26
|
Lee CJ, Tyler CR, Paull GC. Can simple tank changes benefit the welfare of laboratory zebrafish Danio rerio? JOURNAL OF FISH BIOLOGY 2018; 92:653-659. [PMID: 29363145 DOI: 10.1111/jfb.13535] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 12/08/2017] [Indexed: 06/07/2023]
Abstract
This study examined the effects of simple changes in the tank environment on the wellbeing of laboratory-maintained zebrafish Danio rerio. Groups of D. rerio were either housed in stable environments (where they were maintained in the same tanks throughout the study) or in environments subject to change (where they were periodically moved to novel but identical tanks) and the effects of these treatments on morphometry, reproductive success and aggressive behaviour assessed. No effect of simple tank changes was found on body condition, reproductive output or aggression, for the periods of time studied, indicating that more complex scenarios in housing tank conditions are required for significant welfare benefits for captive D. rerio.
Collapse
|
27
|
Stets EG, Lee CJ, Lytle DA, Schock MR. Increasing chloride in rivers of the conterminous U.S. and linkages to potential corrosivity and lead action level exceedances in drinking water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 613-614:1498-1509. [PMID: 28797521 PMCID: PMC7390064 DOI: 10.1016/j.scitotenv.2017.07.119] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 07/05/2017] [Accepted: 07/13/2017] [Indexed: 05/26/2023]
Abstract
Corrosion in water-distribution systems is a costly problem and controlling corrosion is a primary focus of efforts to reduce lead (Pb) and copper (Cu) in tap water. High chloride concentrations can increase the tendency of water to cause corrosion in distribution systems. The effects of chloride are also expressed in several indices commonly used to describe the potential corrosivity of water, the chloride-sulfate mass ratio (CSMR) and the Larson Ratio (LR). Elevated CSMR has been linked to the galvanic corrosion of Pb whereas LR is indicative of the corrosivity of water to iron and steel. Despite the known importance of chloride, CSMR, and LR to the potential corrosivity of water, monitoring of seasonal and interannual changes in these parameters is not common among water purveyors. We analyzed long-term trends (1992-2012) and the current status (2010-2015) of chloride, CSMR, and LR in order to investigate the short and long-term temporal variability in potential corrosivity of US streams and rivers. Among all sites in the trend analyses, chloride, CSMR, and LR increased slightly, with median changes of 0.9mgL-1, 0.08, and 0.01, respectively. However, urban-dominated sites had much larger increases, 46.9mgL-1, 2.50, and 0.53, respectively. Median CSMR and LR in urban streams (4.01 and 1.34, respectively) greatly exceeded thresholds found to cause corrosion in water distribution systems (0.5 and 0.3, respectively). Urbanization was strongly correlated with elevated chloride, CSMR, and LR, especially in the most snow-affected areas in the study, which are most likely to use road salt. The probability of Pb action-level exceedances (ALEs) in drinking water facilities increased along with raw surface water CSMR, indicating a statistical connection between surface water chemistry and corrosion in drinking water facilities. Optimal corrosion control will require monitoring of critical constituents reflecting the potential corrosivity in surface waters.
Collapse
|
28
|
Gorden PJ, Ydstie JA, Kleinhenz MD, Wulf LW, Gehring R, Lee CJ, Wang C, Coetzee JF. A study to examine the relationship between metritis severity and depletion of oxytetracycline in plasma and milk after intrauterine infusion. J Dairy Sci 2016; 99:8314-8322. [PMID: 27522419 DOI: 10.3168/jds.2016-10959] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 06/27/2016] [Indexed: 12/20/2022]
Abstract
Metritis is a frequent problem in postpartum dairy cows. Intrauterine therapy with the antimicrobial oxytetracycline (OTC) is often used, although this therapy has not been shown to be superior to systemic therapy. The objectives of this study were to (1) determine the plasma and milk concentrations of OTC following intrauterine infusion in postpartum dairy cows with varying degrees of metritis severity; (2) determine the depletion time of OTC in an attempt to provide veterinarians withdrawal guidelines, should they use this therapy; and (3) correlate metritis severity scores with OTC concentrations in plasma and milk. Our hypothesis was that cows with more severe metritis would have higher OTC concentrations in milk following intrauterine therapy. Thirty-two cows were selected to participate in the study after farm personnel had determined that they had metritis based on evaluation of vaginal discharge between 4 and 14 DIM, in accordance with the farm's treatment protocols. Metritis scores (1-4) were assigned based on a published scheme: 1 represented yellow-to-orange thick discharge or translucent mucus with no fetid smell; 2 represented blood-tinged vaginal mucus, slightly watery, with little or no fetid smell; 3 represented red to red/brown watery discharge with moderate fetid smell; and 4 represented red to red/brown watery discharge containing pieces of placenta and an intense fetid smell. Trial cows received a single treatment of 4g of OTC (approximately 6.7mg/kg) via intrauterine infusion. Blood samples were collected over 96h, and milk samples were collected before intrauterine therapy and 3 times a day for 4 d following infusion. Following treatment, OTC rapidly diffused to plasma and subsequently to milk. Maximum OTC concentrations in plasma and milk occurred within the first 24h following intrauterine infusion, and 25 of the 32 cows had detectable OTC concentrations in milk at 4 d after intrauterine infusion. Cows with clinical metritis (metritis severity scores of 3 or 4) at the initiation of treatment were significantly and positively correlated with higher milk OTC concentrations at the second [time (T)9 h; r=0.43], fourth (T25 h; r=0.42), and fifth milking following treatment (T33 h; r=0.38) compared with cows with normal vaginal discharge. We also observed a positive correlation between initial metritis score and milk maximum concentration (r=0.36) and milk area under the concentration curve (r=0.36). Given that intrauterine administration of OTC is an extra-label therapy, dairy producers should consult with their veterinarian to ensure that milk is being tested at or below the established tolerance for OTC. This will ensure that violative drug residues do not enter the human food supply.
