BACKGROUND： Glutathione, as an in vivo free radical scavenger, plays an important role in the anti-oxidation defense mechanism in patients with acute cerebral infarction. OBJECTIVE： To observe the relationship betwe...BACKGROUND： Glutathione, as an in vivo free radical scavenger, plays an important role in the anti-oxidation defense mechanism in patients with acute cerebral infarction. OBJECTIVE： To observe the relationship between the levels of glutathione （GSH） and malonaldehyde （MDA）, the metabolite of lipid peroxidation, in erythrocyte and deformation index of erythrocyte in patients at various periods following acute cerebral infarction. DESIGN： Controlled observation.SETTING： Qilu Hospital of Shandong University and Institute of Cerebrovascular Disease of Qingdao Medical College. PARTICIPANTS： We chose 98 inpatients with acute cerebral infarction from Department of Neurology, Qilu Hospital of Shandong University from January to December 2000 , serving as cerebral infarction group, including 50 male and 48 female, with mean age of （62±7）years. There were 23 cases found on the 1^st day after onset; 25 cases on the 3^rd day after onset; 25 cases on the 7^th day after onset; 25 cases on the 14th days after onset, and they were all confirmed by craniocerebral CT or MRI. Another 30 homeochronous inpatients with neurosis, cervical syndrome, lumbar intervertebral disc herniation and motor neuron disease were chosen as control group, including 20 male and 10 female, with mean age of （52±8）years . There was no significant difference in age and gender distribution between two groups （P 〉 0.05）. Patients in the two groups were informed of detected index.METHODS：①Ulnar venous blood was chosen from the patients who were fasted on the 1^st, 3^rd,7^th and 14^th days after onset. Deformation index of erythrocyte was measured with BL88-CKX laser diffraction erythrocyte deformeter and photographing was performed. GSH level in erythrocyte was measured with DTNB assay introduced by Beu-tler. MDA level in erythrocyte was measured with modified thiobarbituric acid colorimetric method.②At each sample collecting , according to the criteria accepted by the Fourth National Conference of Cerebrovascular Disease, intergrant of neurologic impairment 〈 15 points was regarded as mild （n=46）, 15 to 30 points as moderate （n=40）and, 〉 30 points as severe （n=12）. ③ t test was used to compare data between two groups , and linear correlation analysis was used in relationship analysis among indexes. MAIN OUTCOME MEASURES ：① Comparison of erythrocyte GSH and MDA levels and deformation index of erythrocyte at various periods between patients with acute cerebral infarction and controls. ②Correlation of erythrocyte GSH level with erythrocyte MDA level and with deformation index of erythrocyte in patients with cerebral infarction . ③ Relationship between erythrocyte GSH level and severity of disease in patients with acute cerebral infarction. RESULTS： Totally 98 patients with acute cerebral infarction and 30 controls all entered the stage of result analysis. ① Erythrocyte GSH level and deformation index of erythrocyte were lower on the 1^st, 3^rd, 7^th and 14^th days after onset in cerebral infarction group than in control group （P 〈 0.05-0.01）, and erythrocyte MDA level was significantly higher in cerebral infarction group than in control group （P 〈 0.05-0.01）. The three indexes changed most significantly on day 3 after onset in patients, and began to recover or decrease on day 7 after onset and inclined to be normal on day 14 after onset. ② Erythrocyte GSH level was significantly negatively correlated with erythrocyte MDA level in patients with acute cerebral infarction on the 1^st, 3^rd, 7^th and 14^th days after onset （r=-0.534, -0.713, -0.645, -0.656, respectively, P 〈 0.05-0.01 ） ,and significantly positively correlated with erythrocyte deformation index （t-=0.502, 0.560, 0.455, 0.504, respectively, P 〈 0.05）. ③Erythrocyte GSH level was significantly lower in moderate or severe patients with acute cerebral infarction than in mild patients[（0.215±0.088）,（0.192±0.102）, （0.281±0.090） g/L, P〈 0.05]. CONCLUSION：①Erythrocyte GSH and MDA levels and deformation index of erythrocyte change significantly on the 3^rd day following acute cerebral infarction. Index detection results gradually tended to be normal on from the 7^th day to 14^th days day after onset. ② Change of erythrocyte GSH level can reflect the severity of disease of patients with acute cerebral infarction.③Decrease of erythrocyte GSH level in patients with acute cerebral infarction is one of reasons that result in the decrease of deformation ability of erythrocyte.展开更多
