Limb length discrepancy(LLD)is a common orthopedic condition that can result in significant functional impairment,pain,and cosmetic deformities.Current reconstructive techniques for severe LLD are primarily based on c...Limb length discrepancy(LLD)is a common orthopedic condition that can result in significant functional impairment,pain,and cosmetic deformities.Current reconstructive techniques for severe LLD are primarily based on callus distraction,which is a time-consuming process that can lead to complications,such as significant infection,joint stiffness,and stress fractures.To reduce the therapeutic time and minimize the risk of complications,we investigated the use of vascularized bone flaps as a technical supplement to callus distraction in the reconstruction of short limbs.We present two cases of severe LLD in the upper and lower legs,in which a twostage reconstruction approach was used.In the first stage,external fixation was applied to the affected limb to correct the soft tissue length and convert the short deformity into a bone defect.In the second stage,the bone defect was reconstructed using bilateral(patient A)or unilateral(patient B)free vascularized fibula bone grafts.Both patients had complete survival of the fibular grafts without stress fractures,and bone consolidation took 8 months(patient A)and 4 months(patient B).Compared to the traditional callus distraction,the two-stage approach was found to be more time-saving and reliable.The entire reconstructive scheme required 18 and 4 months for patients A and B,respectively,whereas the traditional callus distraction required 41 and 17 months,respectively.These findings suggest that the use of vascularized bone flaps as a technical supplement for callus distraction may provide an effective and efficient alternative for the treatment of severe LLD.Further studies are needed to validate these results and assess the long-term outcomes of this approach.展开更多
AIM: To investigate the potential roles of Delta-like ligand 4 (DLL4) on the biological behavior of gastric cancer cells and its molecular mechanisms. METHODS: A recombinant eukaryotic expression vector containing hum...AIM: To investigate the potential roles of Delta-like ligand 4 (DLL4) on the biological behavior of gastric cancer cells and its molecular mechanisms. METHODS: A recombinant eukaryotic expression vector containing human DLL4 gene was constructed and transfected into the human gastric cancer cell line SGC7901. Clones with up-regulated DLL4 were selected and amplified. The effect of DLL4 up-regulation on gastric cancer cell growth was assessed using cell growth assay. The migration and invasion were assessed using a transwell migration assay and matrigel invasion assay. Matrix metalloproteinases were detected using the zymogram technique. Cells were implanted subcutaneously into male BALB/c nu/nu mice. Tumor volumes were then calculated and compared. DLL4 staining in the implanted tumor was performed using immunohistochemistry technique. RESULTS: Growth curves over a six-day time course showed significantly promoted cell proliferation of SGC7901 cells with up-regulated DLL4. DLL4 up-regulation in SGC7901 cells promoted the migration (205.4 ± 15.2 vs 22.3 ± 12.1, P < 0.05) and invasion (68.8 ± 5.3 vs 18.2 ± 6.0, P < 0.05) in vitro and tumorigenicity in vivo (2640.5 ± 923.6 mm 3 vs 1115.1 ± 223.8 mm 3 , P < 0.05). Furthermore, significantly increased mRNA level and increased secretion of matrix metalloproteinase-2 (MMP-2) proenzyme were observed in SGC7901 cells with up-regulated DLL4. However, increased MMP-9 mRNA level but decreased extracellular MMP-9 proenzyme level was observed. CONCLUSION: Our observations indicated a mechanism by which activation of DLL4-mediated Notch signaling promotes the expression and secretion of MMP-2 proenzyme and influences the progress of gastric cancer.展开更多
The jacket offshore platform structures working in the environment are subjected to various external conditions,such as wave loads,wind loads and corrosion of sea water.Therefore,the research on reinforcement of tubul...The jacket offshore platform structures working in the environment are subjected to various external conditions,such as wave loads,wind loads and corrosion of sea water.Therefore,the research on reinforcement of tubular joints has great practical value for the safety of offshore platforms.In this article,the finite element(FE)models of T-type tubular joint(T-joint)and K-type tubular joint(K-joint)are established by ANSYS software.Triangular rib reinforcement and collar plate reinforcement are used to reinforce the tubular joints.The reinforcement effects are assessed through the ultimate bearing capacity,and the influences of parameters of the rib and the collar plate on the ultimate capacity are analyzed.Besides,the effects of the two reinforcement methods are compared under the combined loads,and the results show that the reinforcement of the ribbed plate is more effective in resisting the deformation caused by bending moment,while the reinforcement of the collar plate is more effective to avoid the plastic damage caused by the axial pressure.展开更多
