Archetype-Cation-Based Room-Temperature Ionic Liquid: Aliphatic Primary Ammonium Bis(trifluoromethylsulfonyl)imide as a Highly Functional Additive for a Hole Transport Material in Perovskite Solar Cells.

Room-temperature ionic liquids (RTILs) have attracted significant attention owing to their unique nature and a variety of potential applications. The archetypal RTIL comprising an aliphatic primary ammonium was discovered over a century ago, but this cation is seldom used in modern RTILs because other bulky cations (e.g., quaternary ammonium-, pyridine-, and imidazole-based cations) are prominent in current major applications, such as electrolytes and solvents, which require low and/or reversible reactivities. However, although the design of materials should change according to the intended application, RTIL designs remain conventional even when applied in unexplored fields, limiting their functions. Herein, RTIL consisting of an archetypal aliphatic primary ammonium (i.e., n-octylammonium: OA) cation and a modern bis(trifluoromethylsulfonyl)imide (TFSI) anion is proposed and demonstrated as a highly functional additive for a 2,2',7,7'-tetrakis(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene (Spiro-OMeTAD), which is the most common hole transport material (HTM), in perovskite solar cells (PSCs). The OA-TFSI additive exhibits prominent functions via permanent reactions of the component ions with the PSC components, thus providing several advantages. The OA cations spontaneously and densely passivate the perovskite layer during the HTM deposition process, leading to both suppression of carrier recombination at the HTM/perovskite interface and hydrophobic perovskite surfaces. Meanwhile, the TFSI anions effectively improve the HTM function most likely via efficient stabilization of the Spiro-OMeTAD radical, enhancing hole collection properties in the PSCs. Consequently, PSC performances involving long-term stability were significantly improved using the OA-TFSI additive. Based on the present results, this study advocates that reconsidering the RTIL design, even when it differs from the current major designs yet is suitable for a target application, can provide functions superior to conventional ones. The insights obtained in this work will spur further study of RTIL designs and aid the development of the broad materials science field including PSCs.

Contribution of tree community structure to forest productivity across a thermal gradient in eastern Asia.

Despite their fundamental importance the links between forest productivity, diversity and climate remain contentious. We consider whether variation in productivity across climates reflects adjustment among tree species and individuals, or changes in tree community structure. We analysed data from 60 plots of humid old-growth forests spanning mean annual temperatures (MAT) from 2.0 to 26.6 °C. Comparing forests at equivalent aboveground biomass (160 Mg C ha-1), tropical forests ≥24 °C MAT averaged more than double the aboveground woody productivity of forests <12 °C (3.7 ± 0.3 versus 1.6 ± 0.1 Mg C ha-1 yr-1). Nonetheless, species with similar standing biomass and maximum stature had similar productivity across plots regardless of temperature. We find that differences in the relative contribution of smaller- and larger-biomass species explained 86% of the observed productivity differences. Species-rich tropical forests are more productive than other forests due to the high relative productivity of many short-stature, small-biomass species.

Excess CO2 Reductions during CH3 COOH Formation from CH4 and CO2 under Periodic Operation: Downhill Side Reactions in an Uphill Target Reaction under Unsteady Conditions.

Acetic acid (CH3 COOH) formation from methane (CH4 ) and carbon dioxide (CO2 ) is an ideal reaction for chemical production, whereas this reaction possesses a severe thermodynamic limitation. To address this issue, it has been reported that periodic operation allowing a non-equilibrium condition can overcome the thermodynamic limitation. However, although an intrinsic issue of uphill reactions in non-equilibrium conditions generally is occurrence of unfavorable downhill reactions, this issue has seldom been discussed for the CH3 COOH formation under periodic operation. Herein, excess CO2 reductions were found to be the unfavorable downhill reactions possibly occurring in the reaction aiming at CH3 COOH formation under periodically operated CH4 and CO2 feeds. The reaction using an isotopic reactant (i. e., 13 CH4 ) unveiled that excess CO2 reductions to CO and even to CH3 moiety could occur, indicating importance of catalyst development. Furthermore, it was proposed that H2 O vapor introduction into the CO2 feed, which increased the CH3 COOH product, most likely facilitated the reverse reaction of the excess CO2 reductions and thereby is effective to hamper the unfavorable side reaction.

