188 research outputs found
Yukawa Hierarchy Transfer from Superconformal Sector and Degenerate Sfermion Masses
We propose a new type of supersymmetric models coupled to superconformal
field theories (SCFT's), leading simultaneously to hierarchical Yukawa
couplings and completely degenerate sfermion masses. We consider models with an
extra Abelian gauge symmetry to generate hierarchical structure for couplings
between the SM sector and the SC sector. Interestingly, this hierarchy is
inversely transferred to the Yukawa couplings in the SM sector. In this type of
models, flavor-independent structure of the superconformal fixed point
guarantees that the sfermion masses of the first and the second generations are
completely degenerate at low energy.Comment: 11 pages, latex, 3 figure
Large Mass Scale by Strong Gauge Dynamics with Infrared Fixed Point
We consider a mechanism for realizing the desired decoupling of
strongly-coupled sector which is supposed to generate hierarchical structure of
the Yukawa couplings. In our mechanism, the same strongly-coupled sector is
responsible for generating a sufficiently flat potential and a large vacuum
expectation value (VEV) of a gauge-singlet scalar field by suppressing its soft
scalar mass and self-coupling. Vacuum instability is caused by
supersymmetry-breaking A-term of order 10 TeV. We explicitly demonstrate the
infrared convergence of soft scalar masses due to strongly-coupled dynamics and
show the soft mass of the singlet is at most comparable to soft masses of
squarks and sleptons, which are much suppressed than the A-term. The physical
mass scale of the decoupling is calculated in a self-consistent way. We also
reinterpret the result in terms of a RG-improved effective potential.Comment: 18 pages, 4 figures, 1 table, LaTeX (PTPTeX style
Induced top Yukawa coupling and suppressed Higgs mass parameters
In the scenarios with heavy top squarks, mass parameters of the Higgs field
must be fine-tuned due to a large logarithmic correction to the soft scalar
mass. We consider a new possibility that the top Yukawa coupling is small above
TeV scale. The large top mass is induced from strong Yukawa interaction of the
Higgs with another gauge sector, in which supersymmetry breaking parameters are
given to be small. Then it is found that the logarithmic correction to the
Higgs soft scalar mass is suppressed in spite of the strong coupling and the
fine-tuning is ameliorated. We propose an explicit model coupled to a
superconformal gauge theory which realizes the above situation.Comment: RevTeX4 style, 10 pages, 3 figure
False-Positive Mediastinal Lymphadenopathy on 18F-Fluorodeoxyglucose Positron Emission Tomography and Computed Tomography after Rectal Cancer Resection: A Case Report of Thoracoscopic Surgery in the Prone Position
18F-fluorodeoxyglucose (FDG) positron emission tomography and computed tomography (integrated FDG PET/CT) has been used to diagnose recurrence and differentiate postoperative changes from lymph node metastasis in colorectal cancer, although its accuracy is questionable. We report a prone thoracoscopic surgery for a rectal cancer patient in which false-positive mediastinal lymph nodes were found on FDG-PET/CT. A 60-year-old man underwent a laparoscopic high anterior resection and D3 lymph node dissection for rectal cancer. The histopathological diagnosis was moderately differentiated adenocarcinoma of the rectum, stage IIIB (pT3N1M0), necessitating oral fluoropyrimidine agent S-1. After the primary surgery, a solitary mediastinal lymph node measuring 30 mm in diameter was detected, and abnormal accumulation was confirmed by FDG-PET/CT (SUVmax, 11.7). Thoracoscopic resection was performed in the prone position, but histopathological results showed no metastasis. He was subsequently diagnosed with reactive lymphadenitis. The patient was discharged on postoperative day 4 in good condition and is alive without recurrence 12 months after surgery. PET/CT is useful for the detection of colorectal cancer recurrence; however, it does have a high false-positive rate for mediastinal lymph nodes. There is a limit to its diagnostic accuracy, and one must determine the indication for surgical treatment carefully. Surgery in the prone position is a useful and minimally invasive approach to the mediastinum and allows aggressive resection to be performed
Yukawa Hierarchy Transfer Based on Superconformal Dynamics and Geometrical Realization in String Models
We propose a scenario that leads to hierarchical Yukawa couplings and
degenerate sfermion masses at the same time, in the context of
extra-dimensional models, which can be naturally embedded in a wide class of
string models. The hierarchy of Yukawa couplings and degeneracy of sfermion
masses can be realized thanks to superconformal gauge dynamics. The sfermion