Lung cancer is one of the diseases with high morbidity and mortality,and non-small cell lung cancer accounts for a large proportion of it.Traditional Chinese medicine has a long history in treating tumors.More and mor...Lung cancer is one of the diseases with high morbidity and mortality,and non-small cell lung cancer accounts for a large proportion of it.Traditional Chinese medicine has a long history in treating tumors.More and more researchers have paid more attention to it.At present,many studies have proved that traditional Chinese medicine extracts such as astragalus,turmeric,ginseng,coix seed,and gallbladder can inhibit tumor cell proliferation,and have synergistic effects when used in combination with radiotherapy and chemotherapy Its mechanism of action is mostly related to regulating the cell cycle,inhibiting the expression of cancer-related genes,and inducing apoptosis.It is believed that with the development of purification technology,Chinese medicine extracts will play a greater role.展开更多
Catalytic ozonation is progressively becoming an attractive technique for quick water purification but efficient and stable catalysts remains elusive. Here we solvothermally synthesized highly-dispersed Co3O4 nanocrys...Catalytic ozonation is progressively becoming an attractive technique for quick water purification but efficient and stable catalysts remains elusive. Here we solvothermally synthesized highly-dispersed Co3O4 nanocrystals over microscale nitrogen-doping graphene （NG） nanosheets and tested it as a synthetic catalyst in the ozonation of phenol in aqueous solutions. Transmission electron microscopy, powder X-ray diffraction, Fourier transform infrared spectra and X-ray photoelectron spectroscopy were used to determine its morphology, crystallinity, elemental composition and molecular bonds, respectively. The comparative experiments confirmed the highest catalytic activity and oxidation degree （AOSC） of Co3O4/NG among four nanocomposites （G, NG, Co3O4/G, and Co3OJNG）. Co3O4/NG also has exhibited the highest degradation rate： complete conversion of a near-saturated concentration of phenol （941.1 mg/L） was achieved within 30 min under ambient conditions with only a small dosage of Co3O4/NG （50 mg/L） and ozone （4 mg/L, flow rate： 0.5 L/min）. It also resulted in 34.6% chemical oxygen demand （CODcr） and 24.2% total organic carbon （TOC） reduction. In this work, graphene nanosheets not only functioned as a support for Co3O4 nanocrystals but also functioned as a co-catalyst for the enhancement in phenol removal efficiency. The surface nitridation and Co3O4 modification treatment further improved the removal rate of the phenol pollutants and brought in the higher oxidation degree. Our finding may open new perspectives for pursuing exceptional activity for catalytic ozonation reaction.展开更多
Natural gas is extensively used as a clean energy source in cities and industries;consequently,there are associ-ated risks of accidental explosions.To reduce the hazards associated with natural gas explosions,it is im...Natural gas is extensively used as a clean energy source in cities and industries;consequently,there are associ-ated risks of accidental explosions.To reduce the hazards associated with natural gas explosions,it is important to study the inherent laws of natural gas blast loads in unconfined spaces and establish load models.Using ex-periments on natural gas explosions in unconfined spaces,this study demonstrates the influence of natural gas concentrations,propagation distances,and gas volumes upon explosion loads.A new load model was proposed for the overpressure-time history curves of natural-gas explosions in an unconfined space.A comparison with the empirical model indicated that the predictive effect was superior to that of previous models,such as the TNT equivalent model and the TNO multi-energy model.展开更多
Due to the influence of many factors,the overpressure-time history load model of vented gas explosions is difficult to describe and is not conducive to further structural design.Based on vented gas explosion test data...Due to the influence of many factors,the overpressure-time history load model of vented gas explosions is difficult to describe and is not conducive to further structural design.Based on vented gas explosion test data,this paper obtains three typical overpressure-time history curves and puts forward a new semi-empirical model-double hump model that considers gas concentration and venting pressure,and gives a formula for peak pressure and overpressure-time history model.The scientificity of the model is then verified by the total impulse in the load.The model is able directly reflect the load characteristics,provide reference for calculating key parameters of a vented gas explosion and provide information on the structural response under the load.The model thereby has the potential to help reduce the impact of gas explosion disasters.展开更多
