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Doping a typical topological insulator, Bi2Se3, with Ag impurity causes a semiconductor–metal (S-M) transition at 35 K. To deepen the understanding of this phenomenon, structural and transport properties of Ag-doped Bi2Se3 were studied. Single-crystal X-ray diffraction (SC-XRD) showed no structural transitions but slight shrinkage of the lattice, indicating no structural origin of the transition. To better understand electronic properties of Ag-doped Bi2Se3, extended analyses of Hall effect and electric-field effect were carried out. Hall effect measurements revealed that the reduction of resistance was accompanied by increases in not only carrier density but carrier mobility. The field-effect mobility is different for positive and negative gate voltages, indicating that the EF is located at around the bottom of the bulk conduction band (BCB) and that the carrier mobility in the bulk is larger than that at the bottom surface at all temperatures. The pinning of the EF at the BCB is found to be a key issue to induce the S-M transition, because the transition can be caused by depinning of the EF or the crossover between the bulk and the top surface transport. [ABSTRACT FROM AUTHOR]

Purpose: The details of the mediastinal fascia have been scarcely described and the bronchopericardial membrane is the only known structure that is present between the bronchi and the pericardium. However, the anatomical description of this structure is unclear. This study aimed to investigate the fascial structures between the bronchi and the pericardium based on surgical findings. Methods: The connective tissues in the mid-mediastinum were observed surgically when lung lobectomy, including mediastinal lymph node dissection for lung cancer, was performed at our institute from April 2011 to March 2016. Results: In total, 96 lobectomies were performed in 94 patients. A firm fibrous structure connecting the tracheobronchus and the fibrous pericardium was observed. It fixes the central bronchi to the pericardium and is composed of three parts. The largest part exists in front of the carina, its appearance is membranous, and runs behind the pulmonary artery. The other parts run over the right pulmonary artery and diverge at its superior trunk. The location at which all these structures fuse to the pericardium is the venous part of the hilum cordis (VHC). Conclusions: The results showed that connections of the dense fibrous tissues existed between the tracheobronchus and VHC. The structure not only works as a ligament that fixes the bronchi to the mid-mediastinum, but also divides the mid-mediastinum into two compartments: the Baréty and subcarinal spaces. The anatomy of the structure observed in this study differs from the previous description of the bronchopericardial membrane. [ABSTRACT FROM AUTHOR]

Background: We report a case of napsin A-positive metastatic lung cancer originating from the colon. No cases of napsin A-positive metastatic lung tumors originating from colorectal cancer have been reported previously. Case presentation: Computed tomography identified a small lung nodule in a 70-year-old male patient, 18 months after resection for rectal cancer. The size of the lung tumor increased from 1.8 to 2.1 cm in 6 months and metastasis from the rectal cancer was suspected. Resection of the lung tumor was performed, and the histological features of the lung tumor revealed findings typical of colorectal adenocarcinoma and resembled those of the original rectal cancer. Furthermore, the metastasis stained positive for napsin A and thyroid transcription factor-1 (TTF-1) on immunohistochemical evaluation, and immunohistochemical analysis identified the same results in the rectal specimen. Conclusions: These findings led us to believe that this was a rare case of napsin A-positive metastatic lung cancer originating in the colon. The patient was treated with chemotherapy for recurrent rectal cancer, and no other metastases were found after the lung resection. This is the first report of napsin A-positive colorectal cancer metastasizing to the lung. [ABSTRACT FROM AUTHOR]

Field-effect transistors (FETs) were fabricated with a thin film of 3,10-ditetradecylpicene, picene-(C14H29)2, formed using either a thermal deposition or a deposition from solution (solution process). All FETs showed p-channel normally-off characteristics. The field-effect mobility, μ, in a picene-(C14H29)2 thin-film FET with PbZr0.52Ti0.48O3 (PZT) gate dielectric reached ∼21 cm2 V-1 s-1, which is the highest μ value recorded for organic thin-film FETs; the average μ value (<μ>) evaluated from twelve FET devices was 14(4) cm2 V-1 s-1. The <μ> values for picene-(C14H29)2 thin-film FETs with other gate dielectrics such as SiO2, Ta2O2, ZrO2 and HfO2 were greater than 5 cm2 V-1 s-1, and the lowest absolute threshold voltage, ∣Vth∣, (5.2 V) was recorded with a PZT gate dielectric; the average ∣Vth∣ for PZT gate dielectric is 7(1) V. The solution-processed picene-(C14H29)2 FET was also fabricated with an SiO2 gate dielectric, yielding μ =3.4× 10-2 cm2 V-1 s-1. These results verify the effectiveness of picene-(C14H29)2 for electronics applications. [ABSTRACT FROM AUTHOR]

