6,194 research outputs found
Pion properties at finite density
In this talk, we report our recent work on the pion weak decay constant
(F_pi) and pion mass (m_pi) using the nonlocal chiral quark model with the
finite quark-number chemical potential (mu) taken into account. Considering the
breakdown of Lorentz invariance at finite density, the time and space
components are computed separately, and the corresponding results turn out to
be: F^t_pi = 82.96 MeV and F^s_pi = 80.29 MeV at mu_c ~ 320 MeV, respectively.
Using the in-medium Gell-Mann Oakes-Renner (GOR) relation, we show that the
pion mass increases by about 15% at mu_c.Comment: 5 pages, 2 figures, Talk given at the 4th Asia-Pacific Conference on
Few-Body Problems in Physics 2008 (APFB08), 19 ~ 23 Aug 2008, Depok,
Indonesi
BRG1 directly regulates nucleosome structure and chromatin looping of the Ī± globin locus to activate transcription
Ī± globin expression must be regulated properly to prevent the occurrence of Ī±-thalassemias, yet many questions remain unanswered regarding the mechanism of transcriptional activation. Identifying factors that regulate chromatin structure of the endogenous Ī± globin locus in developing erythroblasts will provide important mechanistic insight. Here, we demonstrate that the BRG1 catalytic subunit of SWI/SNF-related complexes co-immunoprecipitates with GATA-1 and EKLF in murine fetal liver cells in vivo and is recruited to the far-upstream major-regulatory element (MRE) and Ī±2 promoter. Furthermore, based on our analysis of Brg1null/ENU1 mutant mice, BRG1 regulates DNase I sensitivity, H3ac, and H3K4me2 but not CpG methylation at both sites. Most importantly, BRG1 is required for chromatin loop formation between the MRE and Ī±2 promoter and for maximal RNA Polymerase II occupancy at the Ī±2 promoter. Consequently, Brg1 mutants express Ī± globin mRNA at only 5ā10% of wild-type levels and die at mid-gestation. These data identify BRG1 as a chromatin-modifying factor required for nucleosome remodeling and transcriptional activation of the Ī± globin locus. These data also demonstrate that chromatin looping between the MRE and Ī±2 promoter is required as part of the transcriptional activation mechanism
Imunosni odgovor BALB/c miÅ”eva oralno imuniziranih rekombinantnim cjepivom od serovara Salmonella Typhimurium s ugraÄenim antigenima enterotoksigenog soja Escherichia coli
Salmonella Typhimurium ghost vaccines containing antigens of enterotoxigenic Escherichia coli (ETEC) were obtained by a strain harboring pMMP184, which carries a ghost cassette. The immune responses of BALB/c mice orally vaccinated with these ghost vaccines were determined in this study. Total IgG against S. Typhimurium were highly detected by the oral immunization route in BALB/c mice. IgGs against ETEC antigens in the ghost cells carrying F41 and intimin were detected at 4 weeks after vaccination. However, FedF elicited a delayed induction of IgGs, whereas FedA immune response failed to or barely induced IgGs after vaccination. Proliferations of CD3e/CD4-T cells were observed in splenocytes of BALB/c mice immunized with S. Typhimurium ghost cells carrying FedF. However, CD45R-B220/CD23-B cells were proliferated by ghost cells carrying FedA, F41, and intimin. The immunized BALB/c mice showed 25~50% protection against challenge with wild type S. Typhimurium, when compared to control mice. Therefore, it is assumed that oral vaccination of S. Typhimurium ghost cells has the potential to protect mice against pathogenic E. coli.Salmonella Typhimurium rekombinantna cjepiva Å”to sadrže antigene enterotoksigenih sojeva Escherichia coli (ETEC) proizvedena su od soja koji posjeduje pMMP184 i nosi rekombinantnu kasetu. Istražen je imunosni odgovor BALB/c miÅ”eva oralno cijepljenih tim rekombinantnim cjepivima. Ustanovljena je visoka razina ukupnih IgG za S. Typhimurium nakon oralne imunizacije miÅ”eva BALB/c. Imunoglobulini IgG za antigene ETEC u rekombinantnom cjepivu koje sadrži F41 i intimin bili su dokazani Äetiri tjedna nakon cijepljenja. Ipak, FedF je potaknuo kasnu tvorbu imunoglobulina IgG, dok FedA nije potaknuo ili je potaknuo slab imunosni odgovor nakon cijepljenja. Proliferacija CD3e/CD4-T stanica bila je dokazana u splenocitima miÅ”eva BALB/c imuniziranih rekombinantnim cjepivom S. Typhimurium s ugraÄenim FedF. MeÄutim, stanice CD45R-B220/CD23-B proliferirale su nakon cijepljenja rekombinantom FedA, F41 i intimin. Imunizirani miÅ”evi BALB/c pokazivali su 25~50% zaÅ”titu nakon izazivaÄke infekcije serovarom S. Typhimurium u usporedbi s necijepljenim kontrolnim miÅ”evima. Stoga se pretpostavlja da oralno cijepljenje s rekombinantnim stanicama serovara S. Typhimurium ima potencijal da zaÅ”titi miÅ”eve od infekcije patogenim sojevima E. coli
Duplexer using microwave photonic band gap structure
We propose a frequency selective duplexer using microwave photonic band gap (PBG) structures. It uses two different PBGs to control the propagation of electromagnetic waves in the microwave region. In this structure, an additional narrow reflection band appears in the transmission spectrum when the PBG structure is not properly located relative to the T junction. By considering multiple reflections, it is proved that this additional reflection band in each PBG structure results from the interference between the input wave and the reflected wave from the other PBG structure. An effective way to prevent this interference effect is also discussed
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