Activity Space Assessments to Investigate Neighborhood Exposure to Racism-Related Stress and Related Substance Use Among Young Black Men: Connecticut, 2019.

Objectives. To use activity space assessments to investigate neighborhood exposures that may heighten young Black men's vulnerability to substance use and misuse. Methods. We surveyed young Black men in New Haven, Connecticut in 2019 on the locations (activity spaces) they traveled to in a typical week and their experiences of racism and any alcohol and cannabis use at each location. Results. A total of 112 young Black men (mean age = 23.57 years; SD = 3.20) identified 583 activity spaces. There was significant overlap between racism-related events and substance use (alcohol and cannabis use) at specific locations. Areas with a higher prevalence of violent crime also had a greater frequency of racism-related events and substance use. Conclusions. An activity space approach is a promising method for integrating objective and subjective experiences within neighborhood contexts to better understand the frequency and co-occurrence of racism-related stress and substance use among young Black men. (Am J Public Health. 2023;113(S2):S136-S139. https://doi.org/10.2105/AJPH.2023.307254).

Church Closings Were Associated with Higher COVID-19 Infection Rates: Implications for Community Health Equity.

This study investigates the changes in physical church closings years 2013 to 2019 in New York City (NYC), Philadelphia, and Baltimore and the association with COVID-19 infection rates. We applied Bayesian spatial binomial models to analyze confirmed cases of COVID-19 as of February 28, 2022, in each city at the zip code-level. A one unit increase in the number of churches closed corresponded to a 5% higher COVID-19 infection rate, in NYC (rate ratio = 1.05, 95% credible interval = 1.02-1.08%), where the association was significant. Church closings appears to be an important indicator of neighborhood social vulnerability. Church closings should be routinely monitored as a structural determinant of community health and to advance health equity.

Role of geographic characteristics in the spatial cluster detection of cancer: Evidence in South Korea, 1999-2013.

BACKGROUND: Identification of high-risk areas of cancer, referred to as spatial clusters, can inform targeted policies for cancer control. Although cancer cluster detection could be affected by various geographic characteristics including sociodemographic and environmental factors which impacts could also vary over time, studies accounting for such influence remain limited. This study aims to assess the role of geographic characteristics in the spatial cluster detection for lung and stomach cancer over an extended period. METHODS: We obtained sex-specific age-standardized incidence and mortality rates of lung and stomach cancer as well as geographic characteristics across 233 districts in South Korea for three five-year periods between 1999 and 2013. We classified geographic characteristics of each district into four categories: demography, socioeconomic status, behaviors, and physical environments. Specifically, we quantified physical environments using measures of greenness, concentrations of particulate matter and nitrogen dioxide, and air pollution emissions. Finally, we conducted cluster detection analyses using weighted normal spatial scan statistics with the residuals from multiple regression analyses performed with the four progressive sets of geographic attributes. RESULTS: We found that the size of clusters reduced as we progressively adjusted for geographic covariates. Among the four categories, physical environments had the greatest impact on the reduction or disappearance of clusters particularly for lung cancer consistently over time. Whereas older population affected a decrease of lung cancer clusters in the early period, the contribution of education was large in the recent period. The impact was less clear in stomach cancer than lung cancer. CONCLUSION: Our findings highlight the importance of geographic characteristics in explaining the existing cancer clusters and identifying new clusters, which jointly provides practical guidance to cancer control.

Changes in the Plasma Apurinic/Apyrimidinic Endonuclease 1/Redox Factor-1(APE1/Ref-1) Level during Cancer Surgery: An Observational Study.

Background and Objectives: Propofol-based total intravenous anesthesia (TIVA) is presumed to have more favorable effects on the prognosis of patients with cancer compared with volatile inhaled anesthesia (VIA). We hypothesized that these anesthetics target plasma apurinic apyrimidinic endonuclease/redox effector factor-1 (APE1/Ref-1) as a possible mechanism of action. Materials and Methods: The plasma APE1/Ref-1 level was evaluated three times during surgery for cancer, i.e., before anesthesia, immediately after cancer resection, and finally, in the recovery room. Blood (3 cc) was drawn from the radial artery catheter, and plasma APE1/Ref-1 levels were compared according to measurement time and between the two groups. Spearman's Rho correlation analysis was performed to determine relationships among body mass index, American Society of Anesthesiologists classification, age, sex, cancer type, and tumor-node-metastasis (TNM) stage. A total of 166 patients (VIA: 129; TIVA: 37) were enrolled. Results: Plasma APE1/Ref-1 level increased significantly (p = 0.028) after cancer resection compared with before surgery, but no significant difference was observed between anesthetics (p = 0.134). The post-resection plasma APE1/Ref-1 level showed a positive correlation with the NM stages, but not the T stage. Conclusions: The plasma APE1/Ref-1 level increased during surgery with more severe lymph node invasion, but there were no significant differences according to the anesthetics used.