The temperature dependence of the resistivity (ρ) of Ag-doped Bi2Se3 (AgxBi2−xSe3) shows insulating behavior above 35 K, but below 35 K, ρ suddenly decreases with decreasing temperature, in contrast to the metallic behavior for non-doped Bi2Se3 at 1.5–300 K. This significant change in transport properties from metallic behavior clearly shows that the Ag doping of Bi2Se3 can effectively tune the Fermi level downward. The Hall effect measurement shows that carrier is still electron in AgxBi2−xSe3 and the electron density changes with temperature to reasonably explain the transport properties. Furthermore, the positive gating of AgxBi2−xSe3 provides metallic behavior that is similar to that of non-doped Bi2Se3, indicating a successful upward tuning of the Fermi level. [ABSTRACT FROM AUTHOR]

The [10]phenacene and [11]phenacene molecules have been synthesized using a simple repetition of Wittig reactions followed by photocyclization. Sufficient amounts of [10]phenacene and [11]phenacene were obtained, and thin-film FETs using these molecules have been fabricated with SiO2 and ionic liquid gate dielectrics. These FETs operated in p-channel. The averaged measurements of field-effect mobility, <μ>, were 3.1(7) × 10−2 and 1.11(4) × 10−1 cm2 V−1 s−1, respectively, for [10]phenacene and [11]phenacene thin-film FETs with SiO2 gate dielectrics. Furthermore, [10]phenacene and [11]phenacene thin-film electric-double-layer (EDL) FETs with ionic liquid showed low-voltage p-channel FET properties, with <μ> values of 3(1) and 1(1) cm2 V−1 s−1, respectively. This study also discusses the future utility of the extremely extended π-network molecules [10]phenacene and [11]phenacene as the active layer of FET devices, based on the experimental results obtained. [ABSTRACT FROM AUTHOR]

Background: Juvenile polyposis syndrome (JPS) is an autosomal dominant, inherited disorder characterized by multiple hyperproliferative polyps of the gastrointestinal tract, particularly of the colon, rectum, and stomach. SMAD4 mutations are frequently associated with multiple polyposis of the stomach; the condition causes severe bleeding and hypoproteinemia, which may progress to severe dysplasia and adenocarcinoma formation. We report our experience with the first case of total gastrectomy with pancreaticoduodenectomy following two partial jejunectomies for JPS, who presented with refractory anemia and protein-losing gastroenteropathy due to polyposis of the stomach and duodenum. Case presentation: A 33-year-old Japanese man presented with the chief complaint of shortness of breath on exertion. His family history included gastric polyposis (mother, aunt, and cousin) and cerebral infarction (grandmother). Blood testing at the initial visit indicated iron-deficiency anemia, whereas endoscopy revealed multiple polyps in the duodenum and jejunum. Genetic testing revealed a 4 bp deletion (TGAA) in exon 5 of the SMAD4 gene; two partial small bowel resections were performed, but polyps grew in the remaining stomach, duodenum, and small intestine. The patient developed hypoalbuminemia and anemia, and required central venous nutrition and blood transfusion. However, because the hyponutrition and anemia remained poorly controlled, a total gastrectomy with concomitant pancreaticoduodenectomy was performed. Malnutrition and anemia improved, and there was no polyp recurrence in the remaining intestinal tract at 18 months after the surgery. Conclusions: We report a case of JPS with refractory anemia and protein-losing gastroenteropathy that was treated with total gastrectomy with concomitant pancreaticoduodenectomy. Although the surgery was highly invasive, the patient's nutritional status and anemia improved postoperatively, and the treatment was successful. However, to determine the appropriate surgical procedure, a detailed examination of the gastrointestinal lesions and the effects of the surgical invasion on nutritional status must be undertaken. [ABSTRACT FROM AUTHOR]

