Repairing effect of fly ash （FA） on damage of recycled coarse aggregate was evaluated by characteristics of pores and cracks in the vicinity of interracial transition zone （ITZ）. The interracial structure between ...Repairing effect of fly ash （FA） on damage of recycled coarse aggregate was evaluated by characteristics of pores and cracks in the vicinity of interracial transition zone （ITZ）. The interracial structure between the virgin aggregate and the attached old mortar was investigated and compared with ITZ of recycled aggregate concrete in the presence of FA or ultra-fine FA（UFA） by means of scanning electron microscope （SEM）. Diameter and plumpness frequency distribution of pores as well as width of the old ITZ, length of contacting points and cracks density were analyzed. The SEM results reveal that the diameter of pores is decreases significantly but pores plumpness increases. A decreased ITZ width and cracks density as well as an increased bonding zone length can also been observed, which indicates that FA or UFA repairs damage of recycled coarse aggregate due to its granular effect.展开更多
Composite scarf repair is applied in airplane load-bearing structures. But the repairs would have different boundary supports in real situation, such as simply support, clamped support and flexible support. With diffe...Composite scarf repair is applied in airplane load-bearing structures. But the repairs would have different boundary supports in real situation, such as simply support, clamped support and flexible support. With different boundary supports, the bonded scarf repair of composite structures could have diverse damage mechanisms and responses. This work intends to study the impact performance of different boundaries. For this purpose, experimental tests were carried out on the specimens with two sides support and four sides support. The impact load and deflection was monitored during the tests. After impact being finished, the meso-mechanism was studied by means of micro-cracks of the side section for two sides support condition and cross section for the four sides support condition. It was possible to conclude that the four sides boundary possess higher impact resistance maximum loads, lower displacements and lower extent load dropping. In terms of damage modes, as the impact energy relative low 12 J and 16 J, the central position of scarf bonding zone for two sides support appears adhesive cohesive failure and adhesive-composite interface failure. When the energy increases to 20 J, the dominated damage of two sides support moves down to the feathered tip. For four sides support, the critical energy level is 25 J, under which the scarf adhesive begins to be damaged.展开更多
Mesh hernia repair is one of the commonest open techniques of inguinal hernia repair.The main limiting factor in the use of new meshes is the cost.We carried out a prospective randomized double blind study and compris...Mesh hernia repair is one of the commonest open techniques of inguinal hernia repair.The main limiting factor in the use of new meshes is the cost.We carried out a prospective randomized double blind study and comprising of a hundred patients with 100 inguinal hernias admitted consecutively for elective surgery,divided into the polypropylene mesh(PPM)group and the mosquito net mesh(MNM)group each containing fifty patients.All cases were completed successfully and results revealed no difference in two groups.The results of the present study,in consistent with the published literature,reveal that the cheap indigenous mosquito mesh,which has similar properties of an imported mesh,can be safely used for tension-free inguinal hernia repair in adults.Further trials with a larger number of patients and longer follow-ups are justified and recommended.展开更多
Rational planning of spares configuration project is an effective approach to improve equipment availability as well as reduce life cycle cost （LCC）. With an analysis of various impacts on support system, the spares...Rational planning of spares configuration project is an effective approach to improve equipment availability as well as reduce life cycle cost （LCC）. With an analysis of various impacts on support system, the spares demand rate forecast model is constructed. According to systemic analysis method, spares support effectiveness evaluation indicators system is built, and then, initial spares configuration and optimization method is researched. To the issue of discarding and con-sumption for incomplete repairable items, its expected backorders function is approximated by Laplace demand distribution. Combining the （s-1, s） and （R, Q） inventory policy, the spares resup-ply model is established under the batch ordering policy based on inventory state, and the optimi-zation analysis flow for spares configuration is proposed. Through application on shipborne equipment spares configuration, the given scenarios are analyzed under two constraint targets：one is the support effectiveness, and the other is the spares cost. Analysis reveals that the result is consistent with practical regulation;therefore, the model＇s correctness, method＇s validity as well as optimization project＇s rationality are proved to a certain extent.展开更多
