Nanoshell Formation at the Electrically Charged Gas-Water Interface of Collapsing Microbubbles: Insights from Atomic Force Microscopy Imaging.

AFM imaging has revealed intriguing features when bulk nanobubbles were deposited on a positively charged substrate. Numerous spherical objects, each less than 20 nm in diameter, were observed on the substrate. These objects were adorned with noticeable, tiny protrusions, each measuring a few nanometers. These findings suggest the presence of solid shells contributing to the stability of the gas bodies. Furthermore, electrically charged microbubbles appear to play a critical role in the formation of these solid shells. The collapse of microbubbles in an electrolyte aqueous solution containing iron ions leads to a condensing ionic cloud, creating conditions necessary for solid nucleation at the interface. At the end of the collapsing process, concurrent multinucleation may result in the deposition of solid material on the interface, forming solid shells with specific structures on the surfaces. This study illuminates the phenomenon of electrically charged gas-water interfaces during microbubble collapse and highlights the generation of stabilized nanoshells in aqueous solutions without the need for chemical stabilizers.

Mineralization of Poly(vinyl alcohol) by Ozone Microbubbles under a Wide Range of pH Conditions.

Poly(vinyl alcohol) (PVA) is a well-known recalcitrant pollutant that threatens ecological systems and human health. In this study, ozone-microbubble treatment was evaluated as a physicochemical method to mineralize PVA in solution for wastewater treatment. Microbubbles are very small bubbles (<50 µm in diameter) and shrink in water because of the rapid dissolution of the interior gas. Ozone microbubbles were generated by a hybrid microbubble generator in PVA solutions with pH conditions of 2, 7, and 10. Ordinary ozone bubbling was also performed as control tests. The change in the total-organic-carbon content was measured to evaluate the efficiency of the system for wastewater treatment. Ordinary ozone bubbling was not able to mineralize aqueous PVA solutions under nonalkaline conditions, and approximately 30% of the total organic carbon remained at pH 2 and 7. Conversely, ozone microbubbles effectively mineralized PVA in aqueous solution to almost 0% in total organic carbon regardless of the pH condition. Effective mineralization of PVA, a recalcitrant organic chemical, demonstrates the potential of ozone-microbubble systems for physicochemical wastewater treatment.

Accelerated germination of aged recalcitrant seeds by K+-rich bulk oxygen nanobubbles.

Bulk nanobubbles, measuring less than 200 nm in water, have shown their salient properties in promoting growth in various species of plants and orthodox seeds, and as potential drug-delivery carriers in medicine. Studies of recalcitrant seeds have reported markedly increased germination rates with gibberellin treatment; however, neither the mechanism promoting germination nor the implication for food safety is well elucidated. In our study, recalcitrant wasabi (Eutrema japonicum) seeds treated with bulk oxygen nanobubbles (BONB) containing K+, Na+, and Cl- (BONB-KNaCl) showed significantly accelerated germination. As germination progressed, 99% of K+ ions in the BONB-KNaCl medium were absorbed by the seeds, whereas Ca2+ ions were released. These results suggest that the germination mechanism involves the action of K+ channels for migration of K+ ions down their concentration gradient and Ca2+ pumps for the movement of Ca2+ ions, the first potential discovery in germination promotion in recalcitrant seeds using nutrient solutions with BONB-KNaCl.

Multiple esophageal hematomas with oozing observed and successfully treated after transcatheter mitral valve edge-to-edge repair procedure.

Although previously reported as relatively rare, esophageal hematoma can likely develop in patients on anticoagulants or those with underlying hemorrhagic disorders. From April 2018 to December 2018, among 36 patients who received transcatheter mitral valve edge-to-edge repair (TMVr) at our hospital, seven (19.4%), who were suspected of having digestive tract hemorrhage evidenced by blood stains on a probe extracted after transesophageal echocardiography, underwent esophagogastroduodenoscopy. Esophageal hematomas were noted in all patients, and endoscopic hemostasis was performed in two cases. Depending on their form, hematomas were noted on the submucosa and the epithelium of the shallow esophageal layer. Esophageal hematomas caused by transesophageal echocardiography for TMVr are not rare, and clinicians should be aware of it.

Free-Radical Generation from Bulk Nanobubbles in Aqueous Electrolyte Solutions: ESR Spin-Trap Observation of Microbubble-Treated Water.

