Onionlike hybrid assemblies based on surfactant-encapsulated polyoxometalates.
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Journal Article↗
Biomedical subjects
Hang Sun
Publications and source records attributed to Hang Sun.
Self-organized microporous structures based on surfactant-encapsulated polyoxometalate complexes.
Self-organized microporous structures based on a series of surfactant-encapsulated polyoxometalate complexes (SECs) have been prepared by using ordered condensed droplets as a template. Among these structures, ordered honeycomb structures were obtained and characterized in detail by taking (DODA)(12)H[Eu(SiW(11)O(39))2] (SEC-1) as an example. Optical microscope, atomic force microscopic, and scanning electron microscopic measurements confirmed the formation of three-dimensional microporous structure, in which the top surface shows a highly ordered honeycomb structure. As compared to common solvent-casting films, the corresponding honeycomb films are more hydrophobic and possess more ordered lamellar structures. Both the wettability and the size of SECs exert significant influence on the formation of microporous structures. The proper hydrophobicity of SECs was proposed to be an essential factor for the formation of honeycomb films, and large-sized SECs are favorable for the fabrication of highly ordered honeycomb structures. The conditions for the formation of different surface morphologies have been discussed in terms of the contact angle of SECs at the interface between water and chloroform, and a contact angle slightly greater than 90 degrees is found to be a prerequisite for the formation of honeycomb structures. The results reported in this paper not only help to further comprehend the mechanism of the formation of honeycomb structures, but also provide some guidance for the design of ordered microporous films based on organic/inorganic hybrid materials, exemplified by the organic/nanoparticle complexes.
Journal Article↗
A cytological study on Kelloggia (Rubiaceae), an intercontinental disjunct genus between eastern Asia and western North America.
A cytological study was carried out for the first time on four populations of the only two species of Kelloggia (Rubiaceae), which occur disjunctly in eastern Asia (K. chinensis Franch.) and western North America (K. galioides Torr.). The consistent mitotic prophase chromosome condensation pattern and interphase nuclei type were determined for both species. The chromosome base number of the genus is suggested to be x = 11. The karyotype of 2n = 22 = 2x = 16m + 6sm was examined for both species. The karyotypical asymmetry of 1A and 2A was found in K. chinensis and K. galioides, respectively. According to the predominant evolutionary direction of karyotype asymmetry in angiosperms, K. galioides (2A) seems slightly more evolved than K. chinensis (1A). Our finding is consistent with the hypothesis of the Old World origin of Kelloggia based on molecular study.
Biological Evolution↗
Intercontinental biogeography of subfamily Orontioideae (Symplocarpus, Lysichiton, and Orontium) of Araceae in Eastern Asia and North America.
Symplocarpus, Lysichiton, and Orontium (Orontioideae) are three of the few north temperate genera of the primarily tropical Araceae. Symplocarpus is disjunctly distributed in eastern Asia (3 spp.) and eastern North America (1 sp.); Lysichiton has an intercontinental discontinuous distribution in eastern Asia (1 sp.) and northwestern North America (1 sp.); and the monotypic Orontium is restricted to eastern North America. Phylogenetic analysis of the trnL-F and ndhF sequences supports (1) the monophyly of both Symplocarpus and Lysichiton, (2) the sister-group relationship of Symplocarpus and Lysichiton, and (3) the clade of Orontium, Symplocarpus, and Lysichiton. Although Symplocarpus shows a much wider disjunction than Lysichiton, the estimated divergence time of the former [4.49+/-1.69 or 6.88+/-4.18 million years ago (mya)] was similar to that of the latter (4.02+/-1.60 or 7.18+/-4.33 mya) based on the penalized likelihood and the Bayesian dating methods, respectively. Eastern Asia was suggested to be the ancestral area of the Symplocarpus-Lysichiton clade based on the dispersal-vicariance analysis. Our biogeographic results support independent migrations of Symplocarpus and Lysichiton across the Bering land bridge in the late Tertiary (Pliocene/late Miocene). Fossil evidence suggests Orontioideae dated back to the late Cretaceous in the temperate Northern Hemisphere (72 mya). The relative rate test shows similar substitution rates of the trnL-F sequences between the proto and the true aroids, although the latter has substantially higher species diversity. The proto Araceae perhaps suffered from a higher rate of extinction in the temperate zone associated with periods of climatic cooling in the Tertiary.