Collapse
|
29
|
Chaudhry ZW, Doshi RS, Mehta AK, Jacobs DK, Vakil RM, Lee CJ, Bleich SN, Kalyani RR, Clark JM, Gudzune KA. A systematic review of commercial weight loss programmes' effect on glycemic outcomes among overweight and obese adults with and without type 2 diabetes mellitus. Obes Rev 2016; 17:758-69. [PMID: 27230990 PMCID: PMC5512172 DOI: 10.1111/obr.12423] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 03/25/2016] [Accepted: 03/25/2016] [Indexed: 01/09/2023]
Abstract
OBJECTIVE We examined the glycemic benefits of commercial weight loss programmes as compared with control/education or counselling among overweight and obese adults with and without type 2 diabetes mellitus (T2DM). METHODS We searched MEDLINE, Cochrane Database of Systematic Reviews, and references cited by individual programmes. We included randomized controlled trials of ≥12 weeks duration. Two reviewers extracted information on study design, population characteristics, interventions, and mean changes in haemoglobin A1c and glucose. RESULTS We included 18 randomized controlled trials. Few trials occurred among individuals with T2DM. In this population, Jenny Craig reduced A1c at least 0.4% more than counselling at 12 months, Nutrisystem significantly reduced A1c 0.3% more than counselling at 6 months, and OPTIFAST reduced A1c 0.3% more than counselling at 6 months. Among individuals without T2DM, few studies evaluated glycemic outcomes, and when reported, most did not show substantial reductions. DISCUSSION Few trials have examined whether commercial weight loss programmes result in glycemic benefits for their participants, particularly among overweight and obese individuals without T2DM. Jenny Craig, Nutrisystem and OPTIFAST show promising glycemic lowering benefits for patients with T2DM, although additional studies are needed to confirm these conclusions. © 2016 World Obesity.
Collapse
|
30
|
Lee PB, Kim YC, Lim YJ, Lee CJ, Choi SS, Park SH, Lee JG, Lee SC. Efficacy of Pulsed Electromagnetic Therapy for Chronic Lower Back Pain: A Randomized, Double-blind, Placebo-controlled Study. J Int Med Res 2016; 34:160-7. [PMID: 16749411 DOI: 10.1177/147323000603400205] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
This randomized, double-blind, placebo-controlled clinical trial studied the effectiveness of pulsed electromagnetic therapy (PEMT) in patients with chronic lower back pain. Active PEMT ( n = 17) or placebo treatment ( n = 19) was performed three times a week for 3 weeks. Patients were assessed using a numerical rating scale (NRS) and revised Oswestry disability scores for 4 weeks after therapy. PEMT produced significant pain reduction throughout the observation period compared with baseline values. The percentage change in the NRS score from baseline was significantly greater in the PEMT group than the placebo group at all three time-points measured. The mean revised Oswestry disability percentage after 4 weeks was significantly improved from the baseline value in the PEMT group, whereas there were no significant differences in the placebo group. In conclusion, PEMT reduced pain and disability and appears to be a potentially useful therapeutic tool for the conservative management of chronic lower back pain.
