170 research outputs found

    Film Thickness Changes in EHD Sliding Contacts Lubricated by a Fatty Alcohol

    Full text link
    This paper describes the appearance of abnormal film thickness features formed in elastohydrodynamic contacts lubricated by a fatty alcohol. Experiments were conducted by varying the slide to roll ratio between a steel ball and a glass disk in a ball-on-disk type device. Lauric alcohol was used as lubricant and film thickness was measured in the contact area by optical interferometry. Experimental results showed that the film thickness distributions under pure rolling conditions remained classical whereas the film shape changed when the slide to roll ratio was increased. The thickness in the central contact area increased and in the same time inlet and exit film thicknesses were modified. In addition, the film shapes observed when the ball surface was moving faster than the disk one and those obtained in the opposite case were different, i.e. when opposite signs but equal absolute values of the slide to roll ratio were applied

    Understanding Methane Emission from Rice Paddies in China

    Get PDF
    Symposium Pape

    Effect of Controlled Water Level on CH4 and N2O Emissions fromRice Fields in Indonesia

    Get PDF
    Several options to reduce methane (CH4) emission from rice fields have been reported including straw management,soil amended with Fe(OH)3 and iron slag, encapsulated calcium carbide, and water management by drainage-flooding. In the present paper, field experiments were conducted to determine whether controlled water level below 3 cm and 6 cm might affectCH4 and nitrous oxide (N2O) emissions compared to local rice farmer practice (water level mostly above 6 cm but basicallyuncontrolled) in Maros area, South Sulawesi, Indonesia. CH4 and N2O fluxes were measured at one-week intervals throughouttwo cropping seasons using a closed chamber method. Grain yield was determined at the end of cultivation. The results showedthat CH4 emission in the 1st cultivation was reduced by 36.5% and 33.8% in the plots with 3 cm and 6 cm water levels, respectively,whereas, in the 2nd cultivation, it was reduced by 63.6% and 44.6%, compared to farmer practice plots. N2O emission from paddyfields was not detected and tended to decrease in both cropping seasons. We concluded that controlled water level lower than thatin farmer practice could significantly reduce CH4 emission without affecting rice grain yield and N2O emission. Key words: CH4 and N2O emissions, Controlled water level, Indonesia, Rice fiel

    Acute coronary syndrome after liver transplantation in a young primary biliary cholangitis recipient with dyslipidemia: a case report

    Get PDF
    BACKGROUND: Primary biliary cholangitis (PBC) is a chronic, progressive liver disease associated with dyslipidemia. There is a consensus that PBC does not accelerate coronary artery disease despite high cholesterol levels, so the screening test for the coronary artery is not routinely performed before liver transplantation (LT). To date, no report has described the potential risk of PBC-related dyslipidemia for developing acute coronary syndrome (ACS) after LT. CASE PRESENTATION: A 40-year-old Asian female with a known history of PBC underwent ABO-incompatible living-donor LT, with her husband as the donor. Although she had high cholesterol and triglyceride levels that were refractory to medications, she passed all routine preoperative examinations, including cardiopulmonary function tests and infection screenings. One week after LT, she developed ACS with 90% stenosis of both the left anterior descending artery and left circumflex artery. Emergent stent implantation was successfully performed followed by dual antiplatelet therapy. The long history of PBC and associated severe dyslipidemia for 10 years would have accelerated the atherosclerosis, causing latent stenosis in the coronary artery. Inapparent stenosis might have become apparent due to unstable hemodynamics during the acute phase after LT. CONCLUSIONS: PBC-related dyslipidemia potentially brings a risk for developing ACS after LT. This experience suggests that the preoperative evaluation of the coronary artery should be considered for high-risk patients, especially those who have drug-resistant dyslipidemia

    Optimal surveillance of intraductal papillary mucinous neoplasms of the pancreas focusing on remnant pancreas recurrence after surgical resection

