AC Electromagnetic Field Controls the Biofilms on the Glass Surface by Escherichia coli & Staphylococcus epidermidis Inhibition Effect.

Biofilms, mainly comprised of bacteria, form on materials' surfaces due to bacterial activity. They are generally composed of water, extracellular polymeric substances (polysaccharides, proteins, nucleic acids, and lipids), and bacteria. Some bacteria that form biofilms cause periodontal disease, corrosion of the metal materials that make up drains, and slippage. Inside of a biofilm is an environment conducive to the growth and propagation of bacteria. Problems with biofilms include the inability of disinfectants and antibiotics to act on them. Therefore, we have investigated the potential application of alternating electromagnetic fields for biofilm control. We obtained exciting results using various materials' specimens and frequency conditions. Through these studies, we gradually understood that the combination of the type of bacteria, the kind of material, and the application of an electromagnetic field with various low frequencies (4 kHz-12 kHz) changes the circumstances of the onset of the biofilm suppression effect. In this study, relatively high frequencies (20 and 30 kHz) were applied to biofilms caused by Escherichia coli (E. coli) and Staphylococcus epidermidis (S. epidermidis), and quantitative evaluation was performed using staining methods. The sample surfaces were analyzed by Raman spectroscopy using a Laser Raman spectrometer to confirm the presence of biofilms on the surface.

A desmoid tumor with fluorodeoxyglucose accumulation arising from the anastomotic site of postoperative gastric cancer: a case report.

BACKGROUND: Desmoid tumors are extremely rare borderline benign and malignant tumors that do not exhibit accumulation on fluorodeoxyglucose positron emission tomography-computed tomography. In the present study, we report a rare case of a desmoid tumor with fluorodeoxyglucose accumulation at the anastomotic postoperative gastric cancer site. CASE PRESENTATION: A 68-year-old Japanese man underwent robot-assisted laparoscopic distal gastrectomy for early-stage gastric cancer in 2019. The pathological diagnosis was stage IA cancer, and no adjuvant chemotherapy was administered. Two years after surgery, a soft mass appeared on the greater curvature side of the anastomosis on computed tomography. Fluorodeoxyglucose positron emission tomography-computed tomography revealed fluorodeoxyglucose accumulation, which suggested a malignancy; therefore, surgery was performed for diagnostic treatment. The histopathological findings led to the diagnosis of a desmoid tumor. The patient has not experienced recurrence to date. CONCLUSIONS: In the present study, we encountered a desmoid tumor arising from the anastomotic site of a postoperative gastric cancer. This case is rare as fluorodeoxyglucose positron emission tomography-computed tomography showed fluorodeoxyglucose accumulation in the desmoid tumor, and a preoperative diagnosis could not be reached. We hope that further studies will improve the accuracy of preoperative diagnosis.

Quantitative Analyses of Biofilm by Using Crystal Violet Staining and Optical Reflection.

Biofilms have caused many problems, not only in the industrial fields, but also in our daily lives. Therefore, it is important for us to control them by evaluating them properly. There are many instrumental analytical methods available for evaluating formed biofilm qualitatively. These methods include the use of Raman spectroscopy and various microscopes (optical microscopes, confocal laser microscopes, scanning electron microscopes, transmission electron microscopes, atomic force microscopes, etc.). On the other hand, there are some biological methods, such as staining, gene analyses, etc. From the practical viewpoint, staining methods seem to be the best due to various reasons. Therefore, we focused on the staining method that used a crystal violet solution. In the previous study, we devised an evaluation process for biofilms using a color meter to analyze the various staining situations. However, this method was complicated and expensive for practical engineers. For this experiment, we investigated the process of using regular photos that were quantified without any instruments except for digitized cameras. Digitized cameras were used to compare the results. As a result, we confirmed that the absolute values were different for both cases, respectively. However, the tendency of changes was the same. Therefore, we plan to utilize the changes before and after biofilm formation as indicators for the future.

Proposal for Some Affordable Laboratory Biofilm Reactors and Their Critical Evaluations from Practical Viewpoints.

