Organic-walled microfossils described in this paper have been obtained from the Beidajian Formati... more Organic-walled microfossils described in this paper have been obtained from the Beidajian Formation of the Mesoproterozoic Ruyang Group (ca. 1300Ma) in southern Shanxi Province, China. They are characterized by many eukaryotic organisms, such as acanthomorphic acritarchs, sphaeromorphic acritarchs with a distinct circular excystment, acritarchs with multilayered walls and ornamentation, and multicellular filaments and algal thallose. Recently, more eukaryotic microfossils have
The title compound, C(22)H(36)NO(2)P, features a P atom bonded to a phenyl ring, a cyclo-hexyl-am... more The title compound, C(22)H(36)NO(2)P, features a P atom bonded to a phenyl ring, a cyclo-hexyl-amine unit and the O atom of a menthyl group. In the crystal structure, inter-molecular N-H⋯O hydrogen bonds connect mol-ecules into a one-dimensional chain in the b direction.
Nan Fang Yi Ke Da Xue Xue Bao Journal of Southern Medical University, Sep 1, 2013
OBJECTIVE: Cellular senescence as one of the important steps against tumor is observed in many ca... more OBJECTIVE: Cellular senescence as one of the important steps against tumor is observed in many cancer patients receiving chemotherapy and is related to chemotherapeutic response. To investigate the effect of cisplatin on hepatocellular carcinoma, we treated HepG2 cells exhibiting wild-type TP53 with gradient concentrations of cisplatin.METHODS: The inhibitory effects of cisplatin on human hepatoma HepG2 cells were detected by MTT assay and colony formation test. The changes in cell cycle were analyzed by flow cytometry, and cellular senescence was detected with senescence associated β-galactosidase (SA β-gal) staining. The relative mRNA expression levels of TP53, P21 and P19 was estimated using semi-quantitative real-time RT-PCR, and the protein expressions of P53 and P21 were detected using Western blotting.RESULTS: Cisplatin induced irreversible proliferation inhibition and G1 phase arrest of HepG2 cells. Elevated levels of senescence-associated β-galactosidase was observed in HepG2 cells exposed to low doses of cisplatin. P19 expression immediately increased following cisplatin exposure and reached the maximum level at 48 h, followed then by a rapid decrease to the baseline level, whereas the expressions levels of TP53 and P21 mRNA increased continuously. Western blotting confirmed P53 and P21 expression changes similar to their mRNA expressions during cisplatin-induced cellular senescence in HepG2 cells.CONCLUSION: Our results revealed a functional link between cisplatin and hepatocellular senescence. Cellular senescence induced by cisplatin as a stabile senescent cellular model can be used for further research.
Based on conventional chemical cleaning and physical backflush methods, a novel in situ chemical ... more Based on conventional chemical cleaning and physical backflush methods, a novel in situ chemical backflush method, i.e., chemically assisted maintenance cleaning with NaClO as the principal reagent, was developed for membrane fouling control in membrane bioreactors (MBRs). The results demonstrated that, compared with a control MBR with water backflush, the use of low NaClO loads had few adverse effects on nutrient removal; on the contrary, the exposure to NaClO enhanced the denitrification performance of the MBR as a result of the formation of sludge granules. Measurements of transmembrane pressure (TMP) showed that an NaClO backflush at 0.2 ppm could achieve effective membrane fouling control in MBRs. Ex situ backflush tests showed that an NaClO backflush enhanced the detachment of biopolymers from the fouled membranes compared with a water backflush. Comparative 16S rRNA sequencing showed differing bacterial community composition in the fouling layers of the two MBRs. Specifically...
Methods in molecular biology (Clifton, N.J.), 2014
Allele-specific competitive blocker-polymerase chain reaction (ACB-PCR) is a sensitive approach f... more Allele-specific competitive blocker-polymerase chain reaction (ACB-PCR) is a sensitive approach for the selective amplification of an allele. Using the ACB-PCR technique, hotspot point mutations in oncogenes and tumor-suppressor genes (oncomutations) are being developed as quantitative biomarkers of cancer risk. ACB-PCR employs a mutant specific primer (with a 3'-penultimate mismatch relative to the mutant DNA sequence, but a double 3'-terminal mismatch relative to the wild-type DNA sequence) to selectively amplify rare mutant DNA molecules. A blocker primer (having a non-extendable 3'-end and with a 3'-penultimate mismatch relative to the wild-type DNA sequence, but a double 3'-terminal mismatch relative to the mutant DNA sequence) is included in ACB-PCR to selectively repress amplification from the abundant wild-type molecules. Consequently, ACB-PCR is capable of quantifying the level of a single basepair substitution mutation in a DNA population when present a...