Collapse
|
31
|
Lee CJ, Brown TT, Cheskin LJ, Choi P, Moran TH, Peterson L, Matuk R, Steele KE. Effects of meal composition on postprandial incretin, glucose and insulin responses after surgical and medical weight loss. Obes Sci Pract 2015; 1:104-109. [PMID: 27774253 PMCID: PMC5064622 DOI: 10.1002/osp4.17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/26/2015] [Accepted: 11/03/2015] [Indexed: 12/13/2022] Open
Abstract
Background Meal tolerance tests are frequently used to study dynamic incretin and insulin responses in the postprandial state; however, the optimal meal that is best tolerated and suited for hormonal response following surgical and medical weight loss has yet to be determined. Objective To evaluate the tolerability and effectiveness of different test meals in inducing detectable changes in markers of glucose metabolism in individuals who have undergone a weight loss intervention. Methods Six individuals who underwent surgical or medical weight loss (two Roux‐en‐Y gastric bypass, two sleeve gastrectomy and two medical weight loss) each completed three meal tolerance tests using liquid‐mixed, solid‐mixed and high‐fat test meals. The tolerability of each test meal, as determined by the total amount consumed and palatability, as well as fasting and meal‐stimulated glucagon‐like peptide, glucose‐dependent insulinotropic polypeptide, insulin and glucose were measured. Results Among the six individuals, the liquid‐mixed meal was better and more uniformly tolerated with a median meal completion rate of 99%. Among the four bariatric surgical patients, liquid‐mixed meal stimulated on average a higher glucagon‐like peptide (percent difference: 83.7, 89), insulin secretion (percent difference: 155.1, 158.7) and glucose‐dependent insulinotropic polypeptide (percent difference: 113.5, 34.3) compared with solid‐mixed and high‐fat meals. Conclusions The liquid‐mixed meal was better tolerated with higher incretin and insulin response compared with the high‐fat and solid‐mixed meals and is best suited for the evaluation of stimulated glucose homeostasis.
Collapse
|
32
|
Mak WC, Olesen K, Sivlér P, Lee CJ, Moreno-Jimenez I, Edin J, Courtman D, Skog M, Griffith M. Controlled Delivery of Human Cells by Temperature Responsive Microcapsules. J Funct Biomater 2015; 6:439-53. [PMID: 26096147 PMCID: PMC4493523 DOI: 10.3390/jfb6020439] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 05/25/2015] [Accepted: 06/10/2015] [Indexed: 12/23/2022] Open
Abstract
Cell therapy is one of the most promising areas within regenerative medicine. However, its full potential is limited by the rapid loss of introduced therapeutic cells before their full effects can be exploited, due in part to anoikis, and in part to the adverse environments often found within the pathologic tissues that the cells have been grafted into. Encapsulation of individual cells has been proposed as a means of increasing cell viability. In this study, we developed a facile, high throughput method for creating temperature responsive microcapsules comprising agarose, gelatin and fibrinogen for delivery and subsequent controlled release of cells. We verified the hypothesis that composite capsules combining agarose and gelatin, which possess different phase transition temperatures from solid to liquid, facilitated the destabilization of the capsules for cell release. Cell encapsulation and controlled release was demonstrated using human fibroblasts as model cells, as well as a therapeutically relevant cell line-human umbilical vein endothelial cells (HUVECs). While such temperature responsive cell microcapsules promise effective, controlled release of potential therapeutic cells at physiological temperatures, further work will be needed to augment the composition of the microcapsules and optimize the numbers of cells per capsule prior to clinical evaluation.
Collapse
|
33
|
Gao A, Rizo PJ, Scaccabarozzi L, Lee CJ, Banine V, Bijkerk F. Photoluminescence-based detection of particle contamination on extreme ultraviolet reticles. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:063109. [PMID: 26133830 DOI: 10.1063/1.4922883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Here, we propose a comparison-free inspection technique to detect particle contamination on the reticle of extreme ultraviolet (EUV) lithography systems, based on the photoluminescence spectral characteristics of the contaminant particles and their elemental composition. We have analyzed the spectra from different particles found on reticles in EUV lithographic systems and have determined the minimum detectable particle size: 25 nm for organic particles and 100 nm for Al particles. Stainless steel coatings (50 nm thick and 50 × 50 μm(2) in area) exhibit detectable photoluminescence, and the estimated minimum detectable particle is 2 μm.
