The fluorescence intensity of N,N-dimethyl-4-((2-methylquinolin-6-yl)ethynyl)aniline exhibits an unusual intensification with increasing temperature, by activating more vibrational bands and leading to stronger TICT emissions upon heating in dimethyl sulfoxide. Based on the different temperature dependence at various wavelengths, as shown in the TICT fluorescence spectrum, this dye can be employed to ratiometrically detect temperature.

Targeted gene modification mediated by single-stranded oligonucleotides (SSOs) holds great potential for widespread use in a number of biological and biomedical fields, including functional genomics and gene therapy. By using this approach, specific genetic changes have been created in a number of prokaryotic and eukaryotic systems. In mammalian cells, the precise mechanism of SSO-mediated chromosome alteration remains to be established, and there have been problems in obtaining reproducible targeting efficiencies. It has previously been suggested that the chromatin structure, which changes throughout the cell cycle, may be a key factor underlying these variations in efficiency. This hypothesis prompted us to systematically investigate SSO-mediated gene repair at various phases of the cell cycle in a mammalian cell line. We found that the efficiency of SSO-mediated gene repair was elevated by Ϸ10-fold in thymidine-treated S-phase cells. The increase in repair frequency correlated positively with the duration of SSO͞thymidine coincubation with host cells after transfection. We supply evidence suggesting that these increased repair frequencies arise from a thymidine-induced slowdown of replication fork progression. Our studies provide fresh insight into the mechanism of SSO-mediated gene repair in mammalian cells and demonstrate how its efficiency may be reliably and substantially increased.single-stranded oligonucleotide ͉ targeted gene repair ͉ thymidine D eveloped over the past few years, targeted genetic modification mediated by oligonucleotides promises to be an invaluable technique for use in functional genomic studies and may even form the basis of future gene therapy procedures (1-3). This approach is applicable for the specific alteration of short stretches of DNA to create deletions, short insertions, and point mutations (4, 5). Therefore, it is ideally suited for the study of single-nucleotide polymorphisms (SNPs) in model organisms such as mice and ultimately may be used for the treatment of diseases caused by small DNA alterations (6, 7).Studies have shown that both chimeric RNA͞DNA oligonucleotides (RDOs) and single-stranded DNA oligonucleotides (SSOs), which may contain a number of unnatural or ''modified'' linkages or bases, can introduce targeted genetic alterations in bacteria, fungi, and mammalian cells (8 -13). For RDOmediated repair, in which it is the DNA moiety that directs the genetic conversion event (14), there have been large variations in targeting efficiencies reported and problems with reproducibility (15). Compared with RDOs, SSOs appear to have the greater potential for development, because they have better stability, and are more easily synthesized, modified, and purified. SSOs also exhibit reliably higher in vivo targeting efficiencies than RDOs (16,17).To expedite the optimization of conditions for SSO-mediated repair, it is first vital to establish the exact mechanism(s). Analogous to the situation for RDOs, a two-step mechanism has been proposed, which involves the following st...

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Since the 1980s, Chinese cities have witnessed significant growth, resulting in urban sprawl all over the country. Under the strict land quota system, local government has had to transform its approach of Greenfield development to land consolidation. Under the ‘Increasing and Decreasing Balance’ land use policy, the Shanghai government began to consolidate rural construction land in order to acquire extra quota for state land by transferring development rights from collective land to state land and by establishing a three-level land consolidation planning system. This paper firstly examines the expansion of non-agricultural land in Shanghai since 1990. It explains the policy arrangements of land consolidation from the perspective of property rights transfer between state and collective land. Taking Xinbang Township as an example, this paper examines the roles of various stakeholders in land consolidation, the municipalities, district and township governments, village collectives, local villagers and entrepreneurs, and analyses the impact land consolidation has upon them. The paper concludes with discussion and policy implications of future land consolidation.

To delineate the relationship between epigenetic modifications and hemoglobin switching, we compared the pattern of histone acetylation and pol II binding across the ␤-globin locus at fetal and adult stages of human development. To make this comparison possible, we introduced an external control into experimental samples in chromatin immunoprecipitation (ChIP) assays. Using this common standard, we found that the locus control region (LCR) was acetylated to the same level at all stages, whereas acetylation levels at the individual gene regions correlated with the state of transcription. In the active genes, the promoters were less acetylated compared with the coding regions. Furthermore, all globin promoters were acetylated to a similar level irrespective of the state of transcription. However, after correction for the loss of nucleosomes, the level of acetylation per histone at the active ␥ and ␤ promoters was 5-to 7-fold greater than that at the inactive promoter. Although the histone acetylation level within the LCR was developmentally stable, pol II binding in fetal erythroblasts was 2-to 3-fold greater than that in adult erythroblasts. These results demonstrate that dynamic changes in histone acetylation and pol II take place as the human ␤-globin gene region undergoes its developmental switches. IntroductionThe human ␤-globin locus consists of around 100 kb found on chromosome 11 and is composed of 5 functional genes: ε, G ␥, A ␥, ␦, and ␤, which are arranged in the order of their expression during development. The locus also contains a locus control region (LCR) that consists of 5 DNase I hypersensitive sites (HS). The LCR is essential for physiologic level expression in mice, although it is not required for chromatin opening activities. 1,2 The tissue-specific expression of the embryonic, fetal, and adult globin genes is developmentally regulated and the globin genes undergo 2 switches in expression during development. The ε-globin gene is expressed in embryonic development at the blood island of the yolk sac. At approximately 6 to 8 weeks of gestation, ε-globin is silenced, whereas the G ␥-and A ␥-globin genes are activated in the fetal liver. The second switch occurs late in gestation when the fetal ␥-globin genes are progressively silenced, although ␤-globin is eventually expressed at high levels after birth. 3 The exact mechanism by which these complex switches occur is not yet fully understood.Chromatin epigenetic changes have long been thought to play a role in the expression of genes. 4,5 With regard to the core histones, the effects of covalent modifications are 2-fold. First, modifications such as acetylation, methylation, and phosphorylation help change the access of trans-acting factors to the genetic elements found within the chromatin and affect the binding specificity of certain trans-factors. 6 Second, these modifications can affect the physical property of chromatin, such as compactness, stability, and flexibility. [7][8][9] Generally, histone acetylation makes the chromatin more flexibl...

Long‐term super‐resolution imaging appears to be increasingly important for unraveling organelle dynamics at the nanoscale, but is challenging due to the need for highly photostable and environment‐sensitive fluorescent probes. Here, we report a self‐blinking fluorophore that achieved 12 nm spatial resolution and 20 ms time resolution under acidic lysosomal conditions. This fluorophore was successfully applied in super‐resolution imaging of lysosomal dynamics over 40 min. The pH dependence of the dye during blinking made the fluorophore sensitive to lysosomal pH. This probe enables simultaneous dynamic and pH recognition of all lysosomes in the entire cell at the single‐lysosome‐resolved level, which allowed us to resolve whole‐cell lysosome subpopulations based on lysosomal distribution, size, and luminal pH. We also observed a variety of lysosome movement trajectories and different types of interactions modes between lysosomes.

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A pseudo-rigid fluorophore with multiple conformers enables highly reliable single-fluorophore ratiometric temperature sensing.