Biofilms are a result of bacterial activities and are found everywhere. They often form on metal surfaces and on the surfaces of polymeric compounds. Biofilms are sticky and mostly consist of water. They have a strong resistance to antimicrobial agents and can cause serious problems for modern medicine and industry. Biofilms are composed of extracellular polymeric substances (EPS) such as polysaccharides produced from bacterial cells and are dominated by water at the initial stage. In a series of experiments, using Escherichia coli, we developed three types of laboratory biofilm reactors (LBR) to simulate biofilm formation. For the first trial, we used a rotary type of biofilm reactor for stirring. For the next trial, we tried another rotary type of reactor where the circular plate holding specimens was rotated. Finally, a circular laboratory biofilm reactor was used. Biofilms were evaluated by using a crystal violet staining method and by using Raman spectroscopy. Additionally, they were compared to each other from the practical (industrial) viewpoints. The third type was the best to form biofilms in a short period. However, the first and second were better from the viewpoint of "ease of use". All of these have their own advantages and disadvantages, respectively. Therefore, they should be properly selected and used for specific and appropriate purposes in the future.

Morphology Control of Monomer-Polymer Hybrid Electron Acceptor for Bulk-Heterojunction Solar Cell Based on P3HT and Ti-Alkoxide with Ladder Polymer.

We report the morphology control of a nano-phase-separated structure in the photoactive layer (power generation layer) of organic-inorganic hybrid thin-film solar cells to develop highly functional electronic devices for societal applications. Organic and inorganic-organic hybrid bulk heterojunction solar cells offer several advantages, including low manufacturing costs, light weight, mechanical flexibility, and a potential to be recycled because they can be fabricated by coating them on substrates, such as films. In this study, by incorporating the carrier manager ladder polymer BBL as the third component in a conventional two-component power generation layer consisting of P3HT-the conventional polythiophene derivative and titanium alkoxide-we demonstrate that the phase-separated structure of bulk heterojunction solar cells can be controlled. Accordingly, we developed a discontinuous phase-separated structure suitable for charge transport, obtaining an energy conversion efficiency higher than that of the conventional two-component power generation layer. Titanium alkoxide is an electron acceptor and absorbs light with a wavelength lower than 500 nm. It is highly sensitive to LED light sources, including those used in homes and offices. A conversion efficiency of 4.02% under a 1000 lx LED light source was achieved. Hence, high-performance organic-inorganic hybrid bulk heterojunction solar cells with this three-component system can be used in indoor photovoltaic systems.

Research Activities in Materials Science and Engineering with Academic-Industrial Alliances during the COVID-19 Pandemic.

During the COVID 19 pandemic, the importance of global academia-industrial alliances has increased. It is hoped that the alliances will help us to solve the current problems caused by the pandemic. In this paper, we introduce the application of IT tools and communication skills utilized in a special educational project for an academia-industrial collaboration. Some concrete examples from 2020 are provided from the viewpoint of the national alliance project in Japan. A discussion is included that describes the plans available to increase and strengthen the national project in the future.

Impact of chest subcutaneous fat on the occurrence of central venous port-related infectious complications in cancer patients.

PURPOSE: There is no concrete evidence to support the association between the amount of subcutaneous fat area (SFA) in the central venous port-insertion site (precordium) and port-related complications. We aimed to investigate the relationship between SFA in the midclavicular line and postoperative infectious complications in patients undergoing port-insertion surgery. METHODS: This was a single-institute and historical cohort study of 174 patients who underwent first central venous port implantation surgery for chemotherapy between January 2014 and December 2018. SFA in the midclavicular line was measured using preoperative computed tomography scans. The patients were divided into three groups according to SFA amount tertiles, and we investigated the association of SFA with infectious and all-cause complication events within 1 year. RESULTS: Within a median follow-up of 306 days, the patients with intermediate SFA had significantly higher infection-free survival than those with low and high SFA (low vs. intermediate vs. high: 80.4% vs. 97.7% vs. 83.4%, respectively, p=0.034). In contrast, there was no significant difference in the overall complication-free survival among the groups (low vs. intermediate vs. high: 80.4% vs. 88.9% vs. 81.8%, respectively, p=0.29). Low SFA was independently associated with high risk of infectious complications (hazard ratio, 9.45; 95% confidence interval, 1.07-83.22, p=0.043). CONCLUSION: Low SFA in the midclavicular line was an independent risk factor for infectious complications in the chemotherapy setting. This practical indicator can be useful for optimizing patients' nutritional status and when considering other types of vascular access to support administration of intravenous chemotherapy.

