Search

Objective. Human adipose-derived stem cells (hADSCs) are ideal seed cells for the regeneration of alveolar bone defects. Platelet-rich plasma (PRP), which is rich in growth factors, promotes tissue repair. The purpose of the present study was to investigate whether PRP promotes the osteogenic differentiation of hADSCs and to perform high-throughput sequencing to explore the possible mechanism. Methods. hADSCs were divided into the three following groups: CON group, OM group, and PRP group. Osteogenesis was detected by Alizarin Red staining on day 14. Total RNA was extracted from the OM and PRP groups for high-throughput sequencing. The target genes of the differentially expressed osteogenic-related miRNAs were predicted, and combined miRNA/mRNA analysis was then performed. The mRNA and protein expression levels of hsa-miR-212-5p, type 1 cannabinoid receptor (CNR1), alkaline phosphatase (ALP), Runx2, osteocalcin (OCN), and collagen 1 A1 (COL1A1) in the OM and PRP groups were detected by qRT–PCR and Western blot analyses. The binding between hsa-miR-212-5p and CNR1 was detected by a dual-luciferase reporter assay. Results. Both the OM and PRP groups exhibited enhanced proliferation of hADSCs, and the differences at 48 h and 72 h were statistically significant ( P < 0.05 ). The PRP group had significantly more calcium nodules than the CON group ( P < 0.05 ). Through high-throughput sequencing analysis, differential miRNA and mRNA expression profiles were obtained. During hADSC osteogenesis, the expression of hsa-miR-212-5p was downregulated, and the expression of CNR1 was upregulated. hsa-miR-212-5p was found to bind directly to the 3 ′ UTR of CNR1. Conclusions. The present findings indicated that downregulation of hsa-miR-212-5p and upregulation of CNR1 may be involved in the process by which PRP promotes the osteogenic differentiation of hADSCs.

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.

A new kind of generalized heterochronous synchronization phenomenon is reported. Different kinds of generalized synchronous states (including generalized anticipated, isochronous and lag projective synchronization) coexist among different state variables between two unidirectionally coupled time-delayed chaotic systems. The analytical conditions for generalized heterochronous synchronization are obtained. We also find that the synchronization conditions are independent of the delay times in the original time-delayed system. The theoretical results are well confirmed by the numerical simulations and electronic circuit experiments.

A general method for formulating first-order time-delayed chaotic systems with simple linear time-delayed term is proposed. The formulated systems are realized with electronic circuit experiments. In order to determine the unknown coefficients in a general delayed differential equations for having chaotic solutions, we follow the route of period-doubling bifurcation to chaos. Firstly, the conditions for a time-delayed system having a stable periodic solution, generating from a destablized steady state, is analyzed with Hopf bifurcation theory. Then the delay time parameter is changed according to the bifurcation direction to search the chaotic state, which is identified by the Lyapunov exponents spectra. The theoretical analysis is well confirmed by numerical simulations and circuit experiments.

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. Fifty-six 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–1 at Zhongda and 1051 ± 147 ind. L–1 at Huangpu. There was a positive correlation between rotifer density and chlorophyll a concentration at both sites. At Huangpu, rotifer abundance was significantly negatively correlated with salinity. Analysis of partial correlations suggested that the fluvial hydrodynamics and the physico-chemical 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 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

In the present study, an attempt has been made to enhance tribological properties of AM50 magnesium alloy by laser surface melting (LSM) with a 2 kW continuous wave CO 2 laser. The microstructure of the laser surface melted zone consists of fine columnar dendrites growing epitaxially from the liquid–solid interface. Microhardness of the melted zone was improved to 55–75 HV as compared to 40 HV of the substrate. The friction and wear behavior of the laser surface melted layer were investigated using a ball-on-flat apparatus under dry sliding condition. It was found that the friction coefficient curve of the laser surface melted layer was similar to that of substrate. They showed a lower initial friction coefficient about 0.18 that after the running-in period increased up to about 0.38. Furthermore, compared with the AM50 substrate, the wear volume of the laser surface melted layer was decreased by 42%, the wear resistance of the laser surface melted layer was improved.