Cadmium accumulation in seafood has become a major concern for human health.Recently,there has been an increasing focus on the potential risks associated with food-borne fluorescent carbon dots(CDs)that are formed dur...Cadmium accumulation in seafood has become a major concern for human health.Recently,there has been an increasing focus on the potential risks associated with food-borne fluorescent carbon dots(CDs)that are formed during the thermal processing of seafood.The co-occurrence of cadmium and CDs from cooked seafood become a common phenomenon and co-exposure of them to human has been an inevitable route during long-term seafood consuming.In addition,it has been widely recognized that CDs can be used as nanocarriers for metal ion chelation for their transport into organisms,thereby,they could influence the bioavailability of metal ion.While there have been numerous studies on the toxic effects of cadmium or CDs,none have explored the combined toxicity of food-borne CDs from clams(CCDs)and Cd^(2+).In this study,we investigated the single or co-exposure(combined exposure)of Cd^(2+)and CCDs on PC12 cells to investigate the combined toxicity of them.Our analysis of cell viability revealed that CCDs significantly augmented the cytotoxicity induced by Cd^(2+).More in-depth metabolomics and lipidomics investigation indicated that the combined exposure of Cd^(2+)and CCDs led to significant metabolic disorders,causing an antagonistic effect on energy metabolism,and a synergistic effect on amino acids and lipids metabolism.The disturbance in metabolomics and lipidomics was further supported by the disruption of mitochondrial membrane potential and the accumulation of reactive oxygen species following co-exposure.These findings provide new evidence that support the enhanced cytotoxicity of Cd^(2+)by the CCDs derived from the thermal processing of clams.This study also declares the necessary that prioritize the investigation of the potential impact of other thermal processing hazards originating from heat-processed foods on the toxicity of heavy metal ions.展开更多
The trophic status assessment of lakes in different lake regions may provide important and fundamental information for lake trophic state classification and eutrophication control. In this study, a region-specific lak...The trophic status assessment of lakes in different lake regions may provide important and fundamental information for lake trophic state classification and eutrophication control. In this study, a region-specific lake eutrophication assessment standard was established through a frequency distribution method based on chlorophyll-a concentration. The assessment standards under the oligotrophic state for lakes in the Eastern plain, Yungui Plateau, Northeast Plain and Mountain Mongolia-Xinjiang regions are total phosphorus of 0.068, 0.005, 0.011, 0.005 mg/L; total nitrogen of 1.00, 0.16, 0.37, 0.60 mg/L; Secchi depth of 0.60, 8.00, 1.55, 3.00 m; and CODMn of 2.24, 1.00, 5.1 l, 4.00 mg/L, respectively. Moreover, a region-specific comprehensive trophic level index was developed to provide an understandable assessment method for the public. The results indicated that the frequency distribution analysis based on chlorophyll-a combined with trophic level index provided a useful metric for the assessment of the lake trophic status. In addition, the difference of eutrophication assessment standards in different lake regions was analyzed, which suggested that the sensitivities of algae to nutrients and the assessment standard of trophic status possessed significant regional differences for the four lake ecoregions. Lake eutrophication assessment standards would contribute to maximizing the effectiveness of future management strategies, to control and minimize lake eutrophication problems.展开更多
Lakes play important roles in sustaining the ecosystem and economic development in Inner Mongolia Autonomous Region of China,but the spatial patterns and driving mechanisms of water quality in lakes so far remain uncl...Lakes play important roles in sustaining the ecosystem and economic development in Inner Mongolia Autonomous Region of China,but the spatial patterns and driving mechanisms of water quality in lakes so far remain unclear.This study aimed to identify the spatial changes in water quality and the driving factors of seven lakes(Juyanhai Lake,Ulansuhai Lake,Hongjiannao Lake,Daihai Lake,Chagannaoer Lake,Hulun Lake,and Wulannuoer Lake)across the longitudinal axis(from the west to the east)of Inner Mongolia.Large-scale research was conducted using the comprehensive trophic level index(TLI(Σ)),multivariate statistics,and spatial analysis methods.The results showed