From the C 1s and K 2p photoelectron holograms, we directly reconstructed atomic images of the cleaved surface of a bimetal-intercalated graphite superconductor, (Ca, K)C8, which differed substantially from the expected bulk crystal structure based on x-ray diffraction (XRD) measurements. Graphene atomic images were collected in the in-plane cross sections of the layers 3.3 Å and 5.7 Å above the photoelectron emitter C atom and the stacking structures were determined as AB- and AA-type, respectively. The intercalant metal atom layer was found between two AA-stacked graphenes. The K atomic image revealing 2 × 2 periodicity, occupying every second centre site of C hexagonal columns, was reconstructed, and the Ca 2p peak intensity in the photoelectron spectra of (Ca, K)C8 from the cleaved surface was less than a few hundredths of the K 2p peak intensity. These observations indicated that cleavage preferentially occurs at the KC8 layers containing no Ca atoms. [ABSTRACT FROM AUTHOR]

We previously discovered multiple superconducting phases in the ammoniated Na-doped FeSe material, (NH3)yNaxFeSe. To clarify the origin of the multiple superconducting phases, the variation of Tc was fully investigated as a function of x in (NH3)yNaxFeSe. The 32 K superconducting phase is mainly produced in the low-x region below 0.4, while only a single phase is observed at x = 1.1, with Tc = 45 K, showing that the Tc depends significantly on x, but it changes discontinuously with x. The crystal structure of (NH3)yNaxFeSe does not change as x increases up to 1.1, i.e., the space group of I4/mmm. The lattice constants, a and c, of the low-Tc phase (Tc = 32.5 K) are 3.9120(9) and 14.145(8) Å, respectively, while a = 3.8266(7) Å and c = 17.565(9) Å for the high-Tc phase (~46 K). The c increases in the high Tc phase, implying that the Tc is directly related to c. In (NH3)yLixFeSe material, the Tc varies continuously within the range of 39 to 44 K with changing x. Thus, the behavior of Tc is different from that of (NH3)yNaxFeSe. The difference may be due to the difference in the sites that the Na and Li occupy. [ABSTRACT FROM AUTHOR]

The pressure dependence of the superconducting transition temperature (Tc) and unit cell metrics of tetragonal (NH3)yCs0.4FeSe were investigated in high pressures up to 41 GPa. The Tc decreases with increasing pressure up to 13 GPa, which can be clearly correlated with the pressure dependence of c (or FeSe layer spacing). The Tc vs. c plot is compared with those of various (NH3)yMxFeSe (M: metal atoms) materials exhibiting different Tc and c, showing that the Tc is universally related to c. This behaviour means that a decrease in two-dimensionality lowers the Tc. No superconductivity was observed down to 4.3 K in (NH3)yCs0.4FeSe at 11 and 13 GPa. Surprisingly, superconductivity re-appeared rapidly above 13 GPa, with the Tc reaching 49 K at 21 GPa. The appearance of a new superconducting phase is not accompanied by a structural transition, as evidenced by pressure-dependent XRD. Furthermore, Tc slowly decreased with increasing pressure above 21 GPa, and at 41 GPa superconductivity disappeared entirely at temperatures above 4.9 K. The observation of a double-dome superconducting phase may provide a hint for pursuing the superconducting coupling-mechanism of ammoniated/non-ammoniated metal-doped FeSe. [ABSTRACT FROM AUTHOR]

