66 research outputs found
A New pH-ISFET Based Dissolved Oxygen Sensor
A new dissolved oxygen sensor based on pH-ISFET has been discussed. A platinum working electrode surrounding a pH-sensing gate of the pH-ISFET electrolyzes dissolved oxygen, resulting in a corresponding pH change. The pH-ISFET can determine dissolved oxygen concentration through detecting this pH change. --Summar
Prognostic Value of Postoperative CEA Clearance in Rectal Cancer Patients with High Preoperative CEA Levels
PURPOSE: We determined the prognostic value of carcinoembryonic antigen (CEA) clearance after tumor resection with serial evaluation of postoperative CEA levels in rectal cancer.
METHODS: Between 1994 and 2004, we retrospectively reviewed 122 patients with rectal cancer whose serum CEA levels were measured on the preoperative day and postoperative days 7 and 30. Patients with preoperative CEA levels <5.0 ng/ml were excluded. An exponential trend line was drawn using the three CEA values. Patients were categorized into three groups based on R(2) values calculated through trend line, which indicates the correlation coefficient between exponential graph and measured CEA values: exponential decrease group (group 1: 0.9 < R(2) < or = 1.0), nearly exponential decrease group (group 2: 0.5 < R(2) < or = 0.9), and randomized clearance group (group 3: 0.5 < or = R(2)). We then analyzed the CEA clearance pattern as a prognostic indicator.
RESULTS: With a median follow-up of 57 months, the 5-year overall survival was 62.3% vs. 48.1% vs. 25% and the 5-year disease-free survival was 58.6% vs. 52.7% vs. 25% among groups 1, 2, and 3 (P = 0.014, P = 0.027, respectively) in patients with stage III rectal cancer. For those with stage II rectal cancer, the 5-year overall survival rate of group 1 was significantly better than groups 2 and 3 (88.8% vs. 74.1%, respectively, P = 0.021).
CONCLUSIONS: the postoperative pattern of CEA clearance is a useful prognostic determinant in patients with rectal cancer. Patients with a randomized pattern of CEA clearance after tumor resection should be regarded as having the possibility of a persistent CEA source and may require consideration of intensive follow-up or adjuvant therapy.ope
Explicitly determined sea ice emissivity and emission temperature over the Arctic for surface‐sensitive microwave channels
Data assimilation of satellite microwave measurements is one of the importantkeys to improving weather forecasting over the Arctic region. However, the useofsurface-sensitivemicrowave-soundingchannelmeasurementsfordataassim-ilation or retrieval has been limited, especially during winter, due to the poorlyconstrained sea ice emissivity. In this study, aiming at more use of those channelmeasurements in the data assimilation, we propose an explicit method for speci-fying the surface radiative boundary conditions (namely emissivity and emittinglayer temperature of snow and ice). These were explicitly determined with aradiativetransfermodelforsnowandiceandwithsnow/icephysicalparameters(i.e. snow/ice depths and vertical distributions of temperature, density, salinity,and grain size) simulated from the thermodynamically driven snow/ice growthmodel. We conducted 1D-Var experiments in order to examine whether thisapproach can help to use the surface-sensitive microwave temperature channelmeasurements over the Arctic sea ice region for data assimilation. Results showthat (1) the surface-sensitive microwave channels can be used in the 1D-Varretrieval, and (2) the specification of the radiative boundary condition at thesurface using the snow/sea ice emission model can significantly improve theatmospheric temperature retrieval, especially in the lower troposphere (500hPato surface). The successful retrieval suggests that useful information can beextracted from surface-sensitive microwave-sounding channel radiances oversea ice surfaces through the explicit determination of snow/ice emissivity andemitting layer temperature
Cellular uptake of magnetic nanoparticle is mediated through energy-dependent endocytosis in A549 cells