that most lakes in Inner Mongolia were weakly alkaline.Total dissolved solids and salinity of lake water showed obvious zonation characteristics.Nitrogen and phosphorus were identified as the main pollutants in lakes,with high average concentrations of total nitrogen and total phosphorus being of 4.05 and 0.21 mg/L,respectively.The values of TLI(Σ)ranged from 49.14 to 71.77,indicating varying degrees of lake eutrophication,and phosphorus was the main driver of lake eutrophication.The lakes of Inner Mongolia could be categorized into lakes to the west of Daihai Lake and lakes to the east of Daihai Lake in terms of salinity and TLI(Σ).The salinity levels of lakes to the west of Daihai Lake exceeded those of lakes to the east of Daihai Lake,whereas the opposite trend was observed for lake trophic level.The intensity and mode of anthropogenic activities were the driving factors of the spatial patterns of lake water quality.It is recommended to control the impact of anthropogenic activities on the water quality of lakes in Inner Mongolia to improve lake ecological environment.These findings provide a more thorough understanding of the driving mechanism of the spatial patterns of water quality in lakes of Inner Mongolia,which can be used to develop strategies for lake ecosystem protection and water resources management in this region.展开更多
[Objective] The study aimed at analysing water pollution of four rivers in coastal wetland of Yellow River estuary. [Method] Taking four seriously polluted rivers (Guangli River, Shenxian Ditch, Tiao River and Chao Ri...[Objective] The study aimed at analysing water pollution of four rivers in coastal wetland of Yellow River estuary. [Method] Taking four seriously polluted rivers (Guangli River, Shenxian Ditch, Tiao River and Chao River) in coastal wetland of Yellow River estuary as study objects, water samples were collected from the four rivers in May (dry period), August (wet period) and November (normal period) in 2009 and 2010 respectively, then pollution indices like nutritive salts, COD, chlorophyll-a, petroleum, etc. were measured. Afterwards, the status quo of water pollution was assessed based on Nemero index and comprehensive trophic level index (TLI), so as to find out the integral status quo of water quality of wetland rivers and damages to aquatic ecological environment. [Result] On the whole, water pollution of four rivers in coastal wetland of Yellow River estuary was serious, in the eutrophication state, and the main pollutants were TN, TP, NH+4-N and petroleum. In addition, excessive N and P in the four rivers resulted in water eutrophication of Bohai Bay, so further leading to ride tide, which destroyed the coastal ecological environment of Bohai Sea. Moreover, compared with historical data, water pollution by nitrogen and phosphorus became more serious, while there was no obvious aggravation in the water pollution by petroleum. In a word, water pollution wasn’t optimistic on the whole. [Conclusion] The research could provide theoretical bases for the protection and utilization of river water in coastal wetland of Yellow River estuary and its coastal sea area.展开更多
The main objectives were to (1) calculate the total volatile organic compounds (TVOCs) inhalation dose, (2) analyze the proportions of human’s inhaled contaminant dose from different sources, and (3) present a newly ...The main objectives were to (1) calculate the total volatile organic compounds (TVOCs) inhalation dose, (2) analyze the proportions of human’s inhaled contaminant dose from different sources, and (3) present a newly defined ratio of relative inhalation dose level (RIDL) to assess indoor air quality (IAQ). A user defined function based on CFD (computational fluid dynamics) was developed, which integrated human motion model with TVOCs emission model in a high sidewall air supply ventilation mode. Based on simulation results of 10 cases, it is shown that the spatial concentration distribution of TVOCs is affected by human motion. TVOCs diffusion characteristic of building material is the most effective way to impact the TVOCs inhalation dose. From the RIDL index, case A-2 has the most serious IAQ problem, while case D-1 is of the best IAQ.展开更多
目的通过对L4椎体爆裂骨折模型以及应用不同方法固定后的生物力学测试，探讨Index—level螺钉短节段固定方法在治疗下腰椎爆裂骨折中的意义。方法选取10具新鲜尸体腰骶椎标本，通过截骨、切断部分韧带的方法制作L4椎体爆裂骨折模型，然...目的通过对L4椎体爆裂骨折模型以及应用不同方法固定后的生物力学测试，探讨Index—level螺钉短节段固定方法在治疗下腰椎爆裂骨折中的意义。方法选取10具新鲜尸体腰骶椎标本，通过截骨、切断部分韧带的方法制作L4椎体爆裂骨折模型，然后依序进行长节段固定、短节段固定以及短节段＋Index-level螺钉固定并进行生物力学测试，比较不同固定方法腰椎活动度（range of motion，ROM）的差异。结果与短节段固定比较，短节段＋Index—level螺钉固定在前屈、轴向旋转和侧屈时ROM降低，差异有统计学意义（P〈0．05）。在后伸位时短节段＋Index—level固定稳定性提高，ROM降低32．7％，但差异无统计学意义。结论Index—level螺钉短节段固定较单纯短节段内固定平均提高32．5％的即刻稳定性，而且比长节段固定保留更大范围ROM。展开更多
