1,689 research outputs found
Adaptive Fuzzy Dynamic Surface Sliding Mode Position Control for a Robot Manipulator with Friction and Deadzone
Precise tracking positioning performance in the presence of both the deadzone and friction of a robot manipulator actuator is difficult to achieve by traditional control methodology without proper nonlinear compensation schemes. In this paper, we present a dynamic surface sliding mode control scheme combined with an adaptive fuzzy system, state observer, and parameter estimator to estimate the uncertainty, friction, and deadzone nonlinearities of a robot manipulator system. We design a dynamic surface sliding mode basic controller by systematic recursive design steps that yields several adaptive laws for the compensation of nonlinear friction, deadzone, and other unknown nonlinear dynamics. The boundedness and convergence of this closed-loop system are guaranteed by the Lyapunov stability theorem. Experiments on the Scorbot robot manipulator demonstrate the validity and effectiveness of the proposed control scheme
Hepatic Parasitic Abscess Caused by Clonorchiasis: Unusual CT Findings of Clonorchiasis
Clonorchiasis is caused by a chronic infestation of liver flukes, Clonorchis sinensis, and these reside mainly in the medium- and small-sized intrahepatic bile ducts. Therefore, diffuse, uniform, minimal or mild dilatation of these bile ducts, particularly in the periphery, without dilatation of the extrahepatic bile duct is the typical finding on several imaging modalities. We report here on the CT findings of an unusual case of hepatic parasitic abscess that was caused by clonorchiasis; this malady mimicked cholangiocarcinoma, and there was no dilatation of the intrahepatic bile ducts
Decursinol chloroacrylates useful as fungicides
Natural products decursin and decursinol angelate were recently reported as benign fungicides for controlling rice blast. Inspired by the structural similarity of the cumarin compounds and gained hint from the skeletal motifs, we designed and prepared synthetic compounds to increase the natural product efficacy and evaluated their antifungal activities against various plant disease pathogens in vitro. Synthetically prepared compound 4 and 5 indeed suppressed the mycelial growth of B. cinerea, F. oxysporum, P. italicum, and R. quercus-mongolicae. Additionally, compound 5 effectively prevents the growth of C. coccodes and C. parasitica. Furthermore, both 4 and 5 possess better inhibitory activities on spore germination of F. oxysporum and M. oryzae than the natural product decursin and commercial pesticide Iprodione. These results suggest that the effect of the lead compound for plant disease protection can be improved by tuning the structure of the original natural product and decursinol chloroacrylates 4 and 5 are candidates for the control of F. oxysporum and M. oryzae.This work was supported by Research Resettlement Fund for the new faculty of Seoul National University (to Y. Kwon). Also, Rural Development Administration Republic of Korea supported this research (Project No. PJ016243022021 to H. Son)
Effects of Berberine and Hwangryunhaedok-Tang on Oral Bioavailability and Pharmacokinetics of Ciprofloxacin in Rats
Hwangryunhaedok-Tang (HR) and berberine-containing single herbs are used to treat bacterial infection and inflammatory diseases in eastern Asia. The combination of berberine-containing herbal medicines and ciprofloxacin can be an excellent antibacterial chemotherapy against multidrug resistance bacteria. To evaluate the pretreatment effect of berberine and HR, vehicle, berberine (25 and 50 mg/kg/day), and HR (1.4 g/kg/day) were daily administered to rats for five consecutive days. On day 6, ciprofloxacin was administered (10 mg/kg, i.v. and 20 mg/kg, p.o.) to rats. To assess cotreatment effect of berberine and ciprofloxacin, berberine (50 mg/kg) and ciprofloxacin (20 mg/kg) were coadministered by single oral gavage. Pharmacokinetic data were estimated by noncompartmental model. Compared with ciprofloxacin alone (control group), coadministration of berberine (50 mg/kg) and ciprofloxacin significantly decreased Cmax of ciprofloxacin (P<0.05). In addition, the pretreatment of berberine (50 mg/kg/day) and HR (1.4 g/kg/day) significantly decreased Cmax and AUC0→∞, compared with control group (P<0.05). The oral bioavailability of ciprofloxacin was reduced by cotreatment of berberine and pretreatment of berberine and HR. Our results suggest that the expression of P-glycoprotein and organic anion and/or organic cation transporters (OAT/OCT) could take a role in reduced oral bioavailability of ciprofloxacin by berberine and HR
Glypican-3 level assessed by the enzyme-linked immunosorbent assay is inferior to alpha-fetoprotein level for hepatocellular carcinoma diagnosis
Background/Aims Glypican-3 (GPC3) protein is highly expressed in hepatocellular carcinoma (HCC) tissue. It has been suggested as a diagnostic biomarker, but its inconsistent performance means that it requires further assessment. We therefore investigated the diagnostic value of the plasma GPC3 level compared to the alpha-fetoprotein (AFP) level as a diagnostic biomarker of HCC. Methods We enrolled 157 consecutive patients with newly diagnosed HCC and 156 patients with liver cirrhosis (LC) as the control group. GPC3 plasma levels were measured using two commercially available enzyme-linked immunosorbent assays (ELISAs, named as Assay 1 and 2), and AFP levels were measured using an enzyme-linked chemiluminescent immunoassay. The diagnostic accuracy was analyzed using the receiver operating characteristics (ROC) curve. Results Plasma GPC3 levels in HCC patients were very low (0–3.09 ng/mL) in Assay 1, while only 3 of the 157 patients (1.9%) showed detectable GPC3 levels in Assay 2. The median GPC3 level was not significantly elevated in the HCC group (0.80 ng/mL) compared with the LC group (0.60 ng/mL). The area under the ROC curve (AUC) for GPC3 was 0.559 in Assay 1. In contrast, the median AFP level was significantly higher in HCC (27.72 ng/mL) than in LC (4.74 ng/mL), with an AUC of 0.729. Conclusion The plasma level of GPC3 is a poor diagnostic marker for HCC, being far inferior to AFP. The development of a consistent detection system for the blood level of GPC3 is warranted