Two types of solutions（Zn SO4, Mg SO4） were selected to study the influence of mineral admixtures on the electro-deposition healing effect of concrete cracks. Four parameters（i e, rates of weight gain, surface coat...Two types of solutions（Zn SO4, Mg SO4） were selected to study the influence of mineral admixtures on the electro-deposition healing effect of concrete cracks. Four parameters（i e, rates of weight gain, surface coating, crack closure and crack filling depth） were measured. The mineral composition of electro-deposits in the cracks was analyzed. The study shows that the healing effect of mortar specimens with 10% fly ash is the worst, while the healing effect of mortar specimens with 20% fly ash is better than that of the specimens without fly ash. The rates of weight gain, surface coating, crack closure and crack filling depth decrease with increasing content of the ground granulated blast-furnace slag（GGBS）. The mineral admixtures have no influence on the composition of deposits.展开更多
In this paper, we systematically discuss the basic concepts of grey theory, particularly the grey differential equation and its mathematical foundation, which is essentially unknown in the reliability engineering comm...In this paper, we systematically discuss the basic concepts of grey theory, particularly the grey differential equation and its mathematical foundation, which is essentially unknown in the reliability engineering community. Accordingly, we propose a small-sample based approach to estimate repair improvement effects by partitioning system stopping times into intrinsic functioning times and repair improvement times. An industrial data set is used for illustrative purposes in a stepwise manner.展开更多
背景:将中药有效成分整合于水凝胶体系,作为生长因子的替代品或与生长因子相协同,有望显著增强生物材料在骨缺损修复中的治疗效能。目的:系统总结中药有效成分在改善水凝胶材料生物相容性、机械性能等方面的优势以及中药有效成分与水凝...背景:将中药有效成分整合于水凝胶体系,作为生长因子的替代品或与生长因子相协同,有望显著增强生物材料在骨缺损修复中的治疗效能。目的:系统总结中药有效成分在改善水凝胶材料生物相容性、机械性能等方面的优势以及中药有效成分与水凝胶协同运用促进骨修复方面的最新研究进展。方法:以“中药,中药单体,水凝胶,载体,骨组织工程,生物材料,骨,骨修复,骨缺损”为中文检索词,以“Chinese medicine,Chinese medicine monomer,Hydrogel,Carrier,Bone tissue engineering,Bio-material,Bone,Bone repair,Bone defect”为英文检索词,检索2005-2025年期间中国知网、万方、PubMed、Web of Science数据库内的相关文献,依据纳入及排除标准,最终纳入66篇文献进行归纳总结。结果与结论:中药有效成分可以改善水凝胶的生物相容性、机械性能及降解性能,二者联合应用突破了单一材料在力学、生物活性等方面的瓶颈。中药有效成分与水凝胶结合后,可通过调节骨代谢、促进软骨形成、抑制炎症及氧化应激、血管化与血管生成4个维度显著提升骨修复能力。然而,目前关于中药有效成分与水凝胶结合在骨组织工程中的研究仍有不足,距离实际的临床应用仍有挑战。展开更多
Mecobalamin, a form of vitamin B12 containing a central metal element （cobalt）, is one of the most important mediators of nervous system function. In the clinic, it is often used to accelerate recovery of peripheral...Mecobalamin, a form of vitamin B12 containing a central metal element （cobalt）, is one of the most important mediators of nervous system function. In the clinic, it is often used to accelerate recovery of peripheral nerves, but its molecular mechanism remains unclear. In the present study, we performed sciatic nerve crush injury in mice, followed by daily intraperitoneal administra-tion of mecobalamin （65 μg/kg or 130 μg/kg） or saline （negative control）. Walking track analysis, histomorphological examination, and quantitative real-time PCR showed that mecobalamin signiifcantly improved functional recovery of the sciatic nerve, thickened the myelin sheath in myelinated nerve ifbers, and increased the cross-sectional area of target muscle cells. Further-more, mecobalamin upregulated mRNA expression of growth associated protein 43 in nerve tissue ipsilateral to the injury, and of neurotrophic factors （nerve growth factor, brain-derived nerve growth factor and ciliary neurotrophic factor） in the L4–6 dorsal root ganglia. Our ifndings indicate that the molecular mechanism underlying the therapeutic effect of mecobalamin after sciatic nerve injury involves the upregulation of multiple neurotrophic factor genes.展开更多
AIM To investigate the effects of DNA repair synthesis induced by DNA polymerase β in hepatoma cells after γ ray irradiation. METHODS Cell nuclei were prepared from SMMC LTNM hepatoma which is a transplanted hu...AIM To investigate the effects of DNA repair synthesis induced by DNA polymerase β in hepatoma cells after γ ray irradiation. METHODS Cell nuclei were prepared from SMMC LTNM hepatoma which is a transplanted human liver cancer born on nude mice. Samples were irradiated with 60 Co γ rays at different doses or dose rates. N ethylmaleimide (NEM) and ddTTP were used as selective inhibitors to DNA polymerases. The reaction of DNA repair synthesis was carried out with the selective inhibitor test. RESULTS It was found that the 3H TTP incorporation in irradiated nuclei