Biocompatible silica-overcoated magnetic nanoparticles containing an organic fluorescence dye, rhodamine B isothiocyanate (RITC), within a silica shell [50 nm size, MNP@SiO2(RITC)s] were synthesized. For future application of the MNP@SiO2(RITC)s into diverse areas of research such as drug or gene delivery, bioimaging, and biosensors, detailed information of the cellular uptake process of the nanoparticles is essential. Thus, this study was performed to elucidate the precise mechanism by which the lung cancer cells uptake the magnetic nanoparticles. Lung cells were chosen for this study because inhalation is the most likely route of exposure and lung cancer cells were also found to uptake magnetic nanoparticles rapidly in preliminary experiments. The lung cells were pretreated with different metabolic inhibitors. Our results revealed that low temperature disturbed the uptake of magnetic nanoparticles into the cells. Metabolic inhibitors also prevented the delivery of the materials into cells. Use of TEM clearly demonstrated that uptake of the nanoparticles was mediated through endosomes. Taken together, our results demonstrate that magnetic nanoparticles can be internalized into the cells through an energy-dependent endosomal-lysosomal mechanism
Clinical Outcomes and Adverse Events of Gastric Endoscopic Submucosal Dissection of the Mid to Upper Stomach under General Anesthesia and Monitored Anesthetic Care
Background/Aims Endoscopic submucosal dissection (ESD) of gastric tumors in the mid-to-upper stomach is a technically challenging procedure. This study compared the therapeutic outcomes and adverse events of ESD of tumors in the mid-to-upper stomach performed under general anesthesia (GA) or monitored anesthesia care (MAC). Methods Between 2012 and 2018, 674 patients underwent ESD for gastric tumors in the midbody, high body, fundus, or cardia (100 patients received GA; 574 received MAC). The outcomes of the propensity score (PS)-matched (1:1) patients receiving either GA or MAC were analyzed. Results The PS matching identified 94 patients who received GA and 94 patients who received MAC. Both groups showed high rates ofen bloc resection (GA, 95.7%; MAC, 97.9%; p=0.68) and complete resection (GA, 81.9%; MAC, 84.0%; p=0.14). There were no significant differences between the rates of adverse events (GA, 16.0%; MAC, 8.5%; p=0.18) in the anesthetic groups. Logistic regression analysis indicated that the method of anesthesia did not affect the rates of complete resection or adverse events. Conclusions ESD of tumors in the mid-to-upper stomach at our high-volume center had good outcomes, regardless of the method of anesthesia. Our results demonstrate no differences between the efficacies and safety of ESD performed under MAC and GA
Development of tricuspid regurgitation late after left-sided valve surgery: a single-center experience with long-term echocardiographic examinations
OBJECTIVES: This study sought to investigate the incidence and identify the predictors of significant tricuspid regurgitation (TR) development long after left-sided valve surgery. METHODS: Of 615 patients who underwent surgery for left-sided valve disease between 1992 and 1995, 335 patients without significant TR who completed at least 5 years of clinical and echocardiographic follow-up were enrolled. Late significant TR development was assessed by echocardiography with a mean follow-up duration of 11.6 +/- 2.1 years. RESULTS: Significant late TR was found in 90 patients (26.9%). Patients with late TR showed an advanced age (47.6 +/- 13.4 vs 44.3 +/- 13.2 years, P = .04), a higher prevalence of preoperative atrial fibrillation (83.3 vs 46.5%, P < .001), a greater left atrial dimension (56.9 +/- 13.2 vs 52.4 +/- 11.5 mm, P = .006), and a higher prevalence of prior valve surgery (40.0 vs 25.3%, P = .01). In addition, late TR occurred more frequently in patients who had undergone mitral valve surgery than in those who did not (93.3 vs 72.2%, P < .001). However, multivariate analysis showed that the presence of preoperative atrial fibrillation (odds ratio 5.37; 95% CI 2.71-10.65; P < .001) was the only independent factor of late TR development. Patients who developed late TR had a lower event-free survival rate than those who did not (P = .03). CONCLUSIONS: The development of significant TR long after left-sided valve surgery is not uncommon with an estimated incidence of 27% and is closely associated with a poor prognosis. The presence of preoperative atrial fibrillation was identified as the only independent predictor of the development of late TR
Insulin Resistance Is Associated with Prevalence of Physician-Diagnosed Urinary Incontinence in Postmenopausal Non-Diabetic Adult Women: Data from the Fourth Korea National Health and Nutrition Examination Survey.
