Aqueous Developable and CO2-Sourced Chemical Amplification Photoresist with High Performance.

Seeking high-performance photoresist is an important item for semiconductor industry due to the continuous miniaturization and intelligentization of integrated circuits. Polymer resin containing carbonate group has many desirable properties, such as high transmittance, acid sensitivity and chemical formulation, thus serving as potential photoresist material. In this work, a series of aqueous developable CO2-sourced polycarbonate (CO2-PC) were produced via alternating copolymerization of CO2 and epoxides bearing acid-cleavable cyclic acetal groups in the presence of tetranuclear organoborane catalyst. The produced CO2-PCs were investigated as chemical amplification resists in deep ultraviolet (DUV) lithography. Under the catalysis of photoacid, the acetal (ketal) groups in CO2-PC were hydrolysed into two equivalents of hydroxyl groups, which changes the exposed areas from hydrophobicity to hydrophilicity, thus enabling the exposed regions to be developed in water. Through normalized remaining thickness analysis, the optimal CO2-derived resist achieved a remarkable sensitivity of 1.9 mJ/cm2, a contrast of 7.9, a favorable resolution (750 nm, half pitch), and etching resistance (38% higher than poly(tert-butyl acrylate)). Such performances outperforming commercial KrF and ArF chemical amplification resists (i.e., polyhydroxystyrene-derived and polymethacrylate-based resists), which endows broad application prospects in the field of DUV (248 nm and 193 nm) and extreme ultraviolet (EUV) lithography and nanomanufacturing.

Noninvasive assessment of myocardial work during left ventricular isovolumic relaxation in patients with diastolic dysfunction.

BACKGROUND: This study aims to investigate the value of myocardial work (MW) parameters during the isovolumic relaxation (IVR) period in patients with left ventricular diastolic dysfunction (LVDD). METHODS: This study prospectively recruited 448 patients with risks for LVDD and 95 healthy subjects. An additional 42 patients with invasive measurements of left ventricular (LV) diastolic function were prospectively included. The MW parameters during IVR were noninvasively measured using EchoPAC. RESULTS: The total myocardial work during IVR (MWIVR), myocardial constructive work during IVR (MCWIVR), myocardial wasted work during IVR (MWWIVR), and myocardial work efficiency during IVR (MWEIVR) of these patients were 122.5 ± 60.1 mmHg%, 85.7 ± 47.8 mmHg%, 36.7 ± 30.6 mmHg%, and 69.4 ± 17.8%, respectively. The MW during IVR was significantly different between patients and healthy subjects. For patients, MWEIVR and MCWIVR were significantly correlated with the LV E/e' ratio and left atrial volume index, MWEIVR exhibited a significant correlation with the maximal rate of decrease in LV pressure (dp/dt per min) and tau, and the MWEIVR corrected by IVRT also exhibited a significant correlation with tau. CONCLUSIONS: MW during IVR significantly changes in patients with risks for LVDD, and is correlated to LV conventional diastolic indices, including dp/dt min and tau. Noninvasive MW during IVR may be a promising tool to evaluate the LV diastolic function.

Incremental value of resting three-dimensional speckle-tracking echocardiography in detecting coronary artery disease.

The aim of the present study was to investigate the incremental value of resting three-dimensional speckle-tracking echocardiography (3D-STE) in the detection of early-stage left ventricular dysfunction in patients with coronary artery disease (CAD). A total of 110 patients suspected of having CAD were recruited. All patients underwent 3D-STE and coronary artery angiography (CAG). They were divided to a CAD group and a normal group according to the results of CAG. Using 3D-STE software, the peak values of longitudinal strain (LS), circumferential strain (CS), radial strain (RS) and area strain (AS) and the time to peak value of these strains (T-LS, T-CS, T-RS and T-AS) were measured. A receiver operator characteristic curve (ROC) was used to analyze the sensitivity of these strains for the diagnosis of CAD. ROC analysis indicated that T-LS and composite indices combining the peak strain value and time to peak of LS, CS and AS have diagnostic value for the early detection of CAD; the area under the curve (AUC) values were 0.667, 0.692, 0.621 and 0.672 respectively (P<0.005). The composite index of longitudinal strain demonstrated the highest diagnostic value for CAD with 62% sensitivity and 76% specificity. These results indicate that 3D-STE has incremental value for the diagnosis of CAD in patients at rest.

