Objective:To establish a multi-drug resistant leukemia cell line (K562-n/VCR) with high tumorigenicity in nude mice and to study its biological features. Methods : K562-n cells were induced into multi-drug resistant cell line K562-n/ VCR by a progressively increasing doses of VCR. The biological features of K562-n/VCR,including cell growth,tumorigenicity in nude mice,colony formation percentage in soft agar, ultrastructure under electron microscopy,cell cycle distribution and the intracellular accumulation of DNR by flow cytometer ,were compared with those of K562-n. The cytogenetics analysis of different strains was also done to observe the chromosome karotype. MTT method was used to determine the cytotoxity of some anticancer drugs. Expression of p-gp was detected by immunohistochemical method. RT-PCR was applied for detection of mdr-1 gene expression. Results: K562-n/VCR cells were found to be cross-resistant to VCR,DNR,EPI,HHT,NVT,VP16 and VM26. Compared with K562-n cells,the resistance of K562-n/VCR to VCR was 297. 38 folds. There was no significantly difference of tumorigenicity in nude mice between K562-n/VCR and K562-n cell line. But the latent period of the tumor was much shorter and volume of mass was bigger in nude mice inoculated K562-n/VCR cells. The bcr-abl gene was still positive in K562-n/VCR cell lines. Conclusion: A multi-drug resistant leukemia cell line K562-n/VCR, with high tumorigenicity and u-nique biological feature,had been established.
This article introduced the design and realization of the comprehensive experiment of digital circuit——adjustable frequency random waves generator.It is concerned with logic circuit、memory、timer、D/A converter of digital circuit course,and is favourable to improve student's ability in analysing problems and practice.
The report is based on the investigation on the Manchu literatures and files of the Qing Dynasty and the Republic of China( 1912 - 1949). It Completely introduces the contents and present states of the literatures related with the Heishuiting and Yikeming'an Banner of the local government of Qiqihar. These literatures are of most importance to develop further research into the regional history of that periods.
A scheme of multi-user MIMO-OFDM joint transmission(JT) based on smart antennas(SA) is proposed in this paper. The weight vectors are derived.The system model and algorithm of the data transmission and detection are developed.The results of the simulation and analysis in the TD-SCDMA system are presented,which indicate the bit error rate(BER) of the multi-user JT-SA MIMO-OFDM is less than that of the multi-user JT-SA.
OBJECTIVE To clone the differentially expressed genes in the retina of rds mouse (the animal model of congenital retinitis pigmentosa) during the disease development. METHODS The retinal mRNA of rds mouse during the development of retinitis pigmentosa was analyzed by the mRNA differential display. The differentially expressed mRNA fragments were cloned and sequenced. RESULTS There was obvious difference of gene expression between rds mouse and the control during the development of retinitis pigmentosa. Five differentially expressed bands were cloned and sequenced. One of those had 86% identity (132/154) with the sequence of the human cDNA DKFZp434D1227 from adult testis in GenBank, which was submitted lately (15-Oct-1999) and without much information. The other had lower identity with the sequences in GenBank. A highly expressed clone in the rds mouse on postnatal day 25 had the same length as another clone in the normal on postnatal day 37, which was not expressed in the rds mouse on day 37. The sequences of the two clones were identical in all but two base pairs. CONCLUSION These results indicate that there are a lot of novel differentially expressed genes in the chronic processing diseases, such as retinitis pigmentosa.
ACC oxidase (ACO) is a key enzyme in ethylene synthesis pathway. This study by rt-pcr with RACE technology get a ACO gene cloning, named BnACO2 , total length of the gene cDNA sequence is 1 377 bp, the open reading frame of 957 bp, coded 318 amino acid polypeptide, predict its molecular weight and isoelectric point (pl) 36.145 kD and 5.60, respectively, bioinformatics analysis showed that BnACO2 no encoding protein signal peptide and transmembrane domain structure, subcellular localization in the cytoplasm. The similarity of ACO gene nucleotide sequence and amino acid sequence was more than 82% and 84% respectively. Phylogenetic analysis showed that the ACO gene was closely related to jute and hemp. Real-time fluorescence quantitative PCR analysis showed that BnACO2 gene was expressed in all parts of ramie, especially in female flower buds. The prokaryotic expression vector PQe- BnACO2 was successfully constructed by double enzyme digestion. At 37°C, 1.0mmol/L IPTG induced PQe- BnACO2 to express the target protein, and the molecular weight of the induced protein was about 36.15kda, which was consistent with the predicted protein size. This lays the foundation for further study on the function of BnACO2 gene.
