49 research outputs found

    Nomenclatural and taxonomic notes on Rubus davidianus Kuntze and R. viburnifolius Franch

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    Critical examinations of specimens, with literature reviews, have shown that Rubus davidianus is conspecific with R. lambertianus. Therefore, we treat R. davidianus as a new synonym within Rubus. We propose a new name, Rubus loirensis Ti R. Huang nom. nov. to replace the later homonym of R. pycnanthus Genev. Additionally, lectotypification of three names, R. davidianus Kuntze, R. malifolius Focke and R. viburnifolius Franch., are designated here after examination of previous works

    Homocysteine inhibits hepatocyte proliferation via endoplasmic reticulum stress.

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    Homocysteine is an independent risk factor for coronary, cerebral, and peripheral vascular diseases. Recent studies have shown that levels of homocysteine are elevated in patients with impaired hepatic function, but the precise role of homocysteine in the development of hepatic dysfunction is unclear. In this study, we examined the effect of homocysteine on hepatocyte proliferation in vitro. Our results demonstrated that homocysteine inhibited hepatocyte proliferation by up-regulating protein levels of p53 as well as mRNA and protein levels of p21(Cip1) in primary cultured hepatocytes. Homocysteine induced cell growth arrest in p53-positive hepatocarcinoma cell line HepG2, but not in p53-null hepatocarcinoma cell line Hep3B. A p53 inhibitor pifithrin-α inhibited the expression of p21(Cip1) and attenuated homocysteine-induced cell growth arrest. Homocysteine induced TRB3 expression via endoplasmic reticulum stress pathway, resulting in Akt dephosphorylation. Knock-down of endogenous TRB3 significantly suppressed the inhibitory effect of homocysteine on cell proliferation and the phosphorylation of Akt. LiCl reversed homocysteine-mediated cell growth arrest by inhibiting TRB3-mediated Akt dephosphorylation. These results demonstrate that both TRB3 and p21(Cip1) are critical molecules in the homocysteine signaling cascade and provide a mechanistic explanation for impairment of liver regeneration in hyperhomocysteinemia

    Preparation of Novel High-Temperature Polyol Esters from Vegetable Oils

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    The aim of this work was to synthesize a high-temperature polyol ester from Jatropha oil. The synthesis process was accomplished via chemical modifications involving epoxidation to remove the double bonds in Jatropha oil, hydrolysis to add hydroxyl groups, and then esterification with pentaerythritol to form the saturated polyol ester. The high decomposition temperature 359°C of the polyol ester was determined by thermogravimetric analysis. The lower peroxide value 0.07 meq/kg and iodine value 0.02 mg I2/100 g of the polyol esters were also determined

    Partition Behavior in Aqueous Two-Phase System and Antioxidant Activity of Flavonoids from <i>Ginkgo biloba</i>

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    In this work, the aqueous two-phase extraction parameters and in vitro antioxidant activity of total flavonoids from Ginkgo biloba were investigated. The partition behavior of the flavonoids in an aqueous two-phase system (ATPS) was analyzed, the extraction parameters were optimized using response surface methodology, and the antioxidant activity of the flavonoids was determined by free-radical scavenging tests (1,1-diphenyl-2-picrylhydrazyl (DPPH) assay) and the ferric reducing/antioxidant power (FRAP) assay. The results showed that the concentration of ammonium sulfate was negatively correlated with the phase-volume ratio, whereas the concentration of polyethylene glycol was positively correlated. The maximum yield of flavonoids (4.11 mg g&#8722;1) was obtained under the following optimal extraction conditions: Concentration of polyethylene glycol (PEG)1500 30% and (NH4)2SO4 22% (mass fraction), and liquid/solid ratio 40:1 (mL g&#8722;1). The antioxidant activity tests showed that the flavonoids from the G. biloba leaf exhibited free-radical scavenging activity, with an IC50 of 2.66 mg L&#8722;1, which was superior to that of vitamin C. The free-radical scavenging ability of the flavonoids was proportional to the flavonoid concentration. The total reducing power of the Ginkgo flavonoids was slightly lower than that of vitamin C. In this study, the distribution of flavonoids in an ATPS was analyzed and a mathematical model for the ATPS extraction of Ginkgo flavonoids was established, which provides a reference for further development and utilization of G. biloba

