Using crude glycerol and thin stillage for the production of microbial lipids through the cultivation of Rhodotorula glutinis

Single cell oils (SCO) produced from oleaginous microorganisms are a potential alternative oil feedstock for biodiesel production. The worldwide production of glycerol, a 10% (w/w) byproduct produced in the transesterfication process of oils converted to biodiesel, is increasing as more biodiesel is being produced. For the purposes of cost reduction, crude glycerol was regarded as a suitable carbon source for the cultivation of Rhodotorula glutinis. In addition to using renewable crude glycerol, waste solution collected from the brewing company (called thin stillage) was adopted as a substitute to replace a costly nitrogen source used in the medium. The results of using mixture of crude glycerol and thin stillage indicated about a 27% increase in total biomass as compared to that of using crude glycerol with a standard medium. Using glycerol instead of glucose as the carbon source could also alter the lipid profile, resulting in an increase in linolenic acid (C18:2) to comprise over 20% of the total lipid. Successfully using renewable crude glycerol and thin stillage for the cultivation of oleaginous microorganisms could greatly enhance the economic competition of biodiesel produced from SCO.     

Comparison of high pressure treatment and thermal pasteurization effects on the quality and shelf life of guava puree

The effects of high pressures and thermal pasteurization on the survival of microorganisms, enzyme inactivation and quality changes of guava puree during storage at 4°C were investigated and compared with untreated samples. After treatment at a pressure of 600MPa and 25°C for 15 min, the microorganisms in guava puree were inactivated to less than 10 cfu mL⁻¹ and the product exhibited no change in colour, pectin, cloud and ascorbic acid content as compared with fresh samples. The inactivation of enzymes in guava puree by thermal pasteurization was greater than by high pressures. The microbial count in guava puree reduced to 200 cfu mL⁻¹ and the product showed marked changes in viscosity, turbidity and colour when heated at 88–90°C for 24s. The content of pectin, cloud and ascorbic acid as well as colour in untreated and high pressurized (400MPa) guava puree gradually decreased, whereas these changes were not observed in pasteurized (88–90°C) and high pressurized (6000MPa) puree during storage at 4°C for 60 days. The guava puree treated at 600MPa and 25°C for 15 min retained good quality similar to the freshly extracted puree after storage at 4°C for 40 days.     

Growth inhibitory efficacy of lycopene and β-carotene against androgen-independent prostate tumor cells xenografted in nude mice

Scope : In this study, we evaluated the efficacy of lycopene against the growth of prostate cancer in vivo. Methods and results : Athymic nude mice were implanted subcutaneously with human androgen‐independent prostate carcinoma PC‐3 cells. They were supplemented with a low or a high dose of lycopene (4 and 16 mg/kg) and a single dose of β‐carotene (16 mg/kg) twice a week for 7 wk. At the end of the experiment, both lycopene and β‐carotene strongly inhibited the tumor growth, as evidenced by the decrease in tumor volume and tumor weight. High‐dosage lycopene and β‐carotene significantly decreased the expression of proliferating cell nuclear antigen in tumor tissues and increased the levels of insulin‐like growth factor‐binding protein‐3 in plasma. In addition, high‐dosage lycopene supplementation significantly decreased the vascular endothelial growth factor (VEGF) levels in plasma. In contrast, β‐carotene supplementation significantly increased the VEGF levels, as compared with tumor control group. Conclusion : Lycopene and β‐carotene supplementation suppressed the growth of prostate tumor cells, and the effects are likely associated with reduction of proliferation (attenuation of proliferating cell nuclear antigen expression) and with interference of the insulin‐like growth factor 1 signaling (increased plasma insulin‐like growth factor‐binding protein‐3 levels). Furthermore, the inhibition of VEGF by lycopene suggests that the antitumor mechanisms of lycopene also involve anti‐angiogenesis.     

Induction of cell apoptosis in 3T3-L1 pre-adipocytes by flavonoids is associated with their antioxidant activity

Obesity is biologically characterized at the cellular level by an increase in the number and size of adipocytes differentiated from fibroblastic pre-adipocytes in adipose tissue. In this study, we focused on the relationship between the influence of flavonoids on cell population growth and their antioxidant activity. The results showed that the inhibition of flavonoids (naringenin, rutin, hesperidin, resveratrol, naringin and quercetin) on 3T3-L1 pre-adipocytes was 28.3, 8.1, 11.1, 33.2, 5.6 and 71.5%, respectively. In oxygen radical absorbance capacity (ORAC) assay, quercetin had the highest ORAC(ROO) value among the six flavonoids tested. Apoptosis assays showed that quercetin increased apoptotic cells in time- and dose-dependent manner. Treatment of cells with quercetin decreased the mitochondrial membrane potential in the courses of time and dose. The cell apoptosis/necrosis assay showed that quercetin increased the number of apoptotic cells, but not necrotic cells. Quercetin treatment of cells caused a significant time- and dose-dependent increase in the caspase-3 activity. Western analysis indicated that treatment of quercetin markedly down-regulated PARP and Bcl-2 proteins, and activated caspase-3, Bax, and Bak proteins. These results indicate that quercetin efficiently inhibits cell population growth and induction of apoptosis in 3T3-L1 pre-adipocytes.     