文摘BACKGROUND： Glutathione, as an in vivo free radical scavenger, plays an important role in the anti-oxidation defense mechanism in patients with acute cerebral infarction. OBJECTIVE： To observe the relationship between the levels of glutathione （GSH） and malonaldehyde （MDA）, the metabolite of lipid peroxidation, in erythrocyte and deformation index of erythrocyte in patients at various periods following acute cerebral infarction. DESIGN： Controlled observation.SETTING： Qilu Hospital of Shandong University and Institute of Cerebrovascular Disease of Qingdao Medical College. PARTICIPANTS： We chose 98 inpatients with acute cerebral infarction from Department of Neurology, Qilu Hospital of Shandong University from January to December 2000 , serving as cerebral infarction group, including 50 male and 48 female, with mean age of （62±7）years. There were 23 cases found on the 1^st day after onset; 25 cases on the 3^rd day after onset; 25 cases on the 7^th day after onset; 25 cases on the 14th days after onset, and they were all confirmed by craniocerebral CT or MRI. Another 30 homeochronous inpatients with neurosis, cervical syndrome, lumbar intervertebral disc herniation and motor neuron disease were chosen as control group, including 20 male and 10 female, with mean age of （52±8）years . There was no significant difference in age and gender distribution between two groups （P 〉 0.05）. Patients in the two groups were informed of detected index.METHODS：①Ulnar venous blood was chosen from the patients who were fasted on the 1^st, 3^rd,7^th and 14^th days after onset. Deformation index of erythrocyte was measured with BL88-CKX laser diffraction erythrocyte deformeter and photographing was performed. GSH level in erythrocyte was measured with DTNB assay introduced by Beu-tler. MDA level in erythrocyte was measured with modified thiobarbituric acid colorimetric method.②At each sample collecting , according to the criteria accepted by the Fourth National Conference of Cerebrovascular Disease, intergrant of neurologic impairment 〈 15 points was regarded as mild （n=46）, 15 to 30 points as moderate （n=40）and, 〉 30 points as severe （n=12）. ③ t test was used to compare data between two groups , and linear correlation analysis was used in relationship analysis among indexes. MAIN OUTCOME MEASURES ：① Comparison of erythrocyte GSH and MDA levels and deformation index of erythrocyte at various periods between patients with acute cerebral infarction and controls. ②Correlation of erythrocyte GSH level with erythrocyte MDA level and with deformation index of erythrocyte in patients with cerebral infarction . ③ Relationship between erythrocyte GSH level and severity of disease in patients with acute cerebral infarction. RESULTS： Totally 98 patients with acute cerebral infarction and 30 controls all entered the stage of result analysis. ① Erythrocyte GSH level and deformation index of erythrocyte were lower on the 1^st, 3^rd, 7^th and 14^th days after onset in cerebral infarction group than in control group （P 〈 0.05-0.01）, and erythrocyte MDA level was significantly higher in cerebral infarction group than in control group （P 〈 0.05-0.01）. The three indexes changed most significantly on day 3 after onset in patients, and began to recover or decrease on day 7 after onset and inclined to be normal on day 14 after onset. ② Erythrocyte GSH level was significantly negatively correlated with erythrocyte MDA level in patients with acute cerebral infarction on the 1^st, 3^rd, 7^th and 14^th days after onset （r=-0.534, -0.713, -0.645, -0.656, respectively, P 〈 0.05-0.01 ） ,and significantly positively correlated with erythrocyte deformation index （t-=0.502, 0.560, 0.455, 0.504, respectively, P 〈 0.05）. ③Erythrocyte GSH level was significantly lower in moderate or severe patients with acute cerebral infarction than in mild patients[（0.215±0.088）,（0.192±0.102）, （0.281±0.090） g/L, P〈 0.05]. CONCLUSION：①Erythrocyte GSH and MDA levels and deformation index of erythrocyte change significantly on the 3^rd day following acute cerebral infarction. Index detection results gradually tended to be normal on from the 7^th day to 14^th days day after onset. ② Change of erythrocyte GSH level can reflect the severity of disease of patients with acute cerebral infarction.③Decrease of erythrocyte GSH level in patients with acute cerebral infarction is one of reasons that result in the decrease of deformation ability of erythrocyte.
基金supported by the National Key Research and Development Project of China(2017YFC1600702)the Central Funds Guiding the Local Science and Technology Development of China(2020JH6/10500002).
