1,772 research outputs found
Clinical significance of serum vascular cell adhesion molecule-1 levels in patients with hepatocellular carcinoma
Aim: To evaluate the correlation between serum vascular cellular adhesion molecule-1 (VCAM-1) levels and clinicopathological features in patients with hepatocellular carcinoma (HCC). Methods: Ninety-six patients who underwent HCC resection were recruited in the study. Preoperative serum levels of soluble VCAM-1 were measured by enzyme-linked immunosorbent assay. Results: Serum VCAM-1 level in HCC patients was inversely correlated with platelet count (r=-0.431, P<0.001) and serum albumin level (r=-0.279, P<0.001), and positively correlated with serum bilirubin level (r=-0.379, P<0.001). Serum VCAM-1 level was not associated with tumor characteristics such as tumor size, venous invasion, presence of microsatellite nodules, tumor grade and tumor stage. Serum VCAM-1 level was significantly higher in HCC patients with cirrhosis compared with those without cirrhosis (median 704 vs 546 ng/mL, P<0.001). Furthermore, a significantly better disease-free survival was observed in HCC patients with low VCAM-1 level (P=0.019). Conclusion: Serum VCAM-1 level appears to reflect the severity of underlying chronic liver disease rather than the tumor status in HCC patients, and low preoperative serum VCAM-1 level is predictive of better disease-free survival after surgery. Copyright © 2004 by The WJG Press.published_or_final_versio
A robust computational algorithm for inverse photomask synthesis in optical projection lithography
Inverse lithography technology formulates the photomask synthesis as an inverse mathematical problem. To solve this, we propose a variational functional and develop a robust computational algorithm, where the proposed functional takes into account the process variations and incorporates several regularization terms that can control the mask complexity. We establish the existence of the minimizer of the functional, and in order to optimize it effectively, we adopt an alternating minimization procedure with Chambolle's fast duality projection algorithm. Experimental results show that our proposed algorithm is effective in synthesizing high quality photomasks as compared with existing methods.published_or_final_versio
Silicon Atomic Quantum Dots Enable Beyond-CMOS Electronics
We review our recent efforts in building atom-scale quantum-dot cellular
automata circuits on a silicon surface. Our building block consists of silicon
dangling bond on a H-Si(001) surface, which has been shown to act as a quantum
dot. First the fabrication, experimental imaging, and charging character of the
dangling bond are discussed. We then show how precise assemblies of such dots
can be created to form artificial molecules. Such complex structures can be
used as systems with custom optical properties, circuit elements for
quantum-dot cellular automata, and quantum computing. Considerations on
macro-to-atom connections are discussed.Comment: 28 pages, 19 figure
Anode modification of polyfluorene-based polymer light-emitting devices
A glycerol-modified poly(3,4-ethylene dioxythiophene) (PEDOT): poly(styrene sulfonate) (PSS) layer was used as an anode buffer layer in polymer light-emitting devices using poly(9,9-dioctylfluorene) (F8) as the emitter. Devices with a configuration of indium tin oxide/PEDOT:PSS (with or without glycerol)/F8/CsF/Al were fabricated. It was found that the glycerol-modified device showed a much larger current density than the unmodified device. At an operating voltage of 6 V, the glycerol-modified device showed a luminance of 1300Cd/m 2 and a current efficiency of 1.7 Cd/A compared to the corresponding values of 500Cd/m 2 and 1.3 Cd/A in the unmodified device. Analysis by ultraviolet spectroscopy suggests that the two devices have the same energy level structure and the performance improvement should not be due to change in the PEDOT/polymer interface. It was further found that incorporating a suitable amount of glycerol into the PEDOT:PSS layer can increase its conductivity by six times. This leads to a better balance in the hole and electron currents and thus improved device efficiency. © 2002 American Institute of Physics.published_or_final_versio
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Semi AI-based protection element for MMC-MTDC using local-measurements
