blockage against the transport of water between the different strata of the geological setting. The objective of this research is to investigate the behavior of the cement paste and to estimate its service life. In this paper we present the results of mechanical strength measurements and chemical and mineralogical analysis of samples to detect the changes caused by radiation, temperature and aggressive chemicals of groundwater to which the material will be exposed. Methods of analysis included Inductively Coupled Plasma Atomic Emission Spectroscopy, Ion Chromatography, XRay Diffraction, and Thermo Gravimetric Analysi

The validity and reliability of iridology in the diagnosis of previous acute appendicitis as evi-denced by appendectomy

Iridology is defined as a photographic science that identifies pathological and functional changes within organs via biomicroscopic iris assessment for aberrant lines, spots, and discolourations. According to iridology, the iris does not reflect changes  during  anaesthesia,  due  to  the  drugs inhibitory  effects  on  nerves  impulses,  and  in cases of organ removal, it reflects the pre-surgical condition.The profession of Homoeopathy is frequently associated with iridology and in a recent survey (2009)  investigating  the  perceptions  of  Masters of  Technology  graduates  in  Homoeopathy  of University of Johannesburg, iridology was highly regarded as a potential additional skill requirement for assessing the health status of the patient.This  study  investigated  the  reliability  of iridology  in  the  diagnosis  of  previous  acute appendicitis, as evidenced by appendectomy. A total of 60 participants took part in the study. Thirty of the 60 participants had an appendectomy due to acute appendicitis, and 30 had had no prior history  of  appendicitis.  Each  participant’s  right iris  was  documented  by  photography  with  the use  of  a  non-mydriatic  retinal  camera  that  was reset for photographing the iris. The photographs were then randomized by an external person and no identifying data made available to the three raters.  The  raters  included  the  researcher,  who had little experience in iridology and two highly experienced  practising  iridologists.  Data  was obtained  from  the  analyses  of  the  photographs wherein  the  presence  or  absence  of  lesions (implying acute appendicitis) was indicated by the raters. None of the three raters was able to show a significant  success  rate  in  identifying  correctly the  people  with  a  previous  history  of  acute appendicitis and resultant appendectomies from those  who  had  no  previous  history  of  acute appendicitis.  Therefore the outcome of this study indicated an outcome that was subject to chance.The  null  hypothesis  that  states  that appendectomy due to acute appendicitis does not manifest in corresponding lesions in the iris, is supported. It is in the opinion of the researchers that the  association  of  iridology  with  homoeopathic practice may harm the credibility of the profession and that further research on iridology is needed to disprove this conviction. (S Afr Optom 2013 72(3) 127-132

