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  • Author: Jian Han x
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Abstract

With aim to improve the mechanical and thermal properties of poly (lactic acid) (PLA) melt-blown nonwovens (MBs), polyamide 11 (PA11) was melt blended with PLA at the weight proportions of PLA/PA11 (95/5, 90/10, 85/15, 80/20), and the corresponding PLA/PA11 MBs were also manufactured. The crystallization, thermal and rheological behaviors of PLA/PA11 blends were investigated. PLA/PA11 MBs were also characterized by morphology and mechanical properties. The results indicated that PA11, as globular dispersed phases, formed confined crystals and could improve the thermal stability of PLA matrix. The viscosity of PLA/PA11 blends was slightly increased but the rheological behaviors of “shear-thinning” kept unchanged in comparison with PLA. The average diameter of PLA/PA11 MB fibers was slightly increased, whereas the toughness of PLA/PA11 MBs including the strength and elongation were efficiently enhanced compared with those of PLA MBs.

Abstract

The optimization techniques are explored in the direction of arrival (DOA) estimation based on single acoustic pressure gradient vector sensor (APGVS). By analyzing the working principle and measurement errors of the APGVS, acoustic intensity approaches (AI) and the minimum variance distortionless response beamforming approach based on single APGVS (VMVDR) are deduced. The radius to wavelength ratio of the APGVS must be not bigger than 0.1 in the actual application, otherwise its DOA estimation performance will degrade significantly. To improve the ro-bustness and estimation performance of the DOA estimation approaches based on single APGVS, two modified proce-ssing approaches based on single APGVS are presented. Simulation and lake trial results indicate that the performance of the modified approaches based on single APGVS are better than AI and VMVDR approaches based on single APGVS when the radius to wavelength ratio is not bigger than 0.1, and the two modified DOA estimation methods have excel¬lent estimation performance when the radius to wavelength ratio is bigger than 0.1.

Abstract

The fluvio-lacustrine sequences in the Nihewan Basin, northern China, provide important terrestrial archives about Palaeolithic settlements and, therefore, about early human occupation in high northern latitude in East Asia. Here we present detailed ESR dating of the Donggutuo Palaeolithic site, located in this basin. Four levels A, B, C and E of the Donggutuo archaeological layer yield ESR ages ranging from 1060±129 ka to 1171±132 ka with a mean of 1119±132 ka. The ages are consistent with the paleomagnetic data, which show that the Donggutuo Palaeolithic site lies just below the onset of the Jaramillo normal subchron (0.99–1.07 Ma). Furthermore, our results indicate that the reliable ESR dating range of bleached quartz using Ti-Li centre can be effectively extended to 1100 ka and the Ti-Li centre was zeroed before the last deposition, which requires improvement of the understanding of the bleaching mechanism conditions.

Abstract

Obejective Ademetionine 1,4-butanedisulfonate [S-adenosyl-L-methionine (SAMe)/Transmetil®, Abbott] has been available in China for more than 15 years, and it has been shown to reduce serum bilirubin and transaminase levels in viral hepatitis (VH) patients. However, no large-scale studies have focused on the impact of SAMe treatment regimen on reducing the serum total bilirubin (TBil) in VH patients with intrahepatic cholestasis (IHC). The primary purpose of this study was to evaluate the effectiveness of intravenous SAMe (Transmetil®) treatment in reducing the serum TBil by 50%.

Methods This retrospective, multi-center, cross-sectional medical record review involved patients aged ≥18 years. Records of 1 280 hospitalized VH patients at 16 sites diagnosed with IHC who had received intravenous SAMe 1 000 mg or 2 000 mg q.d. for at least 7 days from January 1, 2006 to June 30, 2009, were screened and 905 records were randomly selected.

Results The safety set (SS) included 834 patients and the full analysis set 826 patients. TBil levels after 14 days injection treatment were available for 763 patients. TBil decreased ≥ 50% versus baseline after 14 days treatment in 288 (37.7%) patients (95% CI 34.3%, 41.2%). Twenty-nine non-serious adverse events (non-SAEs) were reported in 19 (2.3%) patients, and 29 SAEs were reported in 10 patients (1.2%). All adverse events (AEs) were considered unrelated to the study drug.

Conclusions This retrospective study shows that intravenous SAMe administration in VH patients with IHC is associated with significant reduction of TBil levels in more than 30% of patients 14 days after treatment initiation.