Collapse
|
34
|
Lee YH, Lee CJ, Lee HS, Choe EY, Lee BW, Ahn CW, Cha BS, Lee HC, Balkau B, Kang ES. Comparing kidney outcomes in type 2 diabetes treated with different sulphonylureas in real-life clinical practice. DIABETES & METABOLISM 2015; 41:208-15. [PMID: 25687901 DOI: 10.1016/j.diabet.2015.01.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 01/20/2015] [Accepted: 01/22/2015] [Indexed: 11/29/2022]
Abstract
AIM Although several sulphonylureas are widely used in type 2 diabetes (T2D), their differential impacts on long-term major kidney outcomes remain unclear. This study aimed to investigate the effects of the two most commonly prescribed sulphonylureas, glimepiride and gliclazide, on kidney outcomes in patients with T2D. METHODS A total of 4486 patients treated with either glimepiride or gliclazide for more than 2 years were followed for up to 5.5 years (median: 4.7 years). A propensity score based on baseline characteristics was used to match 1427 patients treated with glimepiride with 1427 gliclazide-treated patients; incidences of end-stage renal disease (ESRD) and sustained doubling of creatinine to>132.6 μmol/L (1.5mg/dL) were also compared. RESULTS In the matched cohort with 12,122 person-years of follow-up, there was no significant difference between groups in risk of ESRD [hazard ratio (HR): 0.57, 95% confidence interval (CI): 0.29-1.12] or doubling of creatinine (HR: 0.74, 95% CI: 0.44-1.26), although there was a trend towards higher risks in the glimepiride group. Subgroup analyses showed that, compared with glimepiride, gliclazide was associated with a lower risk of doubling of creatinine in patients with preserved renal function (glomerular filtration rate ≥ 60 mL/min/1.73 m(2), HR: 0.21, 95% CI: 0.04-0.99) and good glycaemic control (HbA1c < 7%, HR: 0.35, 95% CI: 0.14-0.86), and in older subjects (≥ 62 years, HR: 0.52, 95% CI: 0.27-0.99). CONCLUSION In a real-life setting, there was no significant difference in clinical outcomes of kidney disease for patients treated with glimepiride vs gliclazide. However, gliclazide appeared to protect against renal complication progression in certain populations.
Collapse
|
35
|
Fan Y, Oldenbeuving RM, Khan MRH, Roeloffzen CGH, Klein EJ, Lee CJ, Offerhaus HL, Boller KJ. Q-factor measurements through injection locking of a semiconductor-glass hybrid laser with unknown intracavity losses. OPTICS LETTERS 2014; 39:1748-1751. [PMID: 24686595 DOI: 10.1364/ol.39.001748] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The injection locking properties of a newly developed waveguide-based external cavity semiconductor laser have been investigated. Using the injection locking properties to measure the Q-factor of complex optical cavities with unknown internal losses, has been demonstrated for the first time.
Collapse
|
36
|
You H, Kim GE, Na CH, Lee S, Lee CJ, Cho KH, Akiyama Y, Ishida T, No KT. An empirical model for gas phase acidity and basicity estimation. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2014; 25:91-115. [PMID: 24597990 DOI: 10.1080/1062936x.2013.864997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 08/09/2013] [Indexed: 06/03/2023]
Abstract
Gas phase acidity and basicity estimation models have been developed for acidic and basic functional groups of amino acid side-chains and also for a number of small organic molecules. The acidic functional groups include aliphatic and aromatic alcohol, and aliphatic and aromatic carboxylic acid, and the basic functional groups include aliphatic, aromatic and hetero-aromatic amines, and also pyridino-, pyrazolo- and imidazolo-groupings. The models are described in terms of a linear combination of descriptors that highly influence reactivity at the reaction centres of the functional groups. In order to describe the chemical environments of the deprotonating and protonating sites, atomic descriptors such as the effective atomic electronegativity and effective atomic polarizability of the atoms in the reaction field and the electrostatic potentials at the reaction sites have been introduced. The coefficient of determination (r(2)) of each model is above 0.8, apart from the imidazole model. The models are readily applicable, ranging from simple organic molecules to proteins.
Collapse
|
37
|
Lee CJ, Zhang Y, Takao H, Murayama Y, Qian Y. A fluid-structure interaction study using patient-specific ruptured and unruptured aneurysm: the effect of aneurysm morphology, hypertension and elasticity. J Biomech 2013; 46:2402-10. [PMID: 23962529 DOI: 10.1016/j.jbiomech.2013.07.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 07/17/2013] [Accepted: 07/18/2013] [Indexed: 10/26/2022]
Abstract
Fluid-structure interaction (FSI) simulations using five patient-specific aneurysm geometries are carried out to investigate the difference between ruptured and unruptured aneurysms. Two different blood pressure conditions (normal and hypertension, for all cases), and two different values of elastic modulus (1 and 2MPa, for two cases) are tested. Ruptured aneurysms (RA) generally displayed larger displacement at the dome, lower area-average WSS and higher von Mises stress than unruptured aneurysms (URA) regardless of elasticity or blood pressure condition. RAs had a longitudinal expansion whereas URAs had a radial expansion, which was the key difference between the two types. The difference in expansion pattern may be one of the keys to explaining aneurysm rupture, and further analysis is required in the future to confirm this theory.
