4,241 research outputs found
Effects of aromatizable and nonaromatizable androgens on the sex inversion of red-spotted grouper (Epinephelus akaara)
The effects of aromatizable 17α-methyltestosterone (MT) and non-aromatizable 17α-methyldihydrotestosterone (MDHT) on sex inversion in red-spotted grouper, Epinephelus akaara, were investigated. Fish were implanted with MT, MDHT and MT+AI (aromatase inhibitor, AI) respectively for one month. The results showed that the three treated groups turned into transitional stage with intersex gonads, which contained atretic oocytes and spermatogenic germ cells at all stages of spermatogenesis. The controls did not change sex. The gonads of more than half MT-implanted fish were in early transitional stages of sex inversion, whereas those of more than half MDHT and MT+AI-implanted fish were in late transitional stages of sex inversion. No difference in serum estradiol-17β (E2) levels between the controls and the treated groups were observed, whereas 11-ketotestosterone (11-KT) and testosterone (T) levels increased in all treated groups. Significantly lower gonadosomatic index (GSI) and gonadal aromatase activity were observed in the treated groups, which were in accordance with the lower mRNA expression of P450aromA. However, P450aromB mRNA expression increased in the MT group, while it did not change in the MDHT group. These results suggest that the sex inversion of red-spotted grouper by MT and MDHT implantation might be due to the suppression of P450aromA gene expression, and resulting in both the decrease of the ovarian estrogen –secretion, as well as the increase in the 11-KT levels. Furthermore, the main reason for MT being less effective than MDHT might be due to partial aromatization of MT to estrogen
Fine Splitting in Charmonium Spectrum with Channel Coupling Effect
We study the fine splitting in charmonium spectrum in quark model with the
channel coupling effect, including , , and ,
, channels. The interaction for channel coupling is
constructed from the current-current Lagrangian related to the color
confinement and the one-gluon exchange potentials. By adopting the massive
gluon propagator from the lattice calculation in the nonperturbative region,
the coupling interaction is further simplified to the four-fermion interaction.
The numerical calculation still prefers the assignment of X(3872).Comment: Submitted to Chinese Physics
Structure of Co-2 × 2 nanoislands grown on Ag/Ge(111)-√3 × √3 surface studied by scanning tunneling microscopy
We have found that Co-2 × 2 islands grown on an Ag/Ge(111)-√3 × √3 surface have hcp structure with the (11-20) orientation. The island evolution involves transformation of the unit cell shape from parallelogram into rectangular, which is accompanied by the island shape transformation from hexagonal into stripe-like. Identified are two crystallographic directions for the island growth, the pseudo-[0001] and the pseudo-[1-100]. We have observed the occurrence of a lateral shift between the topmost and the underlying bilayers in the case of the island growth along the pseudo-[0001] direction. In contrast, the topmost and the underlying bilayers are unshifted for the growth along the pseudo-[1-100] direction
Inhibition of Caspase-3, -6, -8 and -9 Expression in Rats with Acute Spinal Cord Injury by Cantharidin Treatment
Purpose: To demonstrate the anti-apoptotic effects of cantharidin in mice with acute spinal cord injury (ASCI).Methods: In total, 30 male Sprague-Dawley mice were divided into three groups of 10 animals each. ASCI was induced in two of the groups using a modified Allen's method, consisting of treatment with 10 mg/kg body weight cantharidin after injury, and sacrifice on days 2, 5, 10, 20 and 30 to extract the spinal cord. The activity levels of caspase-3, -6, -8, and -9 were determined spectrophotometrically at 455 nm with a microplate reader.Results: The results showed that cantharidin treatment caused a significant reduction in the expression levels of all four caspases – caspase-3, -6, -8, and -9 – compared with the untreated groups. Two hours after ASCI, caspase levels in the cantharidin-treated group increased, reaching maximum after day 5, but were significantly lower than in the untreated group. The expression levels of caspases in the cantharidin-treated group were similar to those in the control group on days 20 and 30 following ASCI (p> 0.05).Conclusion: Cantharidin treatment exerts an anti-apoptotic effect against secondary spinal cord injury (SCI) by suppressing caspase activity. Thus, cantharidin may be suitable for the treatment of secondary SCI.Keywords: Cantharidin, Caspase, Anti-apoptotic, Inhibition, Regeneratio
Pengaruh Penerapan Strategi Concept Mapping terhadap Hasil Belajar Siswa di Sekolah Dasar
This study aimed to analyze the influence of concept mapping strategy towards the learning result students in social science study on the V B grade of SD Negeri 17 Pontianak Kota. This study used an experimental method with Pre-Experimental design form using One-Group Pretest-Posttest Design. The population in this research were 68 students. The samples in this research was V B as a research class. Based on the t-test, the calculation result obtained t test (7,29) > t table (1,699) with significance level α = 5% means a significant influence using concept mapping strategy. The value of effect size (ES) is 0.39 with moderate category. It means that concept mapping strategy give a moderate effect to the learning result students in social science study on the V B grade of SD Negeri 17 Pontianak Kota
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