Kinetics of a-Si:H bulk defect and a-Si:H/c-Si interface-state reduction

Low-temperature annealing of hydrogenated amorphous silicon (a-Si:H) is investigated. An identical energy barrier is found for the reduction of deep defects in the bulk of a-Si:H films and at the interface such layers form with crystalline Si (c-Si) surfaces. This finding gives direct physical evidence that the defects determining a-Si:H/c-Si interface recombination are silicon dangling bonds and that also kinetically this interface has no unique features compared to the a-Si:H bulk

Gauged Nambu-Jona-Lasinio model with extra dimensions

We investigate phase structure of the D (> 4)-dimensional gauged Nambu-Jona-Lasinio (NJL) model with $\delta(=D-4)$ extra dimensions compactified on TeV scale, based on the improved ladder Schwinger-Dyson (SD) equation in the bulk. We assume that the bulk running gauge coupling in the SD equation for the SU(N_c) gauge theory with N_f massless flavors is given by the truncated Kaluza-Klein effective theory and hence has a nontrivial ultraviolet fixed point (UVFP). We find the critical line in the parameter space of two couplings, the gauge coupling and the four-fermion coupling, which is similar to that of the gauged NJL model with fixed (walking) gauge coupling in four dimensions. It is shown that in the presence of such walking gauge interactions the four-fermion interactions become ``nontrivial'' even in higher dimensions, similarly to the four-dimensional gauged NJL model. Such a nontriviality holds only in the restricted region of the critical line (``nontrivial window'') with the gauge coupling larger than a non-vanishing value (``marginal triviality (MT)'' point), in contrast to the four-dimensional case where such a nontriviality holds for all regions of the critical line except for the pure NJL point. In the nontrivial window the renormalized effective potential yields a nontrivial interaction which is conformal invariant. The exisitence of the nontrivial window implies ``cutoff insensitivity'' of the physics prediction in spite of the ultraviolet dominance of the dynamics. In the formal limit D -> 4, the nontrivial window coincides with the known condition of the nontriviality of the four-dimensional gauged NJL model, $9/(2N_c) < N_f - N_c < 9/2 N_c$.Comment: 34 pages, 6 figures, references added, to appear in Phys.Rev.D. The title is changed in PR

Cytokeratin-Positive Cells in Lymph Nodes in Which Metastases Are Undetectable by Conventional Histological Staining in Advanced Gastric Cancer

Detection of occult metastases in lymph nodes by immunostaining is becoming of increasing interest as a way to improve the accuracy of predicting the prognosis for patients with gastric cancer. Immunohistochemical detection of cytokeratin (CK) is recognized as the most sensitive method for identification of cancerous epithelial cells. In this study, lymph nodes were stained for CK in an effort to detect micrometastases and the clinical implications of the results were examined. We immunostained sections from a total of 1,198 lymph nodes from 25 totally gastrectomized patients with T3 or T4 gastric cancer who had been diagnosed as having no nodal involvement by conventional hematoxylin-eosin (HE) staining. Eighty (6.7%) of 1,198 lymph nodes from 15 (60%) of the 25 patients were immunostained with a CK-specific monoclonal antibody. CK-positive cells were more frequent in patients with macroscopic types of 3,4 and 5 gastric cancer. Patients with nodes that were both HE-negative and CK-negative had the best postoperative survival, followed by patients with HE-negative and CK-positive nodes and, finally, by patiof micrometastases in lymph nodes is a reliable indicator of the prognosis of patients with advanced gastric cancer

