As the only source of stem cells, satellite cells play and extraordinary role in the remediation process of skeletal muscle after injury. This paper overviewed the biological characteristic of skeletal muscle satellit...As the only source of stem cells, satellite cells play and extraordinary role in the remediation process of skeletal muscle after injury. This paper overviewed the biological characteristic of skeletal muscle satellite cells and its role in repairing muscle injury, and put forward the prospects of its application in muscle trauma repair.展开更多
Repair of bulky DNA adducts by the nucleotide excision repair （NER） pathway is one of the more versatile DNA repair pathways for the removal of DNA lesions. There are two subsets of the NER pathway, global genomic-N...Repair of bulky DNA adducts by the nucleotide excision repair （NER） pathway is one of the more versatile DNA repair pathways for the removal of DNA lesions. There are two subsets of the NER pathway, global genomic-NER （GG- NER） and transcription-coupled NER （TC-NER）, which differ only in the step involving recognition of the DNA lesion. Following recognition of the damage, the sub-pathways then converge for the incision/excision steps and subsequent gap filling and ligation steps. This review will focus on the GGR sub-pathway of NER, while the TCR sub-pathway will be covered in another article in this issue. The ability of the NER pathway to repair a wide array of adducts stems, in part, from the mechanisms involved in the initial recognition step of the damaged DNA and results in NER impacting an equally wide array of human physiological responses and events. In this review, the impact of NER on carcinogenesis, neurological function, sensitivity to environmental factors and sensitivity to cancer therapeutics will be discussed. The knowledge generated in our understanding of the NER pathway over the past 40 years has resulted from advances in the fields of animal model systems, mammalian genetics and in vitro biochemistry, as well as from reconstitution studies and structural analyses of the proteins and enzymes that participate in this pathway. Each of these avenues of research has contributed significantly to our understanding of how the NER pathway works and how alterations in NER activity, both positive and negative, influence human biology.展开更多
Bioremediation plays an increasingly important role in the remediation of chromium-contaminated soil because it is an environmentally friendly technology. To investigate the Cr(Ⅵ)reduction process by indigenous micro...Bioremediation plays an increasingly important role in the remediation of chromium-contaminated soil because it is an environmentally friendly technology. To investigate the Cr(Ⅵ)reduction process by indigenous microorganisms in soil, a batch of incubation experiments were carried out in a bioreactor under aerobic conditions. The results showed that in the presence of indigenous microorganisms, the Cr(Ⅵ) concentration in the chromium-contaminated soil decreased from 1521.9 to 199.2 mg/kg within 66 h with culture medium addition, while a slight decrease in the Cr(Ⅵ) concentration was found in the sterilized soil,implying that the indigenous microorganisms contributed to the Cr(Ⅵ) reduction. In the microbial remediation process, Cr(Ⅵ)microbial reduction occurred after the reduction of NO3-, Mn4+ and Fe3+ and,before SO42- reduction. The reduction process of Cr(Ⅵ) can be divided into two phases, characterized by the exponential equation model of microbial reduction and the linear equation model of the combined effect of the major ions. It can be concluded that indigenous Cr(Ⅵ)-reducing bacteria have a potential application for in-situ remediation of Cr(Ⅵ)-contaminated soil.展开更多
DNA mismatch repair guards the integrity of the genome of almost all organisms by correcting DNA biosynthetic errors and by ensuring the fidelity of homologous genetic recombination. MutL is one of the important prote...DNA mismatch repair guards the integrity of the genome of almost all organisms by correcting DNA biosynthetic errors and by ensuring the fidelity of homologous genetic recombination. MutL is one of the important proteins involved in mismatch repair system. It has been suggested to function as a master coordinator or molecular matchmaker because it interacts physically with MutS, the endonuclease MutH, and DNA helicase UvrD. It also binds to DNA and has an ATPase activity. MutL defective bacteria strains have elevated mutation rates and it has been reported recently that MutL defect may have an important impact on bacterial evolution.展开更多
Objective: To seek new method for the treatment of peripheral nerve injury. Methods: In rat model with sciatic nerve defect, chitosan collagen film was sutured into conduit to bridge 5 mm , 10 mm nerve defects. Rats t...Objective: To seek new method for the treatment of peripheral nerve injury. Methods: In rat model with sciatic nerve defect, chitosan collagen film was sutured into conduit to bridge 5 mm , 10 mm nerve defects. Rats that underwent end to end anastomosis were taken as controls. General observation, electrophysiological study, histological study and image analysis were performed at 4, 8, 12 weeks postoperatively. Results: In 5 mm nerve defects, the quality of nerve regeneration was similar to that of the control group. For 10 mm nerve defect, nerve regeneration was inferior to that of the control group. Chitosan collagen film obviously degraded at 12 weeks postoperatively. Conclusions: Chitosan collagen film conduit can be used to bridge peripheral nerve defect.展开更多