Clinical Implications of Residual Urine in Korean Benign Prostatic Hyperplasia (BPH) Patients: A Prognostic Factor for BPH-Related Clinical Events
Purpose Although post-void residual urine (PVR) is frequently utilized clinically in patients with benign prostatic hyperplasia (BPH), mainly because of its procedural simplicity, its role as a clinical prognostic factor, predictive of treatment goals, is still under much dispute. We investigated the predictive value of PVR for BPH-related clinical events including surgery, acute urinary retention (AUR), and admission following urinary tract infection (UTI). Methods From January to June of 2006, patients over 50 years of age who were diagnosed with BPH for the first time at the outpatient clinic and were then treated for at least 3 years with medications were enrolled in this study. The variables of patients who underwent surgical intervention for BPH, had occurrences of AUR, or required admission due to UTI (Group 1, n=43) were compared with those of patients who were maintained with medications only (Group 2, n=266). Results Group 1 had a significantly higher PVR, more severe symptoms, and a larger prostate at the time of the initial diagnosis in both the univariate and the multivariate analysis. In the 39 patients who underwent BPH-related surgery, although there was a significant change in Qmax at the time of surgery (mean, 13.1 months), PVR and the symptom score remained unchanged compared with the initial evaluation. In the receiver-operating characteristic curve analysis, the area under the curve of Group 1 was in the order of prostate volume (0.834), PVR (0.712), and symptom score (0.621). When redivided by arbitrarily selected PVR cutoffs of 50 mL, 100 mL, and 150 mL, the relative risk of clinical BPH progression was measured as 3.93, 2.61, and 2.11. Conclusions These data indicate that, in the symptomatic Korean population, increased PVR at baseline is a significant indicator of BPH-related clinical events along with increased symptom score or prostate volume
Tumoral LINE-1 hypomethylation is associated with poor survival of patients with intrahepatic cholangiocarcinoma
ECC: Extrahepatic cholangiocarcinoma; ICC: Intrahepatic cholangiocarcinoma;
IG: Intraductal growth; LINE-1: Long interspersed element-1; MF: Mass-forming;
PI: Periductal infiltrative; TNM: Tumor, node, and metastasisAbstract
Background
DNA methylation changes occurring in cancer cells are featured with both promoter CpG island hypermethylation and diffuse genomic hypomethylation. Long interspersed element-1 (LINE-1) is repeated in an interspersed manner with an estimated 500,000 copies per genome. LINE-1 has its CpG sites of the 5′ untranslated region methylated heavily in normal cells and undergoes demethylation in association with cancerization. However, little information is available regarding LINE-1 hypomethylation and its prognostic implication in intrahepatic cholangiocarcinomas.
Methods
A total of 172 cases of intrahepatic cholangiocarcinomas were analyzed for their methylation levels at four CpG sites of LINE-1 using bisulfite pyrosequencing. We examined the relation between tumoral LINE-1 methylation level and clinicopathological features, including survival.
Results
Tumor differentiation, lymphatic invasion, and T stage were associated with a low average methylation level of LINE-1 at the four CpG sites; LINE-1 methylation level tended to be lower in high-grade differentiation, lymphatic emboli, and higher T stage. LINE-1 hypomethylation was significantly linked with lower cancer-specific survival in patients with intrahepatic cholangiocarcinoma and was found to be an independent prognostic parameter.
Conclusions
Our findings suggest that tumoral LINE-1 hypomethylation could be a molecular biomarker heralding poor prognosis of patients with intrahepatic cholangiocarcinoma. Our findings need to be validated in further study.This work was supported by a grant from the National Research Foundation (NRF) grants funded by the Korean Ministry of Science, ICT and Future Planning (2011–0030049 and 2016M3A9B6026921), a grant from the Priority Research Centers Program through the NRF (2009–0093820), and a grant from the Korea Health Technology R & D Project through the Korea Health Industry Development Institute funded by the Korean Ministry of Health and Welfare (HI14C1277). The funding bodies had no role in the design of the study, the collection, analysis, and interpretation of the data, or in the writing of the manuscript
The Safety and efficacy of a new self-expandable intratracheal nitinol stent for the tracheal collapse in dogs
To evaluate the potential utility of a self-expandable intratracheal nitinol stent with flared ends for the treatment of tracheal collapse in dogs, endotracheal stenting therapy was performed under fluoroscopic guidance in four dogs with severe tracheal collapse. During the 4 to 7 month follow-up, after stent implantation, clinical signs, including dyspnea and respiratory distress, dramatically improved in all dogs. The radiographs showed that the implanted stents improved the tracheal collapse, and there were no side effects such as collapse, shortening or migration of the stents. In conclusion, the self-expandable intratracheal nitinol stents provided adequate stability to the trachea and were effective for attenuating the clinical signs associated with severe tracheal collapse
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