Collapse
|
38
|
Oldenbeuving RM, Song H, Schitter G, Verhaegen M, Klein EJ, Lee CJ, Offerhaus HL, Boller KJ. High precision wavelength estimation method for integrated optics. OPTICS EXPRESS 2013; 21:17042-17052. [PMID: 23938552 DOI: 10.1364/oe.21.017042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A novel and simple approach to optical wavelength measurement is presented in this paper. The working principle is demonstrated using a tunable waveguide micro ring resonator and single photodiode. The initial calibration is done with a set of known wavelengths and resonator tunings. The combined spectral sensitivity function of the resonator and photodiode at each tuning voltage was modeled by a neural network. For determining the unknown wavelengths, the resonator was tuned with a set of heating voltages and the corresponding photodiode signals were collected. The unknown wavelength was estimated, based on the collected photodiode signals, the calibrated neural networks, and an optimization algorithm. The wavelength estimate method provides a high spectral precision of about 8 pm (5 · 10(-6) at 1550 nm) in the wavelength range between 1549 nm to 1553 nm. A higher precision of 5 pm (3 · 10(-6)) is achieved in the range between 1550.3 nm to 1550.8 nm, which is a factor of five improved compared to a simple lookup of data. The importance of our approach is that it strongly simplifies the optical system and enables optical integration. The approach is also of general importance, because it may be applicable to all wavelength monitoring devices which show an adjustable wavelength response.
Collapse
|
39
|
Lee CJ, Zhang Y, Takao H, Murayama Y, Qian Y. The influence of elastic upstream artery length on fluid-structure interaction modeling: a comparative study using patient-specific cerebral aneurysm. Med Eng Phys 2013; 35:1377-84. [PMID: 23664305 DOI: 10.1016/j.medengphy.2013.03.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 01/15/2013] [Accepted: 03/13/2013] [Indexed: 10/26/2022]
Abstract
Fluid-structure interaction (FSI) simulations using a patient-specific geometry are carried out to investigate the influence the length of elastic parent artery and the position of constraints in the solid domain on the accuracy of patient-specific FSI simulations. Three models are tested: Long, Moderate, and Short, based on the length of the elastic parent artery. All three models use same wall thickness (0.5 mm) and the elastic modulus (5 MPa). The maximum mesh displacement is the largest for the Long model (0.491 mm) compared to other models (0.3 mm for Moderate, and 0.132 mm for Short). The differences of hemodynamic and mechanical variables, aneurysm volume and cross-sectional area between three models are all found to be minor. In addition, the Short model takes the least amount of computing time of the three models (11h compared to 21 h for Long and 19 h for Moderate). The present results indicate that the use of short elastic upstream artery can shorten the time required for pati ent-specific FSI simulations without impacting the overall accuracy of the results.
Collapse
|
40
|
Hong HP, Jung KH, Kim JH, Kwon KH, Lee CJ, Yun KN, Min NK. Percolated pore networks of oxygen plasma-activated multi-walled carbon nanotubes for fast response, high sensitivity capacitive humidity sensors. NANOTECHNOLOGY 2013; 24:085501. [PMID: 23376938 DOI: 10.1088/0957-4484/24/8/085501] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report on the preparation of capacitive-type relative humidity sensors incorporating plasma-activated multi-wall carbon nanotube (p-MWCNT) electrodes and on their performance compared with existing commercial technology. Highly open porous conductive electrodes, which are almost impossible to obtain with conventional metal electrodes, are fabricated by spray-depositing MWCNT networks on a polyimide layer. Oxygen plasma activation of the MWCNTs is also explored to improve the water adsorption of the MWCNT films, by introducing oxygen-containing functional groups on the CNT surface. Polyimide humidity sensors with optimized p-MWCNT network electrodes exhibit exceptionally fast response times (1.5 for adsorption and 2 s for desorption) and high sensitivity (0.75 pF/% RH). These results may be partially due to their percolated pore structure being more accessible for water molecules, expending the diffusion of moisture to the polyimide sensing film, and partially due to the oxygenated surface of p-MWCNT films, allocating more locations for adsorption or attraction of water molecules to contribute to the sensitivity.
Collapse
|
41
|
Lee CJ, Eskandari MK. Imaging for carotid stenting. THE JOURNAL OF CARDIOVASCULAR SURGERY 2011; 52:795-801. [PMID: 22051988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Carotid artery stenting (CAS) using embolic protection devices (EPD) has emerged as a viable alternative to carotid endarterectomy (CEA) in select patients. Imaging plays a critical role in the selection of patients for CAS. Duplex ultrasonography alone is insufficient to assess patients for CAS suitability. Advancements in computed tomography angiography (CTA) and magnetic resonance angiography (MRA) techniques are helping to identify lesions vulnerable to cerebral embolization during carotid interventions - a more prevalent event during CAS in comparison to CEA. Here we review the relevant data on the various imaging techniques available to improve patient selection and minimize neurologic adverse events during carotid artery stenting.