or calf thymus DNA was significantly higher than that in the non irradiated ones, under the conditions of DNA polymerase α or γ being inhibited. When NEM and ddTTP which selectively inhibits DNA polymerase β both existed in the DNA repair synthesis reaction mixture, the 3H TTP incorporation in irradiated DNA did not significantly increased. Furthermore, 3H TTP incorporation into DNA of SMMC LTNM hepatoma nuclei was higher than that of normal hepatocyte nuclei ( P <0 01). The DNA repair synthesis induced by DNA polymerase β reacted more fast in hepatoma nuclei than in hepatocyte nuclei. CONCLUSION The effects of DNA repair synthesis induced by DNA polymerase β in some tumor cells might be stronger than that in normal cells, which may facilitate the cells to repair DNA damages from radiation.展开更多
A conventionally synthesized thio- and cyano-modified single-stranded poly(dNTP) sequences of different molecular sizes (20n - 200n) and the same lengths routine poly(dNTP) and poly(NTP) species were obtained through ...A conventionally synthesized thio- and cyano-modified single-stranded poly(dNTP) sequences of different molecular sizes (20n - 200n) and the same lengths routine poly(dNTP) and poly(NTP) species were obtained through the good services provided by the Russian Federal Bioorganic Products Group and by the ThermoFischer, Inc., and then tested for their impact on catalytic activities of β-like DNA polymerases from chromatin of HL-60, WERI-1A and Y-79 cells as well as for the affinity patterns in DNApolβ-poly(dNTP)/ (NTP) pairs, respectively. An essential link between the lengths of ultrashort (50n - 100n) single-stranded poly(dNTP) sequences of different structures and their inhibitory effects towards the cancer-specific DNA polymerases β has been found. A possible significance of this phenomenon for both DNA repair suppression in tumors and a consequent anti-cancer activity of the DNA repair related short poly(dNTP) fragments has been for the first time emphasized with a respect to their pharmacophore revealing potential. Thus, this work presents an experimental attempt to upgrade a contemporary attitude towards the DNA derived products applied for anti-cancer agenda, particularly, for acute myeloid leukemia and retinoblastoma cell DNA repair machinery breakdown. In this study, tumor specific DNA polymerases β were found of being the targets for attack promoted with the primer-like single-stranded DNA fragments followed by consequent cytostatic phenomena. A novel concept of the DNA related anti-cancer medicines is under discussion.展开更多
基金The Scientific Research Fund of Hunan Provincial Education Department(No.06C113)
文摘Repairing effect of fly ash （FA） on damage of recycled coarse aggregate was evaluated by characteristics of pores and cracks in the vicinity of interracial transition zone （ITZ）. The interracial structure between the virgin aggregate and the attached old mortar was investigated and compared with ITZ of recycled aggregate concrete in the presence of FA or ultra-fine FA（UFA） by means of scanning electron microscope （SEM）. Diameter and plumpness frequency distribution of pores as well as width of the old ITZ, length of contacting points and cracks density were analyzed. The SEM results reveal that the diameter of pores is decreases significantly but pores plumpness increases. A decreased ITZ width and cracks density as well as an increased bonding zone length can also been observed, which indicates that FA or UFA repairs damage of recycled coarse aggregate due to its granular effect.
文摘Composite scarf repair is applied in airplane load-bearing structures. But the repairs would have different boundary supports in real situation, such as simply support, clamped support and flexible support. With different boundary supports, the bonded scarf repair of composite structures could have diverse damage mechanisms and responses. This work intends to study the impact performance of different boundaries. For this purpose, experimental tests were carried out on the specimens with two sides support and four sides support. The impact load and deflection was monitored during the tests. After impact being finished, the meso-mechanism was studied by means of micro-cracks of the side section for two sides support condition and cross section for the four sides support condition. It was possible to conclude that the four sides boundary possess higher impact resistance maximum loads, lower displacements and lower extent load dropping. In terms of damage modes, as the impact energy relative low 12 J and 16 J, the central position of scarf bonding zone for two sides support appears adhesive cohesive failure and adhesive-composite interface failure. When the energy increases to 20 J, the dominated damage of two sides support moves down to the feathered tip. For four sides support, the critical energy level is 25 J, under which the scarf adhesive begins to be damaged.