    Get PDF
    Background The international consensus guidelines for intraductal papillary mucinous neoplasm of the pancreas (IPMN) presented clinical features as indications for surgery. Whereas surveillance for recurrence, including de novo lesions, is essential, optimal surveillance protocols have not been established. Aim and methods This study aimed to assess the clinical features of recurrence at the remnant pancreas (Rem-Panc) and extra-pancreas (Ex-Panc) after surgery for IPMN. Ninety-one patients of IPMN that underwent detailed preoperative assessment and pancreatectomy were retrospectively analyzed, focusing especially on the type of recurrence. Results The IPMNs were finally diagnosed as low-grade dysplasia (LDA, n = 42), high-grade dysplasia (HAD, n = 19), and invasive carcinoma (IPMC, n = 30). Recurrence was observed in 26 patients (29%), of which recurrence was seen at Rem-Panc in 19 patients (21%) and Ex-Panc in 7 patients (8%). The frequency of Rem-Panc recurrence was 10% in LDA, 21% in HDA, and 37% in IPMC. On the other hand, Ex-Panc recurrence was observed only in IPMC (23%). Ex-Panc recurrence showed shorter median recurrence-free survival (RFS) and overall survival (OS) than Rem-Panc recurrence (median RFS 8 months vs. 35 months, p < 0.001; median OS 25 months vs. 72 months, p < 0.001). Regarding treatment for Rem-Panc recurrence, repeat pancreatectomy resulted in better OS than no repeat pancreatectomy (MST 36 months vs. 15.5 months, p = 0.033). On multivariate analysis, main duct stenosis or disruption as a preoperative feature (hazard ratio [HR] 10.6, p = 0.002) and positive surgical margin (HR 4.4, p = 0.018) were identified as risk factors for Rem-Panc recurrence. Conclusions The risk factors for Rem-Panc and Ex-Panc recurrence differ. Therefore, optimal surveillance on these features is desirable to ensure that repeat pancreatectomy for Rem-Panc recurrence can be an appropriate surgical intervention

    Macrophage HIF-1α increases liver tumor

    Get PDF
    Aims/Introduction: Chronic inflammation of the liver is often observed with obesity or type 2 diabetes. In these pathological conditions, the immunological cells, such as macrophages, play important roles in the development or growth of liver cancer. Recently, it was reported that hypoxia‐inducible factor‐1α (HIF‐1α) is a key molecule for the acquisition of inflammatory M1 polarity of macrophages. In the present study, we examined the effects of altered macrophage polarity on obesity‐ and diabetes‐associated liver cancer using macrophage‐specific HIF‐1α knockout (KO) mice. Materials and Methods: To induce liver cancer in the mice, diethylnitrosamine, a chemical carcinogen, was used. Both KO mice and wild‐type littermates were fed either a high‐fat diet (HFD) or normal chow. They were mainly analyzed 6 months after HFD feeding. Results: Development of liver cancer after HFD feeding was 45% less in KO mice than in wild‐type littermates mice. Phosphorylation of extracellular signal‐regulated kinase 2 was also lower in the liver of KO mice. Those effects of HIF‐1α deletion in macrophages were not observed in normal chow‐fed mice. Furthermore, the size of liver tumors did not differ between KO and wild‐type littermates mice, even those on a HFD. These results suggest that the activation of macrophage HIF‐1α by HFD is involved not in the growth, but in the development of liver cancer with the enhanced oncogenic extracellular signal‐regulated kinase 2 signaling in hepatocytes. Conclusions: The activation of macrophage HIF‐1α might play important roles in the development of liver cancer associated with diet‐induced obesity and diabetes

    Serologic Markers in Relation to Parasite Exposure History Help to Estimate Transmission Dynamics of Plasmodium vivax