Porous Ti-lOMo alloys were fabricated by powder metallurgy using a space-holder method. The pore characteristics, m icrostructure, mechanical properties, in vitro biocompatibility, and in vivo osseointegration of the ...Porous Ti-lOMo alloys were fabricated by powder metallurgy using a space-holder method. The pore characteristics, m icrostructure, mechanical properties, in vitro biocompatibility, and in vivo osseointegration of the fabricated alloys were systematically investigated. The results show that with different weight ratios of the space-holder (NH4- HC03) added, all of the porous Ti-10Mo alloys sintered at 1,300℃ exhibited a typical W idmanstatten microstructure. The porosity and average pore size of the porous structures can be controlled in the range of 50.8%-66.9% and 70.1 -381.4μm , respectively. The Ti-10Mo alloy with 63.4% porosity exhibited the most suitable mechanical properties for implant applications with an elastic modulus of 2.9 GPa and a compressive yield strength of 127.5 MPa. In vitro9 the alloyconditioned medium showed no deleterious effect on the cell proliferation. The cell viability in this medium was higher than that of the reference group, suggesting non-toxicity and good biological characteristics of the alloy specimens. In vivo, after eight weeks* implantation, new bone tissue formed surrounding the alloy implants, and no noticeable inflammation was observed at the implantation site. The bone bonding strength of the porous Ti-10Mo alloy increased over time from 46.6N at two weeks to 176.4 N at eight weeks. Suitable mechanical properties together with excellent biocompatibility in vitro and osteointegration in vivo make the porous Ti-10Mo fabricated by powder metallurgy an attractive orthopedic implant alloy.展开更多
Inferring gene regulatory networks （GRNs） is a challenging task in Bioinformatics. In this paper, an algorithm, PCHMS, is introduced to infer GRNs. This method applies the path consistency （PC） algorithm based on ...Inferring gene regulatory networks （GRNs） is a challenging task in Bioinformatics. In this paper, an algorithm, PCHMS, is introduced to infer GRNs. This method applies the path consistency （PC） algorithm based on conditional mutual information test （PCA-CMI）. In the PC-based algorithms the separator set is determined to detect the dependency between variables. The PCHMS algorithm attempts to select the set in the smart way. For this purpose, the edges of resulted skeleton are directed based on PC algorithm direction rule and mutual information test （MIT） score. Then the separator set is selected according to the directed network by considering a suitable sequential order of genes. The effectiveness of this method is benchmarked through several networks from the DREAM challenge and the widely used SOS DNA repair network of Escherichia coll. Results show that applying the PCHMS algorithm improves the precision of learning the structure of the GRNs in comparison with current popular approaches.展开更多
文摘As the only source of stem cells, satellite cells play and extraordinary role in the remediation process of skeletal muscle after injury. This paper overviewed the biological characteristic of skeletal muscle satellite cells and its role in repairing muscle injury, and put forward the prospects of its application in muscle trauma repair.
文摘Repair of bulky DNA adducts by the nucleotide excision repair （NER） pathway is one of the more versatile DNA repair pathways for the removal of DNA lesions. There are two subsets of the NER pathway, global genomic-NER （GG- NER） and transcription-coupled NER （TC-NER）, which differ only in the step involving recognition of the DNA lesion. Following recognition of the damage, the sub-pathways then converge for the incision/excision steps and subsequent gap filling and ligation steps. This review will focus on the GGR sub-pathway of NER, while the TCR sub-pathway will be covered in another article in this issue. The ability of the NER pathway to repair a wide array of adducts stems, in part, from the mechanisms involved in the initial recognition step of the damaged DNA and results in NER impacting an equally wide array of human physiological responses and events. In this review, the impact of NER on carcinogenesis, neurological function, sensitivity to environmental factors and sensitivity to cancer therapeutics will be discussed. The knowledge generated in our understanding of the NER pathway over the past 40 years has resulted from advances in the fields of animal model systems, mammalian genetics and in vitro biochemistry, as well as from reconstitution studies and structural analyses of the proteins and enzymes that participate in this pathway. Each of these avenues of research has contributed significantly to our understanding of how the NER pathway works and how alterations in NER activity, both positive and negative, influence human biology.
