Facile Synthesis of Novel Short-Chain Ligand-Capped Colloidal Metal Oxide Nanoparticles for Printed Flexible Devices.

Colloidal metal oxide nanoparticles are key materials for achieving cost-effective and large-scale production of flexible devices, as they enable the formation of functional oxide thin films at low temperatures (<400 °C) through printing techniques such as inkjet printing, gravure coating, and microcontact printing. The conventional solvothermal synthesis of colloidal metal oxide nanoparticles through the thermal decomposition of precursors results in particles with bulky, long-chain ligands on their surfaces, which hinder the formation of dense oxide films when depositing the colloidal metal oxide nanoparticles. Herein, we have developed a simple and versatile method for synthesizing colloidal metal oxide nanoparticles using base-induced hydrolysis and the condensation of metal acetates as precursors. Various binary and ternary colloidal metal oxide nanoparticles (CuO, Mn3O4, Co3O4, CeO2, In2O3, Co1.8Mn1.2O4) were synthesized using short-chain acetate ligands on their surfaces. The thin acetate ligand-containing colloidal Co1.8Mn1.2O4 nanoparticle film exhibited lower resistivity than the same with long-chain oleate ligands. The films coated onto a polyimide substrate formed a flexible negative temperature coefficient thermistor that exhibited the temperature dependence of resistance comparable to bulk materials with a bending durability of up to 5 mm radius. These findings highlight the effectiveness of utilizing colloidal metal oxide nanoparticles with short-chain ligands in flexible devices.

Prevalence and Risk Factors of Constipation Symptoms among Patients Undergoing Colonoscopy: A Single-Center Cross-Sectional Study.

INTRODUCTION: Constipation is one of the most common gastrointestinal symptoms. It may compromise quality of life and social functioning and result in increased healthcare use and costs. We aimed to evaluate the prevalence and risk factors of constipation symptoms, as well as those of refractory constipation symptoms among patients who underwent colonoscopy. METHODS: Over 4.5 years, patients who underwent colonoscopy and completed questionnaires were analyzed. Patients' symptoms were evaluated using the Gastrointestinal Symptoms Rating Scale. RESULTS: Among 8,621 eligible patients, the prevalence of constipation symptoms was 33.3%. Multivariate analysis revealed female sex (odds ratio [OR] 1.7, p < 0.001), older age (OR 1.3, p < 0.001), cerebral stroke with paralysis (OR 1.7, p = 0.009), chronic renal failure (OR 2.6, p < 0.001), ischemic heart disease (OR 1.3, p = 0.008), diabetes (OR 1.4, p < 0.001), chronic obstructive pulmonary disease (OR 1.5, p = 0.002), benzodiazepine use (OR 1.7, p < 0.001), antiparkinsonian medications use (OR 1.9, p = 0.030), and opioid use (OR 2.1, p = 0.002) as independent risk factors for constipation symptoms. The number of patients taking any medication for constipation was 1,134 (13.2%); however, refractory symptoms of constipation were still present in 61.4% of these patients. Diabetes (OR 1.5, p = 0.028) and irritable bowel syndrome (OR 3.1, p < 0.001) were identified as predictors for refractory constipation symptoms. CONCLUSIONS: Constipation occurred in one-third of patients, and more than half of patients still exhibited refractory symptoms of constipation despite taking laxatives. Multiple medications and concurrent diseases seem to be associated with constipation symptoms.

Vincazalidine A, a unique bisindole alkaloid from Catharanthus roseus.

A new dimeric indole alkaloid, vincazalidine A consisting of an aspidosperma type and a modified iboga type with 1-azatricyclo ring system consisting of one azepane and two piperidine rings coupled with an oxazolidine ring was isolated from Catharanthus roseus, and the structure including absolute stereochemistry was elucidated on the basis of spectroscopic data as well as DP4 statistical analysis. Vincazalidine A induced G2 arrest and subsequent apoptosis in human lung carcinoma cell line, A549 cells.

Efficacy of the pocket-creation method with a traction device in endoscopic submucosal dissection for residual or recurrent colorectal lesions.

