Perovskite Solar Cells Prepared by Advanced Three-Step Method Using Additional HC(NH2)2I Spin-Coating: Efficiency Improvement with Multiple Bandgap Structure

In the conventional two-step prepared perovskite solar cells, the CH3NH3PbI3 (MAPbI3) film usually contains an unreacted PbI2 at the interface between an electron transport layer (ETL) and a perovskite active layer. To reduce the unreacted PbI2 in the two-step prepared MAPbI3 film, we have recently reported a new three-step method, which was realized by an additional MA(I,Br) spin-coating. Here, we propose an advanced three-step method, viz., an additional HC(NH2)2I (FAI) spin-coating on the two-step prepared MAPbI3 film. The additional FAI spin-coating formed a FAxMA1–xPbI3 solid solution by the incorporation of FA ion into MAPbI3. Also, the additional FAI spin-coating yielded a FAyMA1–yPbI3 layer (y > x) by converting the unreacted PbI2, which resulted in the layered structure with different FA concentrations and hence, with the multiple bandgap structure. The best PCE of 18.1% was achieved by optimizing the FAI spin-coating process

Papillo-Choledochectomy in the Operative Management of Mucosal Neoplasms of the Periampullary Region

Two patients with mucosal cancer of the periampullary region were treated with papillocholedochectomy, which entails removal of the papilla of Vater and the whole length of the common bile duct. The neoplasm is dissected out through the plane between the duodenal circular and longitudinal muscles, deep to the sphincter of Oddi and the fibromuscular layer of the bile duct. Pathological examination showed that cancer was confined to the mucosal layer without stromal invasion, and that the operation achieved radical cure. For mucosal cancer, papillo-choledochectomy is an alternative to pancreatoduodenectomy, provided that repeated frozen-section studies confirm the completeness of excision

Pancreatic tumor insulin responsiveness

The aim : Pancreatic cancer, a rapidly progressive malignancy, is often diagnosed in patients with diabetes. The incidence of pancreatic cancer has risen dramatically over recent decades. Early diagnosis of this malignancy is generally difficult because the symptoms do not become apparent until the disease has progressed, generally leading to a poor outcome. To achieve earlier diagnosis, we analyzed the clinical characteristics of pancreatic cancer patients showing deterioration of plasma glucose levels while hospitalized. Method : Thirty-six cases were divided into 2 groups ; those diagnosed with diabetes more than a year prior to identification of pancreatic cancer and diabetes secondary to pancreatic cancer. These 2 groups were further subdivided according to the tumor site (head or body / tail), allowing analysis of 4 subgroups. Anthropometric measurements, laboratory values were determined. Results : Both groups with diabetes lost at least 4 kg and showed HbA1c deterioration of at least 1% within 5 months of the pancreatic cancer diagnosis. The post-meal elevation of serum C-peptide immunoreactivity (CPR) was significantly decreased in the group with cancer of the pancreatic head, and this was unrelated to tumor size. Conclusion : Characteristically, pancreatic head cancer was associated with decreased endogenous insulin secretion as compared to body / tail cancer

Predicting rectal cancer T stage using circumferential tumor extent determined by computed tomography colonography

SummaryBackground and aimPatients with stage T3 or T4 rectal cancer are candidates for neoadjuvant chemoradiation therapy. The aim of this study is to clarify the usefulness of circumferential tumor extent determined by computed tomography (CT) colonography in differentiating T3 or T4 from T1 or T2 rectal cancer.MethodsSeventy consecutive rectal cancer patients who underwent curative-intent surgery were enrolled in this study. All patients underwent colonoscopy and CT colonography on the same day. The circumferential tumor extent was estimated in 10% increments. The pathological T stage was used as the reference.ResultsThe median circumferential tumor extent evaluated by colonoscopy for T1 (n = 6), T2 (n = 21), and T3/T4 (n = 43) were 10%, 30%, and 80%, respectively (T1/T2 vs. T3/T4, p < 0.0001). The median circumferential tumor extent evaluated by CT colonography for T1, T2, and T3/T4 is 10%, 30%, and 70%, respectively (T1/T2 vs. T3/T4, p < 0.0001). The correlation coefficient between colonoscopy and CT colonography was very high (0.94). By defining a circumferential tumor extent ≥50% by CT colonography as the criterion for stage T3 or T4, the sensitivity, specificity, positive predictive value and accuracy were 72%, 88%, 91%, and 79%, respectively.ConclusionCircumferential tumor extent ≥50% determined by CT colonography is a simple and potentially useful marker to identify candidates for neoadjuvant chemoradiation therapy

Reconstruction-Dependent Recovery from Anorexia and Time-Related Recovery of Regulatory Ghrelin System in Gastrectomized Rats

Gastrectomy reduces food intake and body weight (BW) hampering recovery of physical conditions. It also reduces plasma levels of stomach-derived orexigenic ghrelin. This study explored changes in orexigenic ghrelin system in rats receiving total gastrectomy with Billroth II (B-II) or Roux-en-Y (R-Y) method. Feeding and BW were reduced by gastrectomy and subsequently recovered to a greater extent with R-Y than B-II while plasma ghrelin decreased similarly. At postoperative 12th week, ghrelin contents increased in the duodenum and pancreas, plasma ghrelin levels increased upon fasting, and ghrelin injection promoted feeding but not in earlier periods. In summary, gastrectomized rats partially recover feeding and BW, in a reconstruction-dependent manner. At 12th week, ghrelin is upregulated in extra-stomach tissues, plasma ghrelin levels are physiologically regulated, and orexigenic effect of exogenous ghrelin is restored. This time-related recovery of ghrelin system may provide a strategy for promoting feeding, BW, and thereby physical conditions in gastrectomized patients