Camperdown Hemoglobin Associated With β° Thalassemia In A Brazilian Child

We report the coexistence of Hb Camperdown [β 104 (G6) Arg → Ser] and β°-thalassemia [β39 (Gln → stop codon)] in a nine-month-old Brazilian boy. He had a relatively more severe hypochromic and microcytic anemia in comparison to his mother's β-thalassemia trait. His Hb Camperdown heterozygous father was clinically and hematologically normal. To our knowledge, this is the first description of an association of β°-thalassemia with Hb Camperdown. Copyright by the Brazilian Society of Genetics.283394396Araújo, A.S., Silva, W.A., Leao, S.A., Bandeira, F.C., Petrou, M., Modell, B., Zago, M.A., A different molecular pattern of β-thalassemia mutations in Northeast of Brazil (2003) Hemoglobin, 27, pp. 211-217Amone, A., X-ray diffraction study of binding of 2,3-diphosphoglycerate to human deoxyhemoglobin (1972) Nature, 237, pp. 146-149Bertuzzo, C.S., Sonati, M.F., Costa, F.F., Hematological phenotype and the type of β thalassemia mutation in Brazil (1997) Braz J Genet, 20, pp. 319-321Bianco, I., Graziani, B., Carboni, C., Genetic patterns in thalassemia intermedia (constitutional microcytic anemia). Familial hematological and biosynthetic studies (1977) Hum Hered, 27, pp. 257-272Blouquit, Y., Lacombe, C., Arous, N., Le Qurrec, A., Branconnier, F., Bonhomme, J., Soummer, A.M., Galacteros, F., Seven new cases of hemoglobin Camperdown alpha 2 beta 2 104 (G6) ARG → SER found in Malta, Sicily and Tunisia (1984) Hemoglobin, 8, pp. 613-619Chang, J.C., Kan, Y.W., β°-thalassemia, a nonsense mutation in man (1979) Proc Natl Acad Sci USA, 76, pp. 2886-2889Clarke, G.M., Higgins, T.N., Laboratory investigation of hemoglobinopathies and thalassemias: Review and update (2000) Clin Chem, 46, pp. 1284-1290Fonseca, S.F., Kerbauy, J., Escrivçao, C., Figueiredo, M.S., Cançado, R., Arruda, V.R., Saad, S.T.O., Costa, F.F., Genetic analysis of beta-thalassemia major and beta-thalassemia intermedia in Brazil (1998) Hemoglobin, 22, pp. 197-207Grignoli, C.R.E., Carvalho, M.H., Kimura, E.M., Sonati, M.F., Arruda, V.R., Saad, S.T.O., Costa, F.F., β°-thalassemia resulting from a novel mutation: β66/u → stop codon (2000) Eur J Haematol, 64, pp. 137-138Kimura, E.M., Grignoli, C.R.E., Pinheiro, V.R.P., Costa, F.F., Sonati, M.F., Thalassemia intermedia as a result of heterozygosis for β°-thallassemia and αααanti3.7/αα genotype in a Brazilian patient (2003) Braz J Med Biol Res, 36, pp. 699-701Kister, J., Barbadjian, J., Blouquit, Y., Bohn, B., Galacteros, F., Poyart, C., Inhibition of oxygen-linked anion binding in Hb Camperdown [α2β2 104 (G6) ARG → SER] (1989) Hemoglobin, 13, pp. 567-578Miranda, S.R.P., Kimura, E.M., Teixeira, R.C., Bertuzzo, C.S., Ramalho, A.A., Saad, S.T.O., Costa, F.F., Hb Camperdown [α2β2 104 (G6) ARG → SER] identified by DNA analysis in a Brazilian family (1996) Hemoglobin, 20, pp. 147-153Old, J.M., Screening arid genetic diagnosis of haemoglobin disorders (2003) Blood Rev, 17, pp. 43-53Olivieri, N.F., The β-thalassemias (1999) N Engl J Med, 341, pp. 99-109Thein, S.L., Genetic insights into the clinical diversity of beta thalassaemia (2004) Br J Haematol, 124, pp. 264-274Weatherall, D.J., Clegg, J.B., Inherited haemoglobin disorders: An increasing global health problem (2001) Bull World Health Organ, 79, pp. 704-712Wilkinson, T., Chua, C.G., Carrell, R.W., Robin, H., Exner, T., Lee, K.M., Kronenberg, H., Haemoglobin Camperdown β 104(G6) Arginine leads to serine (1975) Biochim Biophys Acta, 393, pp. 195-200Zago, M.A., Costa, F.F., Hereditary hemoglobin disorders in Brazil (1985) Trans R Soc Trop Med Hyg, 79, pp. 385-38

Passive direct methanol fuel cells acting as fully autonomous electrochemical biosensors: Application to sarcosine detection