Glass Additive Influence on the Sintering Behaviors,Magnetic and Electric Properties of Bi–Zn Co‐Doped Co2Y Ferrites

The Bi₂O₃–B₂O₃–ZnO–SiO₂ (BB35SZ) glass effects on the sintering behavior and magnetic properties of Bi–Zn co‐doped Co₂Y ferrites were investigated in developing low‐temperature‐fired ferrites. The results indicate that BB35SZ glass can be used as a sintering aid to reduce the densification temperature of Co₂Y ferrites from 1300°C to 900°C. The 2(Ba_0.9Bi_0.1O)·2(Zn_0.4Co_0.4Cu_0.2O)·6(Fe_1.97Zn_0.03O₃) ferrite with 4 wt% BB35SZ glass can be densified below 900°C, exhibiting an initial permeability of 3.4 and quality factor of 55. This process provides a promising candidate for multilayer chip magnetic devices for microwave applications.     

Two‐dimensional electrolyte nature of exfoliated montmorillonite nanoplatelets fabricated by soap‐free emulsion polymerization and their affinity for cations

Montmorillonite (MMT) nanoplatelets, fabricated by the exfoliation of MMT during participating in the soap‐free emulsion polymerization of methyl methacrylate, were well‐dispersed in water and performed like a two‐dimensional electrolyte. Their ionic conductivity roughly follows the Manning's limiting law for the conduction of a polyelectrolyte. The dissociated MMT nanoplatelets that carry negative charges in water were able to rapidly adsorb cations, such as tris(2,2′‐bipyridyl)ruthenium(II) (Ru(bpy)) and methylene blue (MB⁺), and recover into a smectic configuration floating as a separating phase. By using the Langmuir equation, we were able to estimate the occupied surface areas of MMT nanoplatelets by each Ru(bpy) and MB⁺ cations as 4.708 and 1.806 nm²/ion, respectively. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

鉴别煤成气和油型气若干指标的初步探讨

鉴别煤成气和油型气的普遍性标志初步认为有:1.煤成气的甲烷碳同位素(δ¹³C₁)一般比油型气的重:在Ro≤0.5%,煤成气和油型气δ¹³C₁除-55‰至-74‰是重迭数域值外,当δ¹³C₁<-74‰为油型气型生物成因气;在Ro>0.5%至-2.5%时,δ¹³C₁-43‰至-30‰是煤成气与油型气重迭数域值,故δ¹³C₁≤-43‰至-55‰的气是油型气;而δ¹³C₁>-30‰的气是煤成气。2.煤成气中的汞蒸气比油型气的一般含量高。煤成气中平均汞含量一般在700毫微克/米³以上,多数大于1000毫微克/米³,而油型气中平均汞含量在600毫微克/米³以下,多数小于400毫微克/米³;煤成气中最高含汞量一般大于1000毫微克/米³,而油型气中的一般小于700毫微克/米³。3.当Ro为0.4%至1.35%时,一个含油层系形成以气为主以油为辅,这种气是煤成气。4.在与Ro0.4%至1.0%有成因关系的气中,若普遍见到凝析油,这种气是煤成气。     

昆明住宅冬季室内环境状况调查分析

室内环境问题是21世纪研究的重点和热点.为此,2004年笔者对一百余户家庭进行了“关于昆明市冬季室内环境状况”的问卷调查和室内温湿度现场测试,调查数据显示冬季昆明室内温度15℃左右,相对湿度56.3%RH,超过半数的居住者对冬季住宅室内环境状况感觉满意和无所谓.     

Temperature Change of Light Induced Explosion of explosive material

A theoretical analysis based on the adiabatic consideration of one- dimensional model for initiation of explosive materials by intense light is performed. An expression is obtained which can be used to calculate the explosion temperature.     

On minimal elements of upward-closed sets

Upward-closed sets of integer vectors enjoy the merit of having a finite number of minimal elements, which is behind the decidability of a number of Petri net related problems. In general, however, such a finite set of minimal elements may not be effectively computable. In this paper, we develop a unified strategy for computing the sizes of the minimal elements of certain upward-closed sets associated with Petri nets. Our approach can be regarded as a refinement of a previous work by Valk and Jantzen (in which a necessary and sufficient condition for effective computability of the set was given), in the sense that complexity bounds now become available provided that a bound can be placed on the size of a witness for a key query. The sizes of several upward-closed sets that arise in the theory of Petri nets as well as in backward-reachability analysis in automated verification are derived in this paper, improving upon previous decidability results shown in the literature.