The reorientation of microtubules (MTS) in roots of Oryza sativa L. treated with 2,4_D was studied using confocal laser scanning microscopy. In the control (the roots were not treated with 2,4_D), different distributi...The reorientation of microtubules (MTS) in roots of Oryza sativa L. treated with 2,4_D was studied using confocal laser scanning microscopy. In the control (the roots were not treated with 2,4_D), different distribution patterns of MTS were observed in the different growth zones of root tips. MTS of the cortical cells were randomly aligned in the zone of cell division. They were transversely arranged in the cortical cells of the zone of cell elongation; and obliquely oriented in the root hair zone. After treatment with 2,4_D, MTS displayed distinct changes with reorientation in the cortex of the root tip coupling with the inhibition of root growth. MTS changed their orientation in the cortical cells of the zone of cell division from being randomly oriented to transversely oriented when incubated in 1 mg/L 2,4_D for 1 h. However, they were recovered and became randomly oriented when the roots were treated with 1 mg/L 2,4_D for 24 h. An array of MTS, which was different from that in the control, was observed in the cortical cells of the zone of cell elongation in the roots treated with 1 mg/L 2,4_D for 1 h. After treatment with 10 mg/L 2,4_D for 1 h, the MTS in the cortical cells of the zone of cell division became transversely reorientated, but the pattern of MTS distribution was different from that in the 1_hour treatment of 1 mg/L 2,4_D. MTS were hardly detected in the same type of cells when roots were submerged in 10 mg/L 2,4_D for 24 h. When roots were incubated in 10 mg/L 2,4_D for 1 h, the MTS of the cortical cells in the zone of cell elongation became randomly oriented, and much more randomly when the roots were treated for 24 h.展开更多
ObjectiveThe aim was to assess genetic and physiological toxicity of wastewater from a pharmaceutical factory using root tip micronucleus technology of Vicia faba. MethodThe pollution of wastewater from a pharmaceutic...ObjectiveThe aim was to assess genetic and physiological toxicity of wastewater from a pharmaceutical factory using root tip micronucleus technology of Vicia faba. MethodThe pollution of wastewater from a pharmaceutical factory was detected by using root tip micronucleus technology of Vicia faba, and the genetic and physiological toxicity of the wastewater to Vicia faba was assessed. ResultNon-processed wastewater had an extremely high level of biological toxicity; the cells were unable to live with the wastewater at a high concentration; the cells were able to grow with the wastewater at a low concentration, though the micronucleus ratio was extremely high. The processed wastewater had no significant impact on cell growth, but the micronucleus ratio was extremely high, showing that the processed water also had a high pollution index. ConclusionThe research could provide scientific references for the national treatment of wastewater from a pharmaceutical factory.展开更多
The freshwater luminescent bacteria Vibrio-qinghaiensis sp.-Q67 test and the Vicia faba root tip test associated with solid-phase extraction were applied for cytotoxicity and genotoxicity assessment of organic substan...The freshwater luminescent bacteria Vibrio-qinghaiensis sp.-Q67 test and the Vicia faba root tip test associated with solid-phase extraction were applied for cytotoxicity and genotoxicity assessment of organic substances in three rivers, two lakes and effluent flows from two wastewater treatment plants （WWTPs） in Xi＇an, China. Although the most seriously polluted fiver with high chemical oxygen demand （COD） and total organic carbon （TOC） showed high cytotoxicity （expressed as TIIs0, the toxicity impact index） and genotoxicity （expressed as RMCN, the relative frequency of micronucleus）, no correlative relation was found between the ecotoxicity and organic content of the water samples. However, there was a linear correlative relation between TIIs0 and RMCN for most water samples except that from the Zaohe River, which receives discharge from WWTP and untreated industrial wastewaters. The ecotoxicity of the organic toxicants in the Chanhe River and Zaohe River indicated that cytotoxic and genotoxic effects were related to the pollutant source. The TII50 and RMCN were also found to correlate roughly to the dissolved oxygen concentration of the water. Sufficient dissolved oxygen in surface water is thus proved to be an indicator of a healthy water environmental condition.展开更多
