Kaons in Dense Half-Skyrmion Matter

Dense hadronic matter at low temperature is expected to be in crystal and at high density make a transition to a {\em chirally restored but color-confined} state which is a novel phase hitherto unexplored. This phase transition is predicted in both skyrmion matter in 4D and instanton matter in 5D, the former in the form of half-skyrmions and the latter in the form of half-instantons or dyons. We predict that when $K^-$'s are embedded in this half-skyrmion or half-instanton (dyonic) matter which may be reached not far above the normal density, there arises an enhanced attraction from the soft dilaton field figuring for the trace anomaly of QCD and the Wess-Zumino term. This attraction may have relevance for a possible strong binding of anti-kaons in dense nuclear matter and for kaon condensation in neutron-star matter. Such kaon property in the half-skyrmion phase is highly non-perturbarive and may not be accessible by low-order chiral perturbation theory. Relevance of the half-skyrmion or dyonic matter to compact stars is discussed.Comment: 5 pages, 2 figure

Topological Structure of Dense Hadronic Matter

We present a summary of work done on dense hadronic matter, based on the Skyrme model, which provides a unified approach to high density, valid in the large $N_c$ limit. In our picture, dense hadronic matter is described by the {\em classical} soliton configuration with minimum energy for the given baryon number density. By incorporating the meson fluctuations on such ground state we obtain an effective Lagrangian for meson dynamics in a dense medium. Our starting point has been the Skyrme model defined in terms of pions, thereafter we have extended and improved the model by incorporating other degrees of freedom such as dilaton, kaons and vector mesons.Comment: 13 pages, 8 figures, Talk given at the KIAS-APCTP Symposium in Astro-Hadron Physics "Compact Stars: Quest for New States of Dense Matter", November 10-14, 2003, Seoul, Korea, published by World Scientific. Based on talk by B.-Y. Par

Altered expression of thioredoxin reductase-1 in dysplastic bile ducts and cholangiocarcinoma in a hamster model

Thioredoxin reductase 1 (TrxR) is a homodimeric selenoenzyme catalyzing thioredoxin (Trx) in an NADPHdependent manner. With regard to carcinogenesis, these redox proteins have been implicated in cell proliferation, transformation and anti-apoptosis. In the present study, using a hamster cholangiocarcinoma (ChC) model, we evaluated the immunohistochemical expression pattern of TrxR in precancerous lesions and ChCs as well as in normal bile ducts. The goal of this study was to determine the potential role and importance of TrxR in cholangiocarcinogenesis. For the ChC model, we obtained liver tissue specimens with dysplastic bile ducts prior to the development of ChC 8 weeks after initiation of the experiment and ChC samples at 27 weeks. The immunohistochemical analysis showed diffuse cytoplasmic overexpression of TrxR in the dysplastic bile duct epithelial cells as well as in cholangiocarcinoma; this was comparable to the negative or weakly positive in normal and type 1 hyperplastic bile ducts. However, TrxR appeared to be considerably down-regulated in the ChCs when compared to the higher expression observed in the dysplastic bile ducts. Therefore, these results suggest that TrxR overexpression followed by down-regulation might be an important event in cholangiocarcinogenesis, especially at early stages including the cellular transformation of candidate bile ducts. Further studies are however required to determine whether TrxR may be a potential target molecule for chemoprevention against cholangiocarcinogenesis. In addition, the molecular mechanism as well as the importance of the loss of TrxR in the development of cholangiocarcinoma, following dysplastic transformation of bile duct cells, also remains to be clarified.This study was supported by Kangwon National University and Korea Research Foundation Grant (KRF-2004-041- E00324). The authors wish to thank Dr. Min-Ho Choi, College of Medicine, Seoul National University, for providing Clonorchis sinensis

Bacterial profile of suction drains and the relationship thereof to surgical-site infections in prosthetic breast reconstruction

