2,941 research outputs found
CP violating dimuon charge asymmetry in general left-right models
The recently measured charge asymmetry of like-sign dimuon events by the D0
collaboration at Tevatron shows the 3.9 \sigma\ deviation from the standard
model prediction. In order to solve this mismatch, we investigate the
right-handed current contributions to and
mixings which are the major source of the like-sign dimuon events in production in general left-right models without imposing manifest or
pseudo-manifest left-right symmetry. We find the allowed region of new physics
parameters satisfying the current experimental data.Comment: 9 pages, 4 figure
Discovery of Hits That Can Specifically Inhibit Necroptosis but Not Apoptosis
Necroptosis or programmed necrosis is a specialized and regulated necrosis, and is unmasked when apoptotic machinery for death stress is defective. Initially, it was proposed that necroptotic cell death was pathologically associated with ischemic brain injury and retinal disorders. In contrast, it plays a beneficial significance in innate immune response to viral infection that can evade host’s apoptotic surveillance. Also, it has been therapeutically emerging as the strategy to overcome the cancers with acquired anticancer drug resistance. Presently, a few small molecules to interfere with signaling pathways for necroptosis have been disclosed since necrostatin-1 (Nec-1) was for the first time identified as an inhibitor of receptor interacting protein 1 (RIP1), a key necroptosis regulator. In an effort to discover hits that can selectively inhibit necroptotic cell death, in this study, we screened in-house and in silico chemical libraries in a cell-based format. Eventually, 7 hits were identified from in-house chemical library while 2 hits were from computer modeling. Most hits less protected cells from tumor necrosis factor alpha (TNFα)- and zVAD-mediated necroptosis than a reference compound necrostatin-1, without affecting apoptotic cell death induced in HeLa. Interestingly, a few of hits had preferential protective effects on zVAD or TNFα while Nec-1 exhibited EC50 values at the similar concentrations against both necroptosis inducers, suggesting that chemicals deduced in our study can discriminate signaling pathways leading to receptor or nonreceptor-mediated necroptotic cell death.Therefore, some potent hits will be further improved to use for the treatment of necroptosis-associated disorders.  
Singlet Fermionic Dark Matter with Dark
We present a fermionic dark matter model mediated by the hidden gauge boson.
We assume the QED-like hidden sector which consists of a Dirac fermion and
U(1) gauge symmetry, and introduce an additional scalar electroweak doublet
field with the U(1) charge as a mediator. The hidden U(1) symmetry is
spontaneously broken by the electroweak symmetry breaking and there exists a
massive extra neutral gauge boson in this model which is the mediator between
the hidden and visible sectors. Due to the U(1) charge, the additional
scalar doublet does not couple to the Standard Model fermions, which leads to
the Higgs sector of type I two Higgs doublet model. The new gauge boson couples
to the Standard Model fermions with couplings proportional to those of the
ordinary boson but very suppressed, thus we call it the dark boson. We
study the phenomenology of the dark boson and the Higgs sector, and show
the hidden fermion can be the dark matter candidate.Comment: 10 pages, 3 figure
Vav1 inhibits RANKL-induced osteoclast differentiation and bone resorption
Vav1 is a Rho/Rac guanine nucleotide exchange factor primarily expressed in hematopoietic cells. In this study, we investigated the potential role of Vav1 in osteoclast (OC) differentiation by comparing the ability of bone marrow mononuclear cells (BMMCs) obtained from Vav1-deficient (Vav1−/−) and wild-type (WT) mice to differentiate into mature OCs upon stimulation with macrophage colony stimulating factor and receptor activator of nuclear kappa B ligand in vitro. Our results suggested that Vav1 deficiency promoted the differentiation of BMMCs into OCs, as indicated by the increased expression of tartrate-resistant acid phosphatase, cathepsin K, and calcitonin receptor. Therefore, Vav1 may play a negative role in OC differentiation. This hypothesis was supported by the observation of more OCs in the femurs of Vav1−/− mice than in WT mice. Furthermore, the bone status of Vav1−/− mice was analyzed in situ and the femurs of Vav1−/− mice appeared abnormal, with poor bone density and fewer number of trabeculae. In addition, Vav1-deficient OCs showed stronger adhesion to vitronectin, an αvβ3 integrin ligand important in bone resorption. Thus, Vav1 may inhibit OC differentiation and protect against bone resorption
Antioxidative and Antimutagenic Activities of 70% Ethanolic Extracts from Four Fungal Mycelia-Fermented Specialty Rices
The health-promoting potential of 70% ethanolic extracts of 4 rice varieties fermented with Monascus ruber, Phellinus linteus, Cordyceps sinensis and Agaricus blazei was evaluated mainly focusing on their antioxidative and antimutagenic capacities based on the following parameters: phenolic compound and phytic acid content; inhibitory activity on lipid peroxidation; scavenging activity on DPPH radical; suppressing ability on mitomycin C-induced mutagenesis in E. coli cells; and protective effect on 4-nitroquinoline oxide-triggered DNA lesion in V79 hamster cells. The fermented rice extracts were superior in overall health-promoting parameters compared to the source material. The higher antimutagenic activity of the fermented rice extracts might be in part caused by a larger amount of antioxidant constituents such as phenolic compounds or phytic acid. Of the fungal species, Monascus ruber was found to impart a marked increase in both the antioxidative and antimutagenic abilities to the source material. The current study suggests a possibility that such fermented rice may contribute to the prevention of lifestyle-related diseases such as cancer through a daily intake of rice-based diets
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