Collapse
|
42
|
Sim WS, Choi JW, Lee CJ, Nahm FS, Lee SH, Shin BS, Cho HS. The influence of patient position on withdrawal force of thoracic epidural catheters. Anaesthesia 2011; 67:19-22. [PMID: 21972884 DOI: 10.1111/j.1365-2044.2011.06913.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We investigated the forces required to remove thoracic epidural catheters to determine the effect of patient position on removal. Eighty-four patients undergoing open thoracotomy and thoracic patient-controlled epidural analgesia were enrolled. Catheterisation was performed under fluoroscopic guidance before surgery, and the patients were allocated to one of three position groups for removal: prone; sitting; and lateral. On the third postoperative day, the peak tension during withdrawal in the assigned position was measured. No differences in mean (SD) forces were found between groups: prone 1.61 (0.39) N, supine 1.62 (0.61) N and lateral 1.36 (0.56) N (p = 0.140). The withdrawal forces required to remove thoracic epidural catheters were not affected by the position. Thus, the position for removal can be determined by patient's choice and clinical judgement.
Collapse
|
43
|
Kim WH, Lee CJ, Sim WS, Shin BS, Ahn HJ, Lim HY. Anatomical Analysis of Computed Tomography Images for Determining the Optimal Oblique Fluoroscope Angle for Percutaneous Coeliac Plexus Block. J Int Med Res 2011; 39:1798-807. [DOI: 10.1177/147323001103900522] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
This retrospective study used abdominal computed tomography (CT) scan images to determine the optimal safe oblique angle for fluoroscopy in fluoroscope-assisted coeliac plexus block (CPB). Abdominal CT scans from 131 patients were included in the study: 42 patients with cancer of the pancreas head, 45 with cancer of the pancreas body and tail and 44 with chronic pancreatitis. The oblique angle and entry distance from the midline were measured at the T12 and L1 levels, and the safe angle range that avoided puncture of the organs was also measured. The optimal angle varied between the T12 and L1 levels, and between the right and left sides at the T12 level. There was no difference in the oblique angle between the patient groups. The optimal oblique angle for fluoroscopy was determined to be 17° for right T12, 18° for left T12, and 19° for both left and right L1.
Collapse
|
44
|
Lee CJ, Wu S, Pedersen LG. A proposed ternary complex model of prothrombinase with prothrombin: protein-protein docking and molecular dynamics simulations. J Thromb Haemost 2011; 9:2123-6. [PMID: 21827606 DOI: 10.1111/j.1538-7836.2011.04463.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
45
|
Sakurai A, Jian X, Lee CJ, Manavski Y, Chavakis E, Donaldson J, Randazzo PA, Gutkind JS. Phosphatidylinositol-4-phosphate 5-kinase and GEP100/Brag2 protein mediate antiangiogenic signaling by semaphorin 3E-plexin-D1 through Arf6 protein. J Biol Chem 2011; 286:34335-45. [PMID: 21795701 DOI: 10.1074/jbc.m111.259499] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The semaphorins are a family of secreted or membrane-bound proteins that are known to guide axons in the developing nervous system. Genetic evidence revealed that a class III semaphorin, semaphorin 3E (Sema3E), and its receptor Plexin-D1 also control the vascular patterning during development. At the molecular level, we have recently shown that Sema3E acts on Plexin-D1 expressed in endothelial cells, thus initiating a novel antiangiogenic signaling pathway that results in the retraction of filopodia in endothelial tip cells. Sema3E induces the rapid disassembly of integrin-mediated adhesive structures, thereby inhibiting endothelial cell adhesion to the extracellular matrix. This process requires the activation of small GTPase Arf6 (ADP-ribosylation factor 6), which regulates intracellular trafficking of β1 integrin. However, the molecular mechanisms by which Sema3E-Plexin-D1 activates Arf6 remained to be identified. Here we show that GEP100 (guanine nucleotide exchange protein 100)/Brag2, a guanine nucleotide exchange factor for Arf6, mediates Sema3E-induced Arf6 activation in endothelial cells. We provide evidence that upon activation by Sema3E, Plexin-D1 recruits phosphatidylinositol-4-phosphate 5-kinase, and its enzymatic lipid product, phosphatidylinositol 4,5-bisphosphate, binds to the pleckstrin homology domain of GEP100. Phosphatidylinositol 4,5-bisphosphate binding to GEP100 enhances its guanine nucleotide exchange factor activity toward Arf6, thus resulting in the disassembly of integrin-mediated focal adhesions and endothelial cell collapse. Our present study reveals a novel phospholipid-regulated antiangiogenic signaling pathway whereby Sema3E activates Arf6 through Plexin-D1 and consequently controls integrin-mediated endothelial cell attachment to the extracellular matrix and migration.
