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Ti–NiCrAl coating was fabricated on the substrate of Ti6Al4V alloy by laser cladding (LC), in which the Ti originated from the diluted element of substrate. The results show the Ti–NiCrAl coating is composed of NiTi and NiTi2 phases with the trace CrO and Al2O3 phases, in which the oxide phases are acted as an effective barrier to provide high-temperature protection for the substrate. The coefficient of friction (COF) and wear rate of Ti–NiCrAl coating are decreased with the elevated temperatures, which is attributed to the phase transformation of NiTi and NiTi2. The wear mechanism is the combination of abrasive wear and adhesive wear, in which the phase transformation of NiTi and NiTi2 phases play the roles of friction reduction and wear resistance. [ABSTRACT FROM AUTHOR]

In the present study, we determined whether ultrasound-targeted microbubble destruction (UTMD) combined with dual targeting of transforming growth factor (TGF)-β1 and tissue inhibitors of metalloproteinase (TIMP) 1 recombinant adeno-associated virus (rAAV) can stabilize atherosclerotic vulnerable plaques. First, we used rabbit model to detect the TGF-β1/TIMP1 virus therapy result. H&E staining was used to evaluate the tissues. The protein levels of TGF-β1 and TIMP1 were detected in rabbit models. The THP-1 cells were induced into macrophages, and transfected with TGF-β1 and TIMP1 rAAV under optimized UTMD. The expression of TGF-β1 and TIMP1 was measured by RT-PCR and western blotting. We found that the apoptotic rates were induced when compared to the control group. The rAAV virus group showed a significant decrease in the p-ERT and p-AKT expression. These data support the hypothesis that TGF-β1 and TIMP1 are crucial in the regulation of atherosclerotic plaques. [ABSTRACT FROM AUTHOR]

Rotifers were studied at two sites Zhongda and Huangpu in the tidal Guangzhou segment of the Pearl River in China, from April 2004 to March 2007. Fiftysix species were recorded. Rotifers were most abundant during late fall. Overall, densities ranged from 4 to 5975 ind. L–1, with mean densities of 1627 ± 233 ind. L–1at Zhongda and 1051 ± 147 ind. L–1at Huangpu. There was a positive correlation between rotifer density and chlorophyll aconcentration at both sites. At Huangpu, rotifer abundance was significantly negatively correlated with salinity. Analysis of partial correlations suggested that the fluvial hydrodynamics and the physicochemical characteristics of the river affected chlorophyll and the development of rotifer populations was determined by chlorophyll in the lower reaches of Pearl River. The results also show that rotifer density estimates are significantly affected by sampling method. © 2009 WILEYVCH Verlag GmbH & Co. KGaA, Weinheim [ABSTRACT FROM AUTHOR]

The effects of trichloroisocyanuric acid (TCCA) and ciprofloxacin (CPFX) on the freshwater alga Chlorella vulgaris were assessed by toxicity bioassays and by the values of biomarkers in phase I and phase II. The biomarkers included growth rate, concentration of chlorophyll a, activities of 7-ethoxyresorufin-O-dealkylases (EROD), glutathione S-transferase (GST), catalase (CAT), and total glutathione (GSH). Ciprofloxacin was a weaker growth inhibitor than TCCA but, at a concentration of greater than 12.5 mg/L, decreased the growth of C. vulgaris. Concentration of chlorophyll a showed a similar trend. The 96-h median effective concentration (EC50; i.e., 50% reduction in growth relative to the control) of CPFX was 20.6 mg/L. Trichloroisocyanuric acid was a strong growth inhibitor and, at concentrations of greater than 0.80 mg/L, caused 100% inhibition on 24-h exposure. The 96-h EC50 of TCCA was 0.313 mg/L. Ciprofloxacin and TCCA affected the phase I and phase II enzyme activities differently. On exposure to CPFX, both EROD and GSH decreased at low CPFX concentrations (<5.0 mg/L) and increased at high CPFX concentrations (>12.5 mg/L), and CAT and GST exhibited induction at low concentrations and inhibition at high concentrations. In TCCA exposure, GST activity was significantly stimulated, and GSH concentration was increased. Catalase activity increased only at TCCA concentrations of greater than 0.12 mg/L, and no change in EROD activity was observed. [ABSTRACT FROM AUTHOR]

