Harmonic Quantum Coherence of Multiple Excitons in PbS/CdS Core-Shell Nanocrystals

半導体ナノ粒子が光を電子へ変換する過程を解明 --高効率な太陽電池や光検出器への基礎メカニズム--. 京都大学プレスリリース. 2017-12-14.The generation and recombination dynamics of multiple excitons in nanocrystals (NCs) have attracted much attention from the viewpoints of fundamental physics and device applications. However, the quantum coherence of multiple exciton states in NCs still remains unclear due to a lack of experimental support. Here, we report the first observation of harmonic dipole oscillations in PbS/CdS core-shell NCs using a phase-locked interference detection method for transient absorption. From the ultrafast coherent dynamics and excitation-photon-fluence dependence of the oscillations, we found that multiple excitons cause the harmonic dipole oscillations with ω, 2ω, and 3ω oscillations, even though the excitation pulse energy is set to the exciton resonance frequency, ω. This observation is closely related to the quantum coherence of multiple exciton states in NCs, providing important insights into multiple exciton generation mechanisms

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富山大学香川医科大学Editor : Tazaki, Kazue |田崎, 和

Extracorporeal Shock Wave Lithotripsy (ESWL) without Endoscopic Lithotomy for Pancreatolithiasis : A Report of Two Cases

Extracorporeal shock wave lithotripsy (ESWL) without endoscopic sphincterotomy (EST) for pancreatic duct stones was performed in two patients with chronic pancreatitis. Case 1 was a 37-year-old man. Pancreatic stones were observed in the pancreatic head and tail region with a persistent pancreatic fistula. ESWL without EST for pancreatolithiasis was performed two times. Almost all the stones in the pancreatic head were disintegrated without any complications by ESWL (4700 shock waves at 24.0 KV) under fluoroscopic control using a lithotriptor (Dornier MLF 5000). Consequently, the fistula closed and the pancreatic exocrine function recovered. Case 2 was a 65-year-old woman suffering from chronic relapsing pancreatitis with calcified stones in the pancreatic head region. ESWL (5700 shock waves at 23.0 KV) without EST produced complete disintegration of the stones without any complications. Seven days later, almost all of the stones in the pancreatic head were diminished. Thereafter, we observed not only amelioration of the symptoms of pancreatitis but also improvement in pancreatic exocrine function. Thus, ESWL treatment without EST was a safe and effective method for pancreatolithiasis and should be considered a high-priority non-surgical treatment for pancreatolithiasis

Daikenchuto accelerates the recovery from prolonged postoperative ileus after open abdominal surgery : a subgroup analysis of three randomized controlled trials

Purpose Prolonged postoperative ileus (POI) is a common complication after open abdominal surgery (OAS). Daikenchuto (DKT), a traditional Japanese medicine that peripherally stimulates the neurogenic pathway, is used to treat prolonged POI in Japan. To analyze whether DKT accelerates the recovery from prolonged POI after OAS, we conducted a secondary analysis of three multicenter randomized controlled trials (RCTs). Methods A secondary analysis of the three RCTs supported by the Japanese Foundation for Multidisciplinary Treatment of Cancer (project numbers 39-0902, 40-1001, 42-1002) assessing the effect of DKT on prolonged POI in patients who had undergone OAS for colon, liver, or gastric cancer was performed. The subgroup included 410 patients with no bowel movement (BM) before the first diet, a DKT group (n = 214), and a placebo group (n = 196). Patients received either 5 g DKT or a placebo orally, three times a day. The primary endpoint was defined as the time from the end of surgery to the first bowel movement (FBM). A sensitivity analysis was also performed on the age, body mass index and dosage as subgroup analyses. Results The primary endpoint was significantly accelerated in the DKT group compared with the placebo group (p = 0.004; hazard ratio 1.337). The median time to the FBM was 113.8 h in the placebo group and 99.1 h in the DKT treatment group. Conclusions The subgroup analysis showed that DKT significantly accelerated the recovery from prolonged POI following OAS

Impact of functional studies on exome sequence variant interpretation in early-onset cardiac conduction system diseases

Aims The genetic cause of cardiac conduction system disease (CCSD) has not been fully elucidated. Whole-exome sequencing (WES) can detect various genetic variants; however, the identification of pathogenic variants remains a challenge. We aimed to identify pathogenic or likely pathogenic variants in CCSD patients by using WES and 2015 American College of Medical Genetics and Genomics (ACMG) standards and guidelines as well as evaluating the usefulness of functional studies for determining them. Methods and Results We performed WES of 23 probands diagnosed with early-onset (<65 years) CCSD and analyzed 117 genes linked to arrhythmogenic diseases or cardiomyopathies. We focused on rare variants (minor allele frequency < 0.1%) that were absent from population databases. Five probands had protein truncating variants in EMD and LMNA which were classified as “pathogenic” by 2015 ACMG standards and guidelines. To evaluate the functional changes brought about by these variants, we generated a knock-out zebrafish with CRISPR-mediated insertions or deletions of the EMD or LMNA homologs in zebrafish. The mean heart rate and conduction velocities in the CRISPR/Cas9-injected embryos and F2 generation embryos with homozygous deletions were significantly decreased. Twenty-one variants of uncertain significance were identified in 11 probands. Cellular electrophysiological study and in vivo zebrafish cardiac assay showed that 2 variants in KCNH2 and SCN5A, 4 variants in SCN10A, and 1 variant in MYH6 damaged each gene, which resulted in the change of the clinical significance of them from “Uncertain significance” to “Likely pathogenic” in 6 probands. Conclusions Of 23 CCSD probands, we successfully identified pathogenic or likely pathogenic variants in 11 probands (48%). Functional analyses of a cellular electrophysiological study and in vivo zebrafish cardiac assay might be useful for determining the pathogenicity of rare variants in patients with CCSD. SCN10A may be one of the major genes responsible for CCSD. Translational Perspective Whole-exome sequencing (WES) may be helpful in determining the causes of cardiac conduction system disease (CCSD), however, the identification of pathogenic variants remains a challenge. We performed WES of 23 probands diagnosed with early-onset CCSD, and identified 12 pathogenic or likely pathogenic variants in 11 of these probands (48%) according to the 2015 ACMG standards and guidelines. In this context, functional analyses of a cellular electrophysiological study and in vivo zebrafish cardiac assay might be useful for determining the pathogenicity of rare variants, and SCN10A may be one of the major development factors in CCSD