    Protective Effects of Polydatin from Grapes and Reynoutria japonica Houtt. on Damaged Macrophages Treated with Acetaminophen

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    The unregulated use of acetaminophen (APAP), an antipyretic and analgesic drug, harms hepatocytes and kidney cells, leading to liver failure and acute kidney injury. Herein, we investigate whether APAP damages macrophages in the immune system by observing its effects on macrophage proliferation and apoptosis. Using proteomics, we analyzed the effects of APAP on macrophage protein expression profiles and evaluated whether polydatin, the active ingredient in grapes and wine, can repair the damaged cells. The results showed that APAP alters the morphology and physiological processes of macrophages, inhibits macrophage proliferation, and promotes apoptosis. We observed 528 differentially expressed proteins when 500 &micro;g/mL APAP was administered to the cells. These proteins are involved in biological processes including cell division, apoptosis, and acute phase response. Overall, our findings demonstrate that APAP harms the immune system by damaging macrophages and that polydatin can repair this damage

    Mechanochemistry, solvent-free and scale-up: Application toward coupling of acids and amines to amides

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    Amide is one of the most important molecules in chemistry and biology. Seeking a green and efficient synthesis method for obtaining amide compounds has always been the main research direction. In this paper, it was proposed to use acid and amine as raw materials to synthesize amides under green, fast and mechanochemical conditions, the purification of the product only requires water washing and filtration. This method avoids using a large amount of organic solvents and pollutant generation in the reaction process, the yield of amide is up to 96%. Even when scaled up to 50 mmol for the preparation of moclobemide, the yield of moclobemide is higher than that of traditional methods, and the purification is simple. This green, fast and simple protocol is one of the ideal alternatives to obtain amide

    Water Purification Effect of Ecological Floating Bed Combination Based on the Numerical Simulation

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    The Wuqing urban section of the North Canal Basin, Tianjin, is a significant gathering place for multisource pollution, showing the characteristics of a stagnant water body supplied by unconventional water sources. With the development of the economy and society, the water quality of the Wuqing urban section of the North Canal Basin, Tianjin, has been seriously polluted due to the discharge of sewage outlets and the influx of nonpoint source pollution from farmland. In this study, based on the results of special water experiments, a two-dimensional hydrodynamic water quality model was constructed. The concentrations of ammonia nitrogen (NH3-N), total phosphorus (TP), and chemical oxygen demand (COD) in the study area were simulated, and the model parameters were calibrated and verified with the measured values. Based on the model verification, the water quality improvement scheme of the ecological floating bed with different plant ratios was set up to simulate the water quality. The research results showed that the average concentrations of NH3-N, TP, and COD decreased by 10.4%, 15.7%, and of d 26.3%, respectively, after the ecological floating bed was arranged. During model parameter calibration and validation, the RMSE ranges of NH3-N, TP, and COD were 0.09~0.22 mg/L, 0.00~0.02 mg/L, and 0.37~2.42 mg/L, respectively. Other statistical indicators are also within a reasonable range, and the model accuracy and reliability are high. The simulation results of different scenarios showed that the optimal ratio of ecological floating bed plants was 700 m2 of Scirpus validus Vahl and 700 m2 of Canna in zone 1 of the floating bed combination, 430 m2 of Scirpus validus Vahl, and 170 m2 of Iris in zone 2 of the floating bed combination, and 200 m2 of Iris and 200 m2 of Lythrum salicaria in zone 3 of the floating bed combination. This study can provide a theoretical basis for the sustainable development of water purification in the North Canal. It can also provide a model approach for the implementation of river water purification schemes, exemplified by the North Canal

    The Identity of Rubus pekinensis Focke and R. crataegifolius Bunge (Rosaceae)

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    A critical examination of specimens, with literature and a field survey have shown that Rubus pekinensis is conspecific with R. crataegifolius. Their morphological variations range can be defined as: leaves at the base may be ovate, suborbicular, narrowly ovate, entire, at the middle, ovate, narrowly ovate, oblong-lanceolate, palmately 3-lobed or 5-lobed and at the top, ovate, lanceolate, entire or 3-lobed; flowers solitary in the axillae or several flowers clustered at the terminal of branchlets or formed into short racemes. Therefore, we treat the former species as a synonym for the latter one
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