Spatial heterogeneity in the association between particulate matter air pollution and low birth weight in South Korea.

As many studies showed the spatial heterogeneity in the association between particulate matter (PM) air pollution and low birth weight (LBW), few studies focused on the variation of local associations at the national scale and related areal characteristics. This study aimed to explore different approaches to estimating local effects of PM with an aerodynamic diameter ≤10 µm (PM10) on LBW across 235 districts in South Korea, to investigate the spatial pattern of local associations, and to examine the relationship with local socio-demographic and environmental characteristics. LBW was identified in 5,692,650 mothers from birth certificate data for 2001-2013. We estimated individual annual-average concentrations of PM10 at centroids of mothers' residential districts by using a previously-validated prediction model. Then, we estimated district-specific odds ratios of LBW for PM10 using modified geographically weighted logistic regression. Here, we applied four approaches with different neighborhood definitions: the distance-based approach within 20- and 40-km bandwidth and the hybrid approach replacing with adjacent districts for urban districts <100 km2. In addition, we compared district-specific socioeconomic indicators and emission estimates across three groups of districts that showed significantly positive, no, and significantly negative associations. Medians of district-specific estimates of four approaches were similar to the global estimate and between each other. However, their variability differed with some unreasonably high estimates when a small distance was applied as the neighborhood definition, although spatial pattern was generally similar among the four. The hybrid approach based on the different neighborhood definition by urban and rural areas provided stable risk estimates. Higher risk districts in rural areas were found in more socioeconomically-deprived areas, whereas urban areas showed higher risk districts when their air pollution emissions were higher. Our approach and findings will help identify high risk areas and enhance understanding of geographic determinants.

Clinicopathologic analysis of intraductal papillary neoplasm of bile duct: Korean multicenter cohort study.

BACKGROUND: IPNB is very rare disease and most previous studies on IPNB were case series with a small number due to low incidence. The aim of this study is to validate previously known clinicopathologic features of intraductal papillary neoplasm of bile duct (IPNB) based on the first largest multicenter cohort. METHODS: Among 587 patients previously diagnosed with IPNB and similar diseases from each center in Korea, 387 were included in this study after central pathologic review. We also reviewed all preoperative image data. RESULTS: Of 387 patients, 176 (45.5%) had invasive carcinoma and 21 (6.0%) lymph node metastasis. The 5-year overall survival was 80.9% for all patients, 88.8% for IPNB with mucosal dysplasia, and 70.5% for IPNB with invasive carcinoma. According to the "Jang & Kim's modified anatomical classification," 265 (68.5%) were intrahepatic, 103 (26.6%) extrahepatic, and 16 (4.1%) diffuse type. Multivariate analysis revealed that tumor invasiveness was a unique predictor for survival analysis. (p = 0.047 [hazard ratio = 2.116, 95% confidence interval 1.010-4.433]). CONCLUSIONS: This is the first Korean multicenter study on IPNB through central pathologic and radiologic review process. Although IPNB showed good long-term prognosis, relatively aggressive features were also found in invasive carcinoma and extrahepatic/diffuse type.

Cytochrome P450 4A11 expression in tumor cells: A favorable prognostic factor for hepatocellular carcinoma patients.

