Constructing Metal(II)-Sulfate Site Catalysts toward Low Overpotential Carbon Dioxide Electroreduction to Fuel Chemicals

Precise regulation of the active site structure is an important means to enhance the activity and selectivity of catalysts in CO2 electroreduction. Here, we creatively introduce anionic groups, which can not only stabilize metal sites with strong coordination ability but also have rich interactions with protons at active sites to modify the electronic structure and proton transfer process of catalysts. This strategy helps to convert CO2 into fuel chemicals at low overpotentials. As a typical example, a composite catalyst, CuO/Cu-NSO4/CN, with highly dispersed Cu(II)-SO4 sites has been reported, in which CO2 electroreduction to formate occurs at a low overpotential with a high Faradaic efficiency (-0.5 V vs. RHE, FEHCOO-=87.4%). Pure HCOOH is produced with an energy conversion efficiency of 44.3% at a cell voltage of 2.8 V. Theoretical modeling demonstrates that sulfate promotes CO2 transformation into a carboxyl intermediate followed by HCOOH generation, whose mechanism is significantly different from that of the traditional process via a formate intermediate for HCOOH production.

The determination of the viability of Schistosomal eggs by a novel technique: electrorotation

Human schistosomiasis is widespread in tropical and subtropical environments. In this study, a novel open cell with liquid medium perfusion system for electrorotation measurement to detect the viability of schistosomal eggs is proposed. With no solid top or bottom surface, the liquid medium perfusion system solves some of the problems of conventional electrorotation testing systems. This kind of open cell successfully detect schistosome egg viability, most prominently, there can be no adhesion or friction of eggs on the surface to encumber their rotation. This newly proposed system can be used to test more types of biological particles compared to a conventional system used in electrorotation measurement, providing more exact results. The new system can be used for rapid analysis of various biological particles in water, which will be potentially significant to public health.

A comparative study on anticoagulant activities of three Chinese herbal medicines from the genus Panax and anticoagulant activities of ginsenosides Rg1 and Rg2

CONTEXT

Chemical compositions of three herbal plants from the family Araliaceae genus Panax [Panax ginseng C. A. Mey, P. quinquefolius L. and P. notoginseng (Burk.) F. H. Chen] are quite similar; however, their medicinal natures vary greatly. The reason for differences has been explained in traditional Chinese medicine theory and partially verified by modern pharmacological investigations, such as antiplatelet aggregation. Aside from platelet aggregation, a variety of plasma coagulation factors are also involved in blood coagulation. The anticoagulation profiles of three herbs have not been investigated.

OBJECTIVE

The current research compared the inhibitory effects of three herbal extracts from Panax spp. and the purified ginsenosides from P. ginseng on blood coagulation.

MATERIALS AND METHODS

Human plasma was mixed with the water extracts (0.05 and 0.1 mg/mL) from roots of P. ginseng, P. quinquefolius and P. notoginseng and ginsenosides Rg1 and Rg2 (0.05 and 0.1 mg/mL), the blood clotting time of activated partial thromboplastin, prothrombin and thrombin were measured by a biochemical analyzer.

RESULTS

The water extracts (0.05 mg/mL) of P. ginseng, P. quinquefolius and P. notoginseng could significantly extend blood clotting time as compared to the control group. Among three herbal medicines, 0.05 mg/mL of water extract from P. ginseng exhibited the strongest anticoagulation effects, followed by P. notoginseng, while P. quinquefolius presented the weakest effects. Both ginsenosides Rg1 and Rg2 could significantly extend blood clotting time in all three tests; ginsenoside Rg2 exhibited relative stronger anticoagulation effects as compared to ginsenoside Rg1.

DISCUSSION AND CONCLUSION

Among three herbs tested, P. ginseng as well as its active component ginsenoside Rg2 shows the strongest anticoagulation activity; current results indicate that P. ginseng and ginsenoside Rg2 have great potential to be an anticoagulation drug.

A laser-Compton scattering prototype experiment at 100 MeV linac of Shanghai Institute of Applied Physics

As a prototype of the Shanghai Laser Electron Gamma Source in the Shanghai Synchrotron Radiation Facility, an x-ray source based on laser-Compton scattering (LCS) has been installed at the terminal of the 100 MeV linac of the Shanghai Institute of Applied Physics. LCS x-rays are generated by interactions between Q-switched Nd:yttrium aluminum garnet laser pulses [with wavelength of 1064 nm and pulse width of 21 ns (full width at half maximum)] and electron bunches [with energy of 108 MeV and pulse width of 0.95 ns (rms)] at an angle of 42 degrees between laser and electron beam. In order to measure the energy spectrum of LCS x-rays, a Si(Li) detector along the electron beam line axis is positioned at 9.8 m away from a LCS chamber. After background subtraction, the LCS x-ray spectrum with the peak energy of 29.1+/-4.4|(stat)+/-2.1|(syst) keV and the peak width (rms) of 7.8+/-2.8|(stat)+/-0.4|(syst) keV is observed. Normally the 100 MeV linac operates with the electron macropulse charge of 1.0 nC/pulse, and the electron and laser collision repetition rate of 20 Hz. Therefore, the total LCS x-ray flux of (5.2+/-2.0) x 10(2) Hz can be achieved.