Future Prospects for Clinical Applications of Nanocarbons Focusing on Carbon Nanotubes.

Over the past 15 years, numerous studies have been conducted on the use of nanocarbons as biomaterials towards such applications as drug delivery systems, cancer therapy, and regenerative medicine. However, the clinical use of nanocarbons remains elusive, primarily due to short- and long-term safety concerns. It is essential that the biosafety of each therapeutic modality be demonstrated in logical and well-conducted experiments. Accordingly, the fundamental techniques for assessing nanocarbon biomaterial safety have become more advanced. Optimal controls are being established, nanocarbon dispersal techniques are being refined, the array of biokinetic evaluation methods has increased, and carcinogenicity examinations under strict conditions have been developed. The medical implementation of nanocarbons as a biomaterial is in sight. With a particular focus on carbon nanotubes, these perspectives aim to summarize the contributions to date on nanocarbon applications and biosafety, introduce the recent achievements in evaluation techniques, and clarify the future prospects and systematic introduction of carbon nanomaterials for clinical use through practical yet sophisticated assessment methods.

Feasibility of endoscopic evaluation of Helicobacter pylori infection status by using the Kyoto classification of gastritis in the population-based gastric cancer screening program: A prospective cohort study.

BACKGROUND AND AIMS: We have started a new population-based endoscopic gastric cancer screening program in Kurashiki city with consideration of Helicobacter pylori infection status based on endoscopic features. We aimed to verify the feasibility of this attempt in a prospective case-registration study (UMIN000028629). METHODS: Data were collected from 1784 subjects without past eradication of H. pylori and who underwent endoscopic gastric cancer screening in Kurashiki Central Hospital Preventive Healthcare Plaza from September 2017 to June 2018. Endoscopic judgment of H. pylori infection status was made according to the Kyoto classification of gastritis. For comparison, a combination serum test of anti-H. pylori antibody and pepsinogen I and II, the ABC method, was used. RESULTS: The endoscopic diagnoses were nongastritis, 1215 (68.1%); active or inactive gastritis, 469 (26.3%); and undefined, 23 (1.3%). With the ABC method as a reference standard, the false-negative rate of the endoscopic judgment for H. pylori infection was 16.3% (95% confidence interval: 13.1%-20.0%). Most false-negative cases were of Group B in the ABC method, which is considered gastritis with mild mucosal atrophy. Antibody titers in this population were mostly in the weak-positive range but clinically significant elevation of the antibody suggesting current infection was observed in some cases. CONCLUSIONS: Endoscopic diagnosis of H. pylori infection status in a population-based gastric cancer screening program is mostly reliable, but false-negative results may occur, especially in patients with mild gastric atrophy. To avoid this limitation, we recommend adding H. pylori antibody test to the program.

Exothermic methane coupling with ethylene as a hydrogen acceptor toward two-step methane conversion to ethylene.

Exothermic methane coupling with ethylene (ethene) as a hydrogen acceptor (2CH4 + C2H4 → 2C2H6) was proposed as part of a two-step reaction that includes ethane cracking (C2H6 → C2H4 + H2), which is a common industrial process, to provide methane conversion into ethylene as the net reaction (2CH4 → C2H4 + 2H2).

AIMS65 predicts prognosis of patients with duodenal ulcer bleeding; a comparison with other risk-scoring systems.

BACKGROUND AND AIM: Duodenal ulcer bleeding has a higher risk of mortality than bleeding from other portions of the gastrointestinal tract. AIMS65 is an effective risk-scoring system to predict prognosis of upper gastrointestinal bleeding and can be easily calculated without endoscopic findings. In this study, we investigate the usefulness of AIMS65 to predict prognosis of patients with duodenal ulcer bleeding. METHODS: Two hundred and fifty-five patients with endoscopically diagnosed duodenal ulcer bleeding at Kurashiki Central hospital from July 2007 to June 2017 were studied. We compared AIMS65, Glasgow Blatchford score (GBS), admission Rockall, and full Rockall scoring systems for predicting in-hospital mortality by calculating area under the receiver operating characteristic curve (AUROC). RESULTS: In-hospital mortality due to duodenal ulcer bleeding occurred in 17 (6.7%). Scores of all scoring systems were significantly higher in patients with in-hospital mortality than in patients without it. AUROC values for predicting in-hospital mortality was 0.83 in AIMS65, 0.74 in GBS, 0.76 in admission Rockall score, and 0.82 in full Rockall score, a statistically insignificant difference among the systems. In AIMS65, score more than or equal to 2 was an optimal value to predict in-hospital mortality, with sensitivities of 88.2% and specificities of 59.7%, respectively. CONCLUSIONS: AIMS65 predicted in-hospital mortality of patients with duodenal ulcer bleeding as accurately as did other scoring systems. Given its simplicity of calculation, AIMS65 may be a more clinically practical system in the management of bleeding duodenal ulcer patients.

