We have measured parity-violating asymmetries in elastic electron-proton scattering over the range of momentum transfers 0.12 < or =Q2 < or =1.0 GeV2. These asymmetries, arising from interference of ...the electromagnetic and neutral weak interactions, are sensitive to strange-quark contributions to the currents of the proton. The measurements were made at Jefferson Laboratory using a toroidal spectrometer to detect the recoiling protons from a liquid hydrogen target. The results indicate nonzero, Q2 dependent, strange-quark contributions and provide new information beyond that obtained in previous experiments.
Porphyromonas gingivalis fimA gene encoding fimbrillin, a subunit of fimbriae, has been classified into 5 genotypes (types I to V) based on their nucleotide sequences. Here, we investigated the ...relationship between the prevalence of these fimA genotypes and periodontal health status in adults. Dental plaque specimens obtained from 380 periodontally healthy adults and 139 periodontitis patients were analyzed by the PCR method. P. gingivalis was detected in 36.8% of the healthy subjects and in 87.1% of the periodontitis patients. Among the P. gingivalis-positive healthy adults, the most prevalent fimA type was type I (76.1%), followed by type V. In contrast, a majority of the periodontitis patients carried type II fimA organisms (66.1%), followed by type IV. The univariate analysis illustrated that periodontitis was associated with the occurrences of type I fimA (OR 0.16), type II (OR 44.44), type III (1.96), type IV (13.87), and type V (1.40). These findings clearly indicate that there are both disease-associated and non-disease-associated strains of P. gingivalis, and that their infectious traits influencing periodontal health status could be differentiated based on the clonal variation of fimA genes.
Thick Al wires bonded on chips of power semiconductor devices were examined for thermal cycle tests, then the bonded joints were cut using microtome method, after that those were observed by scanning ...electron microscope and analyzed by electron back scattered diffraction. Some cracks were observed between Al wires and the chips, unexpectedly the crack lengths were almost constant for −40/150
°C, −40/200
°C and −40/250
°C tests. It is considered that re-crystallization has been progressed during the high temperature side of the thermal cycle tests.
Furthermore, joint samples were prepared using high temperature solders such as Zn–Al and Bi with CuAlMn, Direct Bonded Copper insulated substrates and Mo heatsinks. The fabricated samples were evaluated by scanning acoustic microscope before and after thermal cycle tests. Consequently, almost neither serious damages nor delaminations were observed for −40/200
°C and −40/250
°C tests.
A new reliable genotyping method, multilocus sequence typing (MLST), was used to evaluate vertical transmission of the cariogenic pathogen Streptococcus mutans. A total of 136 S. mutans strains were ...isolated from saliva samples of 20 Japanese mother-child pairs, including 5 girls and 5 boys with primary dentition, and 5 girls and 5 boys with mixed dentition. The nucleotide sequences of 8 partial housekeeping genes, aroE, murI, gltA, glnA, glk, tkt, lepC, and gyrA, were analyzed and a similarity for all of those sequences between strains from a mother-child pair was regarded as indicating transmission, which was shown in 70% of the pairs. Interestingly, the rate of transmitted strains from mothers was significantly higher in the girls (90%) than in the boys (p = 0.001). Furthermore, the S. mutans sequence type (ST) with the highest distribution percentage in each maternal saliva sample was found to be transferred to their children. In addition, variations in two large conjugative-transfer associated regions, TnSmu1 and TnSmu2, were determined and compared with the STs defined by MLST. No variations in those two regions shown by PCR patterns were present in any of the strains isolated from the same families with the same STs, though isolates of some STs from different families showed distinct patterns for TnSmu2. Our results indicate that mothers are the main source for transmission of S. mutans to their children, while the present MLST method was also shown to be useful for investigating bacterial transmission.
Muon trigger upgrade at PHENIX Nakagawa, I
Journal of physics. Conference series,
06/2010, Letnik:
230, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The Relativistic Heavy Ion Collider (RHIC) at BNL provides a unique opportunity to collide polarized protons. One of the hightlight of the spin program at 500 GeV is the direct measurement of sea ...quark contribution to the proton spin via W-boson production by measuring parity violating single spin asymmetry. A new trigger on forward muons in PHENIX identifies and triggers on high momentum Ws suppressing a large number of low momentum muons coming from hadronic decays. Since the current muon trigger will fire on any muon above 2 GeV/c, it will not provide the required rejection factor for 500 GeV running, which is about 7500. Two major upgrade projects are parts of this Muon Trigger; 1) Resistive Plate Chambers, 2) the muon tracker front end electronics upgrades. The status of these upgrade projects is discussed in this document as well as physics goal of W program at RHIC.
Although efforts have been made to develop new drugs for infectious and neoplastic diseases utilizing synthetic small interfering RNA(siRNAs), those intrinsically have undesirable effects, including ...silencing of unintended genes (off-target effect) and nonspecific cytotoxicity. Off-target effects can be avoided by DNA substitution in the guide strand (GS) seed region of nucleotide positions 1-8 and its complementary part of the passenger strand plus the 3' overhang, which is designated as a double-strand RNA-DNA chimera (dsRDC). In this study, we found that the specificity of potent siRNAs targeting human papillomavirus 16 (HPV16) E6 and E7 oncogenes, which we previously reported, could be enhanced by short dsRDC modification (first six nucleotides from the 5' end of the GS and its complementary nucleotides of the passenger strand). Such dsRDC modification reduced nonspecific cytotoxicity in two of three siRNAs (497 and 752), although not in the other (573), which correlated with their off-target effects. In addition, silencing activity was marginally impaired in two dsRDCs (497 and 573) and moderately in one (752). Finally, dsRDC-497 induced E6E7-specific growth suppression of cervical cancer cells as well as E6E7-immortalized human keratinocytes. Our results show that dsRDC modification enhances the specificity of E6E7 siRNA, which is required for use in in vivo settings.
PDF
