Applicability of the generalized wind profile model over mountainous forests.

The analytical equation based on Monin-Obukhov (M-O) similarity theory (i.e., wind profile equation) has been adopted since 1970s for using in the prediction of wind vertical profile over flat terrains, which is mature and accurate. However, its applicability over complex terrains remains unknown. This applicability signifies the accuracy of the estimations of aerodynamic parameters for the boundary layer of non-flat terrain, such as zero-displacement height (d) and aerodynamic roughness length (z0), which will determine the accuracy of frequency correction and source area analysis in calculating carbon, water, and trace gas fluxes based on vorticity covariance method. Therefore, the validation of wind profile model in non-flat terrain is the first step to test whether the flux model needs improvement. We measured three-dimensional wind speed data by using the Ker Towers (three towers in a watershed) at Qingyuan Forest CERN in the Mountainous Region of east Liaoning Province, and compared them with data from Panjin Agricultural Station in the Liaohe Plain, to evaluate the applicability of a generalized wind profile model based on the Monin-Obukhov similarity theory on non-flat terrain. The results showed that the generalized wind profile model could not predict wind speeds accurately of three flux towers separately located in different sites, indicating that wind profile model was not suitable for predicting wind speeds in complex terrains. In the leaf-off and leaf-on periods, the coefficient of determination (R2) between observed and predicted wind speeds ranged from 0.12 to 0.30. Compared to measured values, the standard error of the predicted wind speeds was high up to 2 m·s-1. The predicted wind speeds were high as twice as field-measured wind speed, indicating substantial overestimation. Nevertheless, this model correctly predicted wind speeds in flat agricultural landscape in Panjin Agricultural Station. The R2 between observed wind speeds and predicted wind speed ranged from 0.90 to 0.93. The standard error between observed and predicted values was only 0.5 m·s-1. Results of the F-test showed that the root-mean-square error of the observed and predicted wind speeds in each secondary forest complex terrain was much greater than that in flat agricultural landscape. Terrain was the primary factor affecting the applicability of wind profile model, followed by seasonality (leaf or leafless canopy). The wind profile model was not applicable to the boundary-layer flows over forest canopies in complex terrains, because the d was underestimated or both the d and z0 were underestimated, resulting in inaccurate estimation of aerodynamic height.

miR-125a inhibits the migration and invasion of liver cancer cells via suppression of the PI3K/AKT/mTOR signaling pathway.

In order to explore the regulation of the invasive ability of hepatocellular carcinoma cells and the underlying mechanism, mimics sequences of microRNA (miR)-125a (miR-125a-3p/5p) and scramble sequences (miR-125a-3p-s/5p-s) were transfected into human hepatocellular carcinoma cell lines, HCC-LM3 and HepG2, and the non-malignant epithelioid hepatic cell line QZG. To inhibit and upregulate the expression of miR-125a individually. Protein expression was detected by western blotting, and the cell proliferation and migration abilities were evaluated by soft agar colony formation and Transwell assay, respectively. It was revealed that the expression of miR-125a was downregulated in HepG2 and HCC-LM3 cells compared with that of QZG cells, and expression was markedly lower in HCC-LM3 cells than that in HepG2 cells (P<0.01). The colony formation and migration rates of the cells transfected with miR-125a-3p/5p were decreased compared with negative controls, but were increased in cells transfected with miR-125a-3p-3/5p-s (P<0.01). The protein and messenger RNA expression of phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) was decreased following transfection with miR-125a-5p, whereas expression was increased compared with negative controls following transfection with miR-125a-5p-s (P<0.01). Furthermore, the proliferation and migration abilities of cells were attenuated following inhibition of the PI3K/AKT/mTOR pathway by LY294002. The results of the present study indicated that miR-125a inhibits the invasive ability of hepatocellular carcinoma cells via regulation of the PI3K/AKT/mTOR pathway.

[Effects of dynamic aerodynamic parameters on simulating the land-atmosphere flux exchange in maize field: a case study of BATS1e model].

Based on the continuous observations on the land-atmosphere flux exchange and the meteorological and biological elements in a maize field at the Jinzhou Agricultural Ecosystem Research Station in Liaoning Province of Northeast China from 2006 to 2008, and by using the dynamic roughness (z0) and zero-displacement (d) parameterization scheme considering the effects of leaf area index, canopy height and wind speed at different developmental stages of maize, the BATS1e model was modified, and applied to investigate the effects of dynamic aerodynamic parameters on the flux exchange between maize agroecosystem and atmosphere. Compared with the original model, the drag coefficient (C(D)) simulated by the modified model increased, and its diurnal variation was more obvious with increasing vegetation coverage, which was more accordant with practical circumstances. The simulation accuracies of sensible heat (H), latent heat (lambdaE) and soil heat flux were improved in varying degree, and the Nash-Sutcliffes (NSs) were increased by 0.0569, 0.0194 and 0. 0384, with the improvement quantities in the growth season being 0.9%, 1.1% and 1.2% of global radiation, respectively. The dynamic parameterizations of z0 and d played a more remarkable role to increase the simulation accuracies of H and lambdaE with the actual observation of soil water content introduced into the improved model. This research proved that more reasonable dynamic aerodynamic parameterizations could fulfill an obvious function to improve the land surface processes simulation.