Paleogene arthropod biotas have proved important for tracing the faunal turnover and intercontine... more Paleogene arthropod biotas have proved important for tracing the faunal turnover and intercontinental faunal interchange driven by climatic warming and geodynamic events [1-5]. Despite the large number of Paleogene fossil arthropods in Europe and North America [5-8], little is known about the typical Asian (Laurasia-originated) arthropod biota. Here, we report a unique amber biota (50-53 million years ago) from the Lower Eocene of Fushun in northeastern China, which fills a large biogeographic gap in Eurasia. Fushun amber is derived from cupressaceous trees, as determined by gas chromatography-mass spectrometry, infrared spectroscopy, and paleobotanical observations. Twenty-two orders and more than 80 families of arthropods have been reported so far, making it among the most diverse amber biotas. Our results reveal that an apparent radiation of ecological keystone insects, including eusocial, phytophagous, and parasitoid lineages, occurred at least during the Early Eocene Climatic Optimum. Some insect taxa have close phylogenetic affinities to those from coeval European ambers, showing a biotic interchange between the eastern and western margins of the Eurasian landmass during the Early Paleogene.
Asian Pacific journal of cancer prevention : APJCP, 2013
Gallbladder carcinoma, the most frequent malignant neoplasm of the biliary tract system, has alwa... more Gallbladder carcinoma, the most frequent malignant neoplasm of the biliary tract system, has always been considered to feature late clinical presentation and diagnosis, limited treatment options and an extremely poor prognosis. In recent years, while the incidence of gallbladder cancer has appeared to be on the increase, the available treatment methods have not greatly improved survival of the affected patients. Thus, exploring new therapeutic targets for this devastating disease is an urgent matter at present. Epidemical studies have demonstrated that the incidence of gallbladder carcinoma exhibits a distinct gender bias, affecting females two to three times more than males, pointing to crucial roles of estrogen. It is well known that estrogen acts on target tissues by binding to estrogen receptors (ERs), which are mainly divided into three subtypes, ERα, ERβ and ERγ. ERα and ERβ appear to have overlapping but also unique even opposite biological effects. As important pathogenic me...
This study examined the potential induction of tumor-associated mutations in formaldehyde-exposed... more This study examined the potential induction of tumor-associated mutations in formaldehyde-exposed rat nasal mucosa using a sensitive method, allele-specific competitive blocker-PCR (ACB-PCR). Levels of p53 codon 271 CGT to CAT and K-Ras codon 12 GGT to GAT mutations were quantified in nasal mucosa of rats exposed to formaldehyde. In addition, nasal mucosa cell proliferation was monitored because regenerative cell proliferation is considered a key event in formaldehyde-induced carcinogenesis. Male F344 rats (6-7 weeks old, 5 rats/group) were exposed to 0, 0.7, 2, 6, 10, and 15 ppm formaldehyde for 13 weeks (6 h/day, 5 days/week). ACB-PCR was used to determine levels of p53 and K-Ras mutations. Although two of five untreated rats had measureable spontaneous p53 mutant fractions (MFs), most nasal mucosa samples had p53 MFs below 10(-5). All K-Ras MF measurements were below 10(-5). No dose-related increases in p53 or K-Ras MF were observed, even though significant increases in bromodeoxyuridine incorporation demonstrated induced cell proliferation in the 10 and 15 ppm formaldehyde-treatment groups. Therefore, induction of tumor-associated p53 mutation likely occurs after several other key events in formaldehyde-induced carcinogenesis.
In adaptating to perpetual darkness, cave species gradually lose eyes and body pigmentation and e... more In adaptating to perpetual darkness, cave species gradually lose eyes and body pigmentation and evolve alternatives for exploring their environments. Although troglodyte features evolved independently many times in cavefish, we do not yet know whether independent evolution of these characters involves common genetic mechanisms. Surface-dwelling and many cave-dwelling species make the freshwater teleost genus Sinocyclocheilus an excellent model for studying the evolution of adaptations to life in constant darkness. We compared the mature retinal histology of surface and cave species in Sinocyclocheilus and found that adult cavefish showed a reduction in the number and length of photoreceptor cells. To identify genes and genetic pathways that evolved in constant darkness, we used RNA-seq to compare eyes of surface and cave species. De novo transcriptome assemblies were developed for both species, and contigs were annotated with gene ontology. Results from cave-dwelling Sinocyclocheilus revealed reduced transcription of phototransduction and other genes important for retinal function. In contrast to the blind Mexican tetra cavefish Astyanax mexicanus, our results on morphologies and gene expression suggest that evolved retinal reduction in cave-dwelling Sinocyclocheilus occurs in a lens-independent fashion by the reduced proliferation and downregulation of transcriptional factors shown to have direct roles in retinal development and maintenance, including cone-rod homeobox (crx) and Wnt pathway members. These results show that the independent evolution of retinal degeneration in cavefish can occur by different developmental genetic mechanisms.