This work describes an innovative electrochemical biosensor that advances its autonomy toward an equipment-free design. The biosensor is powered by a passive direct methanol fuel cell (DMFC) and signals the response via an electrochromic display. Briefly, the anode side of the DMFC power source was modified with a biosensor layer developed using molecularly imprinted polymer (MIP) technology to detect sarcosine (an amino acid derivative that is a potential cancer biomarker). The biosensor layer was anchored on the surface of the anode carbon electrode (carbon black with Pt/Ru, 40:20). This was done by bulk radical polymerization with acrylamide, bis-acrylamide, and vinyl phosphonic acid. This layer selectively interacted with sarcosine when integrated into the passive DMFC (single or multiple, in a stack of 4), which acted as a transducer element in a concentration-dependent process. Serial assembly of a stack of hybrid DMFC/biosensor devices triggered an external electrochromic cell (EC) that produced a colour change. Calibrations showed a concentration-dependent sarcosine response from 3.2 to 2000 µM, which is compatible with the concentration of sarcosine in the blood of prostate cancer patients. The final DMFC/biosensor-EC platform showed a colour change perceptible to the naked eye in the presence of increasing sarcosine concentrations. This colour change was controlled by the DMFC operation, making this approach a self-controlled and self-signalling device. Overall, this approach is a proof-of-concept for a fully autonomous biosensor powered by a chemical fuel. This simple and low-cost approach offers the potential to be deployed anywhere and is particularly suitable for point-of-care (POC) analysis.The authors acknowledge the financial support of EU-Horizon 2020 (Symbiotic, FET-Open, GA665046), and from national funds from FCT - Fundação para a Ciência e a Tecnologia, I.P., in the scope of the projects LA/P/0037/2020, UIDP/50025/2020, UIDB/50025/2020 and UID/EMS/00532/2019. Nádia Ferreira (SFRH/BD/122955/2016), Liliana Carneiro (SFRH/BD/122954/2016), and Ana Carolina Marques (SFRH/BD/115173/2016) acknowledge Fundação para a Ciência e Tecnologia (FCT) for financial support.info:eu-repo/semantics/publishedVersio

W=0 Pairing in (N,N)(N,N) Carbon Nanotubes away from Half Filling

We use the Hubbard Hamiltonian $H$ on the honeycomb lattice to represent the valence bands of carbon single-wall $(N,N)$ nanotubes. A detailed symmetry analysis shows that the model allows W=0 pairs which we define as two-body singlet eigenstates of $H$ with vanishing on-site repulsion. By means of a non-perturbative canonical transformation we calculate the effective interaction between the electrons of a W=0 pair added to the interacting ground state. We show that the dressed W=0 pair is a bound state for resonable parameter values away from half filling. Exact diagonalization results for the (1,1) nanotube confirm the expectations. For $(N,N)$ nanotubes of length $l$, the binding energy of the pair depends strongly on the filling and decreases towards a small but nonzero value as $l \to \infty$. We observe the existence of an optimal doping when the number of electrons per C atom is in the range 1.2$\div$1.3, and the binding energy is of the order of 0.1 $\div$ 1 meV.Comment: 16 pages, 6 figure

QCD Corrections to QED Vacuum Polarization

We compute QCD corrections to QED calculations for vacuum polarization in background magnetic fields. Formally, the diagram for virtual $e\bar{e}$ loops is identical to the one for virtual $q\bar{q}$ loops. However due to confinement, or to the growth of $\alpha_s$ as $p^2$ decreases, a direct calculation of the diagram is not allowed. At large $p^2$ we consider the virtual $q\bar{q}$ diagram, in the intermediate region we discuss the role of the contribution of quark condensates \left and at the low-energy limit we consider the $\pi^0$, as well as charged pion $\pi^+\pi^-$ loops. Although these effects seem to be out of the measurement accuracy of photon-photon laboratory experiments they may be relevant for $\gamma$-ray burst propagation. In particular, for emissions from the center of the galaxy (8.5 kpc), we show that the mixing between the neutral pseudo-scalar pion $\pi_0$ and photons renders a deviation from the power-law spectrum in the $TeV$ range. As for scalar quark condensates \left and virtual $q\bar{q}$ loops are relevant only for very high radiation density $\sim 300 MeV/fm^3$ and very strong magnetic fields of order $\sim 10^{14} T$.Comment: 15 pages, 4 figures; Final versio

Evaluation of turbulent dissipation rate retrievals from Doppler Cloud Radar

Turbulent dissipation rate retrievals from cloud radar Doppler velocity measurements are evaluated using independent, in situ observations in Arctic stratocumulus clouds. In situ validation data sets of dissipation rate are derived using sonic anemometer measurements from a tethered balloon and high frequency pressure variation observations from a research aircraft, both flown in proximity to stationary, ground-based radars. Modest biases are found among the data sets in particularly low- or high-turbulence regimes, but in general the radar-retrieved values correspond well with the in situ measurements. Root mean square differences are typically a factor of 4-6 relative to any given magnitude of dissipation rate. These differences are no larger than those found when comparing dissipation rates computed from tetheredballoon and meteorological tower-mounted sonic anemometer measurements made at spatial distances of a few hundred meters. Temporal lag analyses suggest that approximately half of the observed differences are due to spatial sampling considerations, such that the anticipated radar-based retrieval uncertainty is on the order of a factor of 2-3. Moreover, radar retrievals are clearly able to capture the vertical dissipation rate structure observed by the in situ sensors, while offering substantially more information on the time variability of turbulence profiles. Together these evaluations indicate that radar-based retrievals can, at a minimum, be used to determine the vertical structure of turbulence in Arctic stratocumulus clouds