文摘Mesh hernia repair is one of the commonest open techniques of inguinal hernia repair.The main limiting factor in the use of new meshes is the cost.We carried out a prospective randomized double blind study and comprising of a hundred patients with 100 inguinal hernias admitted consecutively for elective surgery,divided into the polypropylene mesh(PPM)group and the mosquito net mesh(MNM)group each containing fifty patients.All cases were completed successfully and results revealed no difference in two groups.The results of the present study,in consistent with the published literature,reveal that the cheap indigenous mosquito mesh,which has similar properties of an imported mesh,can be safely used for tension-free inguinal hernia repair in adults.Further trials with a larger number of patients and longer follow-ups are justified and recommended.
基金co-supported by the General Armament Department Pre-research Foundation of China (Nos. 51304010206, 51327 020105)
文摘Rational planning of spares configuration project is an effective approach to improve equipment availability as well as reduce life cycle cost （LCC）. With an analysis of various impacts on support system, the spares demand rate forecast model is constructed. According to systemic analysis method, spares support effectiveness evaluation indicators system is built, and then, initial spares configuration and optimization method is researched. To the issue of discarding and con-sumption for incomplete repairable items, its expected backorders function is approximated by Laplace demand distribution. Combining the （s-1, s） and （R, Q） inventory policy, the spares resup-ply model is established under the batch ordering policy based on inventory state, and the optimi-zation analysis flow for spares configuration is proposed. Through application on shipborne equipment spares configuration, the given scenarios are analyzed under two constraint targets：one is the support effectiveness, and the other is the spares cost. Analysis reveals that the result is consistent with practical regulation;therefore, the model＇s correctness, method＇s validity as well as optimization project＇s rationality are proved to a certain extent.
基金Funded by the National Natural Science Foundation of China(Nos.51479051,51278167)the Natural Science Foundation of Jiangsu Province(No.BK20131374)the Research and Innovation Project for College Graduates of Jiangsu Province(No.CXZZ12_0238)
文摘Two types of solutions（Zn SO4, Mg SO4） were selected to study the influence of mineral admixtures on the electro-deposition healing effect of concrete cracks. Four parameters（i e, rates of weight gain, surface coating, crack closure and crack filling depth） were measured. The mineral composition of electro-deposits in the cracks was analyzed. The study shows that the healing effect of mortar specimens with 10% fly ash is the worst, while the healing effect of mortar specimens with 20% fly ash is better than that of the specimens without fly ash. The rates of weight gain, surface coating, crack closure and crack filling depth decrease with increasing content of the ground granulated blast-furnace slag（GGBS）. The mineral admixtures have no influence on the composition of deposits.
文摘In this paper, we systematically discuss the basic concepts of grey theory, particularly the grey differential equation and its mathematical foundation, which is essentially unknown in the reliability engineering community. Accordingly, we propose a small-sample based approach to estimate repair improvement effects by partitioning system stopping times into intrinsic functioning times and repair improvement times. An industrial data set is used for illustrative purposes in a stepwise manner.