BACKGROUND/AIMS: Endoscopic submucosal dissection (ESD) for residual or recurrent colorectal lesions after incomplete resection is challenging because of severe fibrosis. This study aimed to compare the efficacy of the pocket-creation method (PCM) with a traction device (TD) with that of conventional ESD for residual or recurrent colorectal lesions. METHODS: We retrospectively studied 72 patients with residual or recurrent colorectal lesions resected using ESD. Overall, 31 and 41 lesions were resected using PCM with TD and conventional ESD methods, respectively. We compared patient background and treatment outcomes between the PCM with TD and conventional ESD groups, respectively. The primary endpoints were en bloc resection and R0 resection rates. The secondary endpoints were the dissection speed and incidence of adverse events. RESULTS: En bloc resection was feasible in all cases with PCM with TD, but failed in 22% of cases of conventional ESD. The R0 resection rates for PCM with TD and conventional ESD were 97% and 66%, respectively. Dissection was significantly faster in the PCM with TD group (13.0 vs. 7.9 mm2/min). Perforation and postoperative bleeding were observed in one patient in each group. CONCLUSION: PCM with TD is an effective method for treating residual or recurrent colorectal lesions after incomplete resection.

Risk factors for vertical incomplete resection in endoscopic submucosal dissection of deep invasive submucosal colorectal cancer.

INTRODUCTION: It has been recently reported that deep invasive submucosal (T1b) colorectal cancer (CRC) without other pathological risk factors for lymph node metastasis has a low rate of lymph node metastasis, increasing the possibility of endoscopic submucosal dissection (ESD) in the future. However, ESD for T1b CRC is technically difficult, and some lesions cannot be resected en bloc. This study aimed to identify the risk factors associated with vertical incomplete ESD in T1b CRC. METHODS: We retrospectively studied 140 pathological T1b CRC lesions that underwent initial ESD at our institution between January 2011 and October 2020, and categorized them into positive vertical margin (PVM) and negative vertical margin (NVM) groups. The risk factors for PVM were examined using univariate and multivariate analyses, and a subgroup analysis for T1b CRC with an obvious depressed surface was performed. RESULTS: Multivariate analysis revealed obvious depression (hazard ratio [HR]: 7.4; 95% confidence interval [CI]: 2.47-22.5) and severe fibrosis (HR: 11.4; 95% CI: 3.95-33.0) as significant risk factors for PVM. Length of depressed surface ≥12 mm (HR: 6.19; 95% CI: 1.56 -24.6) was identified as an independent predictor of PVM for T1b CRC with an obvious depression. CONCLUSION: Pathological T1b CRC cases with an obvious depression and severe fibrosis are at a high risk of vertical incomplete ESD.

Safety and Efficacy of Self-Expandable Metallic Stent Placement Using Low Radial Force Stent for Malignant Dysphagia after Radiotherapy.

INTRODUCTION: We aimed to investigate the safety and efficacy of self-expandable metallic stent (SEMS) placement in patients with prior radiotherapy (RT) using the Niti-S stent, which is characterized by low radial force, in comparison to patients without prior RT. METHODS: A consecutive series of 83 patients who were treated by SEMS placement using Niti-S stent for severe malignant esophageal obstruction or fistula were enrolled. The adverse event rates and efficacy were retrospectively compared between patients with/without prior RT before SEMS placement (RT group [n = 32] versus non-RT group [n = 51]). RESULTS: The incidence rate of major adverse events in the RT group was 6.3% and was not significantly different from that in the non-RT group (5.9%, p = 0.95). Among the RT group, 84.4% were able to resume oral intake within a median of 2 days. Among the patients with fistula, 78.6% could resume oral intake and survive for 73 days after SEMS placement. Cox proportional hazard regression analysis identified significant factors affecting overall survival to be prior RT (hazard ratio [HR]: 1.96), low performance status (HR: 3.87), and subsequent anticancer treatment after SEMS placement (HR: 0.41). However, compared to the non-RT group, the RT group had received longer duration of anticancer treatment before SEMS placement and a lower rate of subsequent anticancer treatment after SEMS placement. CONCLUSIONS: With the Niti-S stent, the incidence of major adverse events was sufficiently low even for patients after RT. SEMS with low radial force would be an effective palliative treatment option for patients, regardless of prior RT.

Gastrointestinal endoscopy trends in a designated hospital for specified infectious diseases in Japan during the dawn of the "living with COVID-19" era.

January 2020 marked the very early period of SARS-CoV-2's arrival in Japan. At the time, we immediately and strictly adopted the use of enhanced PPE, including a N95, gown, gloves, eye protection, and an apron, during every endoscopic procedure for every patient, with or without COVID-19. One reason why we use enhanced PPE for every patient is because all endoscopic procedures should be considered aerosol-generating procedures, and another reason is that asymptomatic patients with COVID-19 cannot be identified during a pandemic. The volume of endoscopic screening/surveillance endoscopies decreased markedly, but therapeutic endoscopies did not decrease. In contrast, urgent endoscopic hemostasis has increased more than ever. The most common reason for the increase might be that the lack of protective equipment and the need for medical staff to deal with an unknown virus, creating a pandemic panic in emergency medicine.