Ruptured intra-abdominal testicular seminoma with hemorrhage shock, after inadequate surgical exploration for undescended testis: a case report.

BACKGROUND: Undescended testes are associated with an increased risk of malignancy and infertility, and surgical treatment in childhood is recommended. CASE PRESENTATION: A 35-year-old man presented to the emergency department with abdominal pain and vomiting. Despite a history of surgery for a left undescended testis in infancy, his left-sided scrotum appeared underdeveloped. Contrast-enhanced computed tomography showed a pelvic mass, involving a major axis of approximately 15 cm, with high-density ascites suggestive of hemorrhage. A ruptured gastrointestinal stromal tumor was suspected. As he was in hemorrhagic shock, an emergency laparotomy was indicated. The active bleeding mass was controlled through complete resection. A pathological evaluation of the mass revealed a seminoma arising from an undescended testis. His post-operative course was uneventful, and he was discharged on post-operative day 6. Recurrence on the retroperitoneal lymph nodes was detected 1 year postoperatively, and a retroperitoneal lymph node dissection was performed after chemotherapy. He remains well without any apparent signs of recurrence. CONCLUSIONS: Paying close attention to an empty scrotum is advisable, even postoperatively, for undescended testis because of possible subsequent potential malignancy presenting with hemorrhage, as our patient demonstrated.

Preoperative Magnetic Resonance Cholangiopancreatography for Detecting Difficult Laparoscopic Cholecystectomy in Acute Cholecystitis.

Previous studies have shown that signal intensity variations in the gallbladder wall on magnetic resonance imaging (MRI) are associated with necrosis and fibrosis in the gallbladder of acute cholecystitis (AC). However, the association between MRI findings and operative outcomes remains unclear. We retrospectively identified 321 patients who underwent preoperative magnetic resonance cholangiopancreatography (MRCP) and early laparoscopic cholecystectomy (LC) for AC. Based on the gallbladder wall signal intensity on MRI, these patients were divided into high signal intensity (HSI), intermediate signal intensity (ISI), and low signal intensity (LSI) groups. Comparisons of bailout procedure rates (open conversion and laparoscopic subtotal cholecystectomy) and operating times were performed. The recorded bailout procedure rates were 6.8% (7/103 cases), 26.7% (31/116 cases), and 40.2% (41/102 cases), and the median operating times were 95, 110, and 138 minutes in the HSI, ISI, and LSI groups, respectively (both p < 0.001). During the multivariate analysis, the LSI of the gallbladder wall was an independent predictor of both the bailout procedure (odds ratio [OR] 5.30; 95% CI 2.11-13.30; p < 0.001) and prolonged surgery (≥144 min) (OR 6.10, 95% CI 2.74-13.60, p < 0.001). Preoperative MRCP/MRI assessment could be a novel method for predicting surgical difficulty during LC for AC.

A case of a jejunal gastrointestinal stromal tumor with significantly elevated CA19-9 levels.

INTRODUCTION: A gastrointestinal stromal tumor (GIST) with an elevated serum tumor marker level is very rare. We report a case of jejunal GIST associated with extremely elevated levels of serum carbohydrate antigen 19-9 (CA19-9). PRESENTATION OF CASE: A 61-year-old woman was referred to our hospital for examination of an abdominal tumor. Laboratory tests revealed extremely elevated CA19-9 levels (13,498 U/mL). Enhanced abdominal computed tomography demonstrated a well-enhanced, round 40 mm tumor. The patient underwent a jejunectomy and lymph node dissection. Based on the postoperative pathological findings, the tumor was diagnosed as a GIST. Microscopically, a solid region of the resected tumor showed negative staining for CA19-9. The serum CA19-9 level drastically decreased postoperatively. DISCUSSION: Increased proliferation of epithelial cells secondary to inflammation and ulceration of epithelia may lead to increased secretion and accumulation of CA19-9, which is consequently released into the blood circulation. CONCLUSION: In cases of GIST, an isolated increase of serum CA19-9 is extremely rare; but they are not necessarily associated with malignant transformation.