Organic-walled microfossils described in this paper have been obtained from the Beidajian Formati... more Organic-walled microfossils described in this paper have been obtained from the Beidajian Formation of the Mesoproterozoic Ruyang Group (ca. 1300Ma) in southern Shanxi Province, China. They are characterized by many eukaryotic organisms, such as acanthomorphic acritarchs, sphaeromorphic acritarchs with a distinct circular excystment, acritarchs with multilayered walls and ornamentation, and multicellular filaments and algal thallose. Recently, more eukaryotic microfossils have
The title compound, C(22)H(36)NO(2)P, features a P atom bonded to a phenyl ring, a cyclo-hexyl-am... more The title compound, C(22)H(36)NO(2)P, features a P atom bonded to a phenyl ring, a cyclo-hexyl-amine unit and the O atom of a menthyl group. In the crystal structure, inter-molecular N-H⋯O hydrogen bonds connect mol-ecules into a one-dimensional chain in the b direction.
Nan Fang Yi Ke Da Xue Xue Bao Journal of Southern Medical University, Sep 1, 2013
OBJECTIVE: Cellular senescence as one of the important steps against tumor is observed in many ca... more OBJECTIVE: Cellular senescence as one of the important steps against tumor is observed in many cancer patients receiving chemotherapy and is related to chemotherapeutic response. To investigate the effect of cisplatin on hepatocellular carcinoma, we treated HepG2 cells exhibiting wild-type TP53 with gradient concentrations of cisplatin.METHODS: The inhibitory effects of cisplatin on human hepatoma HepG2 cells were detected by MTT assay and colony formation test. The changes in cell cycle were analyzed by flow cytometry, and cellular senescence was detected with senescence associated β-galactosidase (SA β-gal) staining. The relative mRNA expression levels of TP53, P21 and P19 was estimated using semi-quantitative real-time RT-PCR, and the protein expressions of P53 and P21 were detected using Western blotting.RESULTS: Cisplatin induced irreversible proliferation inhibition and G1 phase arrest of HepG2 cells. Elevated levels of senescence-associated β-galactosidase was observed in HepG2 cells exposed to low doses of cisplatin. P19 expression immediately increased following cisplatin exposure and reached the maximum level at 48 h, followed then by a rapid decrease to the baseline level, whereas the expressions levels of TP53 and P21 mRNA increased continuously. Western blotting confirmed P53 and P21 expression changes similar to their mRNA expressions during cisplatin-induced cellular senescence in HepG2 cells.CONCLUSION: Our results revealed a functional link between cisplatin and hepatocellular senescence. Cellular senescence induced by cisplatin as a stabile senescent cellular model can be used for further research.
Based on conventional chemical cleaning and physical backflush methods, a novel in situ chemical ... more Based on conventional chemical cleaning and physical backflush methods, a novel in situ chemical backflush method, i.e., chemically assisted maintenance cleaning with NaClO as the principal reagent, was developed for membrane fouling control in membrane bioreactors (MBRs). The results demonstrated that, compared with a control MBR with water backflush, the use of low NaClO loads had few adverse effects on nutrient removal; on the contrary, the exposure to NaClO enhanced the denitrification performance of the MBR as a result of the formation of sludge granules. Measurements of transmembrane pressure (TMP) showed that an NaClO backflush at 0.2 ppm could achieve effective membrane fouling control in MBRs. Ex situ backflush tests showed that an NaClO backflush enhanced the detachment of biopolymers from the fouled membranes compared with a water backflush. Comparative 16S rRNA sequencing showed differing bacterial community composition in the fouling layers of the two MBRs. Specifically...
Methods in molecular biology (Clifton, N.J.), 2014
Allele-specific competitive blocker-polymerase chain reaction (ACB-PCR) is a sensitive approach f... more Allele-specific competitive blocker-polymerase chain reaction (ACB-PCR) is a sensitive approach for the selective amplification of an allele. Using the ACB-PCR technique, hotspot point mutations in oncogenes and tumor-suppressor genes (oncomutations) are being developed as quantitative biomarkers of cancer risk. ACB-PCR employs a mutant specific primer (with a 3'-penultimate mismatch relative to the mutant DNA sequence, but a double 3'-terminal mismatch relative to the wild-type DNA sequence) to selectively amplify rare mutant DNA molecules. A blocker primer (having a non-extendable 3'-end and with a 3'-penultimate mismatch relative to the wild-type DNA sequence, but a double 3'-terminal mismatch relative to the mutant DNA sequence) is included in ACB-PCR to selectively repress amplification from the abundant wild-type molecules. Consequently, ACB-PCR is capable of quantifying the level of a single basepair substitution mutation in a DNA population when present a...