Efficacy and safety of cold forceps biopsy for diminutive pharyngeal neoplasms: Single-center, prospective pilot study.

BACKGROUND: Management of diminutive pharyngeal neoplasms is controversial. Thus, we conducted a single-center, prospective pilot study to investigate the efficacy and safety of endoscopic excision with cold forceps biopsy (CFB) of these lesions. PATIENTS AND METHODS: Thirty-nine lesions endoscopically diagnosed with narrow-band imaging as pharyngeal neoplasms of 3 mm or smaller were excised with CFB using jumbo biopsy forceps (cap diameter 2.8 mm, jaw volume 12.4 mm3 ). The primary outcome was endoscopically determined local remnant/recurrence rate 3 months after CFB. The secondary outcomes were histopathologically determined local remnant/recurrence rate; risk factors associated with the endoscopic remnant/recurrence; and incidence of intraoperative or delayed bleeding and other adverse events. RESULTS: Histological diagnosis of the 39 CFB-excised lesions were: 11 high-grade dysplasia (28.2%), 22 low-grade dysplasia (56.4%), two basal cell hyperplasia (5.1%) and four atypical squamous epithelium (10.3%).Twenty-seven patients (30 lesions) underwent follow-up endoscopy 3 months after CFB; the endoscopic and pathological local remnant/recurrence rate was 20% (6/30; 95% confidence interval (CI), 7.7-36.6%) and 16.7% (5/30; 95% CI, 5.6-34.7%), respectively. Location of the lesion in the hypopharynx was a significant risk factor associated with the endoscopic local remnant/recurrence (P = 0.049). No significant adverse events occurred. CONCLUSIONS: Cold forceps biopsy with jumbo biopsy forceps appears to be a safe and effective technique for excising diminutive pharyngeal neoplasms. Although small, the excised lesions may have a remarkably high frequency of high-grade dysplasia. (Clinical trial registration number: UMIN000037980).

Multiwall Carbon Nanotube Composites as Artificial Joint Materials.

Because ultrahigh-molecular-weight polyethylene (UHMWPE) is susceptible to frictional wear when used in sliding members of artificial joints, it is common practice to use cross-linked UHMWPE instead. However, cross-linked UHMWPE has low impact resistance; implant breakage has been reported in some cases. Hence, sliding members of artificial joints pose a major trade-off between wear resistance and impact resistance, which has not been resolved by any UHMWPE. On the other hand, multiwall carbon nanotubes (MWCNTs) are used in industrial products for reinforcement of polymeric materials but not used as biomaterials because of their unclear safety. In the present study, we attempted to solve this trade-off issue by complexing UHMWPE with MWCNTs. In addition, we assessed the safety of these composites for use in sliding members of artificial joints. The results showed the equivalence of MWCNT/UHMWPE composites to cross-linked UHMWPE in terms of wear resistance and to non-cross-linked UHMWPE in terms of impact resistance. In addition, all MWCNT/UHMWPE composites examined complied with the requirements of biosafety testing in accordance with the ISO10993-series specifications for implantable medical devices. Furthermore, because MWCNTs can occur alone in wear dust, MWCNTs in an amount of about 1.5 times that contained in the dust produced from 50 years of wear (in the worst case) were injected into rat knees, which were monitored for 26 weeks. Although mild inflammatory reactions occurred in the joints, the reactions soon became quiescent. In addition, the MWCNTs did not migrate to other organs. Furthermore, MWCNTs did not exhibit carcinogenicity when injected into the knees of mice genetically modified to spontaneously develop cancer. The MWCNT/UHMWPE composite is a new biomaterial expected to be safe for clinical applications in both total hip arthroplasty and total knee arthroplasty as the first sliding member of artificial joints to have both high wear resistance and high impact resistance.