[Correlation of the contents of trace elements in male body fluids with sperm quality].

OBJECTIVE: To explore the contents of trace elements in the blood and seminal plasma of men and their correlation with semen parameters. METHODS: We detected and analyzed the contents of calcium, magnesium, copper, zinc, iron and lead in the blood and semen of 113 men with the BH-5100 5-channel atomic absorption spectrometer, YY-1001 blood lead instrument and Weili color sperm automatic analyzer to investigate the correlation of the contents of trace elements with quality. RESULTS: The contents of lead, copper, zinc and iron in the blood were significantly correlated with those in the seminal plasma, but not the contents of calcium and magnesium. The contents of lead, copper, zinc, calcium, magnesium and iron in the blood were significantly different from those in the semen. In the seminal plasma, the content of calcium showed a significant positive correlation with sperm motility, linear motile sperm motility (LMSM), straight line velocity (VSL), curvilinear velocity (VCL), mean angle of deviation (MAD), active sperm density (ASD), average path velocity (VAP) and lateral head amplitude (ALH), while that of lead was negatively correlated with sperm motility, LMSM, ASD, motile sperm density (MSD) and linear motile sperm density (LMSD), and so was that of magnesium with sperm motility, LMSM and LMSD, and those of calcium, magnesium and iron with seminal pH. In the blood, the content of zinc was negatively correlated with sperm motility and LMSM, and so was that of magnesium with sperm motility, LMSM and VAP, while that of lead was positively correlated with ALH. CONCLUSION: The contents of trace elements in different body fluids are differently correlated with sperm quality.

[Determination of uric acid in seminal plasma and correlation between seminal uric acid and semen parameters].

OBJECTIVE: To establish the method of seminal uric acid (UA) determination and investigate the correlation between the seminal UA level and semen parameters. METHODS: The method of seminal UA determination was established by modifying the method of serum UA detection, and its intraassay coefficient of variation (CV) and the difference of the results between different technicians were also observed to evaluate the acceptability of the method. In the meanwhile, the correlations of the seminal UA level with the patients' age, abstinence time, semen volume, pH, sperm concentration, motility, the percentage of grade a and b sperm, and the percentage of morphologically normal sperm. RESULTS: The intraassay CV was 9. 16% for the method of seminal UA detection, and there was no significant difference in the UA level detected by 2 technicians (P = 0.541). The seminal UA level was positively correlated with the percentage of morphologically normal sperm (r = 0.350, P = 0.025) , with a tendency of positive correlation with sperm motility (r = 0.147, P = 0.085) and the percentage of grade a and b sperm (r = 0.156, P = 0.068), but not with other parameters such as semen volume, pH, sperm concentration, abstinence time and the patients' age. CONCLUSION: An acceptable method of seminal UA determination could be established by modifying the method of serum UA detection. Sperm morphology, motility and the percentage of grade a and b sperm might be related to the level of seminal UA.

QSPR prediction of GC retention indices for nitrogen-containing polycyclic aromatic compounds from heuristically computed molecular descriptors.

Gas chromatographic retention indices of nitrogen-containing polycyclic aromatic compounds (N-PACs) have been predicted by quantitative structure-property relationship (QSPR) analysis based on heuristic method (HM) implemented in CODESSA. In order to indicate the influence of different molecular descriptors on retention indices and well understand the important structural factors affecting the experimental values, three multivariable linear models derived from three groups of different molecular descriptors were built. Moreover, each molecular descriptor in these models was discussed to well understand the relationship between molecular structures and their retention indices. The proposed models gave the following results: the square of correlation coefficient, R(2), for the models with one, two and three molecular descriptors was 0.9571, 0.9776 and 0.9846, respectively.