Total proctocolectomy with end ileostomy for acute onset of ulcerative colitis during chemoradiotherapy for lung adenocarcinoma (successfully treated by surgery): a case report.

BACKGROUND: Ulcerative colitis (UC) developing during chemotherapy is very rare. Here, we describe a case of acute onset during chemoradiotherapy for lung adenocarcinoma, requiring a total proctocolectomy. CASE PRESENTATION: A 52-year-old man was admitted to the hospital for chemoradiotherapy of lung cancer. He had no obvious history of gastrointestinal diseases, and concurrent chemoradiotherapy was initiated. Thirteen days after 2 cycles of cisplatin and vinorelbine, he experienced persistent hematochezia. Findings of the colonoscopy revealed edematous thickening from the rectum to the transverse colon, suggesting UC, drug-induced colitis, or infectious colitis. Results from bacterial culture were negative for Clostridium difficile and methicillin-resistant Staphylococcus aureus (MRSA). Immunohistological staining for cytomegalovirus was also negative. Although he was clinically diagnosed with UC and treated with intravenous glucocorticoid, his symptoms gradually worsened and an abdominal X-ray revealed megacolon. Thirty-five days after conservative therapy, a total proctocolectomy with end permanent ileostomy was performed. Based on pathological findings and clinical course, he was diagnosed with UC. CONCLUSION: Although the pathogenesis of UC during chemotherapy has been unknown, chemotherapy could be one of the causes of UC in this case. UC should be included in the differential diagnosis in patients with progressive colitis during chemotherapy.

Primary cardiac angiosarcoma resection and reconstruction with pedicled autologous pericardium: A case report.

INTRODUCTION: Primary cardiac angiosarcoma is rare, and its prognosis remains poor. Complete surgical resection is the first choice among the available treatments, to ensure prolonged patient survival. PRESENTATION OF CASE: We report the case of a 72-year-old man with right atrial angiosarcoma who presented with bloody pericardial effusion due to tumor hemorrhaging. Emergency surgery was performed. The right atrial free wall and vena cava were reconstructed with pedicled autologous pericardium. The patient died 12 months later because of multiple organ failure due to metastasis. Autopsy showed a maintained right atrial chamber and only mild calcification. DISCUSSION: Pedicled autologous pericardium may have contributed to preserving cardiac function that could withstand chemotherapy and radiotherapy. CONCLUSION: Pedicled autologous pericardium was found to be useful for reconstructing the cardiac chamber after removal of a cardiac tumor.

Gastric remnant necrosis secondary to cholesterol crystal embolization after distal gastrectomy in a gastric cancer patient: a case report.

BACKGROUND: Distal gastrectomy with lymph node dissection, a standard operative technique for gastric cancer treatment, is safely performed because the stomach has a rich vascular supply. Gastric remnant necrosis caused by cholesterol crystal embolization following distal gastrectomy has not been described previously. We report a case of gastric remnant necrosis in a patient with cholesterol crystal embolization. CASE PRESENTATION: A 70-year-old man with a history of cholesterol crystal embolization presented to our surgery department with complaints of anorexia and dysphasia. He was diagnosed with gastric cancer invading the pyloric antrum and underwent distal gastrectomy with Billroth 2 reconstruction. On postoperative day 11, he developed abdominal pain without fever. Emergency laparotomy revealed that most parts of the remnant stomach were necrosed. Total gastrectomy with Roux-en-Y reconstruction and abscess drainage were performed. After surgery, anastomotic leakage occurred and was treated conservatively. However, the superior pancreaticoduodenal artery aneurysm suddenly ruptured and he expired. CONCLUSIONS: Gastric remnant necrosis after distal gastrectomy can be a gastrointestinal presentation of cholesterol crystal embolization. Perioperative/intraoperative risk assessments such as preventive total gastrectomy or intraoperative assessment with indocyanine green fluorescence angiography may be desirable to avoid this complication.