Nine sediment cores of 8−ndash;26 cm in length were collected from two basins of Daya Bay, the South China Sea, by Tokyo University Fisheries Oceanography Laboratory core sampler in August 2001 to investigate the distribution of dinoflagellate resting cysts. In the present study, 51 different cyst morphotypes representing 22 genera were identified from 65 sediment samples. Among them, there were 21 autotrophic species and 30 heterotrophic ones. Cyst species richness in each sample varied from 12 to 29, while the values of Shannon-Weaver diversity index (H′) were between 0.15 and 4.13. There were an obvious increase in both species richness and values of H′ in 2−ndash;6 cm sediments. Cyst concentrations varied from 154 to 113 483 cysts per gram dry weight sediment, and were much higher in upper sediments.Scrippsiella trochoideawas the most dominant cyst type, which took up over 90% of cyst assemblages in the upper sediments. The abrupt increase ofS. trochoideacysts in the surface sediments reflected the bloom of this species in Daya Bay in 2000. The results from cyst assemblages showed some trend of changes in water quality in this area, and indicated a typical type of pollution caused by cultural eutrophication, which started in the 1980s and greatly accelerated in the middle of 1990s. Cysts ofAlexandrium, mainly those ofAlexandrium catenellaandAlexandrium tamarensecomplex, occurred frequently and abundantly in this area, with the highest concentration and relative frequency of 503 cysts per gram dry weight sediment and 22.3%, respectively. The high abundance ofAlexandriumcysts provided rich‘seed bed’ forAlexandriumblooms and was also an important source of paralytic shellfish poisoning toxins, especially in winter. [ABSTRACT FROM AUTHOR]

Surface sediments were collected from 10 locations to study the distribution of dinoflagellate resting cysts in Chinese coastal waters from July 2000 to May 2002. Sixty-one cyst morphotypes representing 14 genera of three orders were identified in this survey. Seventeen cyst types were recorded for the first time from Chinese coasts. Rich cyst assemblages were recorded in closed or semi-closed nearshore harbors.Scrippsiella trochoideawas the most dominant and common cyst type in this survey, especially in sediments from Daya Bay, Dapeng Bay and Shenzhen Bay. However,Protoperidiniumcysts were the most diversified group, predominating in Changjiang River Estuary, Zhujiang River Estuary, Zhelin bay and the Nanao Island area. Cyst concentrations in the top 2 cm surface sediments varied from 258 to 25,037 cysts·g−1 dry weight sediment, and abundance was lower in Changjiang River Estuary and Zhujiang River Estuary. Cysts of two dinoflagellates capable of producing paralytic shellfish poisoning (PSP)– Alexandriumspp. andGymnodinium catenatum– were detected almost in all locations. Furthermore, the ellipsoidalAlexandrium catenellaandA. tamarensecyst complex was frequently observed in the surface sediment from Daya Bay, where high contents of PSP toxin and PSP episodes have been reported. Detailed descriptions and illustrations are provided of those cysts of newly recorded species, unidentified species, toxic species and dominant species. [ABSTRACT FROM AUTHOR]

The year 1998 was an unusual year for Guangdong Province and Hong Kong, both in southern China, as the frequency and intensity of harmful algal blooms (HAB) were much higher than usual. This paper describes the causative organisms found associated with these blooms and speculates on the possible causes of these blooms, including the effects of increased temperature, reduced salinity, eutrophication and meteorological and oceanographic events on the initiation and spread of these blooms. [ABSTRACT FROM AUTHOR]