油酸生色因素的研究

采用对比法，探明了影响油酸生色的主要因素有温度、 Ｏ２ 的氧化及 Ｆｅ３＋ 对氧化的催化作用，解决了用碱炼棉油油脚制取液体脂肪酸颜色过重的问题。

氯化石蜡生色因素及对策的探讨

探讨了氯化石蜡生产中的生色因素,提出了降低氯化石蜡色泽以提高产品质量的措施:优选原材料;注意设备材质;优化生产工艺。

红苕淀粉变色的原因及防止方法

红苕淀粉变色的原因有如下几种: 一、色素本身带来的色变 红苕带的色素,主要是花青素类和花黄素类等色素,这些色素易溶于水,所以,红苕淀粉加工中用大量的水,经多次漂洗是可以去除的。 二、植物鞣质引起的色变 鞣质又叫单宁,其化学结构很复杂,但都能溶于水,所以要去除鞣质引起的色变。

Melanoma differentiation-associated gene-7, MDA-7/IL-24, selectively induces growth suppression, apoptosis in human hepatocellular carcinoma cell line HepG2 by replication-incompetent adenovirus vector

AIM： To investigate the effect of replication-incompetent adenovirus vector expressing MDA-7/IL-24 on tumor growth and apoptosis in human hepatocellular carcinoma （HCC） cell line HepG2 and normal liver cell line L02. METHODS： We constructed the recombinant replication-incornpetent Ad.rnda-7 virus vector and infected it into the human HCC cell line HepG2 and normal liver cell line L02. RT-PCR was performed to detect the rnRNA expressing in cells, by ELISA was used to detect MDA-7/IL-24 protein expression in the culture supernatant. The effect of apoptosis induced by Ad.rnda-7 was confirmed by Hoechst staining and flow cytometry assay with Annexin-V and PI staining. MTT assay was used to determine growth inhibition of HepG2 cells, and cell-cycle and hypodiploidy analyses were performed by flow cytometry. RESULTS： Recombinant replication-defective virus expressing MDA-7/IL-24 was constructed successfully. RTPCR showed that the Ad.rnda-7 could mediate the expression of the exogenous gene MDA-7/IL-24 into HepG2 and L02. The concentration of MDA-7/IL-24 protein in supernatant was 130 pg/mL and 110 pg/mL in Ad.rnda-7-infected L02 and HepG2 ceils, respectively. Ad.mda-7 infection obviously induced apoptosis （from 2.604±0.72% to 33.64±13.2%, P=0.00012） and growth suppression in HepG2 （inhibition ratio IR=68%） and an increase in the percentage of specific cancer cell types at the G2/M phase of the cell cycle （from 6.44% to 32.29%, P〈 0.01）, but not in L02 cells.CONCLUSION： These results confirm selectively induction of apoptosis and growth suppression by the mda-7/ IL-24 gene with replication-incompetent adenovirus vector in human hepatocellular carcinoma cell line HepG2.

Grey analysis of the relationship between grain output and major input factor in Guizhou Province:1983-2005

Because conditions for the grain production are not favorable and the input in the production factors ofmodern agriculture is not sufficient, the grain supply has been less than the demand for a long time. By means of greycorrelation analysis, this paper deals with the correlation situation among such input factors as the grain sown area, thetotal power of agricultural machinery, the fertilizer utilization volume, the actual irrigation area, the damage area, thenumber of farming labor force, in order to understand the major restricting and driving forces that have affected thegrain output in the recent 23 years. The analysis shows that the grain sown area and fertilizer utilization volume are thetwo most important leading factors that affect grain production in Guizhou Province, while the damage area and the totalpower of the farming-used machines are the following factors. Fertilizer utilization volume and the actual agriculturalmachinery and irrigation area are the two increasingly influential factors that affect grain production. The influence of thefarming labor force upon grain production became less strong. The main measures to increase grain production outputin Guizhou Province are to stabilize the arable land, increase the actual irrigation area, expedite the transfer of thefarming labor force and increase the input of modern agriculture.

Complete genome sequence of the rifamycin SV-producing Amycolatopsis mediterranei U32 revealed its genetic characteristics in phylogeny and metabolism

Amycolatopsis mediterranei is used for industry-scale production of rifamycin, which plays a vital role in antimyco- bacterial therapy. As the first sequenced genome of the genus Amycolatopsis, the chromosome of strain U32 comprising 10 236 715 base pairs, is one of the largest prokaryotic genomes ever sequenced so far. Unlike the linear topology found in streptomycetes, this chromosome is circular, particularly similar to that of Saccharopolyspora erythraea and Nocardia farcinica, representing their close relationship in phylogeny and taxonomy. Although the predicted 9 228 protein-coding genes in the A. mediterranei genome shared the greatest number of orthologs with those of S. erythraea, it was unexpectedly followed by Streptomyces coelicolor rather than N. farcinica, indicating the distinct metabolic characteristics evolved via adaptation to diverse ecological niches. Besides a core region analogous to that common in streptomycetes, a novel ＇quasicore＇ with typical core characteristics is defined within the non-core region, where 21 out of the total 26 gene clusters for secondary metabolite production are located. The rifamycin biosynthesis gene cluster located in the core encodes a cytochrome P450 enzyme essential for the conversion of rifamycin SV to B, revealed by comparing to the highly homologous cluster of the rifamycin B-producing strain S699 and further confirmed by genetic complementation. The genomic information of A. mediterranei demonstrates a metabolic network orchestrated not only for extensive utilization of various carbon sources and inorganic nitrogen compounds but also for effective funneling of metabolic intermediates into the secondary antibiotic synthesis process under the control of a seemingly complex regulatory mechanism.

