Contour integral method for obtaining the self-energy matrices of electrodes in electron transport calculations

We propose an efficient computational method for evaluating the self-energy matrices of electrodes to study ballistic electron transport properties in nanoscale systems. To reduce the high computational cost incurred in large systems, a contour integral eigensolver based on the Sakurai-Sugiura method combined with the shifted biconjugate gradient method is developed to solve exponential-type eigenvalue problem for complex wave vectors. A remarkable feature of the proposed algorithm is that the numerical procedure is very similar to that of conventional band structure calculations. We implement the developed method in the framework of the real-space higher-order finite difference scheme with nonlocal pseudopotentials. Numerical tests for a wide variety of materials validate the robustness, accuracy, and efficiency of the proposed method. As an illustration of the method, we present the electron transport property of the free-standing silicene with the line defect originating from the reversed buckled phases.Comment: 36 pages, 13 figures, 2 table

Pathobiology and Chemoprevention of Bladder Cancer

Our understanding of the pathogenesis of bladder cancer has improved considerably over the past decade. Translating these novel pathobiological discoveries into therapies, prevention, or strategies to manage patients who are suspected to have or who have been diagnosed with bladder cancer is the ultimate goal. In particular, the chemoprevention of bladder cancer development is important, since urothelial cancer frequently recurs, even if the primary cancer is completely removed. The numerous alterations of both oncogenes and tumor suppressor genes that have been implicated in bladder carcinogenesis represent novel targets for therapy and prevention. In addition, knowledge about these genetic alterations will help provide a better understanding of the biological significance of preneoplastic lesions of bladder cancer. Animal models for investigating bladder cancer development and prevention can also be developed based on these alterations. This paper summarizes the results of recent preclinical and clinical chemoprevention studies and discusses screening for bladder cancer

Thick polymer blend organic solar cells fabricated by slow drying

AbstractOrganic solar cells (OSCs) were generally fabricated by two types of deposition method, namely, dry and wet. Many OSCs use very thin films that cannot fully absorb light. Thick film deposition for OSCs has numerous benefits, such as highly efficient harnessing of solar light and low leakage. Thick film fabrication for polymer blend organic solar cells by the wet deposition method was investigated. OSCs were fabricated by spin coating and slow drying using P3HT and bis[60]PCBM in a solvent, respectively. Two-dimensional (2D)-mapping images of the photocurrent of the cells were measured by a laser-beam-induced current method. A low-current density area was not found in all the cells. As a result, we succeeded in fabricating OSCs with a power conversion efficiency of more than 4% by slow drying

Differences in clinicopathologic features and subtype distribution of invasive breast cancer between women older and younger than 40 years

OBJECTIVES: We investigated and compared clinicopathologic features and subtype distribution of invasive breast cancer among women <40 and ≥40 years of age. METHODS: We retrospectively compared clinicopathologic characteristics and subtype distribution of invasive breast cancer in women <40 and ≥40 years of age, in a cohort of 1,130 patients. Subtypes included luminal A (positive for hormone receptors [HR]—estrogen receptor [ER] and/or progesterone receptor [PR]—and negative for human epidermal growth factor receptor 2 [HER2] with low Ki67), luminal B (HER2(–)) (HR(+)/HER2(–)/Ki67(High)), luminal B (HER2(+)) (HR(+)/HER2(+)), HER2-overexpressing (HR(–)/HER2(+)), and triple negative (ER(–)/PR(–)/HER2(–)). RESULTS: Breast cancers in younger women had unfavorable clinicopathologic characteristics, including larger tumors and more frequent node involvement. Subtypes among the 1,130 tumors were luminal A: 36.4%, luminal B (HER2(–)): 35.0%, luminal B (HER2(+)): 7.5%, HER2-overexpressing: 7.1%, and triple negative: 14.0%. The age groups significantly differed in subtype distribution (P<0.001). Luminal A subtype was more common in the older group (38.5%) than the younger group (16.2%), and luminal B (HER2(–)) was more common in the younger group (52.2%) than in the older group (33.2%; P<0.001). CONCLUSIONS: Breast cancers in women younger than 40 years have unfavorable clinicopathologic characteristics and are more likely to be luminal B (HER2(–)) and less likely to be luminal A than breast cancers in older women

Peritoneal dissemination of prostate cancer due to laparoscopic radical prostatectomy: a case report