mass degeneracy is guaranteed by taking the superconformal fixed point to be
family independent. In our scenario, the origin of Yukawa hierarchy is
attributed to geometry of compactified dimensions and the consequent volume
dependence of gauge couplings in the superconformal sectors. The difference in
these gauge couplings is dynamically transferred to the hierarchy of the Yukawa
couplings. Thus, our scenario combines a new dynamical approach and the
conventional geometrical approach to the supersymmetric flavor problem.Comment: 12 pages, latex, no figur
動脈遮断肝に対する部分的門脈動脈血化法の検討: ウロキナーゼ固定化カテーテル装着法の有用性について
取得学位 : 博士(医学), 学位授与番号 : 医博甲第1061号, 学位授与年月日:平成4年10月31日,学位授与年:199
Cholecystomucoclasis: Revaluation of safety and validity in aged populations
Background: We evaluated the safety and validity of cholecystomucoclasis (CM) and compared its intraoperative characteristics with those of standard cholecystectomy (SC).Methods: We enrolled 174 patients who underwent cholecystectomy and retrospectively evaluated the outcomes of patients in the SC and CM groups.Results: Significant differences in age (71.1 vs. 61.9 years), American Society of Anesthesiologists physical status (ASA-PS), and serum C-reactive protein levels (CRP) (18.1 vs. 4.7 mg/dL) were observed between the CM and SC groups. Conversely, no significant differences were observed in the operation time (129 vs. 108 min), amount of blood loss (147 vs. 80 mL), intraoperative complications (0% vs. 5.7%), or duration of hospital stay (13.2 vs. 8.9 days) between the 2 groups. A high conversion rate (35.3%), postoperative complications (33%), and frequent drain insertions (94%) were observed in the CM group.Conclusions: CM is a safe and valid surgical procedure and surgeons should not hesitate to transition to CM for patients who are of advanced age, in poor general condition (high ASA classification), or have high levels of serum CRP. © 2012 Tsukada et al.; licensee BioMed Central Ltd
Initial Condition Dependene of Dynamis and Evaporation of Polymer Spallation Partiles Flying in Polymer Ablated Arcs
This paper describes the influence of initial conditions for spallation particles flying in polymer ablation arcs on dynamics and evaporation of the polymer spallation particles using the numerical model. Through our previous experiments, we had found micro-sized `spallation particles\u27 ejected from polyamide materials by thermal plasma contact. To obtain the dynamics of spallation particles in polymer ablation arcs, we have developed a numerical model on dynamics of spallation particles flying in the polymer ablated arcs. The influence of pressure inside the polymer ablated arc, the initial particle diameter and the initial velocity of spallation particles were studied as parameters in the present paper. Under the given temperature and gas flow distributions in specified initial conditions, the trajectories of spallation particles flying in the polymer ablated arc were simulated numerically, considering the time variations in the temperature and the diameter of the particles. The results show that the highest flight altitude of the PA6 spallation particle flying in the PA6 ablated arc is affected by the initial particle diameter and velocity remarkably
Locally advanced breast cancer made amenable to radical surgery after a combination of systemic therapy and Mohs paste: Two case reports
Introduction. Chemotherapy and other systemic therapies are the primary treatments for patients with unresectable, locally advanced breast cancer. The clinical application of supportive care using Mohs paste has become widespread for the purpose of improving patients quality of life. Here, we report two cases of locally advanced breast cancer, for which the patients underwent radical surgery after a combination of systemic therapy and Mohs chemosurgery. Case presentations. Patient 1 was a 90-year-old Japanese woman with right breast cancer diagnosed as stage IIIB (T4bN1M0). The treatment included Mohs paste application and hormonal therapies. Patient 2 was a 60-year-old Japanese woman with right breast cancer diagnosed as stage IIIB (T4cN2aM0). Her treatment included Mohs paste application, together with chemotherapy (four cycles of 5-fluorouracil, epirubicin, and cyclophosphamide, and four cycles of docetaxel). In both cases, a reduction in the primary tumor volume was observed, and radical mastectomy and axillary lymph node dissection were possible without relaxation incision or skin flap. Conclusion: We report patients with no distant metastases who were able to undergo radical resection after a combination of systemic therapy and Mohs chemosurgery. For locally advanced breast cancer, Mohs chemosurgery, in addition to multidisciplinary treatment, is useful. © 2012 Tsukada et al.; licensee BioMed Central Ltd
- …