Silicon nanocrystal hybrid photovoltaic devices for indoor light energy harvesting.

Silicon nanocrystals (SiNCs) featuring size-dependent novel optical and electrical properties have been widely employed for various functional devices. We have demonstrated SiNC-based hybrid photovoltaics (SiNC-HPVs) and proposed several approaches for performance promotion. Recently, owing to the superiorities such as low power operation, high portability, and designability, organic photovoltaics (OPVs) have been extensively studied for their potential indoor applications as power sources. SiNCs exhibit strong light absorption below 450 nm, which is capable of sufficient photocurrent generation under UV irradiation. Therefore, SiNC-HPVs are expected to be preferably used for energy harvesting systems in indoor applications because an indoor light source consists of a shorter wavelength component below 500 nm than solar light. We successfully demonstrated SiNC-HPVs with a PCE as high as 9.7%, corresponding to the output power density of 34.0 µW cm-2 under standard indoor light irradiation (1000 lx). In addition, we have found that SiNC defects working as electron traps influence the electrical properties of SiNCs substantially, a thermal annealing process was conducted towards the suppression of defects and the improvement of the SiNC-HPVs performance.

Novel use of the Nathanson liver retractor to prevent postoperative transient liver dysfunction during laparoscopic gastrectomy.

INTRODUCTION: The Nathanson liver retractor (N) has been known to cause postoperative transient liver dysfunction (POTLD) in laparoscopic gastrectomy (LG). To reduce the incidence of POTLD, specifically we added to the retractor the use of a disk (N + D) to reduce the localized pressure, and furthermore repositioned the retractor every 30 minutes (N + D TM) to reduce the liver retraction time. Before and after introducing this retractor, we assessed four consecutive retraction procedures. These included the following disk suspension methods (D), N, N + D, and N + D TM. METHODS: We retrospectively enrolled 85 patients who underwent an LG. In the D, N, N + D, and N + D TM groups, we evaluated the postoperative serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values. RESULTS: For the D and N groups, the AST value significantly increased from the immediate post-operation time point (IPOT) to the third postoperative day (POD3). Additionally, the ALT value increased from IPOT to POD7. In the N + D group, the only decrease was in the ALT value at IPOT compared to the N group. The N + D TM group decreased in both the AST value from IPOT to POD3 and in the ALT value from IPOT to POD7, compared to the N group. CONCLUSIONS: Our findings demonstrate the importance of reducing both the localized pressure and liver retraction time when using the Nathanson retractor to prevent POTLD during an LG. To make this possible, we successfully introduced the use of both a disk and the repositioning of the retractor at 30 minute intervals.

Intraductal dissemination of ampullary carcinoma after pancreatoduodenectomy.

BACKGROUND: Clinical evidence of intraductal dissemination through the pancreatic duct has been rare. We herein describe a case of ampullary carcinoma that disseminated in the remnant pancreas through the pancreatic duct. CASE PRESENTATION: A 68-year-old woman underwent SSPPD for ampullary carcinoma. The tumor was diagnosed as adenocarcinoma without lymph node metastasis (T2N0M0, stage IB). Computed tomography (CT) performed 3 years later revealed a 14-mm tumor near the site of the pancreaticojejunal anastomosis. Endoscopic ultrasound-guided fine needle aspiration showed adenocarcinoma that was morphologically similar to the specimen from the first surgery. We diagnosed recurrence of ampullary carcinoma in the remnant pancreas. A total remnant pancreatectomy was performed. We found a white solid tumor at the 20-mm distal side of pancreaticojejunal anastomosis. The tumor was morphologically similar and immunostaining showed a pattern identical to that of the original tumor, suggesting that the two tumors were of the same origin. CONCLUSION: The recurrent lesion was most likely the result of tumor cells leaving the tumor and implanting in the remnant pancreatic duct epithelium. Intraductal dissemination of adenocarcinoma is thought to be a cause of remnant recurrence after SSPPD in cases of obstruction of the pancreatic duct or an iatrogenic procedure.