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 trochoidea was the most dominant and common cyst type in this survey, especially in sediments from Daya Bay, Dapeng Bay and Shenzhen Bay. However, Protoperidinium cysts 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) - Alexandrium spp. and Gymnodinium catenatum - were detected almost in all locations. Furthermore, the ellipsoidal Alexandrium catenella and A. tamarense cyst 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.

SUMMARY Nine sediment cores of 8–26 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 2–6 cm sediments. Cyst concentrations varied from 154 to 113 483 cysts per gram dry weight sediment, and were much higher in upper sediments. Scrippsiella trochoidea was the most dominant cyst type, which took up over 90% of cyst assemblages in the upper sediments. The abrupt increase of S. trochoidea cysts 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 of Alexandrium, mainly those of Alexandrium catenella and Alexandrium tamarense complex, 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 of Alexandrium cysts provided rich ‘seed bed’ for Alexandrium blooms and was also an important source of paralytic shellfish poisoning toxins, especially in winter.

Consider the nonlinear delay difference equation \(x_{n + 1} - x_n + \sum\limits_{j = 1}^m {p_j f_j (x_n - x_j ) = 0.} \)

The economic of this system has been evaluated. The system is combined by the photo heat and photovoltaic: the former are made of flat plate collector (FPC), container, bracket, hose, 2 DC pumps; the later are made of solar module, bracket, wire, complex controller, battery. Heat pump water heater (HPWH) links the above two together. The system aims to afford the hot water at all climate and send the surplus power to the grid. This paper analyzes from input, output and environmental protection, which shows the people the advantages and disadvantages of the system. The system has been set up in Guangzhou, China.

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.

There is an argument whether the bloom causative species of the East China Sea is Prorocentrum dentatum or a new species. Based on the scanning electron-microscopic study, we compared the detailed surface structure of the sample from the East China Sea and Prorocentrum dentatum strain (CCMP1517) from the Provasoli-Guillard National Center for Culture of Marine Phytoplankton, USA. The results showed that these two samples belonged to one species. After reviewing literatures, it can concluded that the bloom causative species of the East China Sea is Prorocentrum dentatum, rather than a new species.

An experimental setup has been built, based on the control method of the impulsive proportional feedback in the system variable (IPF-SV), and the results on stabilizing unstable periodic orbits (UPO) embedded in chaotic and hyperchaotic attractors are obtained. In order to enhance the effectiveness of controlling the UPO, a modified IPF-SV method has been suggested and applied to the circuit successfully.

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.

Single-species nonautonomous delay diffusion models with nonlinear growth rates are investigated. Some sufficient conditions are determined that guarantee the permanence of the species and the existence of a positive periodic solution which is global attractively.

The synthesis of Nd‐Fe‐Co‐B by the reduction‐diffusion process from neodymium trichloride and its magnetic properties and microstructure have been investigated by x‐ray diffraction, scanning electron microscope, and magnetic analysis. According to the thermodynamic data, calcium is capable of reducing neodymium trichloride and then a Nd‐Fe‐Co‐B alloy is formed by thermal diffusion in the presence of iron, cobalt, and ferro‐boron powders at high temperature. The reduction reaction starts at 720 °C. Thermal diffusion commenced at 800 °C and forming some Nd2Fe14B phase, but the matrix Nd2Fe14B formed primarily at 860–950 °C. There are three types of phases with different compositions in the sintered Nd‐Fe‐Co‐B R/D powders. The oxygen and calcium contents were 0.2 and 0.1 wt. %, respectively. The best yield of Nd‐Fe‐Co‐B powder was up to 98%. The magnetic properties of the sintered Nd‐Fe‐Co‐B depended on the temperature and time of the reduction‐diffusion process. The best magnetic properties obtained were Br...