Background Despite the increasing popularity of prosthetic breast reconstruction, scant data exist on the microbiological profile of drainage fluid from closed-suction drains and the relationship thereof to surgical-site infections (SSIs) in breast reconstruction surgery. This study aimed to determine whether bacteria isolated from drainage fluid were associated with the development of SSIs, and whether the bacterial profile of drainage fluid could be a clinically useful predictor of SSIs. Methods We performed a retrospective chart review of 61 women who underwent tissue expander/implant or direct-to-implant reconstructions. Patient demographics and culture studies of drainage fluid from suction drains collected on postoperative day 7 were evaluated. Results Sixteen patients (26.23%) were culture-positive, and 45 patients (73.77%) were culture-negative. The most frequently isolated bacteria were coagulase-negative staphylococci, followed by Staphylococcus aureus. SSIs were diagnosed in seven patients and were mostly resolved by systemic antibiotics; however, the tissue expander or implant was explanted in two patients. Positive culture of drainage fluid from closed-suction drains was significantly associated with the development of SSIs (P<0.05). The positive predictive value was 37.50%,and the negative predictive value was 97.78%. Conclusions To our knowledge, this study is the first to demonstrate a significant association between the microbiological profile of drainage fluid from closed-suction drains and the development of SSIs in patients with prosthetic breast reconstructions. The high negative predictive value suggests that microbial testing of drainage fluid from closed-suction drains may have clinical utility. Further prospective studies with larger sample sizes are required to confirm our findings

Unified Approach to Dense Matter

We apply the Skyrme model to dense hadronic matter, which provides a unified approach to high density, valid in the large Nc limit. In our picture, dense hadronic matter is described by the classical soliton configuration with minimum energy for the given baryon number density. By incorporating the meson fluctuations on such ground state we obtain an effective Lagrangian for meson dynamics in a dense medium. Our starting point has been the Skyrme model defined in terms of pions, thereafter we have extended and improved the model by incorporating other degrees of freedom such as dilaton, kaons and vector mesons.Comment: 6 pages, 4 figures, a talk given at the international conference QCD DOWN UNDER, March 10 - 19, Adelaide, Australi

Algorithm for the management of ectropion through medial and lateral canthopexy

Background Patients with ectropion experience devastating symptoms. Therefore, the preventionand management of this condition are of utmost importance. To treat ectropion, it is important to perform medial and lateral canthopexy in an effective way. In this study, we propose a comprehensive algorithm for the prevention and management of ectropion based on a new classification of ectropion according to its signs and causes. Methods Canthopexy was performed in 68 cases according to the proposed algorithm, which starts with a categorization of the types of ectropion and ends with the recommended operative technique. To assess the results, we reviewed clinical preoperative and postoperative photographs. To evaluate improvements in patients’ symptoms, we conducted a survey with responses scored on a Likert scale. Results None of the patients had scleral show postoperatively. The average patient satisfaction score was satisfied or higher for all symptoms, and the most improved symptom was aesthetic appearance. No major complications were reported. Conclusions For the comprehensive management of ectropion, it is crucial to consider both treatment and prevention. Through the simple surgical algorithm proposed in this study, both medically acceptable results and high levels of patient satisfaction were achieved without significant postoperative complications. We recommend using this algorithm for the comprehensive management of ectropion

A comparative study between sterile freeze-dried and sterile pre-hydrated acellular dermal matrix in tissue expander/implant breast reconstruction

Background In implant-based breast reconstruction, acellular dermal matrix (ADM) is essential for supporting the inferolateral pole. Recent studies have compared non-sterilized freeze-dried ADM and sterilized pre-hydrated ADM, but have not assessed whether differences were attributable to factors related to sterile processing or packaging. This study was conducted to compare the clinical outcomes of breast reconstruction using two types of sterile-processed ADMs. Methods Through a retrospective chart review, we analyzed 77 consecutive patients (85 breasts) who underwent tissue expander/implant breast reconstruction with either freeze-dried ADM (35 breasts) or pre-hydrated ADM (50 breasts) from March 2016 to February 2018. Demographic variables, postoperative outcomes, and operative parameters were compared between freeze-dried and pre-hydrated ADM. Biopsy specimens were obtained for histologic analysis. Results We obtained results after adjusting for variables found to be significant in univariate analyses. The total complication rate for freeze-dried and pre-hydrated ADMs was 25.7% and 22.0%, respectively. Skin necrosis was significantly more frequent in the freeze-dried group than in the pre-hydrated group (8.6% vs. 4.0%, P=0.038). All other complications and operative parameters showed no significant differences. In the histologic analysis, collagen density, inflammation, and vascularity were higher in the pre-hydrated ADM group (P=0.042, P=0.006, P=0.005, respectively). Conclusions There are limited data comparing the outcomes of tissue expander/implant breast reconstruction using two types of sterile-processed ADMs. In this study, we found that using pre-hydrated ADM resulted in less skin necrosis and better integration into host tissue. Pre-hydrated ADM may therefore be preferable to freeze-dried ADM in terms of convenience and safety