<p>Abstract</p> <p>Introduction</p> <p>Peritoneal dissemination with no further metastases of prostate cancer is very rare, with only three cases reported in the available literature. We report the first case of iatrogenic peritoneal dissemination due to laparoscopic radical prostatectomy.</p> <p>Case Presentation</p> <p>A 59-year-old Japanese man underwent laparoscopic radical prostatectomy for clinical T2bN0M0 prostate cancer, and the pathological diagnosis was pT3aN0 Gleason 3+4 adenocarcinoma with a negative surgical margin. Salvage radiation therapy was performed since his serum prostate-specific antigen remained at a measurable value. After the radiation, he underwent castration, followed by combined androgen blockade with estramustine phosphate and dexamethasone as each treatment was effective for only a few months to a year. Nine years after the laparoscopic radical prostatectomy, computed tomography revealed a peritoneal tumor, although no other organ metastasis had been identified until then. He died six months after the appearance of peritoneal metastasis. An autopsy demonstrated peritoneal dissemination of the prostate cancer without any other metastasis.</p> <p>Conclusion</p> <p>Physicians should take into account metastasis to unexpected sites. Furthermore, we suggest that meticulous care be taken not to disseminate cancer cells to the peritoneum during laparoscopic radical prostatectomy.</p

Undifferentiated Sarcoma of the Salivary Gland in a Mongolian Gerbil (Meriones unguiculatus)

A subcutaneous mass was found in the lower ventral neck region of a 55-week-old male Mongolian gerbil (Meriones unguiculatus). Histopathologically, the mass involved salivary glands and featured diffuse proliferation of pleomorphic neoplastic cells with large necrotic foci. The lesion was well demarcated from the surrounding tissue, although invasive growth to fibrous septa was occasionally observed. The neoplastic cells were mainly arranged in irregular sheets with severe cellular atypia, round to oval nuclei and varying amounts of eosinophilic cytoplasm. Mitotic figures and multinucleated giant cells were frequent. Immunohistochemical analysis revealed that the neoplastic cells were strongly positive for vimentin and S-100 and negative for NSE, cytokeratin, α-SMA, c-kit, factor VIII, CD34, α-1-antitrypsin, lysozyme and MSR-A. Based on the results, the mass was diagnosed as an undifferentiated sarcoma of the salivary gland. To the best of our knowledge, this is the first report of such a tumor in Mongolian gerbils

Carcinogenesis in Mouse Stomach by Simultaneous Activation of the Wnt Signaling and Prostaglandin E2 Pathway

金沢大学がん研究所附属がん幹細胞研究センター　Background & Aims: Accumulating evidence indicates that prostaglandin E2 (PGE2), a downstream product of cyclooxygenase 2 (COX-2), plays a key role in gastric tumorigenesis. The Wnt pathway is also suggested to play a causal role in gastric carcinogenesis. However, the molecular mechanism remains poorly understood of how the Wnt and PGE2 pathways contribute to gastric tumorigenesis. To investigate the role of Wnt and PGE2 in gastric cancer, we have generated transgenic mice that activate both pathways and examined their phenotypes. Methods: We constructed K19-Wnt1 transgenic mice expressing Wnt1 in the gastric mucosa using the keratin 19 promoter. We then crossed K19-Wnt1 mice with another transgenic line, K19-C2mE, to obtain K19-Wnt1/C2mE compound transgenic mice. The K19-C2mE mice express COX-2 and microsomal prostaglandin E synthase-1 (mPGES-1) in the stomach, showing an increased gastric PGE2 level. We examined the gastric phenotypes of both K19-Wnt1 and K19-Wnt1/C2mE mice. Results: K19-Wnt1 mice had a significant suppression of epithelial differentiation and developed small preneoplastic lesions consisting of undifferentiated epithelial cells with macrophage accumulation. Importantly, additional expression of COX-2 and mPGES-1 converted the preneoplastic lesions in the K19-Wnt1 mice into dysplastic gastric tumors by 20 weeks of age. Notably, we found mucous cell metaplasia in the glandular stomach of the K19-Wnt1/C2mE mice as early as 5 weeks of age, before the dysplastic tumor development. Conclusions: Wnt signaling keeps the gastric progenitor cells undifferentiated. Simultaneous activation of both Wnt and PGE2 pathways causes dysplastic gastric tumors through the metaplasia-carcinoma sequence. © 2006 American Gastroenterological Association (AGA) Institute

A case of locally advanced adenosquamous carcinoma of the cecum with long-term survival

A 63-year-old woman was admitted to our hospital with a right lower abdominal mass and general fatigue. Preoperative examination suggested a large ovarian tumor or cecal carcinoma. However, her intraoperative diagnosis was colon cancer; we therefore performed an ileocecal resection with oophorectomy. The tumor was pathologically diagnosed as adenosquamous carcinoma T4bN1M-stage IIIa. We administrated CapeOX adjuvant chemotherapy for 6 months. Adenosquamous carcinoma is extremely rare, at around 0.1% of all colorectal cancers, and usually has a poor prognosis. The patient is still alive without recurrence after 84 post-operative months, even with later developments of metachronous early colorectal cancer and breast cancer. We herein report a rare case of cecal ASC with good prognosis