BACKGROUND AND AIM: Elevated cytochrome p450 (CYP) 4A gene expression has been linked to the aggravation of various cancers and affects various regulated metabolites. In hepatocellular carcinoma (HCC), the clinicopathological value of CYP4A has not yet been explored, although CYP4A is expressed at high levels in the liver. The goal of this study was to evaluate the clinicopathological value of CYP4A11 expression in HCC. METHODS: We performed immunohistochemical analysis of CYP4A11 and correlated the results with clinicopathological features of HCC (n = 155). Western blotting and reverse transcription-polymerase chain reaction against CYP4A11 and CYP4A22 were also performed for 15 and 20 pairs of fresh-frozen primary HCC and non-neoplastic liver tissue, respectively. Moreover, we analyzed the underlying mechanism by comparing the high and low CYP4A11 mRNA expression groups using gene set enrichment analysis. RESULTS: CYP4A11 expression level was higher in non-neoplastic hepatocytes than those in HCC cells (P < 0.001), and CYP4A11 expression positively correlated with favorable prognostic factors, including tumor size, histological grade, and pathological tumor stage (P = 0.007, P = 0.005, and P = 0.007). Multivariate analysis revealed that CYP4A11 expression was an independent prognostic factor of overall and disease-free survival (P = 0.002 and P = 0.033). Based on gene set enrichment analysis, high CYP4A11 mRNA expression negatively correlated with the expression of cell cycle-related genes. CONCLUSION: These findings support the notion that CYP4A11 expression is a favorable prognostic factor of HCC and suggest potential predictive diagnostic and prognostic roles of CYP4A11 expression in HCC.

Surgical strategy for T1 gallbladder cancer: a nationwide multicenter survey in South Korea.

BACKGROUND: The aim of this study was to investigate the clinical features and clinical outcomes of T1 gallbladder (GB) cancer and to determine an appropriate surgical strategy for T1 GB cancer. METHODS: A nationwide multicenter study, in which 16 University Hospitals in Korea participated, was performed from 1995 to 2004. A total of 258 patients, 117 patients with T1a and 141 patients with T1b disease were enrolled. Clinicopathologic findings and long-term follow-up results were analyzed after a consensus meeting of the Korean Pancreas Surgery Club was held. RESULTS: Simple cholecystectomy was performed in 95 patients (81.2 %) with T1a tumor and in 89 patients (63.1 %) with T1b tumor (p < 0.01). Lymph node metastasis was observed in 2.9 % of T1a patients and in 9.9 % of T1b patients (p = 0.391). A significant difference in 5-year disease-specific survival (DSS) rates was observed between T1a and T1b patients (96.4 vs 84.8 %, respectively, p = 0.03). However, no significant 5-year DSS rate difference was observed between those who underwent simple cholecystectomy or extended cholecystectomy, regardless of whether lymph node dissection was performed or whether lymph node metastasis was present. There was no significant difference in recurrence-free survival between simple cholecystectomy and extended cholecystectomy. CONCLUSIONS: There was no superiority of extended cholecystectomy over simple cholecystectomy in the aspect of survival and recurrence especially in T1b gallbladder cancer. Furthermore, the effectiveness of regional lymphadenectomy for treatment purpose remains questionable. Therefore, simple cholecystectomy could be recommended as a surgical strategy of T1 gallbladder cancer.

Lower abdominal approach in laparoscopic cholecystectomy: A propensity score-matching analysis and prospective cohort study.

BACKGROUND: Classic laparoscopic cholecystectomy) using multiple ports is a widely used method with excellent surgical outcomes. However, the resulting wounds do not meet the cosmetic needs of patients. Therefore, this study aimed to find a new minimally invasive surgical method for invisible wounds while maintaining surgical safety through a new port site. METHODS: In this prospective cohort study, we used propensity score matching analysis to evaluate the perioperative outcomes of multiport laparoscopic cholecystectomy using articulating devices with the lower abdominal approach. We performed a propensity score matching analysis of prospectively maintained data from 228 patients who underwent classic laparoscopic cholecystectomy using straight instruments and laparoscopic cholecystectomy with a lower abdominal approach using articulating devices between January and October 2022. A single surgeon performed all operations included in the study. We evaluated several perioperative outcomes. RESULTS: No differences were found in potential confounding factors, such as sex, age, admission type, previous abdominal surgery, and medical comorbidities, between the 2 groups after propensity score matching. In the classic laparoscopic cholecystectomy group, the mean operation time was shorter (43.73 ± 23.71 vs 50.60 ± 9.75 min; P < .04). No significant difference was noted in the 2 groups' numerical rating scale scores for pain, body mass index, and incidence of postoperative complications. The mean length of hospital stay was longer for patients who underwent classic laparoscopic cholecystectomy (4.27 vs 2.07 days; P = .064). The lower abdominal laparoscopic cholecystectomy group had delayed defecation after surgery. CONCLUSION: Regarding surgical outcomes and minimal invasiveness, lower abdominal laparoscopic cholecystectomy is a feasible cholecystectomy method.