Investigation of potential respiratory adverse effects of micro/nanofibrillated cellulose and cellulose nanocrystals using human lung cell lines.

Abstract publicado em: Environ Mol Mutagen. 2022 Aug;63(Suppl 1):72-73. (Abstracts from the 13th International Conference on Environmental Mutagens and 53rd Annual Meeting of the Environmental Mutagenesis and Genomics Society). https://onlinelibrary.wiley.com/toc/10982280/2022/63/S1Micro/nanofibrillated (CMF/CNF) and nanocrystalline (CNC) celluloses are innovative materials with enormous potential for industrial and biomedical applications. Their expanding production/application urges the investigation of their safety for human health. This study aimed at investigating the potential respiratory outcomes of two CMF/CNF and one CNC produced from bleached Eucalyptus globulus kraft pulp using human alveolar epithelial (A549) cells grown in monoculture or co-cultured with THP-1 monocyte-derived macrophages, by assessing their cellular uptake, cytotoxic, immunotoxic, genotoxic, and epigenetic effects. The nanocelluloses were characterized for their physicochemical properties: CMF displays a low percentage of nanofibrils while CNF comprises 100% fibrils with a diameter (D) circa 11 nm; CNC consists of nanorods with D of 4-5 nm and aspect ratio around 42. TEM analysis evidenced that CMF and CNF were internalised into A549 cells whereas CNC were not. Neither cytotoxicity (colorimetric and clonogenic assays) nor ROS induction was observed for any of the nanocelluloses. CMF caused chromosomal alterations (in vitro micronucleus assay) in A549 cells while negative results were obtained in co-culture and for the other micro/nanocelluloses in mono- or co-culture. Results in progress of DNA damage and gene mutation analyses will complement mutagenesis assessment. Additionally, potential inflammatory and epigenetic effects are being evaluated. These results contribute to the weight of evidence of nanocelluloses biological effects and knowledge of the underlying molecular mechanisms. Such information will drive the synthesis of the safest nanocelluloses,thus minimising potential negative impacts of their use on human and environmental health.FCT/MCTES through nacional funds (PTDC/SAU-PUB/32587/2017; UIDP/00009/2020; UIDB/00009/2020; 020.07168.BD)info:eu-repo/semantics/publishedVersio

Low-diffusion Xe-He gas mixtures for rare-event detection: electroluminescence yield

High pressure xenon Time Projection Chambers (TPC) based on secondary scintillation (electroluminescence) signal amplification are being proposed for rare event detection such as directional dark matter, double electron capture and double beta decay detection. The discrimination of the rare event through the topological signature of primary ionisation trails is a major asset for this type of TPC when compared to single liquid or double-phase TPCs, limited mainly by the high electron diffusion in pure xenon. Helium admixtures with xenon can be an attractive solution to reduce the electron diffu- sion significantly, improving the discrimination efficiency of these optical TPCs. We have measured the electroluminescence (EL) yield of Xe–He mixtures, in the range of 0 to 30% He and demonstrated the small impact on the EL yield of the addition of helium to pure xenon. For a typical reduced electric field of 2.5 kV/cm/bar in the EL region, the EL yield is lowered by ∼ 2%, 3%, 6% and 10% for 10%, 15%, 20% and 30% of helium concentration, respectively. This decrease is less than what has been obtained from the most recent simulation framework in the literature. The impact of the addition of helium on EL statistical fluctuations is negligible, within the experimental uncertainties. The present results are an important benchmark for the simulation tools to be applied to future optical TPCs based on Xe-He mixtures. [Figure not available: see fulltext.]