Microbubbles are very fine bubbles that shrink and collapse underwater within several minutes, leading to the generation of free radicals. Electron spin resonance spectroscopy (ESR) confirmed the generation of hydroxyl radicals under strongly acidic conditions. The drastic environmental change caused by the collapse of the microbubbles may trigger radical generation via the dispersion of the elevated chemical potential that had accumulated around the gas-water interface. The present study also confirmed the generation of ESR signals from the microbubble-treated waters even after several months had elapsed following the dispersion of the microbubbles. Bulk nanobubbles were expected to be the source of the spin-adducts of hydroxyl radicals. Such microbubble stabilization and conversion might be caused by the formation of solid microbubble shells generated by iron ions in the condensed ionic cloud around the microbubble. Therefore, the addition of a strong acid might cause drastic changes in the environment and destroy the stabilized condition. This would restart the collapsing process, leading to hydroxyl radical generation.

Comparison of various risk scores for the prognosis of hemorrhagic upper gastrointestinal mucosal disorder.

BACKGROUND: Various risk scores have been proposed that are useful for the management of upper gastrointestinal bleeding (UGIB), which is an important disease in emergency medicine. Few studies have examined the usefulness of Charlson Comorbidity index (CCI) in this disease, which evaluates the patient's general condition by scoring the patient's underlying disease. There have been no studies investigating the efficacy of CCI compared to other risk scores in the management of UGIB requiring endoscopic hemostasis. METHODS: In addition to the Glasgow-Blatchford score, AIMS65 score, and Rockall score, we investigated the efficacy of the outcome prediction obtained by the original CCI and the updated CCI, scored only with respect to the underlying disease. We also examined the cutoff value when using the risk score. This retrospective study included 265 patients with hemorrhagic upper gastrointestinal mucosal lesions who underwent emergency endoscopic hemostasis during a 6-year period between 2011 and 2016 in our hospital. RESULTS: The updated CCI and AIMS65 score correlated with prognosis in multivariate analysis (p = 0.002 and p = 0.003, respectively). In clinical practice, the prognosis might be worse if both updated CCI and AIMS65 score were 3 point or more. CONCLUSION: In addition to the AIMS65 score, the updated CCI can be a useful tool for managing upper gastrointestinal mucosal disorder bleeding that requires endoscopic hemostasis.

Novel surgical approach without bowel resection for multiple gastrointestinal lipomatosis: A case report.

INTRODUCTION: Asymptomatic lipoma only requires observation, whereas symptomatic lipoma requires treatment such as endoscopic or surgical resection. However, in case of multiple lipomas, with evident diffusion and malignancy, resection procedure and range cannot be determined. We experienced GI lipomatosis (multiple lipomas) diffusely existing from the duodenum to the small intestine and involved recurrent intussusception. PRESENTATION OF CASE: 47 year-old female was a history of open bowel resection for intestinal obstruction caused by intussusceptions of multiple small intestinal lipoma 11 years ago. EGD showed duodenal lipoma, and CT showed diffuse multiple lipomas from the proximal jejunum to the distal ileum. Another CT also showed intussusception of small intestine, but no signs of intestinal obstruction. Surgical procedures performed included diagnostic laparoscopy. All intestinal lipomas were resected with local excision, and duodenal lipoma was resected with ESD without any bowel resection. DISCUSSION: Multiple local excision ESD for multiple GI lipomatosis have not been reported. The most problematic thing is that if extensive resection is performed to cut off all multiple lipoma, short bowel syndrome may occur. Determining the range to be cut remains unclear. CONCLUSIONS: Multiple local excision ± ESD seemed to be one of the methods in resecting multiple GI lipomatosis. In the future, cases and indications of surgery and resection method for GI lipoma should be accumulated and considered, respectively.

Risk factors for delayed bleeding from endoscopic submucosal dissection of gastric neoplasms.