Changes in spatial clusters of cancer incidence and mortality over 15 years in South Korea: Implication to cancer control.

BACKGROUND: The temporal investigation of high-risk areas of cancer incidence and mortality can provide practical implications in cancer control. We aimed to investigate the changes in spatial clusters of incidence and mortality from 1999 through 2013 by major cancer types in South Korea. METHODS: We applied flexible scan statistics to identify spatial clusters of cancer incidence and mortality by three 5-year periods and seven major cancer types using the counts of new cases and deaths and population in 244 districts during 1999-2013. Then, we compared the changes across three periods in the locations of primary clusters of incidence and mortality by cancer types. To explore the determinants that possibly affect cancer cluster areas, we compared geographic characteristics between clustered and non-clustered areas. RESULTS: While incidence clusters for lung, stomach, and liver cancer remained in the same areas over 15 years, mortality clusters were relocated to the areas similar to those of incidence clusters. In contrast, colorectal, breast, cervical, and prostate cancer displayed consistently different locations of clusters over time, indicating the disappearance of existing clusters and the appearance of new clusters. Cluster areas tended to show higher portions of older population, unemployment, smoking, and cancer screening compared to non-cluster areas particularly for mortality. CONCLUSIONS: Our findings of diverse patterns of changes in cancer incidence and mortality clusters over 15 years can indicate the degree of effectiveness in cancer prevention and treatment depending on the area and suggest the need for area-specific applications of different cancer control programs.

Association of Poor Mental-Health Days With COVID-19 Infection Rates in the U.S.

INTRODUCTION: Limited evidence exists about the association between prior prevalence of poor mental health at the area level and subsequent rates of COVID-19 infections. This association was tested using area-level nationwide population data in the U.S. METHODS: A nationwide study including 2,839 U.S. counties was conducted. Poor mental health was the age-adjusted average number of days within the past 30 days that adults reported poor mental health, including depression, stress, and problems with emotions, from the Behavioral Risk Factor Surveillance System. COVID-19 infection rates were cumulative confirmed cases between January 22 and October 7, 2020 per 100,000 people in the general population. Bayesian spatial mixed-effects regression estimated the relationship between COVID-19 infection and poor mental-health days at the county level in 2019 and change in poor mental health between 2010 and 2019, adjusted for several covariates. RESULTS: Poor mental-health days in 2019 were positively associated with higher COVID-19 infection rates (RRR=1.059, 95% credible interval=1.003, 1.117). Change in mental health was not significantly associated with COVID-19. CONCLUSIONS: Prior rates of poor mental health in a county were associated with a higher burden of COVID-19 infection. Interventions that improve well-being and strengthen mental-health systems at the community and other geographic levels are needed to address post-COVID-19 mental health problems.

Impact of limited residential address on health effect analysis of predicted air pollution in a simulation study.

BACKGROUND: Recent epidemiological studies of air pollution have adopted spatially-resolved prediction models to estimate air pollution concentrations at people's homes. However, the benefit of these models was limited in many studies that used existing health data relying on incomplete addresses resulting from confidentiality concerns or lack of interest when designed. OBJECTIVE: This simulation study aimed to understand the impact of incomplete addresses on health effect estimation based on the association between particulate matter with diameter ≤10 µm (PM10) and low birth weight (LBW). METHODS: We generated true annual average concentrations of PM10 at 46,007 mothers' homes and their LBW status, using the parameters obtained from our data analysis and a previous study in Seoul, Korea. Then, we hypothesized that mothers' address information is limited to the district and compared the properties of their health effect estimates of PM10 with those using complete addresses. We performed this comparison across eight environmental scenarios that represent various spatial distributions of PM10 and nine exposure prediction methods that provide different sets of predicted PM10 concentrations of mothers. RESULTS: We observed increased bias and root mean square error consistently across all environmental scenarios and prediction methods using incomplete addresses compared to complete addresses. However, the bias related to incomplete addresses decreased when we used population-representative exposures averaged to the district from predicted PM10 at census tract centroids. SIGNIFICANCE: Our simulation study suggested that individual exposure estimated by prediction approaches and averaged across population-representative points can provide improved accuracy in health effect estimates when complete address data are unavailable. IMPACT STATEMENT: Our simulation study focused on a common and practical challenge of limited address information in air pollution epidemiology, and investigated its impact on health effect analysis. Cohort studies of air pollution have developed advanced exposure prediction model to allow the estimation of individual-level long-term air pollution concentrations at people's addresses. However, it is common that address information of existing health data is available at the coarse spatial scale such as city, district, and zip code area. Our findings can help understand the possible consequences of limited address information and provide practical guidance in achieving the accuracy in health effect analysis.