Simple one-step synthesis of a two-dimensional perovskite consisting of perfluoroalkyl-based ammonium spacers using acetone as the solvent.

Acetone, regarded as a poor solvent for perovskite materials, was found to be suitable for synthesis of the perfluoroalkyl-based two-dimensional (2D) perovskite (C3F7CH2NH3)2PbBr4. One-step synthesis gave this material as a pure phase exhibiting quantum- and dielectric-confinement effects. However, N,N-dimethylformamide (DMF), a traditional perovskite solvent, did not produce these properties.

Effect of Vonoprazan on Delayed Bleeding after Endoscopic Submucosal Dissection for Gastric Neoplasia among Antithrombotic Drug Users: A Single-Center, Single-Arm Prospective Observational Case Control Study.

Antithrombotic therapy is a major risk factor for delayed bleeding after endoscopic submucosal dissection (ESD) for gastric neoplasia. A potassium-competitive acid blocker, vonoprazan, is expected to prevent delayed bleeding better than conventional proton pomp inhibitors (PPIs), but the evidence is controversial. We sought to clarify the efficacy of vonoprazan for prevention of delayed bleeding after gastric ESD in patients under antithrombotic therapy. We prospectively registered 50 patients who underwent gastric ESD while receiving antithrombotic therapy and vonoprazan in our institution between October 2017 and September 2018. The incidence of delayed bleeding was compared with that in a historical control group of 116 patients treated with conventional PPI. We also evaluated risk factors associated with delayed bleeding. Delayed bleeding was observed in 8 of 50 patients (16.0%), which was not dissimilar from the incidence in the historical control group (12.1%) (p=0.49). In the univariate analysis, age (> 70 years) (p=0.034), multiple antithrombotic drug use (p<0.01), procedure time (> 200 min) (p=0.038) and tumor size (> 40 mm) (p<0.01) were associated with delayed bleeding after gastric ESD, but vonoprazan was not (p=0.49). Vonoprazan may not be more effective than conventional PPIs in preventing delayed bleeding after gastric ESD in patients receiving antithrombotic therapy.

Impact of submucosal saline solution injection for cold snare polypectomy of small colorectal polyps: a randomized controlled study.

BACKGROUND AND AIMS: Cold snare polypectomy (CSP) of small colorectal polyps is widely used. However, the technique is still troubled by insufficient resection depth, which may prevent precise pathologic evaluation. In this study, we investigated whether submucosal injection of saline solution helps to achieve deeper resection in CSP. METHODS: The study was a single-center, prospective, randomized trial. Patients with small (3- to 10-mm diameter) nonpedunculated adenomatous or sessile serrated colorectal polyps were randomly allocated to either conventional CSP (C-CSP) or CSP with submucosal injection (CSP-SI). Primary outcome was the rate of complete muscularis mucosae (MM) resection, defined by the proportion of MM under the tumor more than 80% of the tumor's horizontal dimension. Secondary outcomes were the rates of negative lateral and vertical margins, fragmentation of resected specimens, conversion to hot snare mucosal resection, intraprocedural bleeding, delayed bleeding, and perforation. RESULTS: Two hundred fourteen patients were randomly assigned to the CSP-SI (n = 107) or C-CSP (n = 107) group. The rate of complete MM resection was 43.9% in the CSP-SI group and 53.3% in the C-CSP group, a statistically insignificant difference. The rates of negative lateral margin and vertical margin (42.3% and 56.7%, respectively) in the CSP-SI group were significantly lower than those (58% and 76%) in the C-CSP group (P = .03 and P = .006, respectively). There was no polypectomy-related major bleeding or perforation. CONCLUSIONS: Saline solution injection into the submucosa did not improve the resection depth of CSP of small colorectal polyps, and the method resulted in lower rates of negative lateral and vertical margins of resected lesions. (Clinical trial registration number: UMIN000037980.).

Spatial variation in bird pollination and its mitigating effects on the genetic diversity of pollen pools accepted by Camellia japonica trees within a population at a landscape level.