A temperature-precipitation based leafing model and its application in Northeast China.

Plant phenology models, especially leafing models, play critical roles in evaluating the impact of climate change on the primary production of temperate plants. Existing models based on temperature alone could not accurately simulate plant leafing in arid and semi-arid regions. The objective of the present study was to test the suitability of the existing temperature-based leafing models in arid and semi-arid regions, and to develop a temperature-precipitation based leafing model (TP), based on the long-term (i.e., 12-27 years) ground leafing observation data and meteorological data in Northeast China. The better simulation of leafing for all the plant species in Northeast China was given by TP with the fixed starting date (TPn) than with the parameterized starting date (TPm), which gave the smallest average root mean square error (RMSE) of 4.21 days. Tree leafing models were validated with independent data, and the coefficient of determination (R(2)) was greater than 0.60 in 75% of the estimates by TP and the spring warming model (SW) with the fixed starting date. The average RMSE of herb leafing simulated by TPn was 5.03 days, much lower than other models (>9.51 days), while the average R(2) of TPn and TPm were 0.68 and 0.57, respectively, much higher than the other models (<0.22). It indicates that TPn is a universal model and more suitable for simulating leafing of trees and herbs than the prior models. Furthermore, water is an important factor determining herb leafing in arid and semi-arid temperate regions.

[Establishment of a 5-DFUR-resistant human hepatocellular carcinoma cell model and preliminary study of the mechanisms of the drug resistance].

OBJECTIVE: To establish a multidrug-resistant hepatocellular carcinoma cell line BEL-7402/5-deoxy-5-fluorouridine (5'-DFUR) and study the mechanisms of the drug resistance. METHODS: BEL-7402/5'-DFUR cell line was induced by pulse therapy combined with continuous stepwise exposure to 5'-DFUR in vitro. The multidrug resistance of BEL-7402/5'-DFUR cell line to the antitumor agents was evaluated by MTT assay. The distribution of the cell cycle, the expressions of P-gp, bcl-2 and GST-pi were detected by flow cytometry. RESULTS: The established BEL-7402/5'-DFUR cell line was resistant to multiple antitumor agents, with IC(50) of 5'-DFUR 12.9 times higher than that of the parental cell line 7204. The BEL-7402/5'-DFUR cells in S phase decreased while those in G(1) and G(2) phase increased, with significantly increased expressions of P-gp and bcl-2 but stable expression of GST-pi. CONCLUSION: Compared with its parent cell line BEL-7402, the multidrug resistant cell line BEL-7402/5'-DFUR has a 12.9-fold increase in IC(50) of 5'-DFUR with decreased drug accumulation and altered cell cycle distribution. The multi-drug resistance of this cell line is closely related to the overexpression of P-gp and bcl-2.

[Non-myeloablative allogeneic stem cell transplantation in patients with hematologic malignancies].

In order to investigate the clinical efficacy of non-myeloablative allogeneic stem cell transplantation (allo-NST) and related technology in patients with hematologic malignancies, twenty-six cases of hematological malignancies (10 AL, 14 CML, 2 MM patients) received NST following conditioning regimens with fludara + cyclophosphamide + ATG (14 cases) and busulfan or melphalan + cyclophosphamide + ATG (12 cases), G-CSF (600 micro g/d) or G-CSF (300 micro g/d) + GM-CSF (300 micro g/d) were used for mobilizing peripheral blood stem cell. A combination of cyclosporine A (CsA) and methotrexate (MTX) was administered for GVHD prophylaxis. Patients will be eligible for donor lymphocyte infusion (DLI) or donor stem cell infusion (DSI) given in graded increments according to the chimeric formation and clinical reaction. Generally the dose of the first infusion was 1 x 10(7)/kg at 4th week post-transplantation. The engraftment analysis included the detection of microsatellite short tandem repeats (STRs), Bcr/Abl fusion gene, Philadelphia chromosome, HLA-locus analysis, sex chromosome and ABO blood type or blood subtype. The results showed that 22 patients (84.62%) were engrafted, among which 18 patients were full donor chimerism (FDC) up to now. Acute GVHD occurred in 3/26 cases (11.54%). Chronic GVHD was diagnosed in 6 of 26 (23.07%) evaluable patients. The incidence of infection and hemorrhage was low and slight. It is concluded that allo-NST is a safe and effective therapeutic method for hematologic malignancies, but the related technology such as selection of indication, conditioning regimen and transplantation immunotherapy should be studied further.