Sialyl stage-specific embryonic antigen-1: a useful marker for differentiating the etiology of pleural effusion

OBJECTIVES: To assess the usefulness of sialyl stage-specific embryonic antigen-1 (SSEA-1) levels in differentiating the etiology of pleural effusion (PE). DESIGN: A solid-phase immunoradiometric sandwich assay with an FH6 monoclonal antibody was used to measure sialyl SSEA-1 levels in PEs of 132 patients with various diseases. Paired serum sialyl SSEA-1 levels were measured simultaneously in 47 patients with various subtypes of lung cancer RESULTS: The pleural sialyl SSEA-1 levels were significantly higher in patients who had adenocarcinoma of the lung with positive cytology than in all the other patients, including those having malignancies other than adenocarcinoma of the lung, adenocarcinoma of the lung with cytology-negative PE, and benign diseases. There were no significant differences among sialyl SSEA-1 levels in the pleural fluid containing no adenocarcinoma cells. Using the cutoff value of 265 U/mL, the sensitivity was 64% (25/39) and the specificity was 95% (88/93) for the pleural sialyl SSEA-1 level to differentiate adenocarcinoma from other effusions. CONCLUSIONS: With high specificity and modest sensitivity, the pleural sialyl SSEA-1 level is a useful biochemical marker for differentiating the etiology of PEs caused by adenocarcinoma from other diseases.     

Comparison of thermal degradation characteristics of poly(arylene sulfone)s using thermogravimetric analysis/mass spectrometry

Thermal degradation of poly(arylene sulfone)s had been studied by the combination of thermogravimetric analysis/mass spectrometry (TG/MS) with pyrolysis/gas chromatography/mass spectrometry (Py‐GC/MS) techniques. Through these two methods, the pyrolysates from poly(ether sulfone) (PES) and polysulfone (PSF) were identified in 11 and 21 sets of evolution curves, respectively, from room temperature to 900 °C. Among these pyrolysates, 12 products from PES and 25 products from PSF were obtained. The major mechanism for both PES and PSF was one‐stage pyrolysis involving main chain random scission and carbonization with evolution of SO₂ and phenol as major products. Although the initial thermal stability of PES was lower than that of PSF, the formation of sulfide groups in the condensed phase from PES, through reduction of sulfone group by hydrogen radicals, increased the fire retardation behavior of PES. In PES, the ether and sulfone groups showed similar thermal stability. The thermal stability of functional groups in PSF were in the order of sulfone < ether < isopropylidene group. The scission of the ether group in PSF, with evolution of phenol as the major product, reached maximum evolution amount at the temperature of the maximum thermogravimetry loss of TG (T_max). The scission of isopropylidene groups at high temperature (>580 °C) evolved higher mass derivatives that lower the fire retardancy of PSF. By using a simplified kinetic model, PES showed maximum activation energy with a conversion ratio of 0.2–0.3, which implies a high fire retardant effect of sulfide formation in PES. A comparative study with the proposed model and experimental data showed the theoretical pyrolysis curves to be in agreement with the experimental curves for PES and PSF pyrolysis, respectively. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2387–2398, 2001     

Thermal decomposition characteristics of poly(ether imide) by TG/MS

Thermal degradation of poly(ether imide) (PEI) was studied by the combination of pyrolysis/gas chromatography/mass spectrometry (Py-GC/MS) and thermogravimetric analysis/mass spectrometry (TG/MS) techniques. The composition of evolved gases was determined by Py-GC/MS and the real-time formation curves were obtained through TG/MS. The thermal degradation mechanisms of PEI were resolved through TG/MS methods. The major pyrolysis mechanisms with the two-stage reaction regions were main chain random scission and carbonization. In the first stage pyrolysis, the decomposition of the hydrolyzed-imide, ether and isopropylene groups caused the evolution of CO₂ and phenol as major products accompanied by a chain transfer of carbonization to form partially carbonized solid residue. In the second stage pyrolysis, the decomposition of partially carbonized solid residue and the remaining imide group produced CO₂ as a major product along with benzene and small a amount of benzonitrile. Afterward, the chain transfer of carbonization dominated the decomposition of solid residue in higher temperatures to produce a high char yield. A kinetic model was proposed from the calculation of two flat regions in the activation energy curve. The theoretical pyrolysis curve from the proposed model was calculated and compared with the experimental curve, which were quite well matched.     