Altered expression of mitochondrial related genes in the native Tibetan placents by mitochondrial cDNA array analysis

Objective： To explore the mechanism of native Tibetan fetuses adaptation to hypoxia, we tried to find the different expression genes about mitochondrial function in the native Tibetan placents. Methods： In this study, the placents of native Tibetan and the high-altitude Hart （ha-Hart） were collected. After the total RNA extraction, the finally synthesized cDNAs were hybridized to mitochondrial array to find the altered expression genes between them. Then, the cytochrome c oxidase 17 （Coxl7）, dynactin 2 （DCTN2, also known as p50）, and vascular endothelial growth factor receptor （VEGFR, also known as KDR） were chosen from the altered expression genes to further verify the array results using the SYBR Green real-time PCR. Because the altered expression genes （such as Cybb and Cox 17） in the array results related to the activities of COXI and COXIV, the placental mitochondria activities of COXI and COXIV were measured to find their changes in the hypoxia. Results： By a standard of≥1.5 or ≤0.67, there were 24 different expressed genes between the native Tibetan and the ha-Han placents, including 3 up-regulated genes and 21 down-regulated genes. These genes were related to energy metabolism, signal transduction, cell proliferation, electron transport, cell adhesion, nucleotide-excision repair. The array results of Cox17, DCTN2 and KDR were further verified by the real-time RT-PCR. Through the mitochondria respiration measurements, the activity of COXI in the native Tibetan placents were higher than that of ha-Han, there was no difference in COXIV activity between them. Conclusion： The altered mitochondrial related genes in the native Tibetan placents may have a role in the high altitude adaptation for fetuses through changing the activity of mitochondrial COX.

Immunohistochemical evaluation of vitamin D receptor(VDR) expression in cutaneous melanoma tissues and four VDR gene polymorphisms

Objective:Vitamin D receptor(VDR)mediates vitamin D activity.We examined whether VDR expression in excised melanoma tissues is associated with VDR gene(VDR)polymorphisms.Methods:We evaluated VDR protein expression(by monoclonal antibody immunostaining),melanoma characteristics,and carriage of VDR-Fok I-rs2228570(C>T),VDR-Bsm I-rs1544410(G>A),VDR-ApaI-rs7975232(T>G),and VDR-TaqI-rs731236(T>C)polymorphisms(by restriction fragment length polymorphism).Absence or presence of restriction site was denoted by a capital or lower letter,respectively:"F"and"f"for Fok I,"B"and"b"for Bsm I,"A"and"a"for ApaI,and "T"and"t"for TaqI endonuclease.Seventy-four Italian cutaneous primary melanomas(52.1±12.7 years old)were studied;51.4% were stage Ⅰ,21.6% stage Ⅱ ,13.5% stage Ⅲ,and 13.5% stage Ⅳ melanomas.VDR expression was categorized as follows:100% positive vs.<100%;over the median 20%(high VDR expression)vs.≤20%(low VDR expression);absence vs.presence of VDR-expressing cells.Results:Stage I melanomas,Breslow thickness of<1.00 mm,level II Clark invasion,Aa heterozygous genotype,and AaTT combined genotype were more frequent in melanomas with high vs.low VDR expression.Combined genotypes BbAA,bbAa,AATt,BbAATt,and bbAaTT were more frequent in 100%vs.<100%VDR-expressing cells.Combined genotype AATT was more frequent in melanomas lacking VDR expression(odds ratio=14.5;P=0.025).VDR expression was not associated with metastasis,ulceration,mitosis>1,regression,tumor-infiltrating lymphocytes,tumoral infiltration of vascular tissues,additional skin and non-skin cancers,and melanoma familiarity.Conclusions:We highlighted that VDR polymorphisms can affect VDR expression in excised melanoma cells.Low VDR expression in AATT carriers is a new finding that merits further study.VDR expression possibly poses implications for vitamin D supplementation against melanoma.VDR expression and VDR genotype may become precise medicinal tools for melanoma in the future.

A PKS gene, pks-1, is involved in chaetoglobosin biosynthesis, pigmentation and sporulation in Chaetomium globosum

Chaetomium globosum is one of the most common fungi in nature. It is best known for producing chaetoglobosins; however, the molecular basis of chaetoglobosin biosynthesis is poorly understood in this fungus. In this study, we utilized RNA inter- ference （RNAi） to characterize a polyketide synthase gene, pks-1, in C. globosum that is involved in the production of chaeto- globosin A. When pks-1 was knocked down by RNAi, the production of chaetoglobosin A dramatically decreased. Knock-down mutants also displayed a pigment-deficient phenotype. These results suggest that the two polyketides, melanin and chaetoglobosin, are likely to share common biosynthetic steps. Most importantly, we found that pks-I also plays a critical role in sporulation. The silenced mutants ofpks-1 lost the ability to produce spores. We propose that polyketides may modulate cellular development via an unidentified action. We also suggest that C. globosum pks-1 is unique because of its triple role in melanin formation, chaetoglobosin biosynthesis and sporulation. This work may shed light on chaetoglobosin biosynthesis and indicates a relationship between secondary metabolism and fungal morphogenesis.