Animals↗
[Screening the hALR-interacting protein from the cDNA library of hepatocarcinoma cells and studying its biological functions].
OBJECTIVES: To screen the hALR-interacting protein by phage-displayed technique and identify its biological activities. METHODS: The specific phage clones that interacted with target protein hALR from a cDNA library of hepatocarcinoma cells were selected using the T7 phage-displayed technique. The acquired cDNA inserts were sequenced and analyzed by bioinformatic tools. The biological activities of the phage-displayed peptide affecting QGY hepatocarcinoma cells were studied using 3H-TdR method. RESULTS: The cDNA inserts with 212 bp were acquired after 4 rounds of biopanning. They showed 100% homology with citron kinase. The phage-displayed peptide and the peptide combined with hALR affected QGY cells proliferation. CONCLUSIONS: hALR-interacting peptide can be specifically screened by phage-displayed technique. Citron kinase that interacted with hALR potentially plays an important role in the proliferation of hepatocarcinoma cells.
Carcinoma, Hepatocellular↗
[Inhibitory effect of blocking expression of human augmenter of liver regeneration (hALR) on proliferation of hepatocellular carcinoma cell line HepG2].
BACKGROUND & OBJECTIVE: Human augmenter of liver regeneration (hALR) is highly expressed in hepatocellular carcinoma (HCC), but rarely expressed in normal liver cells. ALR could stimulate the proliferation of HCC cell line in vitro, but has no effect on normal hepatocytes. This study was to investigate the inhibitory effect of blocking the expression of hALR on the proliferation of HCC cell line HepG2 using small interfering RNA (siRNA) targeting ALR and anti-ALR monoclonal antibody (McAb). METHODS: RNA interference (RNAi) plasmid pSIALR-A targeting hALR cDNA and control plasmid pSIALR-B were constructed and transfected into HepG2 cells, respectively. After transfection, the expression of green fluorescent protein was observed under a fluorescent microscope to calculate transfection efficiency, the protein level of hALR was measured by immunocytochemistry, meanwhile, the expression of hALR mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR). (3)H-TdR incorporation approach was performed to detect the proliferation of HepG2 cells after transfection and after neutralization with anti-hALR McAb. RESULTS: hALR was expressed in HepG2 cells. Plasmids pSIALR-A and pSIALR-B were successfully constructed. Both immunocytochemistry and RT-PCR showed that pSIALR-A inhibited the expression of hALR in HepG2 cells significantly by 83% as compared with pSIALR-B. pSIALR-A specifically inhibited the growth of HepG2 cells after transfection. (3)H-TdR incorporation of pSIALR-A/HepG2 cells was significantly lower than that of pSIALR-B/HepG2 cells (67 687+/-6 548 vs. 104 807+/-5 713, P<0.05). Anti-hALR McAb markedly inhibited the autonomous growth of HepG2 cells (P<0.05). CONCLUSIONS: hALR is highly expressed in HepG2 cells. The short interfering RNA targeting hALR gene could specifically suppress the expression of hALR, and subsequently inhibit the growth of HepG2 cells. Anti-hALR McAb could partially inhibit the autonomous growth of HepG2 cells.
Antibodies, Monoclonal↗
Polyoxometalate-based vesicle and its honeycomb architectures on solid surfaces.
The introduction of cationic surfactant DODA as counterions of [Eu(H2O)2SiW11O39]5- can form a mesoscopic supramolecular assembly of (DODA)4H[Eu(H2O)2SiW11O39], which aggregates into vesicles in chloroform. This POM-based vesicle can be further transferred into three-dimensional microporous architectures under moist air. The present methodology shows that, by combining inorganic chemistry and colloidal surface chemistry, a sequential self-assembling approach based on a series of linkable preorganized building blocks allows access to the fabrication of technological applicably POM-based microsized patterns, alternated with the soft lithographic method.
Journal Article↗
[Establishing a rat insulin-resistant fatty liver model].