文摘Cadmium accumulation in seafood has become a major concern for human health.Recently,there has been an increasing focus on the potential risks associated with food-borne fluorescent carbon dots(CDs)that are formed during the thermal processing of seafood.The co-occurrence of cadmium and CDs from cooked seafood become a common phenomenon and co-exposure of them to human has been an inevitable route during long-term seafood consuming.In addition,it has been widely recognized that CDs can be used as nanocarriers for metal ion chelation for their transport into organisms,thereby,they could influence the bioavailability of metal ion.While there have been numerous studies on the toxic effects of cadmium or CDs,none have explored the combined toxicity of food-borne CDs from clams(CCDs)and Cd^(2+).In this study,we investigated the single or co-exposure(combined exposure)of Cd^(2+)and CCDs on PC12 cells to investigate the combined toxicity of them.Our analysis of cell viability revealed that CCDs significantly augmented the cytotoxicity induced by Cd^(2+).More in-depth metabolomics and lipidomics investigation indicated that the combined exposure of Cd^(2+)and CCDs led to significant metabolic disorders,causing an antagonistic effect on energy metabolism,and a synergistic effect on amino acids and lipids metabolism.The disturbance in metabolomics and lipidomics was further supported by the disruption of mitochondrial membrane potential and the accumulation of reactive oxygen species following co-exposure.These findings provide new evidence that support the enhanced cytotoxicity of Cd^(2+)by the CCDs derived from the thermal processing of clams.This study also declares the necessary that prioritize the investigation of the potential impact of other thermal processing hazards originating from heat-processed foods on the toxicity of heavy metal ions.
基金supported by the Mega-projects of Science Research for Water Environment Improvement (No.2009ZX07106-0012012ZX07101-002)+1 种基金the National Natural Science Foundation of China (No.40901248)the China Environmental Public Welfare Program (No.2010009032)
文摘The trophic status assessment of lakes in different lake regions may provide important and fundamental information for lake trophic state classification and eutrophication control. In this study, a region-specific lake eutrophication assessment standard was established through a frequency distribution method based on chlorophyll-a concentration. The assessment standards under the oligotrophic state for lakes in the Eastern plain, Yungui Plateau, Northeast Plain and Mountain Mongolia-Xinjiang regions are total phosphorus of 0.068, 0.005, 0.011, 0.005 mg/L; total nitrogen of 1.00, 0.16, 0.37, 0.60 mg/L; Secchi depth of 0.60, 8.00, 1.55, 3.00 m; and CODMn of 2.24, 1.00, 5.1 l, 4.00 mg/L, respectively. Moreover, a region-specific comprehensive trophic level index was developed to provide an understandable assessment method for the public. The results indicated that the frequency distribution analysis based on chlorophyll-a combined with trophic level index provided a useful metric for the assessment of the lake trophic status. In addition, the difference of eutrophication assessment standards in different lake regions was analyzed, which suggested that the sensitivities of algae to nutrients and the assessment standard of trophic status possessed significant regional differences for the four lake ecoregions. Lake eutrophication assessment standards would contribute to maximizing the effectiveness of future management strategies, to control and minimize lake eutrophication problems.
基金funded by the National Key Research and Development Program of China(2021YFC3201203)the Major Science and Technology Projects of Inner Mongolia Autonomous Region(2020ZD0009)+2 种基金the National Natural Science Foundation of China(51869014)the Open Project Program of the Ministry of Education Key Laboratory of Ecology and Resources Use of the Mongolian Plateau(KF2020006)the Special Funds for Innovation and Entrepreneurship of Postgraduates in Inner Mongolia University(11200-121024).
