1,029 research outputs found
A revision of the Lower Cretaceous foraminiferal genus Falsogaudryinella from northwest Europe and Romania, and its relationship to Uvigerinammina
We emend the definition of the foraminiferal genus Falsogaudryinella Bartenstein, 1977 based on
observations of the type species, F. tealbyensis from the Barremian Lower Tealby Clay of
Lincolnshire, U.K. The genus was described by Loeblich & Tappan (1987) as having initial triserial
coiling which reduces to biserial and finally uniserial. However, topotype specimens display high
trochospiral coiling in the microsphaeric generation, with at least four chambers in the initial
whorl. The genus, therefore, does not belong in the family Verneuilinidae, but must be transferred
to the Prolixoplectidae. The wall is solid, non-canaliculate. The connections between chambers are
in the form of tubes that extend from the basal part of the chamber lumina toward a terminal
aperture. This tubular connection is partially separated from the main part of the chamber lumina
by a septum. The presence of this tubular connection in F. tealbyensis is closely analogous to that
observed in the type species of Uvigerinammina Majzon, 1943. The two genera, therefore, are
separated mainly on the basis of cement type, with Falsogaudryinella possessing calcareous cement
and Uvigerinammina organic cement.
We illustrate five species of Falsogaudryinella from the Barremian of Lincolnshire, the U.K.
sector of the Central North Sea, and from the Barremian and the Albian of Romania (F. neagui
Bartenstein, 1981, F. praemoesiana n.sp. F. tealbyensis (Bartenstein, 1956), F. xenogena n.sp. and F.
moesiana (Neagu, 1966)). Our investigations reveal that upper Hauterivian to Barremian specimens
from the North Sea that have been previously regarded as F. moesiana (e.g. King et al., 1989) in fact
belong in a new species, Falsogaudryinella praemoesiana n.sp. A second new species, Falsogaudryinella
xenogena n.sp. is described from the Barremian of the Central North Sea. Evolution within the mid-
Cretaceous Falsogaudryinella group appears to progress by reduction of the terminal uniserial part,
since the coiling in the stratigraphically youngest form (F. moesiana) is predominantly triserial. Our
interpretations of the phylogeny of the Cretaceous Falsogaudryinella and Uvigerinammina lineages
are presented
Characterization Methods for Elastic Properties of Wood Fibers from Mats for Composite Materials
Wood fibers offer excellent specific properties at low cost and are of interest as reinforcement in composites. This work compares two alternative test methods to determine the stiffness of wood fibers from simple macroscopic tests on fiber mats. One method is compression of the fiber mat in the thickness direction, which uses a statistical micromechanical model based on first-order beam theory to describe the deformation. The other method is tensile testing of fiber mats and back calculation of the fiber stiffness with a laminate model. Experiments include compression tests and tensile stiffness index tests as well as determination of fiber content, orientation, and dimensional distribution. For mats with unbleached softwood kraft fibers, an effective value of the Young's modulus of 20.1 GPa determined by the compression method can be compared with values of 17.4-19.0 GPa obtained from tensile tests. These are in agreement with values for similar cellulosic fibers found in literature. The compression method is more appropriate for low-density fiber mats, while the tensile test works better for well-consolidated high-density fiber mats. The two methods have different ranges of applicability and are complementary to one another. Limitations of the methods are also discussed. The main advantage of the methods is that they are quantitative. The potential as stiffening reinforcement of various types of fibers can be systematically investigated, even if the fiber mat microstructures are different
Antibacterial, antioxidant and anti-proliferative properties and zinc content of five south Portugal herbs
Context: Crataegus monogyna L. (Rosaceae) (CM), Equisetum telmateia L. (Equisataceae) (ET), Geranium purpureum Vil. (Geraniaceae) (GP), Mentha suaveolens Ehrh. (Lamiaceae) (MS), and Lavandula stoechas L. spp. luisieri (Lamiaceae) (LS) are all medicinal. Objective: To evaluate the antioxidant, antiproliferative and antimicrobial activities of plant extracts and quantify individual phenolics and zinc. Material and methods: Aerial part extracts were prepared with water (W), ethanol (E) and an 80% mixture (80EW). Antioxidant activity was measured with TAA, FRAP and RP methods. Phenolics were quantified with a HPLC. Zinc was quantified using voltammetry. Antibacterial activity (after 48 h) was tested using Enterococcus faecalis, Bacillus cereus, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Listeria monocytogenes. Antiproliferative activity (after 24 h) was tested using HEP