Determination of malignant and invasive predictors in branch duct type intraductal papillary mucinous neoplasms of the pancreas: a suggested scoring formula.

Prediction of malignancy or invasiveness of branch duct type intraductal papillary mucinous neoplasm (Br-IPMN) is difficult, and proper treatment strategy has not been well established. The authors investigated the characteristics of Br-IPMN and explored its malignancy or invasiveness predicting factors to suggest a scoring formula for predicting pathologic results. From 1994 to 2008, 237 patients who were diagnosed as Br-IPMN at 11 tertiary referral centers in Korea were retrospectively reviewed. The patients' mean age was 63.1 ± 9.2 yr. One hundred ninty-eight (83.5%) patients had nonmalignant IPMN (81 adenoma, 117 borderline atypia), and 39 (16.5%) had malignant IPMN (13 carcinoma in situ, 26 invasive carcinoma). Cyst size and mural nodule were malignancy determining factors by multivariate analysis. Elevated CEA, cyst size and mural nodule were factors determining invasiveness by multivariate analysis. Using the regression coefficient for significant predictors on multivariate analysis, we constructed a malignancy-predicting scoring formula: 22.4 (mural nodule [0 or 1]) + 0.5 (cyst size [mm]). In invasive IPMN, the formula was expressed as invasiveness-predicting score = 36.6 (mural nodule [0 or 1]) + 32.2 (elevated serum CEA [0 or 1]) + 0.6 (cyst size [mm]). Here we present a scoring formula for prediction of malignancy or invasiveness of Br-IPMN which can be used to determine a proper treatment strategy.

HIV Infection Prevalence Significantly Intersects With COVID-19 Infection At the Area Level: A US County-Level Analysis.

BACKGROUND: Limited empirical evidence exists about the extent to which the current HIV epidemic intersects with COVID-19 infections at the area/geographic level. Moreover, little is known about how demographic, social, economic, behavioral, and clinical determinants are jointly associated with these infectious diseases. SETTING: Contiguous US counties (N = 3108). METHODS: We conducted a cross-sectional analysis and investigated the joint association between new HIV infection prevalence in 2018 and COVID-19 infections (January 22, 2020 and October 7, 2020) and explore the contribution of factors such as income inequality, binge drinking, and socioeconomic deprivation. We used Bayesian multivariate spatial models to estimate the cross-disease correlations between these diseases and identified hotspots, which we defined as a county with a posterior probability greater than 80% of being in the top decile of that disease. RESULTS: New HIV infection prevalence and COVID-19 infection moderately and significantly intersect [spatial correlation = 0.37, 95% credible interval (CrI) = 0.36-0.37]. Seventy-five counties, mostly in the south, were at elevated burden for HIV and COVID-19 infections. Higher income inequality was positively associated with both COVID-19 (relative risk 1.05, 95% CrI = 1.03-1.07) and HIV infection (relative risk = 1.12, 95% CrI = 1.09-1.15). CONCLUSIONS: We found that there is a considerable intersection between the current distribution of HIV burden with COVID-19 infections at the area level. We identified areas that federal funding and vaccination campaigns should prioritize for prevention and care efforts.

Feasibility of using the homologous parietal peritoneum as a vascular substitute for venous reconstruction during abdominal surgery: An animal model.