OBJECTIVE: To create a rat insulin resistant fatty liver model. METHODS: 14 male Wistar rats were randomly divided into a model and a control group. The model rats were fed a high-fat diet (45% of energy from fat) for 8 weeks, and the control group a standard diet (19% of energy from fat). Insulin sensitivity was measured with glucose infusion rate (GIR) by the euglycermic hyperinsulinemia clamp technique. The aminotransferase, triglyceride (TG), free fatty acid (FFA), superoxide dismutase (SOD) and malondialdehyde (MDA) were measured by biochemical methods, and insulin was measured by radioimmunoassay. The histological and ultrastructural changes of all rat livers were scored using light and electron microscopy. RESULTS: Rats fed the high-fat diet developed panlobular macrovesicular steatosis, lobular inflammatory cell infiltration and abnormal mitochondria, whereas those fed the standard diet had normal livers. All model group rats had elevated levels of aminotransferase, TG, FFA, insulin and liver index, and low GIR. In addition, the high-fat diet increased MDA and decreased SOD. CONCLUSION: A fatty liver and insulin resistance model was successfully developed in rats fed a high-fat diet for 8 weeks, which provided a useful experimental tool for elucidating pathogenesis and treatment of fatty liver.
Animals↗
[Expression of augmenter of liver regeneration in hepatic tumor cells and its clinical significance].
OBJECTIVE: To investigate the effects of augmenter of liver regeneration (ALR) on the proliferation of hepatocytes and hepatic tumor cells and the expression of ALR in herpatocellular carcinoma (HCC). METHODS: Primary rat hepatocytes, QGY and HepG2 cells were cultured separately with ALR from different species. Cell proliferation was detected by their 3H-TdR uptake. The expression of ALR was examined in 9 normal hepatic tissues and 21 HCC cases using immunohistochemistry method. RESULTS: Different ALRs could stimulate the proliferation of HepG2 and QGY cells in a dose-dependent way in vitro, but all ALR had no influence in the proliferation of primary rat hepatocytes. The expression of ALR was absent in normal hepatic tissues, but present in all HCC hepatic tissues. However, the expression of ALR had no relationship with the differentiation and size of the carcinomas. CONCLUSION: ALR might play an important role in the occurrence and development of HCC.
Animals↗
[Expression of CD14 protein in U937 cells induced by vitamin D3].
AIM: To observe the 1, 25-dihydroxy vitamin D3 (Vit D3) induced CD14 expression in human U937 cell line and the reaction of the cells to LPS stimulation following the induction. METHODS: U937 cells were cocultured with 0.1 mumol/L Vit D3 for 24 hours to induce the expression of CD14 gene and the sensitiveness of U937 cells to stimulation of LPS at various concentrations and for different times were observed. RESULTS: Vit D3 stably induced U937 cells to express CD14 mRNA and CD14 protein. The sensitivity of U937 cells to LPS stimulation increased notably after Vit D3 induction. It was demonstrated that low concentration of LPS stimulated the activation of NF-kappaB in U937/CD14 cells, and enhanced the transcription and expression of TNF-alpha gene, and even release of TNF-alpha into the culture supernatant. CONCLUSION: Vit D3 can induce U937 cells to express CD14 gene and CD14 protein and enhance the reactivity of U937/CD14 cells to LPS stimulation.
Animals↗
[Effects of metformin on fatty liver in insulin-resistant rats].
OBJECTIVES: To investigate the effects of metformin on fatty livers in insulin-resistant rats. METHODS: Thirty-one male Wistar rats were randomly divided into a normal (n=8) and an experimental group (n=23). The normal group rats were fed a standard diet, and those of the experimental group with a high-fat diet. After 8 weeks, 7 rats from the experimental group were sacrificed to verify whether the model was established successfully. Then the experimental group was randomly subdivided into two groups: one with metformin treatment (n=8) and one without (n=8). After 6 weeks, insulin sensitivity was measured with glucose infusion rate (GIR) by euglycermic hyperinsulinemia clamp technique. Aminotransferase, triglyceride (TG) and free fatty acids (FFA) were measured by biochemical methods, insulin by radioimmunoassay and tumor necrosis factor-alpha (TNF alpha) by ELISA. The steatosis changes and inflammation activity of all rat livers were scored histologically. RESULTS: Compared with the model group, the insulin resistance, liver index, visceral adiposity and weight loss of the metformin group were dramatically ameliorated. The steatosis and the inflammatory activity in the livers and the level of serum aminotransferase of the metformin group were also significantly decreased. Furthermore, metformin treatment lowered serum TG, liver lipid accumulation and the production of FFA and TNF alpha. CONCLUSION: Metformin can significantly improved insulin resistance and fatty liver development in rats fed a high-fat diet. It may become a new choice for fatty liver treatment in the future.