Paleogene arthropod biotas have proved important for tracing the faunal turnover and intercontine... more Paleogene arthropod biotas have proved important for tracing the faunal turnover and intercontinental faunal interchange driven by climatic warming and geodynamic events [1-5]. Despite the large number of Paleogene fossil arthropods in Europe and North America [5-8], little is known about the typical Asian (Laurasia-originated) arthropod biota. Here, we report a unique amber biota (50-53 million years ago) from the Lower Eocene of Fushun in northeastern China, which fills a large biogeographic gap in Eurasia. Fushun amber is derived from cupressaceous trees, as determined by gas chromatography-mass spectrometry, infrared spectroscopy, and paleobotanical observations. Twenty-two orders and more than 80 families of arthropods have been reported so far, making it among the most diverse amber biotas. Our results reveal that an apparent radiation of ecological keystone insects, including eusocial, phytophagous, and parasitoid lineages, occurred at least during the Early Eocene Climatic Optimum. Some insect taxa have close phylogenetic affinities to those from coeval European ambers, showing a biotic interchange between the eastern and western margins of the Eurasian landmass during the Early Paleogene.
Asian Pacific journal of cancer prevention : APJCP, 2013
Gallbladder carcinoma, the most frequent malignant neoplasm of the biliary tract system, has alwa... more Gallbladder carcinoma, the most frequent malignant neoplasm of the biliary tract system, has always been considered to feature late clinical presentation and diagnosis, limited treatment options and an extremely poor prognosis. In recent years, while the incidence of gallbladder cancer has appeared to be on the increase, the available treatment methods have not greatly improved survival of the affected patients. Thus, exploring new therapeutic targets for this devastating disease is an urgent matter at present. Epidemical studies have demonstrated that the incidence of gallbladder carcinoma exhibits a distinct gender bias, affecting females two to three times more than males, pointing to crucial roles of estrogen. It is well known that estrogen acts on target tissues by binding to estrogen receptors (ERs), which are mainly divided into three subtypes, ERα, ERβ and ERγ. ERα and ERβ appear to have overlapping but also unique even opposite biological effects. As important pathogenic me...
This study examined the potential induction of tumor-associated mutations in formaldehyde-exposed... more This study examined the potential induction of tumor-associated mutations in formaldehyde-exposed rat nasal mucosa using a sensitive method, allele-specific competitive blocker-PCR (ACB-PCR). Levels of p53 codon 271 CGT to CAT and K-Ras codon 12 GGT to GAT mutations were quantified in nasal mucosa of rats exposed to formaldehyde. In addition, nasal mucosa cell proliferation was monitored because regenerative cell proliferation is considered a key event in formaldehyde-induced carcinogenesis. Male F344 rats (6-7 weeks old, 5 rats/group) were exposed to 0, 0.7, 2, 6, 10, and 15 ppm formaldehyde for 13 weeks (6 h/day, 5 days/week). ACB-PCR was used to determine levels of p53 and K-Ras mutations. Although two of five untreated rats had measureable spontaneous p53 mutant fractions (MFs), most nasal mucosa samples had p53 MFs below 10(-5). All K-Ras MF measurements were below 10(-5). No dose-related increases in p53 or K-Ras MF were observed, even though significant increases in bromodeoxyuridine incorporation demonstrated induced cell proliferation in the 10 and 15 ppm formaldehyde-treatment groups. Therefore, induction of tumor-associated p53 mutation likely occurs after several other key events in formaldehyde-induced carcinogenesis.
In adaptating to perpetual darkness, cave species gradually lose eyes and body pigmentation and e... more In adaptating to perpetual darkness, cave species gradually lose eyes and body pigmentation and evolve alternatives for exploring their environments. Although troglodyte features evolved independently many times in cavefish, we do not yet know whether independent evolution of these characters involves common genetic mechanisms. Surface-dwelling and many cave-dwelling species make the freshwater teleost genus Sinocyclocheilus an excellent model for studying the evolution of adaptations to life in constant darkness. We compared the mature retinal histology of surface and cave species in Sinocyclocheilus and found that adult cavefish showed a reduction in the number and length of photoreceptor cells. To identify genes and genetic pathways that evolved in constant darkness, we used RNA-seq to compare eyes of surface and cave species. De novo transcriptome assemblies were developed for both species, and contigs were annotated with gene ontology. Results from cave-dwelling Sinocyclocheilus revealed reduced transcription of phototransduction and other genes important for retinal function. In contrast to the blind Mexican tetra cavefish Astyanax mexicanus, our results on morphologies and gene expression suggest that evolved retinal reduction in cave-dwelling Sinocyclocheilus occurs in a lens-independent fashion by the reduced proliferation and downregulation of transcriptional factors shown to have direct roles in retinal development and maintenance, including cone-rod homeobox (crx) and Wnt pathway members. These results show that the independent evolution of retinal degeneration in cavefish can occur by different developmental genetic mechanisms.
Uploads