Collapse
|
46
|
Oldenbeuving RM, Lee CJ, Van Voorst PD, Offerhaus HL, Boller K. Modeling of mode locking in a laser with spatially separate gain media. OPTICS EXPRESS 2010; 18:22996-23008. [PMID: 21164639 DOI: 10.1364/oe.18.022996] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We present a novel laser mode locking scheme and discuss its unusual properties and feasibility using a theoretical model. A large set of single-frequency continuous-wave lasers oscillate by amplification in spatially separated gain media. They are mutually phase-locked by nonlinear feedback from a common saturable absorber. As a result, ultra-short pulses are generated. The new scheme offers three significant benefits: the light that is amplified in each medium is continuous-wave, thereby avoiding issues related to group-velocity dispersion and nonlinear effects that can perturb the pulse shape. The set of frequencies on which the laser oscillates, and therefore the pulse repetition rate, is controlled by the geometry of resonator-internal optical elements, not by the cavity length. Finally, the bandwidth of the laser can be controlled by switching gain modules on and off. This scheme offers a route to mode-locked lasers with high average output power, repetition rates that can be scaled into the THz range, and a bandwidth that can be dynamically controlled. The approach is particularly suited for implementation using semiconductor diode laser arrays.
Collapse
|
47
|
Gross P, Lindsay ID, Lee CJ, Nittmann M, Bauer T, Bartschke J, Warring U, Fischer A, Kellerbauer A, Boller KJ. Frequency control of a 1163 nm singly resonant OPO based on MgO:PPLN. OPTICS LETTERS 2010; 35:820-822. [PMID: 20237610 DOI: 10.1364/ol.35.000820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report the realization of a singly resonant optical parametric oscillator (SRO) that is designed to provide narrow-bandwidth, continuously tunable radiation at a wavelength of 1163 nm for optical cooling of osmium ions. The SRO is based on periodically poled, magnesium-oxide-doped lithium niobate and pumped at 532 nm. The output coupling of the resonant idler wave is adjusted to yield up to 400 mW of 1163 nm radiation, with a bandwidth of a few megahertz. For continuous frequency tuning of the idler wave, the SRO is equipped with an intracavity etalon, and the cavity length is controlled with a piezo-actuated mirror synchronized to the etalon angle.
Collapse
|
48
|
Abstract
Emerging evidence suggests that malignant tumors are composed of a small subset of distinct cancer cells, termed "cancer stem cells" (typically less than 5% of total cancer cells based on cell surface marker expression), which have great proliferative potential, as well as more differentiated cancer cells, which have very limited proliferative potential. Data have been provided to support the existence of cancer stem cells in several different types of cancer, including human blood, brain, prostate, ovarian, melanoma, colon, and breast cancers. We have recently reported the identification of a subpopulation of pancreatic cancer cells that express the cell surface markers CD44+CD24+ESA+ (0.2-0.8% of all human pancreatic cancer cells) that function as pancreatic cancer stem cells. The CD44+CD24+ESA+ pancreatic cancer cells are highly tumorigenic and possess the stem cell-like properties of self-renewal and the ability to produce differentiated progeny. Pancreatic cancer stem cells also demonstrate upregulation of molecules important in developmental signaling pathways, including sonic hedgehog and the polycomb gene family member Bmi-1. Of clinical importance, cancer stem cells in several tumor types have shown resistance to standard therapies and may play a role in treatment failure or disease recurrence. Identification of pancreatic cancer stem cells and further elucidation of the signaling pathways that regulate their growth and survival may provide novel therapeutic approaches to treat pancreatic cancer, which is notoriously resistant to standard chemotherapy and radiation.
Collapse
|
49
|
Kim YH, Lee CJ, Lee SC, Huh J, Nahm FS, Kim HZ, Lee MK. Effect of pulsed radiofrequency for postherpetic neuralgia. Acta Anaesthesiol Scand 2008; 52:1140-3. [PMID: 18840116 DOI: 10.1111/j.1399-6576.2008.01752.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Postherpetic neuralgia (PHN) is one of the most intractable pain disorders, particularly among elderly patients. Lesioning of dorsal root ganglion (DRG) using pulsed radiofrequency (PRF) has shown pain reduction for PHN. We assessed the efficacy of PRF lesioning of DRG for PHN via an open, nonrandomized study. METHODS Forty-nine patients with PHN refractory to conservative therapy were involved. After impedance and sensory electrical nerve stimulation thresholds were assessed, PRF was performed three times adjacent to the DRG of corresponding levels at 42 degrees C for 120 s under the fluoroscopic guidance. Pain ratings were conducted on a visual analogue scale at 4-, 8- and 12-week follow-up. The data were analyzed using the one-way ANOVA test. P<0.05 was considered to be statistically significant. RESULTS There was excellent pain relief (about 55%) at 4 weeks after PRF lesioning adjacent to the DRG and the effectiveness was maintained at the subsequent 12-week follow-up. The pain duration, age and stimulation level did not influence the outcome. There were no procedure-related complications. CONCLUSIONS PRF lesioning of DRG showed significant pain relief compared with the conventional treatments in patients with intractable PHN. In order to elucidate the mode of action of PRF, further research is needed and the optimal electrical parameters of PRF have to be determined.