Current Status and Prospects of Endoscopic Resection Technique for Colorectal Tumors.

Currently, endoscopic submucosal dissection (ESD) is a well-established and common treatment for intramucosal colorectal cancer in Japan. However, colorectal ESD is technically more difficult to perform than esophageal and gastric ESD, and some lesions, such as fibrotic lesions, are difficult to dissect by endoscopy. Several techniques, such as the pocket-creation method and laparoscopically assisted endoscopic polypectomy, have been utilized for challenging targets. In recent years, endoscopic full-thickness resection (EFTR) using full-thickness resection devices have mainly been performed in Western countries. We have used laparoscopy and endoscopy cooperative surgery for colorectal tumors (LECS-CR) since 2011 for the challenging treatment of colorectal ESD. Improvements in ESD techniques have resulted in an increase in the literature on EFTR, and LECS-CR may be considered an effective endoscopic technique for colorectal ESD in the future.

Clinical utility of the pocket-creation method with a traction device for colorectal endoscopic submucosal dissection.

BACKGROUND: Colorectal endoscopic submucosal dissection (ESD) is technically demanding while ensuring safety, especially in cases with fibrosis and/or poor maneuverability. To overcome such difficulties, we developed a novel method called the pocket-creation method with a traction device (PCM with TD). We then evaluated the effectiveness and safety of PCM with TD in colorectal ESD compared to other conventional methods. METHODS: In total, 324 colorectal lesions treated with ESD from July 2018 to June 2019 were included. The following three treatment strategies were used: conventional ESD (CE), CE with TD, and PCM with TD. Patient backgrounds and treatment outcomes were retrospectively compared and analyzed. RESULTS: As ESD methods, CE, CE with TD, and PCM with TD account for 58% (187/324), 24% (78/324), and 18% (59/324), respectively. No significant difference was observed among the three groups in en bloc and R0 resection rates or adverse events. The rate of lesions with fibrosis and poor maneuverability was significantly higher in the PCM with TD group (CE group vs CE with TD group vs PCM with TD group: fibrosis, 24% vs 47% vs 64%, p < 0.001; poor maneuverability, 5.3% vs 13% vs 20%, p = 0.002). Dissection speed was significantly higher in the PCM with TD than in the CE with TD group (p = 0.003). CONCLUSIONS: PCM with TD can achieve a stable en bloc resection rate and R0 dissection rate without adverse events even in the hands of trainees, irrespective of the size and location of the lesion, presence of fibrosis, and under poor maneuverability conditions.

Optical Fiber-Type Sugar Chip Using Localized Surface Plasmon Resonance.

Optical fiber-type Sugar Chips were developed using localized surface plasmon resonance (LSPR) of gold (Au) nanoparticles. The endface of an optical fiber was first aminosilylated and then condensed with α-lipoic acid containing a dithiol group. Second, gold nanoparticles were immobilized onto the endface via an Au-S covalent bond. Finally, sugar moieties were attached to the gold nanoparticle using our original sugar chain-ligand conjugates to obtain fiber-type Sugar Chips, by which the sugar moiety-protein interaction was analyzed. The specificity, sensitivity, and quantitative binding potency against carbohydrate-binding protein were found to be identical to that of a conventional SPR sensor. In this analysis, only a small sample volume (approximately 10 µL) was required compared with 100 µL for the conventional SPR sensor, suggesting that the fiber-type Sugar Chip and LSPR are applicable for nonpure small masses of proteins.

A case of intraductal papillary mucinous neoplasm with high serum pepsinogen II level.

We report the case of a 65-year-old woman who had a high level of serum pepsinogen II. Several months earlier, she had found a mass on the right side of her upper abdomen. Esophagogastroduodenoscopy did not reveal atrophic or inflammatory findings. She had not taken proton pump inhibitors, and there was no indication of renal dysfunction. Imaging tests showed a mass of approximately 80mm in the pancreatic head. We performed pancreatoduodenectomy, and the histopathological examination revealed an intraductal papillary mucinous neoplasm (IPMN) of gastric type. Serum pepsinogen II levels substantially lowered after surgery. To the best of our knowledge, this is the first report on a relationship between IPMN and serum pepsinogen II.

