1.Influence of the technology of supercritical CO_2 extraction on the separate rate of the extractives from fruits of Cnidium Monnieri(L.) Cuss.
Zhuyun GONG ; Gaoyong ZHANG ; Yongliang NIE ; Huixian GU
Chinese Traditional Patent Medicine 1992;0(08):-
AIM: To use secondary regression coherent design to explore the extraction parameters of fruits of Cnidiunm by supercritical CO_2 extraction. METHODS: Extraction pressure,extraction temperature,isolation pressure,isolation temperature Ⅰ and Ⅱ were viewed as factors. RESULTS: The best technological conditions were: extractive kettle pressure was 20 MPa,extractive kettle temperature was at 40(?C);separate kettle Ⅰ pressure was 15 MPa,separate kettle Ⅰ temperature was at 65(?C);separate kettle Ⅱ pressure was 5 MPa,separate ketle Ⅱ temperature was at 38(?C);CO_2 flow rate was 18 L/H,extractive time was 80 min. CONCLUSION: Under these conditions,the separate rate of the extractives from fruits of Cnidium Monnieri(L.) Cuss.could be(24.03%).Using secondary regression coherent design could naturally react the influence of the rule on the every factor to the goal function.
3.Kinetics and related thermodynamics on the extraction of flavonoids from Fagopyrum tartarjcum
Ping OUYANG ; Gaoyong ZHANG ; Baoan KANG ; Yongliang NIE ;
Chinese Traditional Patent Medicine 1992;0(12):-
AIM: To explore the kinetics and thermodynamics parameters in the extraction of flavonoids from Fagopyrum tartarjcum . METHODS: Rutin was adopted as marker substance to create a regression equation between Rutin concentration and absorbance by meaus of UV. RESULTS: According to Fick diffusion principle Ⅱ, extraction process was analysed to gain parameters, such as K, Ea, Y, t 1/2 , K ?. CONCLUSION: The method would be useful for the process design and the choice of operation condition to extract flavonoids from Fagopyrum tartarjcum.
4.A Multifunctional Lentiviral-Based Gene Knockdown with Concurrent Rescue that Controls for Off-Target Effects of RNAi
Feng YUNFENG ; Nie LINGHU ; Thakur Das MEGHNA ; Su QIN ; Chi ZHENFEN ; Zhao YONGLIANG ; D.Longmore GREGORY
Genomics, Proteomics & Bioinformatics 2010;08(4):238-245
The efficient,stable delivery of siRNA into cells,and the appropriate controls for non-specific off-target effects of siRNA are major limitations to functional studies using siRNA technology.To overcome these drawbacks,we have developed a single lentiviral vector that can concurrently deplete endogenous gene expression while expressing an epitope-tagged siRNA-resistant target gene in the same cell.To demonstrate the functional utility of this system,we performed RNAi-depleted α-actinin-1 (α-ACTN1) expression in human T cells,α-ACTN1 RNAi resulted in inhibited chemotaxis to SDF-1α,but it can be completely rescued by concurrent expression of RNAi-resistant α-ACTN1 (rr-α-ACTN1) in the same cell.The presence of a GFP tag on rr-α-ACTN1 allowed for detection of appropriate subcellular localization of rr-α-ACTN1.This system provides not only an internal control for RNAi off-target effects,but also the potential tool for rapid structure-function analyses and gene therapy.
5.Regulation of U6 Promoter Activity by Transcriptional Interference in Viral Vector-Based RNAi
Nie LINGHU ; Thakur Das MEGHNA ; Wang YUMEI ; Su QIN ; Zhao YONGLIANG ; Feng YUNFENG
Genomics, Proteomics & Bioinformatics 2010;08(3):170-179
The direct negative impact of the transcriptional activity of one component on the second one in c/s is referred to as transcriptional interference (TI).U6 is a type Ⅲ RNA polymerase Ⅲ promoter commonly used for driving small hairpin RNA (shRNA) expression in vector-based RNAi.In the design and construction of viral vectors,multiple transcription units may be arranged in close proximity in a space-limited vector.Determining if U6 promoter activity can be affected by TI is critical for the expression of target shRNA in gene therapy or loss-of-function studies.In this research,we designed and implemented a modified retroviral system where shRNA and exogenous gene expressions were driven by two independent transcriptional units.We arranged U6 promoter driving.shRNA expression and UbiC promoter in two promoter arrangements.In primary macrophages,we found U6 promoter activity was inhibited by UbiC promoter when in the divergent arrangement but not in tandem.In contrast,PKG promoter had no such negative impact.Instead of enhancing U6 promoter activity,CMV enhancer had significant negative impact on U6 promoter activity in the presence of UbiC promoter.Our results indicate that U6 promoter activity can be affected by TI in a proximal promoter-specific and arrangement-dependent manner.