Objective: Aim of the study was to investigate the pathomorphological changes in the liver and triangular cord of the porta hepatis in biliary atresia and assess the relationship between the degree of differentiation of fibroblasts in the triangular cord of the porta hepatis and the liver fibrosis scores. Methods: From September 2005 to May 2006, 21 patients with biliary atresia (66 ± 20 days old) underwent a Kasai procedure. The liver biopsy and the remnant of the porta hepatis were conserved. Five cases with cholestasis syndrome and 10 cases with choledochal cyst were used as a control group. Liver biopsies were performed in the control group. The micro- and ultrastructure of the liver and the remnant of the porta hepatis were assessed in the biliary atresia and the control group. Ultrastructural features were examined by transmission electron microscopy. The semiquantitative differences in liver fibrosis grading between the biliary atresia and the control group was evaluated with a 3-grade staging system. The degree of differentiation of fibroblasts (FB) in the triangular cord of the porta hepatis was assessed as follows: 1) juvenile type: above 50 % FBs were juvenile, 2) senior type: above 50 % FBs were senior, 3) median type: between the former 2 types. The differentiation scores of FB in the porta hepatis were assessed in relation to the liver fibrosis score. Results: 1) The pathological changes with BA are characterized by inflammation and fibrosis in the hepatic portal area. The fibrosis scores in the biliary atresia group (I: 2 cases, II: 12 cases, III: 7 cases) were significantly higher than in the control group (I: 8 cases, II: 5 cases, III: 2 cases; p = 0.01. 2) In the biliary atresia group, the extrahepatic biliary system of all cases showed a triangular cord in the porta hepatis. The triangular cord of porta hepatis was characterized by hyperplasia of canaliculi, atresia or stenosis of the bile ducts, inflammation infiltration, cholestasis, and interstitial fibrosis. 3) The ultrastructural features of BA showed active fibroblasts, a loss of microvilli, dense deposits in the hepatocytes and liver sinusoid, and dilatation of canaliculi. 4) The differentiation scores of FB in the porta hepatis were positively related to the liver fibrosis score (p = 0.04). Conclusion: The main pathological changes of biliary atresia are inflammation and fibrosis in the hepatic portal area. The ultrastructural features of biliary atresia suggested that the differentiation scores of FB in the triangular cord of the porta hepatis were positively related to the liver fibrosis score.
Deep space exploration is an important way for mankind to innovate space science and technology, and to promote the development and utilization of space resources. Remote sensing technology plays an extremely important role in these exploration missions. Visible and near infrared reflectance spectra are the effective means to study the composition of celestial objects. The Chang'E-5 (CE-5) lunar exploration mission has achieved China's first sample return from the moon, helping scientific research on the origin and evolution of the moon. The landing areas of CE-5 and Apollo 12 were located in the north and south of the Oceanus Procellarum, respectively. In this paper, the spectral data of the craters near the CE- 5 landing site and the similar Apollo 12 lunar rock (12063) spectrum with its mineral composition are compared and analyzed. The band area ratio method and the modified Gaussian model method were applied to study the spectral characteristics and mineral composition of these craters and rocks. The chemical compositions and evolutionary trends of major constituent minerals are consistent with the basalts returned by the Apollo missions. The spectral deconvolution results indicate that the mafic minerals in the crater rocks near the CE-5 landing site are dominated by clinopyroxene, followed by orthopyroxene and olivine, which is significantly lower than the orthopyroxene mineral abundance in the Apollo 12063 lunar rock. It may indicate that the young basalts of CE-5 landing area originate from the lunar mantle source region, which is rich in clinopyroxene and contains a small amount of olivine material. Remote sensing and space exploration help us solve many meaningful scientific problems. In general, remote sensing is an important and useful, even the only, means for us to understand the solar system and extrasolar celestial bodies.
Using the data of historical occurrence level of brown planthopper (BPH) in Tongzhou City, Jiangsu Province and meteorological factor, the long-term predictive warning system of neural network was established according to the principle of neural network. It could be seen from the example that its prediction accuracy was 80%, and it offers a new method to predictability of long term in insect pest.
In regional economic research,it is a common research method to comparably analyse the development condition and the relative importance of economy in different regions?But a problem worth to be thinked over carefully and explored deeply is which index choosed as the gist of assessment can guarantee the accuracy and justice.We put forward an assumption that we can use the contributory coefficient to reflect the differences of economic development and the extent of effect among regions accurately.
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