BACKGROUND Several previous studies have reported an unusual root formation in which a fractured apical fragment of an immature root continued to develop independent of the main root after trauma to an immature tooth....BACKGROUND Several previous studies have reported an unusual root formation in which a fractured apical fragment of an immature root continued to develop independent of the main root after trauma to an immature tooth.To date,there have been only rare reports of the continuing apical formation of the fractured root associated with dens evaginatus(DE).This paper presents a case of a separated root tip formation associated with a fractured tubercle of DE.CASE SUMMARY An 11-year-old boy was referred for gingival sinus on the buccal side of the right mandibular second premolar(tooth#45).Clinically,tooth#45 was free of caries,but there was a sign of a fractured tubercle of DE on the occlusal surface.Radiography showed that the root canal of tooth#45 was widely radiolucent.A separated root apex was found apically under the main root and was nearly completely formed with an apical orifice at the apical tip.Tooth#45 was diagnosed as tubular fracture of DE with chronic apical periodontitis.A revascularization technique was recommended to treat the tooth.At 3-mo and 1-yr follow-up,the patient remained asymptomatic.Periapical radiography revealed that the separated root tip distally drifted with closure of the apex.However,the root length and thickness of the main root did not increased.CONCLUSION Clinicians should be aware that even if tubercle of DE is fractured in an immature tooth,the root tip may be separated from the main root and completely formed.展开更多
Allium cepa bioassay had been used from decades for the assessment of toxicants and their harmful effects on environment as well as human health. Magnesium oxide（MgO） particles are being utilized in different fields...Allium cepa bioassay had been used from decades for the assessment of toxicants and their harmful effects on environment as well as human health. Magnesium oxide（MgO） particles are being utilized in different fields. However, reports on the adverse effects of MgO nanoparticles on the environment and mankind are scarce. Hence, the toxicity of MgO particles is of concern because of their increased utilization. In the current study, A. cepa was used as an indicator to assess the toxicological efficiency of MgO nano-and microparticles（NPs and MPs） at a range of exposure concentrations（12.5, 25, 50, and100 μg/m L）. The toxicity was evaluated by using various bioassays on A. cepa root tip cells such as comet assay, oxidative stress and their uptake/internalization profile. Results indicated a dose dependent increase in chromosomal aberrations and decrease in mitotic index（MI） when compared to control cells and the effect was more significant for NPs than MPs（at p 〈 0.05）. Comet analysis revealed that the Deoxyribonucleic acid（DNA） damage in terms of percent tail DNA ranged from 6.8–30.1 over 12.5–100 μg/m L concentrations of MgO NPs and was found to be significant at the exposed concentrations. A significant increase in generation of hydrogen peroxide and superoxide radicals was observed in accordance with the lipid peroxidation profile in both MgO NPs and MPs treated plants when compared with control. In conclusion, this investigation revealed that MgO NPs exposure exhibited greater toxicity on A. cepa than MPs.展开更多
[Objective] This study aimed to establish an effective detection technology for rapidly identifying Bt transgenic sugarcane, promptly removing non-Bt transgenic plants and increasing breeding efficiency of Bt transgen...[Objective] This study aimed to establish an effective detection technology for rapidly identifying Bt transgenic sugarcane, promptly removing non-Bt transgenic plants and increasing breeding efficiency of Bt transgenic plants, thereby improving breeding efficiency of insect-resistant sugarcane cultivars in China. [ Method] Approximately 1 mg of root tips and other materials were crushed, placed in the bottom of PCR tubes, added successively with solution I and mineral oil, headed at 95 ℃ for 15 rain, added with solution Ⅱ, and finally added with solution III containing GBt primer for PCR. After separated by using electrophoresis on agarese gel, amplification products were observed and photographed under a gel imaging system. [ Result] Various materials treated with different concentrations of solution led to different amplification results. Specifically, the appropriate concentration of NaOH in solution I was 0.1 -0.2 mol/L; the appropriate pH value of solution II was 2. No bands were amplified from mature leaves, tender leaves and old roots of Bt transgenic sugarcane, while root tips successfully amplified 545 bp target bands. The established method was used to identify and analyze 63 hybrid seedlings of YT 91 -976 × SBR216, results showed that a total of 17 samples exhibited 545 bp bands, accounting for approximately 27% of the total number of hybrid seedlings, indicating that these 17 seedlings were Bt transgenic sugarcane plants. [ Conclusion] The rapid detection method established in this study is conducive to identifying Bt transgenic sugarcane and improving breeding efficiency of insect-resistant sugarcane lines, which provides basis for screening of other transgenic materials.展开更多