Animals↗
Expression of human augmenter of liver regeneration in pichia pastoris yeast and its bioactivity in vitro.
AIM: To construct a yeast expression system of human augmenter of liver regeneration (hALR) and to examine its bioactivity in vitro. METHODS: With PCR and gene recombination techniques, cDNA of open reading frame of hALR was obtained from recombinant plasmid pcDNA3.1-hALR and inserted into plasmid pPIC9. The cDNA of hALR from recombinant plasmid pPIC9-hALR demonstrated by sequencing was subcloned into plasmid pPIC9K. The recombinant plasmid pPIC9K-hALR was transformed into GS115 with electroporation. hALR was expressed by GS115 under the induction of 5 mL/L methanol and purified with ultrafiltration after it was analyzed by 15% SDS-PAGE and Western blot. The effects of hALR on in vitro proliferation of QGY and HepG(2) cells were evaluated by (3)H-TdR methods. RESULTS: The correctness and integrity of recombinant plasmids pPIC9-hALR and pPIC9K-hALR were identified by restriction digestion, PCR and sequencing methods, respectively. hALR as a secretive protein was successfully expressed by GS115. Its molecular weight was about 15 ku and the target protein was about 60% of the total protein in the supernatant from GS115 with plasmid pPIC9K-hALR. The results of Western blot of hALR showed the specific band. The high qualitative hALR was obtained through ultrafiltration. hALR could stimulate in vitro proliferation of QGY and HepG(2) cells in a dose-dependent manner, but there was a difference in reactivity to hALR between QGY and HepG(2). CONCLUSION: The hALR as a secretive protein can be successfully expressed by GS115. It may stimulate in vitro proliferation of QGY and HepG(2) cells at a dose-dependent manner. But QGY and HepG(2) cells have different reactivities to hALR.
Blotting, Western↗
[Construction and identification of expressing siRNA plasmid against human augmenter of liver regeneration].
OBJECTIVES: To detect whether there is an expression of human augmenter of liver regeneration (hALR) in HepG2 cells. To develop a kind of RNAi that specifically targets human augmenter of liver regeneration by synthesizing small interfering RNA (siRNA) in vivo, and to assess the inhibitory effect of this siRNA on hALR expression. METHODS: The expression of hALR in HepG2 cells was observed with immunocytochemistry. The RNAi plasmid pSIALR-A and the unrelated control plasmid pSIALR-B were transfected into HepG2 cells. Forty-eight hours after transfection, the protein level of hALR was measured with immunocytochemistry; meanwhile, the reverse transcription PCR (RT-PCR) was performed to detect the expression of hALR mRNA. RESULTS: hALR was expressed by HepG2 cells. siRNA plasmid pSIALR-A, which targets the cDNA of hALR and the unrelated control plasmid pSIALR-B, was successfully constructed. Both immunocytochemistry and RT-PCR showed that pSIALR-A inhibited the expression of hALR in HepG2 cells significantly, compared with that of pSIALR-B. CONCLUSION: The results showed that the small interfering RNA targeting hALR suppresses the expression of hALR in a sequence-specific manner
Base Sequence↗
Assessment of a method for detecting serum HBV DNA with HBV DNA probe labelled directly by alkaline phosphatase.