OBJECTIVE: Delayed bleeding is a major complication of endoscopic submucosal dissection (ESD) of gastric neoplasms. We aimed to clarify risk factors for delayed bleeding from ESD. MATERIAL AND METHODS: This study included 447 patients in whom 544 gastric neoplasms were resected by ESD between April 2006 and March 2011 in Yamaguchi University Hospital. We analyzed risk factors for delayed bleeding from ESD in relation to various clinical and pathological factors. RESULTS: En bloc resection rate was 95.4% (519/544), and curative resection rate was 87.8% (477/544). Delayed bleeding occurred in 7.0% (38/544) and perforation occurred in 1.8% (10/544) of patients. Univariate analysis revealed platelet count (Plt) <15 × 104/µl (p = 0.013), prothrombin time (PT) <70% (p = 0.044), resected size ≥ 50 mm (p = 0.038), and positive/indeterminate lateral margin (p = 0.012) to be risk factors for delayed bleeding. Multivariate analysis showed that Plt <15 × 104/µl (odds ratio [OR], 2.62; 95% confidence interval [CI]: 1.17-5.53, p = 0.020) and positive/indeterminate lateral margin (OR, 5.45; 95% CI: 1.39-17.95, p = 0.018) were independent risk factors for delayed bleeding. CONCLUSIONS: Low Plt, low PT, large resected size, and positive/indeterminate lateral margin were significant risk factors for delayed bleeding from ESD. Patients with these risk factors must be carefully observed for signs of delayed bleeding.

Adjunctive gabapentin for treatment-resistant insomnia of bipolar disorder: a case report.

We report a case with bipolar II disorder having mixed features, in which refractory insomnia persisted. We diagnosed his case as mixed depression with mood fluctuations because increased impulsivity and buying sprees became remarkable, with diminished ability to think or concentrate. Switching to carbamazepine and risperidone improved his mood fluctuations and impulsivity. Nevertheless, his intermittent awakening (fragmentation of the sleep-wake rhythm), related dysfunctional beliefs, anxiety about sleep, and mild impulsivity persisted. The addition of various benzodiazepine sleeping drugs, bromovalerylurea, and antipsychotics did not improve insomnia. His intractable insomnia was markedly responsive to gabapentin, engendering further improvement of mood symptoms. Eventually, its efficacy achieved his reinstatement at work. Results of this case suggest the clinical use of gabapentin for treating bipolar disorder, especially in cases with intractable insomnia, which is a very important point in the symptoms and therapeutics of bipolar disorder.

Usefulness of magnifying endoscopy with narrow-band imaging for determining gastric tumor margin.

BACKGROUND AND AIM: Magnifying endoscopy with narrow-band imaging (ME-NBI) enhances images of the irregular mucosal structures and microvessels of gastric carcinoma, and could be useful for determining the margin between cancerous and non-cancerous mucosa. We evaluated the usefulness of ME-NBI for determining the tumor margin compared with indigocarmine chromoendoscopy (ICC). METHODS: The subjects were 110 patients (with 118 lesions) who underwent endoscopic submucosal dissection for gastric tumors. They were randomized into ME-NBI and ICC groups. Marking was carried out by electrocautery with the tip of a high-frequency snare at the tumor margins determined by each observation. The distance from the marking dots to the tumor margin was measured histopathologically in the resected specimens. Marking was diagnosed as accurate if the distance was less than 1 mm. RESULTS: Of the 118 gastric lesions, 55 were allocated to the ME-NBI group, and 63 to the ICC group. Seventeen lesions in the ME-NBI group and 18 lesions in the ICC group were excluded because the distance from the marking dots to the tumor margin was immeasurable histopathologically. Thirty-eight lesions in the ME-NBI group and 45 lesions in the ICC group were evaluated. The rate of accurate marking of the ME-NBI group was significantly higher than that of the ICC group (97.4% vs 77.8%, respectively; P-value = 0.009). CONCLUSION: Magnifying endoscopy with narrow-band imaging can identify gastric tumor margins more clearly than ICC.

Fine-tuning the criteria for strip biopsy and endoscopic submucosal dissection improves the outcome of early gastric carcinoma treatment.

