548 research outputs found
Rewrite Closure and CF Hedge Automata
We introduce an extension of hedge automata called bidimensional context-free
hedge automata. The class of unranked ordered tree languages they recognize is
shown to be preserved by rewrite closure with inverse-monadic rules. We also
extend the parameterized rewriting rules used for modeling the W3C XQuery
Update Facility in previous works, by the possibility to insert a new parent
node above a given node. We show that the rewrite closure of hedge automata
languages with these extended rewriting systems are context-free hedge
languages
Comparison of formaldehyde and methanol fixatives used in the detection of ion channel proteins in isolated rat ventricular myocytes by immunofluorescence labelling and confocal microscopy
In this study, a fixation protocol using a 10% neutral buffered formalin (FA) solution and another protocol using a methanol (MeOH) solution were compared for detection of ion channels, Kv1.5, Kv4.2, Cav1.2, Kir6.2, Nav1.5 and Nav1.1 in rat myocytes by immunolabelling. Kv1.5 and Kv4.2 at intercalated discs and Cav1.2 at transverse tubules were not detected by FA but were detected by MeOH. Kir6.2 at transverse tubules and Nav1.5 at sarcolemma were detected by FA but not by MeOH. It is suggested that both FA and MeOH fixation protocols should be used for the detection of cardiac ion channels by immunolabellin
Molekyylinmallinnusohjelma
Työn tavoitteena on suunnitella ja toteuttaa käyttökelpoinen molekyylinmallinnus-ohjelma, jota voisi mahdollisesti hyödyntää koulujen kemianopetuksessa tavanomaisen oppimisen ohella. Projektin idea lähti tekijän omasta mielenkiinnosta aiheeseen, ja käyttötarpeen selvittäminen sekä mahdollinen käyttöönotto on tarkoitus aloittaa vasta työn päättymisen jälkeen.
Työn etenemiseen riitti teorian kannalta lukiossa opitut kemian sekä pitkän matematiikan taidot, joita jouduttiin kuitenkin kertaamaan internetlähteitä hyödyntäen. Ohjelma toteutettiin Unity-pelimoottorilla, joka on suunniteltu erilaisten ohjelmien helppoon tuottamiseen ja jonka käyttöönottokynnys on suhteellisen matala.
Työn ohjelmointipuolen hankaluudesta johtuen sen jää kesken, joten jatkokehitystä on tehtävä, ennen kuin ohjelman käyttöä voidaan harkita opetuksessa.The aim of the thesis was to design and implement a 3D molecule modelling application that could be used in schools to help visualize molecules alongside with the traditional teaching methods. It remains to be seen whether the program will actually see any use, as the marketing side of the project was intentionally left out of the thesis work and will be conducted on a later date.
For this thesis it was enough to know the basics of molecular chemistry and maths learned in high school, even though some rehearsing was necessary. The software was made using the Unity-engine, which is designed for easy developing of software. Its deployment has also been made simple, which helped in choosing it for this work.
Due to the difficulties encountered during the development process the application was not made to the point originally planned. Further development is however planned for it and is needed before it can be considered to be used for teaching in schools
Menaquinone-4 enhances testosterone production in rats and testis-derived tumor cells
<p>Abstract</p> <p>Background</p> <p>Vitamin K is essential for the posttranslational modification of various Gla proteins. Although it is widespread in several organs, including the testis, the function of vitamin K in these organs is not well characterized. In this study, we investigated the function of vitamin K in the testis and analyzed its role in steroidogenesis.</p> <p>Methods</p> <p>Eight-week-old male Wistar rats were fed a diet supplemented with menaquinone-4 (MK-4, 75 mg/kg diet), one of the predominant K<sub>2 </sub>vitamins present in the testis, for 5 weeks. <it>In vivo </it>testosterone levels of the rats' plasma and testes were measured by enzyme-linked immunosorbent assay, and <it>in vitro </it>testosterone levels of testis-derived tumor cells (I-10 cells) maintained in Ham's F-10 medium with 10% fetal bovine serum were measured following treatment with MK-4 (0 to 100 μM) at several time points. Testosterone and cellular protein levels were analyzed with respect to their effects on steroidogenesis.</p> <p>Results</p> <p>Testosterone levels in the plasma and testes of MK-4-fed rats were significantly increased compared to those of control rats, with no obvious differences in plasma luteinizing hormone levels. Secreted testosterone levels from I-10 cells were elevated by MK-4, but not by vitamin K<sub>1</sub>, in a dose-dependent manner independent of cAMP treatment. Western blot analysis revealed that expression of CYP11A, the rate-limiting enzyme in steroidogenesis, and phosphorylation levels of protein kinase A (PKA) and the cAMP response element-binding protein were all stimulated by the presence of MK-4. Enhancement of testosterone production was inhibited by H89, a specific inhibitor of PKA, but not by warfarin, an inhibitor of γ-glutamylcarboxylation.</p> <p>Conclusions</p> <p>MK-4 stimulates testosterone production in rats and testis-derived tumor cells via activation of PKA. MK-4 may be involved in steroidogenesis in the testis, and its supplementation could reverse the downregulation of testosterone production in elders.</p
Non-resonant direct p- and d-wave neutron capture by 12C
Discrete gamma-rays from the neutron capture state of 13C to its low-lying
bound states have been measured using pulsed neutrons at En = 550 keV. The
partial capture cross sections have been determined to be 1.7+/-0.5,
24.2+/-1.0, 2.0+/-0.4 and 1.0+/-0.4 microb for the ground (1/2-), first (1/2+),
second (3/2-) and third (5/2+) excited states, respectively. From a comparison
with theoretical predictions based on the non-resonant direct radiative capture
mechanism, we could determine the spectroscopic factor for the 1/2+ state to be
0.80 +/- 0.04, free from neutron-nucleus interaction ambiguities in the
continuum. In addition we have detected the contribution of the non-resonant
d-wave capture component in the partial cross sections for transitions leading
to the 1/2- and 3/2- states. While the s-wave capture dominates at En < 100
keV, the d-wave component turns out to be very important at higher energies.
From the present investigation the 12C(n,gamma)13C reaction rate is obtained
for temperatures in the range 10E+7 - 10E+10 K.Comment: Accepted for publication in Phys. Rev. C. - 16 pages + 8 figure
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