Dynamical chiral symmetry breaking in gauge theories with extra dimensions

We investigate dynamical chiral symmetry breaking in vector-like gauge theories in $D$ dimensions with ($D-4$) compactified extra dimensions, based on the gap equation (Schwinger-Dyson equation) and the effective potential for the bulk gauge theories within the improved ladder approximation. The non-local gauge fixing method is adopted so as to keep the ladder approximation consistent with the Ward-Takahashi identities. Using the one-loop $\bar{\rm MS}$ gauge coupling of the truncated KK effective theory which has a nontrivial ultraviolet fixed point (UV-FP) $g_*$ for the (dimensionless) bulk gauge coupling ${\hat g}$, we find that there exists a critical number of flavors, $N_f^{\rm crit}$ ($\simeq 4.2, 1.8$ for $D=6, 8$ for SU(3) gauge theory): For $N_f > N_f^{\rm crit}$, the dynamical chiral symmetry breaking takes place not only in the ``strong-coupling phase'' (${\hat g} >g_*$) but also in the ``weak-coupling phase'' (${\hat g} <g_*$) when the cutoff is large enough. For $N_f < N_f^{\rm crit}$, on the other hand, only the strong-coupling phase is a broken phase and we can formally define a continuum (infinite cutoff) limit, so that the physics is insensitive to the cutoff in this case. We also perform a similar analysis using the one-loop ``effective gauge coupling''. We find the $N_f^{\rm crit}$ turns out to be a value similar to that of the $\bar{\rm MS}$ case, notwithstanding the enhancement of the coupling compared with that of the $\bar{\rm MS}$.Comment: REVTEX4, 38 pages, 18 figures. The abstract is shortened; version to be published in Phys. Rev.

Significance of p53-Binding Protein 1 Nuclear Foci in Cervical Squamous Intraepithelial Lesions: Association With High-Risk Human Papillomavirus Infection and P16INK4a Expression

As p53-binding protein 1 (53BP1) localizes to the sites of DNA double-strand breaks and rapidly forms nuclear foci (NF), and itspresence may be an indicator of endogenous genomic instability (GIN). We previously showed that 53BP1 NF in cervical cellsincrease with neoplastic progression, indicating the significance of 53BP1 expression for the estimation of malignant potential during cervical carcinogenesis. This study aimed to further elucidate the impact of 53BP1 expression as a biomarker for cervical squamous intraepithelial lesion (SIL). A total of 81 tissue samples, including 17 of normal cervical epithelium, 22 of cervical intraepithelial neoplasia (CIN) 1, 21 of CIN2, and 21 of CIN3, from patients positive for high-risk human papillomavirus (HR-HPV)were used for double-label immunofluorescence of 53BP1 and Ki-67/p16INK4a expression and HR-HPV in situ hybridization. We analyzed associations between 53BP1 expression type with parameters such as CIN grade, HR-HPV infection status, p16INK4a expression, and CIN prognosis. Expression type of 53BP1 was significantly associated with histological grade of CIN and HR-HPV in situ hybridization signal pattern (P < .0001). There was a significant correlation between 53BP1 and p16INK4a expression levels(r ? .73, P < .0001). However, there was no association between 53BP1 expression type and CIN prognosis. We propose that 53BP1 expression type is a valuable biomarker for SIL, which can help estimate the grade and GIN of cervical lesions reflecting replication stress caused by the integration of HR-HPV to the host genome

Topped MAC with extra dimensions?

We perform the most attractive channel (MAC) analysis in the top mode standard model with TeV-scale extra dimensions, where the standard model gauge bosons and the third generation of quarks and leptons are put in D(=6,8,10,...) dimensions. In such a model, bulk gauge couplings rapidly grow in the ultraviolet region. In order to make the scenario viable, only the attractive force of the top condensate should exceed the critical coupling, while other channels such as the bottom and tau condensates should not. We then find that the top condensate can be the MAC for D=8, whereas the tau condensation is favored for D=6. The analysis for D=10 strongly depends on the regularization scheme. We predict masses of the top (m_t) and the Higgs (m_H), m_t=172-175 GeV and m_H=176-188 GeV for D=8, based on the renormalization group for the top Yukawa and Higgs quartic couplings with the compositeness conditions at the scale where the bulk top condenses. The Higgs boson in such a characteristic mass range will be immediately discovered in H -> WW^(*)/ZZ^(*) once the LHC starts.Comment: REVTEX4, 24 pages, 21 figures, to appear in PRD. The title is changed in PRD. One reference added, typos correcte