Left Ventricular Metastasis From Renal Cell Carcinoma Causing Left Ventricular Outflow Tract Obstruction

Most cases of cardiac metastasis from renal cell carcinoma (RCC) involve the vena cava or right atrium. Left ventricular metastases from RCC without involving the vena cava or right atrium are extremely rare. Herein we report a case of RCC with left ventricular metastasis causing left ventricular outflow obstruction (LVOT)

Choice of recipient vessels in muscle-sparing transverse rectus abdominis myocutaneous flap breast reconstruction: A comparative study

Background Thoracodorsal vessels (TDVs) and internal mammary vessels (IMVs) have both been widely employed as recipient vessels for use in free muscle-sparing transverse rectus abdominis myocutaneous (MS-TRAM) flaps. However, whether TDVs or IMVs are preferable as recipient vessels for autologous breast reconstruction with a free MS-TRAM flap remains controversial. The purpose of this study was to compare the clinical outcomes when TDVs were used as recipient vessels to those obtained when IMVs were used as recipient vessels for autologous breast reconstruction with a free MS-TRAM flap. Methods A retrospective matched-cohort study was performed. We retrospectively reviewed data collected from patients who underwent a free MS-TRAM flap for autologous breast reconstructions after mastectomy between March 2003 and June 2013. After a one-to-one matching using age, 100 autologous breast reconstructions were selected in this study. Of the 100 breast reconstructions, 50 flaps were anastomosed to TDVs and 50 to IMVs. Patient demographics and clinical outcomes including operation time, length of hospital stay, postoperative complications, and aesthetic score were compared between the two groups. Results No statistically significant differences were found between the two groups in patient demographics and clinical outcomes, including the complication rates and aesthetic scores. There were no major complications such as total or partial flap loss in either group. Conclusions The results of our study demonstrate that both TDVs and IMVs were safe and efficient as recipient vessels in terms of the complication rates and aesthetic outcomes

Comprehensive understanding of cathodic and anodic polarization effects on stability of nanoscale oxygen electrode for reversible solid oxide cells

Whereas solid oxide cells (SOCs), which perform dual functions of power generation (fuel-cell mode) and energy storage (electrolysis mode) with high efficiency at high temperatures, are considered a potent candidate for future energy management systems, it is yet far from their practical use due to the fact that the stable long-term operations have not been achieved. Particularly, degradations of oxygen-electrode in the both electrolysis and fuel-cell operations are considered as the most imminent issues that should be overcome. Unfortunately, even the origins and mechanisms of degradation in the oxygen-electrode have not been clearly established due to the difficulties in precise assessments of microstructural/compositional changes of porous electrode, which is a typical form in actual solid oxide cells, and due to the diversities in operating conditions, electrode structure and material, fabrication history, and so on. We simultaneously investigated the degradation phenomena in electrolysis and fuel-cell operations for 540h using identical two half cells composed of a geometrically well-defined, nanoscale La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) dense film with a thickness of ~ 70 nm on Ce0.9Gd0.1O2-δ electrolyte. Owing to the benefit of well-defined geometry of LSCF thin film, the microstructural/compositional changes in LSCF films were successfully analyzed in nanoscale, and the correlation between the components of electrochemical impedance and the major origins resulting in degradations was clarified. Furthermore, we suggest the most probable degradation mechanisms, and importantly, it is newly suggested that kinetic demixing/decomposition of LSCF, which is not readily observable in the typical porous-structured electrode, are highly probable to affect the both fuel-cell and electrolysis long-term degradations