OBJECTIVE: To assess a sensitive and specific technique for detecting serum HBV DNA with an HBV DNA probe labelled directly by alkaline phosphatase (AlkPhos Direc probe). METHODS: AlkPhos Direc probe was prepared with purified HBV DNA labelled directly by alkaline phosphatase. The probe and chemiluminescent substrate CDP-star for AP were used in hybridization assay. HBV DNA was detected by autoradiography on a film. The results of 80 samples were compared between the chemiluminescent dot blot hybridization assay with the AlkPhos Direc probe and another assay with the digoxigenin-labelled HBV DNA probe. The correlation of seventy-sample results of fluorescent quantitative HBV DNA PCR assay and dot blot hybridization assay with the AlkPhos Direc probe was analysed. RESULTS: The sensitivity of the AlkPhos Direc probe was 10 pg at least. The coincidence of the AlkPhos Direc probe was 100% compared with that of the digoxigenin-labelled HBV DNA probe. A correlation coefficient of HBV DNA quantitative results between fluorescent quantitative HBV DNA PCR assay and dot blot hybridization assay with the AlkPhos Direc probe was 0.98 (P<0.01). CONCLUSIONS: The method detecting HBV DNA in serum with the HBV DNA AlkPhos Direc probe is sensitive and specific. The results of the two assays with the AlkPhos Direc probe or with the digoxigenin-labelled HBV DNA probe are completely coincident. The correlation of HBV DNA quantitative results between fluorescent QPCR assay and dot blot hybridization assay with the AlkPhos Direc probe is satisfactory.
Alkaline Phosphatase↗
Cytological study of Tibetia (Fabaceae) in the Hengduan Mountains region, China.
The Hengduan Mountains comprise one of the world's most important hot spots of biodiversity. Tibetia (Ali) H.P. Tsui (Fabaceae), which has four or five species in two sections, is one of the genera endemic to the region. This paper describes for the first time the karyotype of three of those species. The chromosome counts of all three are 2 n = 16. The karyotypes of the species examined contain chromosomes of variable karyotypic symmetry with centromeres at median and submedian positions that correlate with the morphological characteristics of the species. Karyotypic variation at the diploid level appears to be the predominant feature of chromosome evolution in the genus and may provide a clue to the study of evolutionary patterns of plants in this region.
Journal Article↗
New chemical syntheses of cholest-4,6-dien-3-one.
Steroidal dienones represent a significant class of compounds that are useful intermediates in the further functionalization of the steroid nucleus. Their chemical synthesis can be problematic owing to the lack of a simplified method of preparation and the occurrence of impurities that can be difficult to remove. We have endeavored to develop new methods of chemical synthesis of cholest-4,6-dien-3-one that would yield a product of high purity.
Cholestenones↗
[Establishment and evaluation of the method for detecting HBV DNA in serum using HBV DNA probe labeled directly by alkaline phosphatase].
OBJECTIVE: To establish a sensitive and specific technique for detecting HBV DNA in serum using HBV DNA probe labeled directly by alkaline phosphatase (AlkPhos Direc probe). METHODS: The probe that purified HBV DNA sequence was labeled directly by alkaline phosphatase and chemiluminescent substrate CDP-star for AP was used in the hybridization assay. HBV DNA was detected by autoradiography on the film. The test compared the chemiluminescen dot blot hybridization assay for 80 samples with digoxigenin-labeled HBV DNA probe detective method. The correlation of 70 samples test results between fluorescent quantitative HBV DNA PCR method and dot blot hybridization assay by AlkPhos Direc probe was analysed. RESULTS: The sensitivity of the probe labeled directly by alkaline phosphatase was 10pg at least. The coincidence was 100% compared with digoxigenin-labeled HBV DNA probe detection. A correlation coefficient of HBV DNA quantitative results between fluorescent quantitative HBV DNA PCR (QPCR) method and dot blot hybridization assay by AlkPhos Direc probe was 0.98 (P<0.01). CONCLUSIONS: The method detecting HBV DNA in serum by HBV DNA AlkPhos Direc probe is sensitive and specific. The results between two methods with AlkPhos Direc and digoxigenin-labeled HBV DNA probe are coincident completely. The correlation of HBV DNA quantitative results between fluorescent QPCR method and dot blot hybridization assay by AlkPhos Direc probe is satisfactory.
Alkaline Phosphatase↗