Short-term outcomes of robotic-assisted laparoscopic rectal surgery: A pilot study during the introductory period at a local municipal hospital.

OBJECTIVES: The aim of this pilot study was to confirm the safety and feasibility of the induction of robotic-assisted laparoscopic rectal surgery (RRS) at a local municipal hospital. A municipal hospital does not indicate a small hospital. The most significant difference between a municipal hospital and a center or university hospital is that most surgeons in a municipal hospital are general surgeons. METHODS: The first 30 patients who underwent RRS at the municipal hospital were enrolled between April 2015 and June 2016. All surgeries were performed by a single trained surgeon using the da VinciⓇ Si surgical system. The primary endpoint was the incidence of postoperative major complications. RESULTS: Of the study patients, 29 had adenocarcinoma and 1 had ulcerative colitis. The surgical procedures included anterior resection (n = 22), intersphincteric resection (n = 2), abdominoperineal resection (n = 4), Hartmann's procedure (n = 1), and total coloproctectomy (n = 1). There were no intraoperative complications and conversion cases. The median operative time and blood loss were 283.5 min and 9 ml, respectively. The incidence rate of postoperative major complications was 10%, which included anastomotic leakage in 2 patients and ileus in 1 patient. Postoperative urinary dysfunction did not occur in any patient. Complete resection was achieved for all patients. CONCLUSIONS: We demonstrated that the induction of RRS was safe and feasible, even at a local municipal hospital, given that the surgeons had the sufficient skills and experience in both laparoscopic and colorectal surgery. *The study protocol was registered at the University Hospital Medical Information Network (UMIN000017022).

Laparoscopic surgery of a presacral epidermoid cyst: A case report.

INTRODUCTION: The best approach for resecting epidermoid cysts is still controversial. We describe a case of an epidermoid cyst in which laparoscopic resection was performed successfully. PRESENTATION OF CASE: 63 × 55-mm well-defined cystic mass was incidentally detected by computed tomography in the presacral cavity of a 50-year-old woman during evaluation for upper abdominal pain. Magnetic resonance imaging showed a cystic tumor with a low signal intensity on T1-weighted images and, high signal on T2-weighted images in the left dorsal side of the rectum. This tumor was diagnosed as a developmental cyst, and laparoscopic resection was performed. Resection of the tumor was performed with negative margins. This tumor was histopathologically diagnosed as an epidermoid cyst. There was no evidence of malignancy, and no postoperative event or signs of recurrence occurred 6 months postoperatively. DISCUSSION: In our patient, there was no difficulty in the field of view and forceps operability during laparoscopic surgery. Furthermore, it is possible to perform laparoscopic surgery with minimal damage to the muscles, nerves, and rectum, leading to the preservation of anal function. CONCLUSION: Laparoscopic resection of an epidermoid cyst may be a better option in carefully selected cases with consideration of the tumor size and location.

Evaluation of Hepatic Resection in Liver Metastasis of Gastric Cancer.

Gastric cancer is the second most common malignancy globally and the third most common cause of cancer-related deaths in Japan. In gastric cancer, benefit of surgical resection of liver metastasis, which was shown in colorectal cancer, is not well established. The present study aimed to examine the feasibility of hepatic resection for liver metastasis of gastric cancer. In this retrospective study, we reviewed the medical records of 10 patients with liver-only metastases of gastric cancer who underwent hepatectomy among 2043 patients with gastric cancer who underwent gastric resection between January and December 2016 at a single institution in Japan. Median 1-, 3-, and 5-year overall survival (OS) rates were 78.0%, 33.3%, and 22.2%, respectively, among 10 patients who underwent hepatic resection. There was a significant difference in OS rates between tumors measuring ≥ 5 cm and < 5 cm (hazard ratio [HR] 6.524, 95% confidence interval [CI] 1.145-37.171, p = 0.035). The longest survival was 205 months for one patient who was alive at the time of the analysis. Hepatic resection of liver metastasis in gastric cancer was associated with long-term survival in some patients. Additionally, primary tumor size was associated with long-term survival.