Traumatic Gastric Perforation Associated with Cardiopulmonary Resuscitation: A Case Report

Sternal and rib fractures are well-known complications of cardiopulmonary resuscitation (CPR). We experienced a rare case of traumatic gastric perforation associated with CPR that required emergency laparotomy. In this case, we examined whether surgery is essential for gastric perforation associated with CPR. A 67-year-old man experienced cardiopulmonary arrest in the workplace, and bystander CPR was performed by his colleagues. He was then transported by ambulance to our hospital. A large amount of free air was found in the peritoneal cavity on computed tomography at presentation, and perforation of the gastrointestinal tract was suspected. During emergency laparotomy, a 2-cm serosal-muscular layer tear was found in the gastric lesser curvature. The damaged stomach wall was repaired, the abdominal cavity was lavaged, and surgery was completed by placing a drainage tube. The patient’s postoperative course was good and he was discharged on the 26th postoperative day. Emergency laparotomy has been performed frequently for traumatic gastric perforation associated with CPR. However, emergency laparotomy may be avoided by conservative treatment in some cases. Traumatic gastric perforation associated with CPR is a serious complication; however, the life prognosis of cardiopulmonary arrest patients depends on the original disease and the success of CPR. Traumatic gastric perforation associated with CPR is rarely fatal, and bystanders should not hesitate to initiate CPR

Intraperitoneal cancer-immune microenvironment promotes peritoneal dissemination of gastric cancer

A solid tumor consists of cancer and stromal cells, which comprise the tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are usually abundant in the TME, contributing to tumor progression. In cases of peritoneal dissemination of gastric cancer (GC), the contribution of intraperitoneal TAMs remains unclear. Macrophages from peritoneal washings of GC patients were analyzed, and the link between intraperitoneal TAMs and GC cells was investigated to clarify the interaction between them in peritoneal dissemination. Macrophages were predominant among leukocytes constituting the microenvironment of the peritoneal cavity. The proportion of CD163-positive TAMs was significantly higher in stage IV than in stage I GC. Co-culture with TAMs potentiated migration and invasion of GC. IL-6 was the most increased in the medium of in vitro co-culture of macrophages and GC, and IL-6 elevation was also observed in the peritoneal washes with peritoneal dissemination. An elevated concentration of intraperitoneal IL-6 was correlated with a poor prognosis in clinical cases. In conclusion, intraperitoneal TAMs are involved in promoting peritoneal dissemination of GC via secreted IL-6. TAM-derived IL-6 could be a potential therapeutic target for peritoneal dissemination of GC

Mucin-hypersecreting bile duct neoplasm characterized by clinicopathological resemblance to intraductal papillary mucinous neoplasm (IPMN) of the pancreas

<p>Abstract</p> <p>Background</p> <p>Although intraductal papillary mucinous neoplasm (IPMN) of the pancreas is acceptable as a distinct disease entity, the concept of mucin-secreting biliary tumors has not been fully established.</p> <p>Case presentation</p> <p>We describe herein a case of mucin secreting biliary neoplasm. Imaging revealed a cystic lesion 2 cm in diameter at the left lateral segment of the liver. Duodenal endoscopy revealed mucin secretion through an enlarged papilla of Vater. On the cholangiogram, the cystic lesion communicated with bile duct, and large filling defects caused by mucin were observed in the dilated common bile duct. This lesion was diagnosed as a mucin-secreting bile duct tumor. Left and caudate lobectomy of the liver with extrahepatic bile duct resection and reconstruction was performed according to the possibility of the tumor's malignant behavior. Histological examination of the specimen revealed biliary cystic wall was covered by micropapillary neoplastic epithelium with mucin secretion lacking stromal invasion nor ovarian-like stroma. The patient has remained well with no evidence of recurrence for 38 months since her operation.</p> <p>Conclusion</p> <p>It is only recently that the term "intraductal papillary mucinous neoplasm (IPMN)," which is accepted as a distinct disease entity of the pancreas, has begun to be used for mucin-secreting bile duct tumor. This case also seemed to be intraductal papillary neoplasm with prominent cystic dilatation of the bile duct.</p

Generation of electromagnetic waves from 0.3 to 1.6 terahertz with a high-T-c superconducting Bi2Sr2CaCu2O8+delta intrinsic Josephson junction emitter

To obtain higher power P and frequency f emissions from the intrinsic Josephson junctions in a high-T-c superconducting Bi2Sr2CaCu2O8+delta single crystal, we embedded a rectangular stand-alone mesa of that material in a sandwich structure to allow for efficient heat exhaust. By varying the current-voltage (I-V) bias conditions and the bath temperature T-b, f is tunable from 0.3 to 1.6 THz. The maximum P of a few tens of mu W, an order of magnitude greater than from previous devices, was found at T-b similar to 55K on an inner I-V branch at the TM(1,0) cavity resonance mode frequency. The highest f of 1.6 THz was found at T-b = 10K on an inner I-V branch, but away from cavity resonance frequencies. A possible explanation is presented