基金supported by the National Nature Science Foundation(grant nos.81871577 and 81971864)。
文摘Limb length discrepancy(LLD)is a common orthopedic condition that can result in significant functional impairment,pain,and cosmetic deformities.Current reconstructive techniques for severe LLD are primarily based on callus distraction,which is a time-consuming process that can lead to complications,such as significant infection,joint stiffness,and stress fractures.To reduce the therapeutic time and minimize the risk of complications,we investigated the use of vascularized bone flaps as a technical supplement to callus distraction in the reconstruction of short limbs.We present two cases of severe LLD in the upper and lower legs,in which a twostage reconstruction approach was used.In the first stage,external fixation was applied to the affected limb to correct the soft tissue length and convert the short deformity into a bone defect.In the second stage,the bone defect was reconstructed using bilateral(patient A)or unilateral(patient B)free vascularized fibula bone grafts.Both patients had complete survival of the fibular grafts without stress fractures,and bone consolidation took 8 months(patient A)and 4 months(patient B).Compared to the traditional callus distraction,the two-stage approach was found to be more time-saving and reliable.The entire reconstructive scheme required 18 and 4 months for patients A and B,respectively,whereas the traditional callus distraction required 41 and 17 months,respectively.These findings suggest that the use of vascularized bone flaps as a technical supplement for callus distraction may provide an effective and efficient alternative for the treatment of severe LLD.Further studies are needed to validate these results and assess the long-term outcomes of this approach.
基金Supported by The Key Project of Science and Technology of Zhejiang Province, No. 2009C14017the National Natural Science Foundation of China, No. 81071959 and No. 81101837+1 种基金the Zhejiang Provincial Medical and Healthy Science Foundation of China, No. 2013KYA100 and No. 2009B043the Public Welfare Technology Research Project of Zhejiang Province, No. 2010C34001
文摘AIM: To investigate the potential roles of Delta-like ligand 4 (DLL4) on the biological behavior of gastric cancer cells and its molecular mechanisms. METHODS: A recombinant eukaryotic expression vector containing human DLL4 gene was constructed and transfected into the human gastric cancer cell line SGC7901. Clones with up-regulated DLL4 were selected and amplified. The effect of DLL4 up-regulation on gastric cancer cell growth was assessed using cell growth assay. The migration and invasion were assessed using a transwell migration assay and matrigel invasion assay. Matrix metalloproteinases were detected using the zymogram technique. Cells were implanted subcutaneously into male BALB/c nu/nu mice. Tumor volumes were then calculated and compared. DLL4 staining in the implanted tumor was performed using immunohistochemistry technique. RESULTS: Growth curves over a six-day time course showed significantly promoted cell proliferation of SGC7901 cells with up-regulated DLL4. DLL4 up-regulation in SGC7901 cells promoted the migration (205.4 ± 15.2 vs 22.3 ± 12.1, P < 0.05) and invasion (68.8 ± 5.3 vs 18.2 ± 6.0, P < 0.05) in vitro and tumorigenicity in vivo (2640.5 ± 923.6 mm 3 vs 1115.1 ± 223.8 mm 3 , P < 0.05). Furthermore, significantly increased mRNA level and increased secretion of matrix metalloproteinase-2 (MMP-2) proenzyme were observed in SGC7901 cells with up-regulated DLL4. However, increased MMP-9 mRNA level but decreased extracellular MMP-9 proenzyme level was observed. CONCLUSION: Our observations indicated a mechanism by which activation of DLL4-mediated Notch signaling promotes the expression and secretion of MMP-2 proenzyme and influences the progress of gastric cancer.
基金National Natural Science Foundation of China(Nos.51879272,51579246)Fundamental Research Funds for the Central Universities,China(No.18CX02074A)
文摘The jacket offshore platform structures working in the environment are subjected to various external conditions,such as wave loads,wind loads and corrosion of sea water.Therefore,the research on reinforcement of tubular joints has great practical value for the safety of offshore platforms.In this article,the finite element(FE)models of T-type tubular joint(T-joint)and K-type tubular joint(K-joint)are established by ANSYS software.Triangular rib reinforcement and collar plate reinforcement are used to reinforce the tubular joints.The reinforcement effects are assessed through the ultimate bearing capacity,and the influences of parameters of the rib and the collar plate on the ultimate capacity are analyzed.Besides,the effects of the two reinforcement methods are compared under the combined loads,and the results show that the reinforcement of the ribbed plate is more effective in resisting the deformation caused by bending moment,while the reinforcement of the collar plate is more effective to avoid the plastic damage caused by the axial pressure.