Bird pollination can vary spatially in response to spatial fluctuations in flowering even within plant populations. In this study, we examined the hypothesis that the spatial variation in bird pollination may induce mitigating effects, which maintains or increases genetic diversity of pollen pools at local sites with low flowering densities. To test this hypothesis, we analyzed the landscape-level genetic effects within a population of Camellia japonica on the pollen pools accepted by individuals in two reproductive years by using genotypes at eight microsatellite loci of 1323 seeds from 19 seed parents. Regression analyses using the quadratic models of correlated paternity between pollen pools against spatial distances between the seed-parent pairs revealed not only local pollination but also some amount of long-distance pollen dispersal. The genetic diversity of pollen pools accepted by seed parents tended to be negatively related to the densities of flowering individuals near the seed parents during winter (when the effective pollination of C. japonica is mediated mostly by Zosterops japonica). We show that the low density of flowering individuals may induce the expansion of the foraging areas of Z. japonica and consequently increase the genetic diversity of pollen pools. This spatial variation in bird pollination may induce the mitigating effects on the C. japonica population. The comparisons between the two study years indicate that the overall pattern of bird pollination and the genetic effects described here, including the mitigating effects, may be stable over time.

Post-polypectomy bleeding in hot-snare polypectomy of colonic polyps under continued warfarin or short interruption of direct oral anticoagulants.

BACKGROUND: Newly published guidelines of the Japanese Gastroenterological Endoscopy Society (JGES) suggest to consider endoscopic procedures with high risk of bleeding without stopping warfarin and with stopping direct oral anticoagulants (DOACs) only on the day of the procedure. In this study, we aimed to test the validity of these recommendations. PATIENTS AND METHODS: We retrospectively reviewed medical records of 344 patients with anticoagulant therapy who underwent hot-snare polypectomy between January 2012 and October 2018. Patients (n = 132) with interruption of anticoagulants (3-7 days for warfarin and 2-3 days for DOACs before the procedure) and without heparin-bridging were excluded. Among the remaining 212 patients, the incidence of post-polypectomy bleeding was compared between the following 2 patient groups: patients who had interruption of anticoagulants with heparin-bridging (HB group, n = 139) and patients treated according to the new JGES guideline (FG group, n = 73). RESULTS: The rate of post-polypectomy bleeding (PPB) in FG group (9.6%) was not significantly different from that in HB group (12.9%, p = 0.5). In subgroup analysis, the incidence of bleeding in patients with warfarin (12.2%) and with DOAC (6.3%) in FG group was not significantly different from corresponding figures in HB group (14.2%, 0%). In multivariate analysis, number of resected polyps was associated with PPB, but the administration of anticoagulants according to the new guidelines was not a significant risk factor for PPB (p = .98). CONCLUSIONS: Our study affirms the recommendations of JGES for the management of anticoagulants in patients who undergo colonic polypectomy regarding post-polypectomy bleeding.

[Sclerosing mesenteritis diagnosed using computed tomography- and ultrasound-guided needle biopsy -utility of the coaxial technique].

Here, we report the case of an 82-year-old woman with sclerosing mesenteritis diagnosed using needle biopsy under the guidance of computed tomography (CT) and ultrasound (US). The patient manifested appetite loss, weight loss, and epigastric pain. CT of the abdomen and pelvis revealed increased density of the mesentery adjacent to the small bowel along with enlarged lymph nodes. Hence, we suspected sclerosing mesenteritis but also considered malignancies, such as lymphoma. We then performed CT- and US-guided needle biopsy with coaxial technique. We inserted an introducer needle by verifying its location using CT and extracted multiple specimens using a finer needle that passed through the introducer without incident. The collected specimens were adequate and histological diagnosis revealed sclerosing mesenteritis. We treated the patient with corticosteroids, and her symptoms and radiographic findings improved. Thus, the coaxial technique was a useful and minimally invasive tool for the diagnosis of sclerosing mesenteritis.

Severe Bleeding due to Cytomegalovirus Esophagitis in a Patient with Diabetes after Interbody Fusion Surgery.