Background: Although various biomarkers are useful in predicting cancer prognosis, the most effective preoperative systemic biomarkers for pancreatic ductal adenocarcinoma (PDAC) have not been established. This study aimed to evaluate whether the lymphocyte-to-monocyte ratio (LMR) can predict the long-term outcomes for patients who were to undergo surgical resection of PDAC. Methods: The study involved 170 patients with PDAC who underwent resection. Multivariate analysis was performed to identify the independent prognostic factors for overall survival (OS) and disease-free survival (DFS) among clinicopathologic, surgical, and seven systemic biomarker-related factors including LMR. Subgroup analysis of PDAC located in the body and tail of the pancreas (B/T PDAC) was performed (n = 60) to eliminate the influence of preoperative cholangitis and surgical procedure. Furthermore, OS according to the postoperative course of the LMR value group was investigated. Results: A low LMR (<3.3) was the only independent predictive factor for OS (hazard ratio [HR], 3.52; p < 0.001) and DFS (HR, 3.31; p < 0.001) among the systemic biomarkers. Subgroup analysis of the B/T PDAC also showed that low the LMR was the independent predictive factor for OS (HR, 3.24; p = 0.002) and DFS (HR, 4.42; p = 0.003). The PDAC that maintained a high LMR from before surgery to 1 year after surgery showed good long-term outcomes (median OS, 8.5 years; 5-year survival rate, 61.8 %). Conclusions: Preoperative LMR was an independent predictor of OS and DFS after surgery for PDAC. Maintaining a high LMR through the pre- and postoperative courses might improve the prognosis for patients with PDAC. [ABSTRACT FROM AUTHOR]

It is challenging to secure a cytopathologic diagnosis using minute amounts of tumor fluids and tissue fragments. Hence, we developed a rapid, accurate, low-cost method for detecting tumor cell-derived DNA from limited amounts of specimens and samples with a low tumor cellularity, to detect KRAS mutations in pancreatic ductal carcinomas (PDA) using digital PCR (dPCR). The core invention is based on the suspension of tumor samples in pure water, which causes an osmotic burst; the crude suspension could be directly subjected to emulsion PCR in the platform. We examined the feasibility of this process using needle aspirates from surgically resected pancreatic tumor specimens (n = 12). We successfully amplified and detected mutant KRAS in 11 of 12 tumor samples harboring the mutation; the positive mutation frequency was as low as 0.8%. We used residual specimens from fine-needle aspiration/biopsy and needle flush processes (n = 10) for method validation. In 9 of 10 oncogenic KRAS pancreatic tumor samples, the "water-burst" method resulted in a positive mutation call. We describe a dPCR-based, super-sensitive screening protocol for determining KRAS mutation availability using tiny needle aspirates from PDAs processed using simple steps. This method might enable pathologists to secure a more accurate, minimally invasive diagnosis using minute tissue fragments. [ABSTRACT FROM AUTHOR]

Background. Metachronous solitary metastasis of renal cell carcinoma (RCC) to the contralateral adrenal gland is very rare. We assessed the clinocopathological findings of such patients who received adrenalectomy. Methods. We retrospectively reviewed the records of all 495 patients who underwent nephrectomy for RCC; excluding those in stage IV, between 1980 and 1993. Of these patients, 5 who showed metachronous solitary metastasis to the contralateral adrenal gland, and also received adrenalectomy were the subjects of this study. Results. The adrenal metastasis was found between 14 and 132 months (median, 81 months) after nephrectomy. After the solitary adrenalectomy, patient survival ranged from 450 to 2160 days (median, 660 days); 2 patients were alive with no evidence of disease at 660 and 1830 days, respectively, and 3 patients died of this disease, at 450, 480, and 2160 days, respectively, after adrenalectomy. The overall survival rate was 100% at 5 years, 80% at 6 years, 60% at 7 years, and 40% thereafter. The 2 patients with no evidence of disease did not receive steroid supplementation, because they had not received ipsilateral adrenalectomy. No significant difference was observed between survivors and non-survivors in terms of clinicopathological factors such as affected side, location of the tumor, tumor size of primary/metastatic lesion, and stage or grade of primary/metastatic lesion. From the viewpoint of outcome, patients with early recurrence tended to show an unfavorable prognosis compared with prognosis in those with late recurrence. Conclusion. The prediction of outcome in patients with RCC who undergo, adrenalectomy for metachronous solitary metastasis to the contralateral adrenal gland is difficult. Although the factors that affect prognosis are uncertain, long-term observation for unusual metachronous metastasis to the contralateral adrenal gland is mandatory in patients with RCC. [ABSTRACT FROM AUTHOR]