Presence of serum anti-p53 antibodies is associated with pleural effusion and poor prognosis in lung cancer patients

This study was designed prospectively to evaluate the development of anti-p53 antibodies (Abs) in lung cancer patients in relation to their clinical outcome. Sera, derived from 125 lung cancer patients, consisting of 14 small cell lung cancers (SCLC) and 111 non-SCLCs (NSCLC), were surveyed. The p53-null human NSCLC cell line, NCI-H1299, transfected with a human mutant p53 gene was prepared as the source of p53 antigen for immunoblotting analyses to detect the presence of serum anti-p53 Abs. The control group included sera from 10 healthy adults and 14 patients with benign pulmonary diseases. Clinical data including staging and survival were recorded for statistical analyses. The anti-p53 Abs were found in 8% (10 of 125) of the lung cancer patients studied (8.1% of NSCLC versus 7.1% of SCLC patients), whereas none of the control sera had detectable anti-p53 Abs. The presence of anti-p53 Abs was closely associated with malignant pleural effusions (P = 0.001). The p53 Ab-positive patients had a worse prognosis than the p53 Ab-negative patients (P < 0.02; median survival, 20 versus 41 weeks). In both univariate and multivariate analyses, the tumor extension and probably the presence of anti-p53 Abs were significant predictors for cancer death. The development of anti-p53 Abs (n = 9) was also a predictor for poor survival in patients with malignant effusions (n = 51). In conclusion, the presence of serum anti-p53 Abs is closely associated with malignant pleural effusions in lung cancer patients. It may serve as a negative prognostic factor for survival independent of malignant pleural effusions and tumor staging.     

HfO/sub 2/ MIS capacitor with copper gate electrode

Metal-insulator-semiconductor capacitors were fabricated using atomic vapor deposition HfO/sub 2/ dielectric with sputtered copper (Cu) and aluminum (Al) gate electrodes. The counterparts with SiO/sub 2/ dielectric were also fabricated for comparison. Bias-temperature stress and charge-to-breakdown (Q/sub BD/) test were conducted to examine the stability and reliability of these capacitors. In contrast with the high Cu drift rate in an SiO/sub 2/ dielectric, Cu in contact with HfO/sub 2/ seems to be very stable. The HfO/sub 2/ capacitors with a Cu-gate also depict higher capacitance without showing any reliability degradation, compared to the Al-gate counterparts. These results indicate that HfO/sub 2/ with its considerably high density of 9.68 g/cm/sup 3/ is acting as a good barrier to Cu diffusion, and it thus appears feasible to integrate Cu metal with the post-gate-dielectric ultralarge-scale integration manufacturing processes.     

Data mining for government construction procurement

A new data-mining model for government construction procurement was developed to consider data preparation, domain knowledge and a conceptual model to reflect the needs of the knowledge economy. Prototype experiments and analysis were performed to test the data mining using information from a typical Taiwanese local construction procurement unit. The application of the data-mining algorithm to this construction procurement management model improves government procurement effectiveness and efficiency. By complying with this governmental procurement information system and revealing the information required by the World Trade Organization and the Government Procurement Agreement, the model has the potential to improve government procurement and industry effectiveness and efficiency. It also provides a platform for government access to the international community.     

TRANSIENT LAMINAR NATURAL CONVECTION IN AN ENCLOSURE PARTITIONED BY AN ADIABATIC BAFFLE

Transient laminar natural convection in a two-dimensional enclosure partitioned by an adiabatic baffle is investigated numerically, A penalty finite-element method with a Newton-Raphson iteration algorithm and a backward difference scheme dealing with the time term are adopted to solve governing equations. The effects of the baffle and Rayleigh number on the heat transfer mechanism are found to be substantial during the transient process for Rayleigh numbers of 10⁴ and 10⁶. However, the variations of the heat transfer mechanism occur mainly in the first one-third of the time period of the transient, in spite of the presence, absence, or location of a baffle.     

Two-stage optimum design of the dual-lead worm

The dual-lead worm and worm gear drive is a convenient anti-backlash mechanism. It can be used in precision machine tools and indexing tables. The objective is to minimize the frictional force between the worm and the gear. The constraints include the worm geometry, stresses, displacements and the natural frequency of the worm. To avoid a difficult 3-D shape optimization problem, a two-stage optimization method is introduced in this paper. The first stage optimization uses an approximate worm model. The threads of the worm are approximated by plate elements in this stage. The design variables are pitch diameter of the worm, the module of the gear and the difference of the left and the right modules. The second stage optimization uses a true 3-D solid model with continuous spiral threads to determine the optimum shape of worm threads. Examples show the approach is feasible and efficient.