BACKGROUND: The interest in vascular substitutes has recently increased. We evaluated the feasibility of using a homologous parietal peritoneum as a vascular substitute for venous reconstruction during abdominal surgery. METHODS: The inferior vena cava was replaced with a homologous parietal peritoneum after cross-linking with glutaraldehyde in 36 rabbits. At 7, 14, and 28 days, the patency rate, outer and inner graft diameters, histology, and immunohistochemistry were evaluated. RESULTS: Both the 7- and 14-day groups maintained vascular patency. Vascular patency was maintained in 3 rabbits in the 28-day group. The inner diameters of the anastomotic sites were 6.23 ± 0.18, 5.64 ± 0.16, and 2.34 ± 0.21 mm in the 7-day, 14-day, and 28-day groups, respectively. The midpoint inner diameters of the homologous parietal peritoneum grafts were 624 ± 0.46, 5.74 ± 0.26, and 2.14 ± 0.28 mm in each group, respectively. Endothelial cell proliferation on the homologous parietal peritoneum graft surfaces in all groups was based on the histological findings from the first group. Multiple neovascularizations of the homologous parietal peritoneum graft were found in the 14- and 28-day groups, indicating neo-media formation. Acute inflammation appeared to progress to the entire layer of the homologous parietal peritoneum graft without an intraluminal thrombus, but the graft was patent in the 14-day group. In the 28-day group, 6 rabbits showed near-total occlusion and a thrombus formed in the homologous parietal peritoneum graft at the anastomosis site with severe stricture; however, the rabbits were alive and had collateral vessel formation. CONCLUSION: Using homologous parietal peritoneum is feasible for venous reconstruction in abdominal surgery.

Long-term outcome of intraoperative radiofrequency ablation for hepatocellular carcinoma and its efficacy as a primary treatment.

BACKGROUNDS/AIMS: We conducted this study to identify long-term outcomes following intraoperative radiofrequency ablation (IO-RFA) for hepatocellular carcinoma (HCC) and to reveal independent prognostic factors for survival. METHODS: From December 1998 to February 2019, 183 patients underwent IO-RFA for HCC. These patients were divided into two groups according to whether RFA was done as a first-line (1-RFA group, n=106) or secondary-line (2-RFA group, n=77) treatment. Furthermore, we compared the survival outcomes between the 1-RFA and 2-RFA groups. RESULTS: There were no significant differences in type of surgical approaches between the two groups (p=0.079). The number of tumors and largest tumor size were not significantly different between the two groups. Overall recurrence rate was 53%, and the 2-RFA group showed a higher recurrence rate (46.2% in 1-RFA group versus 62.3% in 2-RFA group; p=0.031). The 5-year overall survival (OS) and disease-free survival (DFS) rates of all the patients were 75.2% and 27.9%, respectively. The OS and DFS rates were significantly higher in the 1-RFA group. The 5-year OS rates were 83.6% and 64.9% in the 1-RFA and 2-RFA groups, respectively (p=0.010), whereas the 5-year DFS rates were 32.2% and 21.6%, respectively (p=0.012). On multivariate analysis, HBV-LC, 2-RFA, recurrence, and postoperative complications were independent predictive factors for survival. CONCLUSIONS: Therapeutic outcomes of IO-RFA were comparable to those of surgical resection. Additionally, 1-RFA might be an alternative treatment for naïve HCC in patients with uncompensated liver function and severe comorbidities.

Web-Based Visualization of Scientific Research Findings: National-Scale Distribution of Air Pollution in South Korea.

BACKGROUND: As scientific findings of air pollution and subsequent health effects have been accumulating, public interest has also been growing. Accordingly, web visualization is suggested as an effective tool to facilitate public understanding in scientific evidence and to promote communication between the public and academia. We aimed to introduce an example of easy and effective web-based visualization of research findings, relying on predicted concentrations of particulate matter ≤ 10 µg/m3 (PM10) and nitrogen dioxide (NO2) obtained from our previous study in South Korea and Tableau software. Our visualization focuses on nationwide spatial patterns and temporal trends over 14 years, which would not have been accessible without our research results. METHODS: Using predicted annual average concentrations of PM10 and NO2 across approximately 250 districts and maps of administrative divisions in South Korea during 2001-2014, we demonstrate data preprocessing and design procedures in the Tableau dashboard, comprising maps, time-series plots, and bar charts. RESULTS: Our visualization allows one to identify high concentration areas, a long-term temporal trend, and the contrast between two pollutants. The application of easy tools for user-interactive options in Tableau suggests possible easy access to the scientific knowledge of non-experts. CONCLUSION: Our example contributes to future studies that develop the visualization of research findings in further intuitive designs.

Arrangement optimization of water-driven triboelectric nanogenerators considering capillary phenomenon between hydrophobic surfaces.