基金Project(2018SK2044)supported by the Innovation Program of Science&Technology of Hunan Province,ChinaProject(51304250)supported by the National Natural Science Foundation of China
文摘Bioremediation plays an increasingly important role in the remediation of chromium-contaminated soil because it is an environmentally friendly technology. To investigate the Cr(Ⅵ)reduction process by indigenous microorganisms in soil, a batch of incubation experiments were carried out in a bioreactor under aerobic conditions. The results showed that in the presence of indigenous microorganisms, the Cr(Ⅵ) concentration in the chromium-contaminated soil decreased from 1521.9 to 199.2 mg/kg within 66 h with culture medium addition, while a slight decrease in the Cr(Ⅵ) concentration was found in the sterilized soil,implying that the indigenous microorganisms contributed to the Cr(Ⅵ) reduction. In the microbial remediation process, Cr(Ⅵ)microbial reduction occurred after the reduction of NO3-, Mn4+ and Fe3+ and,before SO42- reduction. The reduction process of Cr(Ⅵ) can be divided into two phases, characterized by the exponential equation model of microbial reduction and the linear equation model of the combined effect of the major ions. It can be concluded that indigenous Cr(Ⅵ)-reducing bacteria have a potential application for in-situ remediation of Cr(Ⅵ)-contaminated soil.
文摘DNA mismatch repair guards the integrity of the genome of almost all organisms by correcting DNA biosynthetic errors and by ensuring the fidelity of homologous genetic recombination. MutL is one of the important proteins involved in mismatch repair system. It has been suggested to function as a master coordinator or molecular matchmaker because it interacts physically with MutS, the endonuclease MutH, and DNA helicase UvrD. It also binds to DNA and has an ATPase activity. MutL defective bacteria strains have elevated mutation rates and it has been reported recently that MutL defect may have an important impact on bacterial evolution.
文摘Objective: To seek new method for the treatment of peripheral nerve injury. Methods: In rat model with sciatic nerve defect, chitosan collagen film was sutured into conduit to bridge 5 mm , 10 mm nerve defects. Rats that underwent end to end anastomosis were taken as controls. General observation, electrophysiological study, histological study and image analysis were performed at 4, 8, 12 weeks postoperatively. Results: In 5 mm nerve defects, the quality of nerve regeneration was similar to that of the control group. For 10 mm nerve defect, nerve regeneration was inferior to that of the control group. Chitosan collagen film obviously degraded at 12 weeks postoperatively. Conclusions: Chitosan collagen film conduit can be used to bridge peripheral nerve defect.
基金supported by the Fundamental Research Funds for the Central Universities (FRF-GF-17-B39)the financial support for this research by the National Health and Medical Research Council (NHMRC), Australia through project grant (GNT1087290)
文摘Porous Ti-lOMo alloys were fabricated by powder metallurgy using a space-holder method. The pore characteristics, m icrostructure, mechanical properties, in vitro biocompatibility, and in vivo osseointegration of the fabricated alloys were systematically investigated. The results show that with different weight ratios of the space-holder (NH4- HC03) added, all of the porous Ti-10Mo alloys sintered at 1,300℃ exhibited a typical W idmanstatten microstructure. The porosity and average pore size of the porous structures can be controlled in the range of 50.8%-66.9% and 70.1 -381.4μm , respectively. The Ti-10Mo alloy with 63.4% porosity exhibited the most suitable mechanical properties for implant applications with an elastic modulus of 2.9 GPa and a compressive yield strength of 127.5 MPa. In vitro9 the alloyconditioned medium showed no deleterious effect on the cell proliferation. The cell viability in this medium was higher than that of the reference group, suggesting non-toxicity and good biological characteristics of the alloy specimens. In vivo, after eight weeks* implantation, new bone tissue formed surrounding the alloy implants, and no noticeable inflammation was observed at the implantation site. The bone bonding strength of the porous Ti-10Mo alloy increased over time from 46.6N at two weeks to 176.4 N at eight weeks. Suitable mechanical properties together with excellent biocompatibility in vitro and osteointegration in vivo make the porous Ti-10Mo fabricated by powder metallurgy an attractive orthopedic implant alloy.
文摘Inferring gene regulatory networks （GRNs） is a challenging task in Bioinformatics. In this paper, an algorithm, PCHMS, is introduced to infer GRNs. This method applies the path consistency （PC） algorithm based on conditional mutual information test （PCA-CMI）. In the PC-based algorithms the separator set is determined to detect the dependency between variables. The PCHMS algorithm attempts to select the set in the smart way. For this purpose, the edges of resulted skeleton are directed based on PC algorithm direction rule and mutual information test （MIT） score. Then the separator set is selected according to the directed network by considering a suitable sequential order of genes. The effectiveness of this method is benchmarked through several networks from the DREAM challenge and the widely used SOS DNA repair network of Escherichia coll. Results show that applying the PCHMS algorithm improves the precision of learning the structure of the GRNs in comparison with current popular approaches.