Data Access Statement: Data supporting this study cannot be made available due to the research data are confidential, because of the arrangement the research groups have made with the commercial partner supporting the research.Copyright © 2022 The Authors. The multi-terminal HVDC system based on the modular multilevel converter (MMC-MTDC) is a promising technique for flexible power transmissions to multiple regions. As such a system is quite sensitive to DC faults, there is an acute need to propose a protection element that can trip the local DC circuit breaker (CB) within several milliseconds once there is an internal DC line fault. However, the existing main protection scheme faces a dilemma balancing selectivity and sensitivity. To solve this problem, a novel semi artificial-intelligence (AI) based protection element is proposed, including a start-up criterion and a fault-identification criterion. The start up criterion is based on the propagation characteristics of the initial fault-induced surge. To enhance the real time performance of the protection element, it will not trip the fault-identification process unless the fault is identified as a forward one. The fault-identification criterion is based on artificial intelligence (AI), and further determines whether the forward fault is internal, which only works if the start-up criterion trips. Simulation results indicate that the proposed protection element has satisfactory speed, sensitivity, and selectivity against internal DC faults and is quite secure under external fault conditions. The impact of disturbances, such as the white noise, abnormal samplings, etc., on the security of the proposed protection element is also discussed.National Natural Science Foundation of China under Grant No. 51907069; Natural Science Foundation of Guangdong Province under Grant No. 2022A1515011079 and 2020A1515010766
Efficacy of mycophenolate mofetil in patients with diffuse proliferative lupus nephritis
Background: The combination of cyclophosphamide and prednisolone is effective for the treatment of severe lupus nephritis but has serious adverse effects. Whether mycophenolate mofetil can be substituted for cyclophosphamide is not known. Methods: In 42 patients with diffuse proliferative lupus nephritis we compared the efficacy and side effects of a regimen of prednisolone and mycophenolate mofetil given for 12 months with those of a regimen of prednisolone and cyclophosphamide given for 6 months, followed by prednisolone and azathioprine for 6 months. Complete remission was defined as a value for urinary protein excretion that was less than 0.3 g per 24 hours, with normal urinary sediment, a normal serum albumin concentration, and values for serum creatinine and creatinine clearance that were no more than 15 percent above the base-line values. Partial remission was defined as a value for urinary protein excretion that was between 0.3 and 2.9 g per 24 hours, with a serum albumin concentration of at least 3.0 g per deciliter. Results: Eighty-one percent of the 21 patients treated with mycophenolate mofetil and prednisolone (group 1) had a complete remission, and 14 percent had a partial remission, as compared with 76 percent and 14 percent, respectively, of the 21 patients treated with cyclophosphamide and prednisolone followed by azathioprine and prednisolone (group 2). The improvements in the degree of protelnuria and the serum albumin and creatinine concentrations were similar in the two groups. One patient in each group discontinued treatment because of side effects. Infections were noted in 19 percent of the patients in group 1 and in 33 percent of those in group 2 (P=0.29). Other adverse effects occurred only in group 2; they included amenorrhea (in 23 percent of the patients), hair loss (19 percent), leukopenia (10 percent), and death (10 percent). The rates of relapse were 15 percent and 11 percent, respectively. Conclusions: For the treatment of diffuse proliferative lupus nephritis, the combination of mycophenolate mofetil and prednisolone is as effective as a regimen of cyclophosphamide and prednisolone followed by azathioprine and prednisolone. (C) 2000, Massachusetts Medical Society.published_or_final_versio
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Transient extraction transform based fault location method with enhanced accuracy
The fast determination of internal or external fault for the VSC-MTDC is essential for its safety and continuous operation. As very limited time is permitted in an internal fault, transient-based protection elements are widely applied to locate the fault in a very small-time window. However, with such a short time window, location methods based on the wavelet transform or the mathematical morphology show limited performance balancing the resolution in the time and frequency domains. In recent years, there has been a novel time-frequency domain analysis method, naming the transient extraction transform (TET), with high accuracy in both domains. In this paper, a TET-based fast fault-location method is proposed with enhanced accuracy. Comparison studies are made to highlight the performance of such a method against internal faults for the VSC-MTDC.This work is supported by the National Natural Science Foundation of China under Grant No. 51907069 and the
Natural Science Foundation of Guangdong Province under Grant No. 2021A151501239
Two-dose Covid-19 vaccination and possible arthritis flare among patients with rheumatoid arthritis in Hong Kong
Objectives: To investigate the relationship between COVID-19 full vaccination (two completed doses) and possible arthritis flare.