    Get PDF
    Plasmodium vivax infection has been gaining attention because of its re-emergence in several parts of the world. Southeastern Turkey is one of the places in which persistent focal malaria caused exclusively by P. vivax parasites occurs. Although control and elimination studies have been underway for many years, no detailed study has been conducted to understand the mechanisms underlying the ineffective control of malaria in this region. Here, for the first time, using serologic markers we try to extract as much information as possible in this region to get a glimpse of P. vivax transmission. We conducted a sero-immunological study, evaluating antibody responses of individuals living in Sanliurfa to four different P. vivax antigens; three blood-stage antigens (PvMSP119, PvAMA1-ecto, and PvSERA4) and one pre-erythrocytic stage antigen (PvCSP). The results suggest that a prior history of malaria infection and age can be determining factors for the levels and sustainability of naturally acquired antibodies. Significantly higher antibody responses to all the studied antigens were observed in blood smear-negative individuals with a prior history of malaria infection. Moreover, these individuals were significantly older than blood smear-negative individuals with no prior history of infection. These data from an area of sole P. vivax-endemic region may have important implications for the global malaria control/elimination programs and vaccine design

    The relationship between the PD-L1 expression of surgically resected and fine-needle aspiration specimens for patients with pancreatic cancer

    Get PDF
    BACKGROUND: Recently, therapeutic antibodies against programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) have shown promising clinical results for several solid tumors, including pancreatic cancer. In this study, we evaluated the relationship between the PD-L1 expression of surgical resected and fine-needle aspiration (FNA) specimens for patients with pancreatic cancer. METHODS: Of 121 patients who underwent endoscopic ultrasound-guided (EUS)-FNA before surgery for pancreatic cancer in an academic center, the 94 (78%) with adequate FNA specimens for a histological evaluation were retrospectively analyzed. All the patients had undergone upfront surgery without any chemotherapy or radiotherapy. We performed immunohistochemistry (IHC) staining to investigate the PD-L1 expression in both resected and FNA specimens. The positive-stained cells were counted, and their percentage was used for the investigation. RESULTS: Of the 94 patients, 16 (17%) and 11 (10%) were defined as positive on resected cancer specimens using cutoff points of 5% and 10% positively stained cancer cell counts, respectively. The concordance rates for the positive frequency of PD-L1 expression between resected and FNA specimens were 44% (7/16) and 55% (6/11) when the positivity was set to ≥ 5% and ≥ 10%, respectively. The concordance rates for the negative frequency of PD-L1 expression between two specimens were 97% (76/78) and 99% (82/83) when the positivity was set to ≥ 5% and ≥ 10%, respectively. CONCLUSIONS: Approximately, half of the patients with PD-L1 expression positive and almost all the patients with PD-L1 expression negative could be diagnosed on FNA specimens

    Hemobilia after bile duct resection: perforation of pseudoaneurysm into intra-pancreatic remnant bile duct: a case report

    Get PDF
    Background Hemobilia occurs mainly due to iatrogenic factors such as impairment of the right hepatic or cystic artery, and/or common bile duct in hepatobiliary-pancreatic surgery. However, little or no cases with hemobilia from the intra-pancreatic remnant bile duct after bile duct resection (BDR) has been reported. Here, we report a case of massive hemobilia due to the perforation of psuedoaneurysm of the gastroduodenal artery (GDA) to the intra-pancreatic remnant bile duct after hepatectomy with BDR. Case presentation A 68-year-old male underwent extended right hepatectomy with BDR for gallbladder carcinoma. He presented with upper gastrointestinal bleeding 2 months after the initial surgery. Upper endoscopy identified a blood clot from the ampulla of Vater and simultaneous endoscopic balloon tamponade contributed to temporary hemostasis. Abdominal CT and angiography revealed a perforation of the psuedoaneurysm of the GDA to the intra-pancreatic remnant bile duct resulting in massive hemobilia. Subsequent selective embolization of the pseudoaneurysm with micro-coils could achieve complete hemostasis. He survived without any recurrence of cancer and bleeding. Conclusion Hemobilia could occur in a patient with BDR due to perforation of the pseudoaneurysm derived from the GDA to the intra-pancreatic remnant bile duct. Endoscopic balloon tamponade was useful for a temporal hemostasis and a subsequent radiologic interventional approach
    corecore