文摘Lakes play important roles in sustaining the ecosystem and economic development in Inner Mongolia Autonomous Region of China,but the spatial patterns and driving mechanisms of water quality in lakes so far remain unclear.This study aimed to identify the spatial changes in water quality and the driving factors of seven lakes(Juyanhai Lake,Ulansuhai Lake,Hongjiannao Lake,Daihai Lake,Chagannaoer Lake,Hulun Lake,and Wulannuoer Lake)across the longitudinal axis(from the west to the east)of Inner Mongolia.Large-scale research was conducted using the comprehensive trophic level index(TLI(Σ)),multivariate statistics,and spatial analysis methods.The results showed that most lakes in Inner Mongolia were weakly alkaline.Total dissolved solids and salinity of lake water showed obvious zonation characteristics.Nitrogen and phosphorus were identified as the main pollutants in lakes,with high average concentrations of total nitrogen and total phosphorus being of 4.05 and 0.21 mg/L,respectively.The values of TLI(Σ)ranged from 49.14 to 71.77,indicating varying degrees of lake eutrophication,and phosphorus was the main driver of lake eutrophication.The lakes of Inner Mongolia could be categorized into lakes to the west of Daihai Lake and lakes to the east of Daihai Lake in terms of salinity and TLI(Σ).The salinity levels of lakes to the west of Daihai Lake exceeded those of lakes to the east of Daihai Lake,whereas the opposite trend was observed for lake trophic level.The intensity and mode of anthropogenic activities were the driving factors of the spatial patterns of lake water quality.It is recommended to control the impact of anthropogenic activities on the water quality of lakes in Inner Mongolia to improve lake ecological environment.These findings provide a more thorough understanding of the driving mechanism of the spatial patterns of water quality in lakes of Inner Mongolia,which can be used to develop strategies for lake ecosystem protection and water resources management in this region.
基金Supported by Scientific Research Project of National Ocean Public Welfare (200805070,200905009-5,200905020)
文摘[Objective] The study aimed at analysing water pollution of four rivers in coastal wetland of Yellow River estuary. [Method] Taking four seriously polluted rivers (Guangli River, Shenxian Ditch, Tiao River and Chao River) in coastal wetland of Yellow River estuary as study objects, water samples were collected from the four rivers in May (dry period), August (wet period) and November (normal period) in 2009 and 2010 respectively, then pollution indices like nutritive salts, COD, chlorophyll-a, petroleum, etc. were measured. Afterwards, the status quo of water pollution was assessed based on Nemero index and comprehensive trophic level index (TLI), so as to find out the integral status quo of water quality of wetland rivers and damages to aquatic ecological environment. [Result] On the whole, water pollution of four rivers in coastal wetland of Yellow River estuary was serious, in the eutrophication state, and the main pollutants were TN, TP, NH+4-N and petroleum. In addition, excessive N and P in the four rivers resulted in water eutrophication of Bohai Bay, so further leading to ride tide, which destroyed the coastal ecological environment of Bohai Sea. Moreover, compared with historical data, water pollution by nitrogen and phosphorus became more serious, while there was no obvious aggravation in the water pollution by petroleum. In a word, water pollution wasn’t optimistic on the whole. [Conclusion] The research could provide theoretical bases for the protection and utilization of river water in coastal wetland of Yellow River estuary and its coastal sea area.
基金Projects(2006BAJ02A08, 2006BAJ02A05) supported by the National Science and Technology Pillar Program Project during the 11th Five-Year Plan PeriodProject(2007-209) supported by the Excellent Youth Teacher of Ministry of Education of China
文摘The main objectives were to (1) calculate the total volatile organic compounds (TVOCs) inhalation dose, (2) analyze the proportions of human’s inhaled contaminant dose from different sources, and (3) present a newly defined ratio of relative inhalation dose level (RIDL) to assess indoor air quality (IAQ). A user defined function based on CFD (computational fluid dynamics) was developed, which integrated human motion model with TVOCs emission model in a high sidewall air supply ventilation mode. Based on simulation results of 10 cases, it is shown that the spatial concentration distribution of TVOCs is affected by human motion. TVOCs diffusion characteristic of building material is the most effective way to impact the TVOCs inhalation dose. From the RIDL index, case A-2 has the most serious IAQ problem, while case D-1 is of the best IAQ.
文摘目的通过对L4椎体爆裂骨折模型以及应用不同方法固定后的生物力学测试，探讨Index—level螺钉短节段固定方法在治疗下腰椎爆裂骨折中的意义。方法选取10具新鲜尸体腰骶椎标本，通过截骨、切断部分韧带的方法制作L4椎体爆裂骨折模型，然后依序进行长节段固定、短节段固定以及短节段＋Index-level螺钉固定并进行生物力学测试，比较不同固定方法腰椎活动度（range of motion，ROM）的差异。结果与短节段固定比较，短节段＋Index—level螺钉固定在前屈、轴向旋转和侧屈时ROM降低，差异有统计学意义（P〈0．05）。在后伸位时短节段＋Index—level固定稳定性提高，ROM降低32．7％，但差异无统计学意义。结论Index—level螺钉短节段固定较单纯短节段内固定平均提高32．5％的即刻稳定性，而且比长节段固定保留更大范围ROM。