Methods: Patients with rheumatoid arthritis (RA) were identified from population-based electronic medical records with vaccination linkage and categorised into BNT162b2 (mRNA vaccine), CoronaVac (inactive virus vaccine) and non-vaccinated groups. The risk of possible arthritis flare after vaccination was compared using a propensity-weighted cohort study design. We defined possible arthritis flare as hospitalisation and outpatient consultation related to RA or reactive arthritis, based on diagnosis records during the episode. Weekly prescriptions of rheumatic drugs since the launch of COVID-19 vaccination programme were compared to complement the findings from a diagnosis-based analysis.
Results: Among 5493 patients with RA (BNT162b2: 653; CoronaVac: 671; non-vaccinated: 4169), propensity-scored weighted Poisson regression showed no significant association between arthritis flare and COVID-19 vaccination ((BNT162b2: adjusted incidence rate ratio 0.86, 95% Confidence Interval 0.73 to 1.01); CoronaVac: 0.87 (0.74 to 1.02)). The distribution of weekly rheumatic drug prescriptions showed no significant differences among the three groups since the launch of the mass vaccination programme (all p values >0.1 from Kruskal-Wallis test).
Conclusions: Current evidence does not support that full vaccination of mRNA or inactivated virus COVID-19 vaccines is associated with possible arthritis flare
Monoclonal antibodies and Fc-fusion protein biologic medicines: A multinational cross-sectional investigation of accessibility and affordability in Asia Pacific regions between 2010 and 2020
Background: Monoclonal antibody (mAb) and Fc-fusion protein (FcP) are highly effective therapeutic biologics. We aimed to analyse consumption and expenditure trends in 14 Asia-Pacific countries/regions (APAC) and three benchmark countries (the UK, Canada, and the US).
Methods: We analysed 440 mAb and FcP biological products using the IQVIA-MIDAS global sales database. For each year between 2010 and 2020 inclusive, we used standard units (SU) sold per 1000 population and manufacture level price (standardised in 2019 US dollars) to evaluate consumption (accessibility) and expenditure (affordability). Changes of consumption and expenditure were estimated using compound annual growth rate (CAGR). Correlations between consumption, country's economic and health performance indicators were measured using Spearman correlation coefficient.
Findings: Between 2010 and 2020, CAGRs of consumption in each region ranged from 7% to 34% and the CAGRs of expenditure ranged from 9% to 31%. The median consumption of biologics was extremely low in lower-middle-income economies (0·29 SU/1000 population) compared with upper-middle-income economies (1·20), high-income economies (40·94) and benchmark countries (109·55), although the median CAGRs of biologics consumption in lower-middle-income economies (31%) was greater than upper-middle-income (14%), high-income economies (13%) and benchmark countries (9%). Consumption was correlated with GDP per capita [Spearman's rank correlation coefficient (r) = 0·75, p < 0·001], health expenditure as a percentage of total (r = 0·83, p < 0·001) and medical doctors’ density (r = 0·85, p < 0·001).
Interpretation: There have been significant increases in mAb and FcP biologics consumption and expenditure, however accessibility of biological medicines remains unequal and is largely correlated with country's income level.
Funding: This research was funded by NHMRC Project Grant GNT1157506 and GNT1196900; Enhanced Start-up Fund for new academic staff and Internal Research Fund, Department of Medicine, LKS Faculty of Medicine, University of Hong Kong
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