A 49-year-old man with diabetes taking clopidogrel and celecoxib underwent interbody fusion surgery for spinal spondylolysis. Ten days after the surgery, he vomited a large amount of fresh blood. A blood examination revealed hemodynamic failure. Esophagogastroduodenoscopy showed an adherent blood clot and multiple superficial ulcers in the esophagus. Endoscopic hemostasis was successfully achieved. Biopsy specimens from the esophageal ulcer showed positive immunohistochemical staining results for anti-CMV antibodies. The esophageal ulcer improved after the oral administration of ganciclovir. This case emphasizes that CMV esophagitis with bleeding can occur in a diabetic patient with a poor nutritional status due to relative immune dysfunction.

Photon upconversion utilizing energy beyond the band gap of crystalline silicon with a hybrid TES-ADT/PbS quantum dots system.

The recent introduction of inorganic semiconductor quantum dots (QDs) as triplet sensitizers for molecular semiconductors has led to significant interest in harvesting low energy photons, which can then be used for photon upconversion (PUC), via triplet-triplet annihilation (TTA). A key goal is the harvesting of photons from below the bandgap of crystalline silicon 1.12 eV (≈1100 nm) and their upconversion into the visible region. In practice, the systems demonstrated so far have been limited to harvesting photons with energies above 1.2 eV (≈1 µm), due to two reasons: firstly the need to use transmitter ligands which allow efficient energy harvesting from the QD but introduce an energy loss of larger than 200 meV in transmission from the QD to the annihilator, and secondly due to the use of molecules such as tetracene which cannot accept smaller energy than 1.2 eV. Here, we introduce a new strategy to overcome these difficulties by using a low energy triplet annihilator that also harvests excitations efficiently from QDs. Specifically, we show that 5,11-bis(triethylsilylethynyl)anthradithiophene (TES-ADT, triplet energy of 1.08 eV: ca. 1150 nm) functions as a triplet annihilator (20% TTA efficiency) while also rapidly extracting triplet excitons from lead sulfide (PbS) QDs with a rate constant of k = ca. 2 × 10-8 s-1 with an excitation at 1064 nm. This rate is consistent with an orbital overlap between TES-ADT and PbS QDs, which we propose is due to the thiophene group of TES-ADT, which enables a close association with the PbS surface, allowing this system to function both as annihilator and transmitter. Our results pave the way for the design of triplet annihilators that can closely associate with the QD surface and harvest low energy excitons with minute losses in energy during the TET process, with the ultimate goal of efficiently utilizing photon energy beyond the bandgap of crystalline silicon.

Early gastric cancer with ball valve syndrome treated by endoscopic submucosal dissection.

An 84-year-old woman with pneumonia, congestive heart failure and chronic renal failure presented for iron-deficiency anemia and appetite loss. Esophagogastroduodenoscopy revealed a 60-mm sub-pedunculated tumor arising from the antrum of the stomach. The tumor was friable, with bleeding, and prolapsed into the duodenal bulb, the ball valve syndrome. The tumor was considered the cause of the anemia and appetite loss. Attempted endoscopic reduction of the prolapsing tumor was unsuccessful, but the base of its stalk could be identified through the transparent hood; thus, we removed the tumor with endoscopic submucosal dissection. The tumor was retrieved successfully, and pathohistological examination revealed the tumor to be a well-differentiated adenocarcinoma. This case suggests that endoscopic submucosal dissection is useful as an alternative to surgery for removal of gastric tumors that have prolapsed into the duodenal bulb when polypectomy was difficult, but provided the tumor's attachment site can be identified endoscopically.

Endoscopic Submucosal Dissection for Gastric-phenotype Adenoma on the Surface of Gastric Gastrointestinal Stromal Tumor.

We herein report a rare case of a gastric adenoma overlying a gastrointestinal stromal tumor (GIST) that was removed by endoscopic submucosal dissection (ESD). A 78-year-old woman was referred to our hospital. Esophagogastroduodenoscopy revealed an elevated lesion of 15 mm in diameter overlying a submucosal mass in the gastric cardia. ESD was performed for the epithelial neoplasm, and biopsy specimens were obtained directly from the exposed surface of the submucosal tumor. The epithelial tumor was a tubular adenoma with focal severe atypia and a gastric phenotype. Biopsy specimens revealed a GIST, which was resected by laparoscopic intragastric surgery afterward.