G2 cells and fibroblasts. Results: Solvents influenced results; the best were E and 80EW. GP had the highest antioxidant activity (TAA and FRAP of 536.90mg AAE/g dw and 783.48mg TE/g dw, respectively). CM had the highest zinc concentration (37.21 mg/kg) and phenolic variety, with neochlorogenic acid as the most abundant (92.91 mg/100 g dw). LS was rich in rosmarinic acid (301.71 mg/100 g dw). GP and LS inhibited the most microorganisms: B. cereus, E. coli and S. aureus. GP also inhibited E. faecalis. CM had the lowest MIC: 5830 mu g/mL. The antibacterial activity is explained by the phenolics present. LS and CM showed the most significant anti-proliferative activity, which is explained by their zinc content. Conclusion: The most promising plants for further studies are CM, LS and GP.FCT, Fundacao para a Ciencia e a Tecnologia of Portugal [SFRH/BSA/139/2014
Immunoassay Techniques Highlighting Biomarkers in Immunogenetic Diseases
Diagnosis of autoimmune diseases is crucial for the clinician and the patient alike. The immunoassay techniques most commonly used for this purpose are immunohistochemistry, ELISA, and Western blotting. For the detection of more specific biomarkers or the discovery of new ones for diagnostic purposes and as therapeutic targets, microarray techniques are increasingly used, for example, protein microarray, Luminex, and in recent years, surface plasmon resonance imaging. All of these technologies have undergone changes over time, making them easier to use. Similar technologies have been invented but responding to specific requirements for both diagnostic and research purposes. The goals are to study more analytes in the same sample, in a shorter time, and with increased accuracy. The reproducibility and reliability of the results are also a target pursued by manufacturers. In this chapter, we present these technologies and their utility in the diagnosis of immunogenetic diseases
New type of microengine using internal combustion of hydrogen and oxygen
Microsystems become part of everyday life but their application is restricted
by lack of strong and fast motors (actuators) converting energy into motion.
For example, widespread internal combustion engines cannot be scaled down
because combustion reactions are quenched in a small space. Here we present an
actuator with the dimensions 100x100x5 um^3 that is using internal combustion
of hydrogen and oxygen as part of its working cycle. Water electrolysis driven
by short voltage pulses creates an extra pressure of 0.5-4 bar for a time of
100-400 us in a chamber closed by a flexible membrane. When the pulses are
switched off this pressure is released even faster allowing production of
mechanical work in short cycles. We provide arguments that this unexpectedly
fast pressure decrease is due to spontaneous combustion of the gases in the
chamber. This actuator is the first step to truly microscopic combustion
engines.Comment: Paper and Supplementary Information (to appear in Scientific Reports
Application of the Nanofiltration Process for Concentration of Polyphenolic Compounds from Geranium robertianum and Salvia officinalis Extracts
The aim of this study was to prove the efficiency of the nanofiltration process for the concentration of polyphenolic compounds from Geranium robertianum and Salvia officinalis extracts and to evaluate the extract’s antioxidant activity. A lab-scale cross-flow set-up using flat-sheet configuration membrane was employed for all experiments.
Two nanofiltration membranes have been used: SelRO MPF-36 (Koch membrane) and an organic-inorganic membrane (polysulfone with SBA-15-NH2). When the organic-inorganic membranes were used in the nanofiltration process, the obtained concentrated extracts proved to have higher polyphenol and flavonoid rejections, in both cases (Geranium robertianum and Salvia officinalis). The obtained values were over 88 % DPPH inhibition, for concentrated extracts, using the DPPH method. The concentrated extracts obtained after nanofiltration NF2 (organic-inorganic membrane) had the strongest scavenging activity for all extracts and almost completely inhibited DPPH absorption (92.9 % for Geranium robertianum concentrated extract and 90.1 % for Salvia officinalis concentrated extract). These features turn the studied, concentrated extracts into a good source for further medicinal applications
Induced Parity-Breaking Term at Finite Chemical Potential and Temparature
We exactly calculated the parity-odd term of the effective action induced by
the fermions in 2+1 dimensions at finite chemical potential and finite
temperature. It shows that gauge invariance is still respected. A more gerneral
class of background configurations is considered. The knowledge of the reduced
1+1 determinant is required in order to draw exact conclusions about the gauge
invariance of the parity-odd term in this latter case.Comment: 8 pages, LATEX, no figure
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