Marked decrease in serum pepsinogen II levels resulting from endoscopic resection of a large duodenal tumor.

Studies have indicated that serum pepsinogen (PG) levels are not only markers for chronic atrophic gastritis but also predictive risk factors for gastric cancer. However, serum PG levels can change because of pathological conditions other than gastritis. We report the first case in which abnormally high serum PG II levels (168.8 ng/mL) led to the discovery of a large tumor covering a wide area in the duodenum, and after resection of the tumor, the serum PG II levels markedly decreased. Because endoscopic and histopathological examinations showed no indications of atrophic changes, inflammation of the gastric mucosa, or Helicobacter pylori infection, the serum PG II levels eventually returned to normal (10.1 ng/mL). The preoperative abnormally high PG II levels were probably caused by the large duodenal tumor that prevented PG II (which is produced by the duodenal Brunner's glands) from being secreted into the lumen, a condition that increased the amount transferred to the bloodstream. No previous reports have investigated serum PG II levels before and after resection of a large duodenal tumor. We believe this case provides valuable insight regarding the dynamics of PG II in the body and has important diagnostic implications.

Effect of functional group on the monolayer structures of biodegradable quaternary ammonium surfactants.

The monolayer structures and conformational ordering of cationic surfactants including the biodegradable quaternary ammonium molecules have been systematically characterized by π-A isotherm, surface potential, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and sum frequency generation (SFG) vibrational spectroscopy. It was found that the monolayer of the typical dialkyl dimethylammonium on the water surface was less densely packed along with many conformational gauche defects. The packing density and ordering of these monolayers were improved as halide ions were added to the subphase. A similar condensation effect was also observed when amide or ester groups are present in the alkyl tails of the surfactant. These results are discussed on the basis of the repulsive electrostatic interactions between the terminal ammonium moieties, the hydrogen bonding between the functional groups in the alkyl chains, as well as the flexibility of the alkyl chains in these surfactants. The present study is crucial to understanding the relationship between the interfacial structures and the functionalities of the biodegradable quaternary ammonium surfactants.

Stereoselective synthesis of optically active disilanes and selective functionalization by the cleavage of silicon-naphthyl bonds with bromine.

Optically active disilanes with one chiral silicon center, (R)-1,2-dimethyl-1-(naphth-1-yl)-1,2,2-triphenyldisilane and (R)-1,2,2-trimethyl-2-(4-methoxynaphth-1-yl)-1-(naphth-1-yl)-1-phenyldisilane, were obtained by the reaction of (S)-methyl(naphth-1-yl)phenylchlorosilane (> 99% ee) with methyldiphenylsilyllithium or by the reaction of methyldiphenylchlorosilane with optically active (S)-methyl(naphth-1-yl)phenylsilyllithium and by the reaction of (S)-methyl(naphth-1-yl)phenylchlorosilane (> 99% ee) with dimethyl(4-methoxynaphth-1-yl)silyllithium. Under the optimized conditions, the reactions proceeded with almost complete inversion for the cholorosilanes and retention for the silyl anions. Optically active disilanes with two chiral centers, (1R,2R)-1,2-dimethyl-1,2-di(naphth-1-yl)-1,2-diphenyldisilane and (1S,2S)-1,2-di(4-methoxynaphth-1-yl)-1,2-dimethyl-1,2-diphenyldisilane, were obtained in high optical purity by the reactions of corresponding optically active halogenosilanes (Cl or F) with optically active silyllithiums. The silicon-silicon bond and the silicon-naphthyl bond of (R)-1,1,2-trimethyl-1,2-di(naphth-1-yl)-2-phenyldisilane and (1R,2R)-1,2-dimethyl-1,2-di(naphth-1-yl)-1,2-diphenyldisilane were cleaved without selectivity on bromination. The silicon-(4-methoxynaphth-1-yl) bond of (R)-1,2,2-trimethyl-2-(4-methoxynaphth-1-yl)-1-(naphth-1-yl)-1-phenyldisilane was regiospecifically cleaved, followed by the stereoselective cleavage of the remaining chiral silicon-naphthyl bond (94% inversion). Although the silicon-(4-methoxynaphth-1-yl) bonds of (1S,2S)-1,2-di(4-methoxynaphth-1-yl)-1,2-dimethyl-1,2-diphenyldisilane (> 99% ee) were regioselectively cleaved without silicon-silicon bond scission, remarkable racemization could not be avoided during the one-pot reaction.