基金Shanghai municipal health and wellness commission excellent talent training program project(No.1705)。
文摘Lung cancer is one of the diseases with high morbidity and mortality,and non-small cell lung cancer accounts for a large proportion of it.Traditional Chinese medicine has a long history in treating tumors.More and more researchers have paid more attention to it.At present,many studies have proved that traditional Chinese medicine extracts such as astragalus,turmeric,ginseng,coix seed,and gallbladder can inhibit tumor cell proliferation,and have synergistic effects when used in combination with radiotherapy and chemotherapy Its mechanism of action is mostly related to regulating the cell cycle,inhibiting the expression of cancer-related genes,and inducing apoptosis.It is believed that with the development of purification technology,Chinese medicine extracts will play a greater role.
基金supported by the research fund of Hanyang University (HY-2013 year)
文摘Catalytic ozonation is progressively becoming an attractive technique for quick water purification but efficient and stable catalysts remains elusive. Here we solvothermally synthesized highly-dispersed Co3O4 nanocrystals over microscale nitrogen-doping graphene （NG） nanosheets and tested it as a synthetic catalyst in the ozonation of phenol in aqueous solutions. Transmission electron microscopy, powder X-ray diffraction, Fourier transform infrared spectra and X-ray photoelectron spectroscopy were used to determine its morphology, crystallinity, elemental composition and molecular bonds, respectively. The comparative experiments confirmed the highest catalytic activity and oxidation degree （AOSC） of Co3O4/NG among four nanocomposites （G, NG, Co3O4/G, and Co3OJNG）. Co3O4/NG also has exhibited the highest degradation rate： complete conversion of a near-saturated concentration of phenol （941.1 mg/L） was achieved within 30 min under ambient conditions with only a small dosage of Co3O4/NG （50 mg/L） and ozone （4 mg/L, flow rate： 0.5 L/min）. It also resulted in 34.6% chemical oxygen demand （CODcr） and 24.2% total organic carbon （TOC） reduction. In this work, graphene nanosheets not only functioned as a support for Co3O4 nanocrystals but also functioned as a co-catalyst for the enhancement in phenol removal efficiency. The surface nitridation and Co3O4 modification treatment further improved the removal rate of the phenol pollutants and brought in the higher oxidation degree. Our finding may open new perspectives for pursuing exceptional activity for catalytic ozonation reaction.
基金support from the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20180081)the National Key R&D Program of China(Great No.2020YFB2103300)the National Basic Research Program of China(973 Program)(Grant No.2015CB058000).
文摘Natural gas is extensively used as a clean energy source in cities and industries;consequently,there are associ-ated risks of accidental explosions.To reduce the hazards associated with natural gas explosions,it is important to study the inherent laws of natural gas blast loads in unconfined spaces and establish load models.Using ex-periments on natural gas explosions in unconfined spaces,this study demonstrates the influence of natural gas concentrations,propagation distances,and gas volumes upon explosion loads.A new load model was proposed for the overpressure-time history curves of natural-gas explosions in an unconfined space.A comparison with the empirical model indicated that the predictive effect was superior to that of previous models,such as the TNT equivalent model and the TNO multi-energy model.
基金The authors gratefully acknowledge the financial support from Natural Science Foundation of Jiangsu Province of China(Grant No.BK20180081)National Key R&D Program of China(Great No.2020YFB2103300)National Basic Research Program of China(973 Program)(Grant No.2015CB058000).
文摘Due to the influence of many factors,the overpressure-time history load model of vented gas explosions is difficult to describe and is not conducive to further structural design.Based on vented gas explosion test data,this paper obtains three typical overpressure-time history curves and puts forward a new semi-empirical model-double hump model that considers gas concentration and venting pressure,and gives a formula for peak pressure and overpressure-time history model.The scientificity of the model is then verified by the total impulse in the load.The model is able directly reflect the load characteristics,provide reference for calculating key parameters of a vented gas explosion and provide information on the structural response under the load.The model thereby has the potential to help reduce the impact of gas explosion disasters.
