Combined Stochastic Process and Value at Risk: A Real-World Information System Decision Case.

In this study, we used a combined stochastic process and value-at-risk (VaR) method to examine an electronic commerce expansion decision. By modeling uncertain benefits as a stochastic process, maximum losses of alternative decisions were quantified and compared to help managers to make information system/information technology (IS/IT) project decisions. Our results, based on the maximum loss perspective, demonstrated that uncertainty plays a critical role in evaluating IS/IT projects. More importantly, the results illustrate that VaR serves as a useful tool in decision-making for managers to quantify the value of maximum possible loss and to help them reach decisions.

Nitrogen isotope variations in camphor (Cinnamomum Camphora) leaves of different ages in upper and lower canopies as an indicator of atmospheric nitrogen sources.

Nitrogen isotopic composition of new, middle-aged and old camphor leaves in upper and lower canopies has been determined in a living area, near a motorway and near an industrial area (Jiangan Chemical Fertilizer Plant). We found that at sites near roads, more positive δ(15)N values were observed in the camphor leaves, especially in old leaves of upper canopies, and ∆δ(15)N=δ(15)N(upper)-δ(15)N(lower)>0, while those near the industrial area had more negative δ(15)N values and ∆δ(15)N<0. These could be explained by two isotopically different atmospheric N sources: greater uptake from isotopically heavy pools of atmospheric NO(x) by old leaves in upper canopies at sites adjacent to roads, and greater uptake of (15)N-depleted NH(y) in atmospheric deposition by leaves at sites near the industrial area. This study presents novel evidence that (15)N natural abundance of camphor leaves can be used as a robust indicator of atmospheric N sources.

[Experimental study on selective hepatic lobectomy using nitinol alloy net blocker of biliary intrahepatic duct].

OBJECTIVE: To investigate the feasibility and possible mechanism of non traditional hepatic lobectomy using nitinol alloy net blocker of biliary intrahepatic duct. METHODS: Biliary intrahepatic ducts of the experimental pigs were blocked with and without dissepiment blockers. The histological changes and expressions of TGF-betal and TIMP-1 in the livers were compared. RESULTS: Blockage of biliary intrahepatic duct using nitinol alloy net blocker without dissepiment resulted in obvious atrophy of the focus liver. The mean weight and size of the focus liver was only 1/4 of the controls (P < 0.05), with liver cells almost completely taken by collagen fibers. Higher expressions of TGF-beta1 and TIMP-1 were found in the group without dissepiment than in the group with dissepiments (P < 0.05). CONCLUSION: Using nitinol alloy net blocker for selective hepatic lobectomy is as effective as traditional hepatic lobectomy. It may offer a new way for treating intrahepatic bile duct stones.

[Effect of ligand pioglitazone activating PPAR-gamma on the invasiveness of cholangiocarcinoma cell in vitro and the expression regulation of related genes].

OBJECTIVE: To explore the effect and mechanism of ligand pioglitazone (PGZ) activating PPAR-gamma on the invasiveness of cholangiocarcinoma cell in vitro. METHODS: Human hilar cholangiocarcinoma cell line QBC939 was selected and cultured in vitro for this research. The rate of QBC939 cell growth inhibition was detected by MTT, and the influence of PGZ on the expression of MMP-7 mRNA and TIMP-1 mRNA was measured by using FQ-PCR. The in vitro invasiveness and mobility of QBC939 were quantified by Matrigel invasion assay and crossing-river test. RESULTS: Among the low concentration (5 micromol/L-40 micromol/L) groups at the point of 12-hours, PGZ did not show to inhibit significantly the growth of QBC939 cells (P>0. 05). However, the PGZ could down-regulate the expression of MMP-7 mRNA in QBC939 cells (P<0. 01), and up-regulate the TIMP-1 mRNA expression to be without obvious statistics significance (P>0. 05). At last, PGZ could reduce the number of QBC939 cell breaking through the matrigel and prolonging the time of crossing-river significantly (P< 0. 01) in a dose-dependent manner. CONCLUSION: For ligand PGZ to activate PPAR-gamma can inhibit the invasiveness of QBC939 cells in vitro via regulating the expression of MMP-7 and the mobility of QBC939 cells probably.

[Effect of PPAR-gamma ligand RGZ on inhibiting the cell proliferation of cholangiocarcinoma].

OBJECTIVE: To investigate the effect that PPAR-gamma (peroxisome proliferator-activated receptor gamma, PPAR-gamma) ligand rosiglitazone (rosiglitazone, RGZ) inhibits the cell proliferation of cholangiocarcinoma. METHODS: The cell line QBC939 of cholangiocarcinoma was interfered with different concentration of RGZ, and then calculated for the rate of cell proliferation inhibited at different concentration. The change of cell cycle and the rate of cell apoptosis at each concentration were detected by FCM. RESULTS: RGZ showed the significant effect on inhibiting the cell proliferation of cholangiocarcinoma, especially on the 1200 mg/L concentration group. The highest inhibited rate of QBC939 cell proliferation could be up to 83.66%. After RGZ used to treat the cultured QBC939 cell for 48 h and 72 h, the inhibited rates of QBC939 cell proliferations of 1200 mg/L, 600 mg/L,300 mg/ L,150 mg/L, 75 mg/L and 37.45 mg/L groups were compared to those of control group, and with the statistics result of P < 0.001. Meanwhile the cell cycles were controlled significantly as well, 62.77% of the cells were detained in stage G0/G1. CONCLUSION: In vitro PPAR-gamma ligand rosiglitazone has the significant proliferation inhibition effect to cell lines QBC939 of cholangiocarcinoma.