To investigate the association between insulin resistance (IR) and urinary incontinence in Korean adult women by analyzing the data from the Korea National Health and Nutrition Examination Survey IV (KNHANES) 2007-2009.A nationally representative sample of 5318 non-diabetic Korean women ≥19-years-of-age (3043 premenopausal and 2275 postmenopausal women) was included from KNHANES 2008-2010. IR was measured using the homeostasis model assessment of IR (HOMA-IR). Participants in the highest and lowest quartile of HOMA-IR were defined as insulin-resistant and insulin-sensitive respectively. Women who have current physician-diagnosed urinary incontinence were classified as having urinary incontinence.Incontinence was found in 9.18% of the total population, 8.51% of the premenopausal population, and 10.86% of the postmenopausal population. The prevalence of incontinence increased with age, reaching a peak at 60-69-years-of-age. The prevalence of urinary incontinence increased significantly with higher HOMA-IR quartiles in pre- and post-menopausal women (p for linear association = 0.0458 and 0.0009 respectively). Among post-menopausal women, those in the highest quartile of HOMA-IR were significantly more likely to have urinary incontinence compared to those in the lowest quartile [adjusted odds ratio, 1.72; 95% confidence interval, 1.07-2.77]. However premenopausal population exhibited no association between incontinence and HOMA-IR quartiles.Our results suggest that the prevalence of incontinence increased across HOMA-IR in non-diabetic adult women, and especially, IR might be a risk factor for incontinence in postmenopausal non-diabetic women
Hemodynamic and prognostic implications of net atrioventricular compliance in patients with mitral stenosis
BACKGROUND: On the basis of the close association of left atrial compliance with pulmonary hypertension in patients with mitral stenosis, we hypothesized that: (1) Doppler-derived net atrioventricular compliance (C(n)) can be used for predicting the occurrence of mitral valve (MV) replacement or percutaneous mitral commissurotomy (PMC); and (2) determinants of exercise capacity are variable depending on C(n). METHODS: We consecutively enrolled 26 patients (22 women; mean age, 47.0 +/- 6.1 years; range, 35-59 years) with pure moderate or severe mitral stenosis, in whom comprehensive echocardiography was performed at rest. C(n) was derived from the equation that has been previously validated (ie, C(n) = 1270 x [MV area by 2-dimensional planimetry/mitral E-wave downslope]. Measurements of stroke volume and systolic pulmonary artery pressure were repeated immediately after symptom-limited treadmill exercise test within 60 seconds. RESULTS: On the basis of earlier reports, C(n) less than 4 mL/mm Hg was selected to define abnormally small C(n). During a mean duration of 24-month follow-up, C(n) of less than 4 mL/mm Hg could reliably predict the occurrence of either MV replacement or PMC, which was confirmed by multivariate logistic regression analysis. In patients with C(n) less than 4 mL/mm Hg, exercise duration was found to be closely correlated primarily with resting systolic pulmonary artery pressure (r = -0.73, P = .03), whereas in patients with C(n) greater than or equal to 4 mL/mm Hg, postexercise stroke volume was the only determinant of exercise capacity (r = 0.49, P = .04). When combining C(n) less than 4 mL/mm Hg with MV area less than 1.0 cm(2) as a cut-off value for predicting MV replacement or PMC, the sensitivity improved from 63.6% to 81.8% (P = .05). CONCLUSIONS: Left atrial compliance estimated by C(n) with Doppler echocardiography allows us to effectively predict the future occurrence of MV replacement or PMC, with a special usefulness in patients with moderate mitral stenosis. In addition, determinants of exercise capacity were variable depending on the degree of C(n)
- …