文摘背景:将中药有效成分整合于水凝胶体系,作为生长因子的替代品或与生长因子相协同,有望显著增强生物材料在骨缺损修复中的治疗效能。目的:系统总结中药有效成分在改善水凝胶材料生物相容性、机械性能等方面的优势以及中药有效成分与水凝胶协同运用促进骨修复方面的最新研究进展。方法:以“中药,中药单体,水凝胶,载体,骨组织工程,生物材料,骨,骨修复,骨缺损”为中文检索词,以“Chinese medicine,Chinese medicine monomer,Hydrogel,Carrier,Bone tissue engineering,Bio-material,Bone,Bone repair,Bone defect”为英文检索词,检索2005-2025年期间中国知网、万方、PubMed、Web of Science数据库内的相关文献,依据纳入及排除标准,最终纳入66篇文献进行归纳总结。结果与结论:中药有效成分可以改善水凝胶的生物相容性、机械性能及降解性能,二者联合应用突破了单一材料在力学、生物活性等方面的瓶颈。中药有效成分与水凝胶结合后,可通过调节骨代谢、促进软骨形成、抑制炎症及氧化应激、血管化与血管生成4个维度显著提升骨修复能力。然而,目前关于中药有效成分与水凝胶结合在骨组织工程中的研究仍有不足,距离实际的临床应用仍有挑战。
基金supported by Nanjing Medical University Technology Development Fund of China(General Program),No.2013NJMU182
文摘Mecobalamin, a form of vitamin B12 containing a central metal element （cobalt）, is one of the most important mediators of nervous system function. In the clinic, it is often used to accelerate recovery of peripheral nerves, but its molecular mechanism remains unclear. In the present study, we performed sciatic nerve crush injury in mice, followed by daily intraperitoneal administra-tion of mecobalamin （65 μg/kg or 130 μg/kg） or saline （negative control）. Walking track analysis, histomorphological examination, and quantitative real-time PCR showed that mecobalamin signiifcantly improved functional recovery of the sciatic nerve, thickened the myelin sheath in myelinated nerve ifbers, and increased the cross-sectional area of target muscle cells. Further-more, mecobalamin upregulated mRNA expression of growth associated protein 43 in nerve tissue ipsilateral to the injury, and of neurotrophic factors （nerve growth factor, brain-derived nerve growth factor and ciliary neurotrophic factor） in the L4–6 dorsal root ganglia. Our ifndings indicate that the molecular mechanism underlying the therapeutic effect of mecobalamin after sciatic nerve injury involves the upregulation of multiple neurotrophic factor genes.
文摘AIM To investigate the effects of DNA repair synthesis induced by DNA polymerase β in hepatoma cells after γ ray irradiation. METHODS Cell nuclei were prepared from SMMC LTNM hepatoma which is a transplanted human liver cancer born on nude mice. Samples were irradiated with 60 Co γ rays at different doses or dose rates. N ethylmaleimide (NEM) and ddTTP were used as selective inhibitors to DNA polymerases. The reaction of DNA repair synthesis was carried out with the selective inhibitor test. RESULTS It was found that the 3H TTP incorporation in irradiated nuclei or calf thymus DNA was significantly higher than that in the non irradiated ones, under the conditions of DNA polymerase α or γ being inhibited. When NEM and ddTTP which selectively inhibits DNA polymerase β both existed in the DNA repair synthesis reaction mixture, the 3H TTP incorporation in irradiated DNA did not significantly increased. Furthermore, 3H TTP incorporation into DNA of SMMC LTNM hepatoma nuclei was higher than that of normal hepatocyte nuclei ( P <0 01). The DNA repair synthesis induced by DNA polymerase β reacted more fast in hepatoma nuclei than in hepatocyte nuclei. CONCLUSION The effects of DNA repair synthesis induced by DNA polymerase β in some tumor cells might be stronger than that in normal cells, which may facilitate the cells to repair DNA damages from radiation.
文摘A conventionally synthesized thio- and cyano-modified single-stranded poly(dNTP) sequences of different molecular sizes (20n - 200n) and the same lengths routine poly(dNTP) and poly(NTP) species were obtained through the good services provided by the Russian Federal Bioorganic Products Group and by the ThermoFischer, Inc., and then tested for their impact on catalytic activities of β-like DNA polymerases from chromatin of HL-60, WERI-1A and Y-79 cells as well as for the affinity patterns in DNApolβ-poly(dNTP)/ (NTP) pairs, respectively. An essential link between the lengths of ultrashort (50n - 100n) single-stranded poly(dNTP) sequences of different structures and their inhibitory effects towards the cancer-specific DNA polymerases β has been found. A possible significance of this phenomenon for both DNA repair suppression in tumors and a consequent anti-cancer activity of the DNA repair related short poly(dNTP) fragments has been for the first time emphasized with a respect to their pharmacophore revealing potential. Thus, this work presents an experimental attempt to upgrade a contemporary attitude towards the DNA derived products applied for anti-cancer agenda, particularly, for acute myeloid leukemia and retinoblastoma cell DNA repair machinery breakdown. In this study, tumor specific DNA polymerases β were found of being the targets for attack promoted with the primer-like single-stranded DNA fragments followed by consequent cytostatic phenomena. A novel concept of the DNA related anti-cancer medicines is under discussion.