Collapse
|
50
|
Lee CJ, Scheiman J, Anderson MA, Hines OJ, Reber HA, Farrell J, Kochman ML, Foley PJ, Drebin J, Oh YS, Ginsberg G, Ahmad N, Merchant NB, Isbell J, Parikh AA, Stokes JB, Bauer T, Adams RB, Simeone DM. Risk of malignancy in resected cystic tumors of the pancreas < or =3 cm in size: is it safe to observe asymptomatic patients? A multi-institutional report. J Gastrointest Surg 2008; 12:234-42. [PMID: 18040749 DOI: 10.1007/s11605-007-0381-y] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2007] [Accepted: 09/26/2007] [Indexed: 01/31/2023]
Abstract
Recent international consensus guidelines propose that cystic pancreatic tumors less than 3 cm in size in asymptomatic patients with no radiographic features concerning for malignancy are safe to observe; however, there is little published data to support this recommendation. The purpose of this study was to determine the prevalence of malignancy in this group of patients using pancreatic resection databases from five high-volume pancreatic centers to assess the appropriateness of these guidelines. All pancreatic resections performed for cystic neoplasms < or =3 cm in size were evaluated over the time period of 1998-2006. One hundred sixty-six cases were identified, and the clinical, radiographic, and pathological data were reviewed. The correlation with age, gender, and symptoms (abdominal pain, nausea and vomiting, jaundice, presence of pancreatitis, unexplained weight loss, and anorexia), radiographic features suggestive of malignancy by either computed tomography, magnetic resonance imaging, or endoscopic ultrasound (presence of solid component, lymphadenopathy, or dilated main pancreatic duct or common bile duct), and the presence of malignancy was assessed using univariate and multivariate analysis. Among the 166 pancreatic resections for cystic pancreatic tumors < or =3 cm, 135 cases were benign [38 serous cystadenomas, 35 mucinous cystic neoplasms, 60 intraductal papillary mucinous neoplasms (IPMN), 1 cystic papillary tumor, and 1 cystic islet cell tumor], whereas 31 cases were malignant (14 mucinous cystic adenocarcinomas and 13 invasive carcinomas and 4 in situ carcinomas arising in the setting of IPMN). A greater incidence of cystic neoplasms was seen in female patients (99/166, 60%). Gender was a predictor of malignant pathology, with male patients having a higher incidence of malignancy (19/67, 28%) compared to female patients (12/99, 12%; p < 0.02). Older age was associated with malignancy (mean age 67 years in patients with malignant disease vs 62 years in patients with benign lesions (p < 0.05). A majority of the patients with malignancy were symptomatic (28/31, 90%). Symptoms that correlated with malignancy included jaundice (p < 0.001), weight loss (p < 0.003), and anorexia (p < 0.05). Radiographic features that correlated with malignancy were presence of a solid component (p < 0.0001), main pancreatic duct dilation (p = 0.002), common bile duct dilation (p < 0.001), and lymphadenopathy (p < 0.002). Twenty-seven of 31(87%) patients with malignant lesions had at least one radiographic feature concerning for malignancy. Forty-five patients (27%) were identified as having asymptomatic cystic neoplasms. All but three (6.6%) of the patients in this group had benign disease. Of the patients that had no symptoms and no radiographic features, 1 out of 30 (3.3%) had malignancy (carcinoma in situ arising in a side branch IPMN). Malignancy in cystic neoplasms < or =3 cm in size was associated with older age, male gender, presence of symptoms (jaundice, weight loss, and anorexia), and presence of concerning radiographic features (solid component, main pancreatic duct dilation, common bile duct dilation, and lymphadenopathy). Among asymptomatic patients that displayed no discernable radiographic features suggestive of malignancy who underwent resection, the incidence of occult malignancy was 3.3%. This study suggests that a group of patients with small cystic pancreatic neoplasms who have low risk of malignancy can be identified, and selective resection of these lesions may be appropriate.
Collapse
|