BACKGROUND AND AIM: Strip biopsy and endoscopic submucosal dissection (ESD) have been developed as a local treatment for early gastric cancer (EGC). However, the lesion criteria for the use of ESD, rather than strip biopsy, remain to be elucidated. METHODS: On the basis of reviews of literature and our observations concerning the outcome of strip biopsy, we set the criteria for selecting strip biopsy and ESD as follows. The indications for strip biopsy were lesions less than 10 mm in size and located in the anterior wall or greater curvature of the lower and middle stomach. ESD was indicated for all other lesions. The validity of the criteria was then analyzed prospectively in 156 patients. The rate of en bloc R0 resection and local recurrence were evaluated. RESULTS: Subsequently, 156 lesions were divided according to the criteria and were endoscopically resected by strip biopsy (n = 13) or ESD (n = 143). The en bloc R0 resection rates for the whole group and the strip biopsy and ESD groups was 93.5% (146/156), 92.3% (12/13), and 93.7% (134/143), respectively. None of the patients had suffered from local recurrence in either the strip biopsy or ESD groups. CONCLUSION: The validity of our criteria for selecting strip biopsy and ESD was verified. Our criteria exploit the advantages of both procedures and obtain better endoscopic therapy outcomes for EGC.

[Special characteristics and necessary equipments for intraoperative neurological monitoring].

An intraoperative monitoring is essential for performing surgery, especially in the neurosurgical field. Intraoperative neurological monitoring methods may involve an application of evoked potential examinations in clinical physiology. Accordingly, it is necessary to perform intraoperative neurological monitoring to basically understand the principles and techniques of evoked potential examinations. Furthermore, the point of intraoperative neurological monitoring is to clarify environmental differences between the operating room and clinical physiological laboratory. In the laboratory, evoked potential examination are almost always performed in a shielded room. Therefore, there is little noise on records of these evoked potentials. However, records of intraoperative neurological monitoring are contaminated with a lot of noise caused by medical electronic equipment used in the operating room. Most of this noise results from electromagnetic factors. And the remaining noise is caused by mechanical, optical, and acoustic factors. Consequently elimination of noise from these various sources from the monitoring records would promote the success of intoraoperative neurological monitoring. In this study, differential amplifiers, class I medical electronic equipments, and shield mats were tested to eliminate the alternating current noise that frequently contaminates the intraoperative neurological monitoring record. In addition, neurological monitoring system, recording electrodes, and extension cables are introduced as necessary equipment and materials for the intraoperative neurological monitoring.

Prospective randomized study on the use of a computer-based endoscopic simulator for training in esophagogastroduodenoscopy.

BACKGROUND AND AIM: Computer-based endoscopic simulators have been developed in recent years, and their usefulness has been reported. However, there is no blinded prospective randomized controlled study on esophagogastroduodenoscopy (EGD) training using virtual reality simulators. The present study aimed to assess the effectiveness of a computer-based simulator for basic training in EGD. METHODS: The GI-Mentor II simulator was used. The subjects were 20 hospital medical residents. After receiving an explanation regarding the fundamentals of endoscopy, 10 trainees were each randomized into a simulator group and a non-simulator group. The simulator group received 5 h of training with the GI-Mentor II plus bedside training, while the non-simulator group received bedside training. Subsequently, each subject performed endoscopy twice for assessment. Performance was evaluated according to a five-grade scale for a total of 11 items. RESULTS: The score was significantly higher in the skills required for insertion into the esophagus, passing from the esophagogastric junction (EGJ) to the antrum, passing through the pylorus, and examination of the duodenal bulb and the fornix. CONCLUSIONS: The performance of endoscopy was improved by 5 h of simulator training. The simulator was more effective with regard to the items related to manipulation skills. Computer-based simulator training in EGD is useful for beginners.

[Novel apnomonitor for use at home].

The monitoring technique for assessing suspected sleep apnea syndrome is a polysomnogram (PSG) performed in hospital. The typical PSG includes EEG, EOG, EMG, air flow at the nose and mouth, SO2, thoracicoabdominal motion and snoring sound. But the PSG test is expensive, and also is a stress load for the patient because this test requires recording throughout the night. Recently, a home-type apnomonitor that is used at home has been developed for the screening of apnea, but this monitor can not distinguish obstructive sleep apnea (OSA) from central sleep apnea (CSA). We evaluated a new home-type apnomonitor that was able to distinguish OSA from CSA using the change of amplitude in the fingertip plethysmogram and respiratory flow curve attained by oronasal transducer. In this study, the respiratory flow curve became flat under OSA conditions, but the change of amplitude on plethysmogram corresponded to thoracioabdominal motion. On the other hand, the change of amplitude in the plethysmogram did not corresponded with thoracicoabdominal motion under CSA conditions. These findings suggest that it is possible to distinguish between OSA and CSA using an apnomonitor system which records a respiratory flow curve and a plethysmogram, and also to develop a new home-type apnomonitor.