The rise in environmental issues has stimulated research on alternative energy. In this regard, triboelectric generation has received much attention as one of several new alternative energy sources. Among the triboelectric generation methods, solid-liquid triboelectric nanogenerators (SLTENGs) have been actively investigated owing to their durability and broad applicability. In this paper, we report on the optimum arrangement of SLTENGs to increase the generation of electrical energy. When hydrophobic SLTENGs are arranged in parallel with a specific intervening gap, the friction area between the water and the surface of the SLTENGs is changed owing to the different penetration distances of water between them. This difference affects the amount of triboelectricity generated; this change in the water contact area is caused by the capillary phenomenon. Therefore, we investigated the effect of the gap on water penetration and formulated an optimum arrangement to achieve optimum electricity generation efficiency when multiple SLTENGs are contained in a limited volume. The proposed optimum arrangement of SLTENGs is expected to have high utilization in energy harvesting from natural environment sources such as wave energy or water flow.

The appropriate surgical strategy for T1b gallbladder cancer incidentally diagnosed after a simple cholecystectomy.

BACKGROUNDS/AIMS: The appropriate surgical treatment was investigated for T1b gallbladder (GB) cancer through a retrospective analysis of the clinical outcomes of patients with incidental T1 GB cancer. METHODS: Patients with T1 GB cancer who were incidentally diagnosed while undergoing a simple cholecystectomy at Chungnam University Hospital from January 2004 to December 2017 were enrolled. Overall, 39 patients with T1 GB cancer, 17 patients with T1a, and 22 patients with T1b were included. We retrospectively analyzed the patients' clinical and pathologic findings and follow-up results. RESULTS: Among the 6490 patients who underwent cholecystectomy during the study period, 165 patients were diagnosed with GB cancer (T1=42 [25.5%]). The risk factor associated with recurrence and cancer-related death in patients with T1 GB cancer was lymphovascular invasion (recurrence, p=0.028; death, p=0.004). In the T1b group, the 5-year disease-free survival (DFS) rate showed a statistical difference between patients with and without lymphovascular invasion (45.7% vs. 83.6%, p=0.048). There was no statistically significant difference in 5-year DFS and overall survival rate between simple cholecystectomy and extended cholecystectomy in T1b GB cancer with lymphovasular invasion (p=0.054 and p=0.091, respectively). CONCLUSIONS: In incidental T1b GB cancer, extended cholecystectomy was not superior to simple cholecystectomy in terms of the 5-year DFS rate and nor in overall survival rate or recurrence rate, even when lymphovascular invasion was identified after simple cholecystectomy. Therefore, simple cholecystectomy may be recommended as a primary surgical strategy for T1b GB cancer.

High nuclear NADPH oxidase 4 expression levels are correlated with cancer development and poor prognosis in hepatocellular carcinoma.

NADPH oxidase (NOX) is a key source of reactive oxygen species (ROS). This study aimed to verify NOX2 and NOX4 expression levels in hepatocellular carcinoma (HCC). A total of 134 matched pairs of HCC cells and non-tumour hepatocytes from 134 patients were examined by immunohistochemical staining, and the association of NOX2 and NOX4 expression with clinicopathological parameters was analysed. Western blotting in four HCC cell lines and reverse transcription digital droplet polymerase chain reaction (RT-ddPCR) in 20 pairs of HCC and non-tumour tissue samples were also performed to detect NOX4. Cytoplasmic NOX2 and nuclear NOX4 expression levels were shown by immunohistochemistry to be higher in HCC cells than in non-tumour hepatocytes (p<0.001 each). The western blotting results for NOX4 in four HCC cell lines were consistent with the immunohistochemical results. Increased cytoplasmic expression of NOX2 and NOX4 in HCC cells was significantly correlated with liver cirrhosis (p<0.001 and p<0.031, respectively). However, decreased cytoplasmic expression of NOX2 and NOX4 was significantly correlated with advanced pathological TNM stage (p<0.029 and p<0.007, respectively). Multivariate analysis with clinicopathological parameters showed that high nuclear and low cytoplasmic NOX4 expression levels are correlated with short overall survival (p=0 .021). Our findings imply that cytoplasmic NOX2 and nuclear NOX4 expression is upregulated during HCC development. In particular, NOX4 translocation into the nucleus may affect the development and progression of HCC. NOX2 and NOX4 could be diagnostic markers and have therapeutic implications in HCC.