A comparative study on phenolic profiles and antioxidant activities of legumes as affected by extraction solvents

The objective of this study was to investigate how 6 commonly used solvent systems affected the yields of phenolic substances and the antioxidant capacity of extracts from 8 major classes of food legumes. Several antioxidant-related phytochemical compositions, namely, total phenolic content (TPC), total flavonoids content (TFC), and condensed tannins content (CTC), were investigated. In addition, antioxidant activities were tested using 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging, ferric-reducing antioxidant power (FRAP), and the oxygen radical absorbance capacity (ORAC). The results showed that the 50% acetone extracts exhibited the highest TPC for yellow pea, green pea, chickpea, and yellow soybean. Acidic 70% acetone (+0.5% acetic acid) extracts exhibited the highest TPC, TFC, and FRAP values for black bean, lentil, black soybean, and red kidney bean. The 80% acetone extracts exhibited the highest TFC, CTC, and DPPH-free radical scavenging activity for yellow pea, green pea, chickpea, and yellow soybean. The 70% ethanol extracts exhibited the greatest ORAC value for all selected legumes. These results indicated that solvents with different polarity had significant effects on total phenolic contents, extracted components, and antioxidant activities. High correlations between phenolic compositions and antioxidant activities of legume extracts were observed. The information is of interest to the nutraceutical food/ingredient industries since legumes are a rich source of antioxidants.

Natural medicines for alcoholism treatment: a review

Alcoholism is a serious problem throughout the world. The development of alcoholism remedies have medical, social and economical significance. In view of the pitfalls of psychological dependence and adverse behavioural effects of synthetic drugs, the development of low toxicity and high efficiency medicines derived from natural products exhibits expansive market prospects. Based on these considerations, we summarize briefly folk application of traditional hangover remedies and clinical application of herbal complex and patent medicines for alcoholism treatment. We have reviewed the effects of natural medicines on intake, absorption and metabolism of alcohol, as well as the protective effects on alcohol-induced acute and chronic tissue injury.

Studies on a poly(styrene-divinylbenzene)-encapsulated sub-micrometer sized organic–inorganic hybrid silica packing, its synthesis, some of its characteristics and applications

The hydrolyzed product of a mixture of tetraethoxysilane (TEOS) and vinyltriethoxysilane (VTEOS) was used to produce organic-inorganic hybrid silica by sol-gel processing. The product was a kind of composite with vinyl groups incorporated into the structure of the final particles through C-Si bonds. These hybrid silica particles were spherical and the average diameter was about 350 nm as measured by scanning electron microscopy (SEM). The particles were non-porous as proved by BET method. The hybrid silica particles were subsequently encapsulated with a layer of PS-DVB, a polymeric mixture of styrene and divinylbenzene, with the vinyl groups on the particle surface as anchors of the polymer chains. The encapsulated packing was used as stationary phases in CEC, and the chromatographic behaviors were studied. Experimental results showed that, as expected, the smaller diameter stationary phase resulted in higher column efficiencies. In comparison with the columns packed with 5 microm diameter encapsulated-silica stationary phases of the same kind and other sub-micron stationary phases reported, it can be concluded that the EOF velocity is independent of the particle diameter when using 350 nm phase, but determined by the surface nature of the stationary phase.

Platycodi radix affects lipid metabolism in mice with high fat diet-induced obesity

An aqueous extract of Platycodi radix inhibited the hydrolysis of triolein emulsified with phosphatidylcholine by pancreatic lipase in vitro and it reduced the elevation of rat plasma triacylglycerol level 2-4 h after oral administration of a lipid emulsion containing corn oil. These preliminary results suggested that the aqueous extract of Platycodi radix may inhibit the intestinal absorption of dietary fat by inhibiting its hydrolysis. Therefore, we examined the antiobesity activity of the aqueous extract of Platycodi radix by testing whether the extract prevented the obesity induced by feeding a high fat diet to mice for 8 wk. Body weights at 3-8 wk and the final parametrial adipose tissue weights were significantly lower in mice fed the high fat diet containing 5% aqueous extract of Platycodi radix than in the controls fed the high fat diet. The aqueous extract of Platycodi radix also significantly reduced hepatic triacylglycerol concentrations that were elevated in mice fed the high fat diet alone. Inulin, which is a major component of Platycodi radix, had no effect on the hydrolysis of triolein emulsified with phosphatidylcholine by pancreatic lipase in vitro, and did not prevent obesity or the fatty liver induced by the high fat diet. On the other hand, the total saponin fraction of the aqueous extract inhibited pancreatic lipase activity in vitro. Therefore, the antiobesity effect of the aqueous extract of Platycodi radix in mice fed a high fat diet may be due in part to the inhibition of intestinal absorption of dietary fat by the saponins of Platycodi radix.

The formation and crystal structure of dihydronitidine and discussion of anticancer mechanism of nitidine cation

The paper reports the formation and crystal structure of dihydronitidine, expounds the reasons and conditions of easily formed oxynitidine, and discusses anticancer mechanism of nitidine (cation). The crystallographic parameters of dihydronitidine are: space group P(2)1/n, a = 12.54(1), b = 9.148(5), c = 14.748(8) A, beta = 92.12(6)degrees, Z = 4. 4108 independent reflections were collected within the range of 3 degrees < or = 2 theta < or = 54 degrees, of which 2137 intensity data with I > or = 3 sigma (I) were used in the structural determination. The crystal structure has been refined by full matrix least-square method to a final R of 0.050.