Seeds of japonica rice cv.Zhenuo 2 with twodifferent physiological states(dry seeds withwater content 13% and wet seeds soaked in thewater for 36 h)were irradiated by COlaser infour different power-densities and durat...Seeds of japonica rice cv.Zhenuo 2 with twodifferent physiological states(dry seeds withwater content 13% and wet seeds soaked in thewater for 36 h)were irradiated by COlaser infour different power-densities and durations re-spectively.The treatment irradiated with 200GY ofCo γ-rays was considered as control.The flesh root tips were cut and fixed inCarnoy’s fluid for cytological examination.展开更多
Root tips are the main components of absorptive fine roots,but their seasonal dynamics and relationship to environmental factors remain unclear due to the difficulties in methodology.In this study,we explored the temp...Root tips are the main components of absorptive fine roots,but their seasonal dynamics and relationship to environmental factors remain unclear due to the difficulties in methodology.In this study,we explored the temporal patterns of root-tip production and mortality in monoculture plantations of five temperate tree species at a common site in northeastern China,and identified the general environmental controls on such processes.We made monthly in-situ assessments of root tip length(RTL)production and mortality in two hardwood and three coniferous species with a minirhizotron(MR)method during the growing seasons of 2008 and 2009.Air temperature,rainfall,soil temperature and water content at 10 cm depth were determined concurrently.RTL production in all species exhibited consistent peaks in summer(June–August)in two growing seasons.RTL mortality showed substantial interannual and interspecific variability,with peaks in autumn and winter in 2008,but various patterns in 2009.RTL production positively correlated with monthly soil and air temperature across all species,and with monthly rainfall in three coniferous species.However,there was no significant correlation between RTL production and soil water content.By contrast,RTL mortality was weakly related to environmental factors,showing positive correlations with soil temperature in Korean spruce,and with rainfall in Korean pine and Korean spruce.Our findings suggest that the seasonal patterns of RTL production are convergent across the five temperate tree species due to the overlapped distribution of heat and rainfall,which can conduce roots to maximizing the acquisition of nutrient resources in the soil.展开更多
目的比较生物陶瓷材料iRoot BP Plus和无机三氧化物聚合物(MTA)形成根尖屏障修复根尖未发育完全恒牙的效果。方法回顾2018年1月至2022年8月医院牙体牙髓专家门诊收治的80例(80颗患牙)根尖未发育完全恒牙患者,按材料差异应用差异分为两...目的比较生物陶瓷材料iRoot BP Plus和无机三氧化物聚合物(MTA)形成根尖屏障修复根尖未发育完全恒牙的效果。方法回顾2018年1月至2022年8月医院牙体牙髓专家门诊收治的80例(80颗患牙)根尖未发育完全恒牙患者,按材料差异应用差异分为两组,A组40例:根尖屏障修复术中应用iRoot BP Plus材料;B组40例:术中应用MTA材料;对比两组修复效果。结果A组、B组效果评价比较(P>0.05)。A组充填操作时间(8.51±1.38)min,短于B组的(15.48±2.09)min,差异有统计学意义(P<0.05)。A组治疗6个月O-PAI评分低于B组,并发症发生率2.50%低于B组的20.00%(P<0.05)。结论iRoot BP Plus和MTA形成根尖屏障修复根尖未发育完全恒牙均有相似效果,但iRoot BP Plus充填时间短,并发症少,值得应用。展开更多
文摘The reorientation of microtubules (MTS) in roots of Oryza sativa L. treated with 2,4_D was studied using confocal laser scanning microscopy. In the control (the roots were not treated with 2,4_D), different distribution patterns of MTS were observed in the different growth zones of root tips. MTS of the cortical cells were randomly aligned in the zone of cell division. They were transversely arranged in the cortical cells of the zone of cell elongation; and obliquely oriented in the root hair zone. After treatment with 2,4_D, MTS displayed distinct changes with reorientation in the cortex of the root tip coupling with the inhibition of root growth. MTS changed their orientation in the cortical cells of the zone of cell division from being randomly oriented to transversely oriented when incubated in 1 mg/L 2,4_D for 1 h. However, they were recovered and became randomly oriented when the roots were treated with 1 mg/L 2,4_D for 24 h. An array of MTS, which was different from that in the control, was observed in the cortical cells of the zone of cell elongation in the roots treated with 1 mg/L 2,4_D for 1 h. After treatment with 10 mg/L 2,4_D for 1 h, the MTS in the cortical cells of the zone of cell division became transversely reorientated, but the pattern of MTS distribution was different from that in the 1_hour treatment of 1 mg/L 2,4_D. MTS were hardly detected in the same type of cells when roots were submerged in 10 mg/L 2,4_D for 24 h. When roots were incubated in 10 mg/L 2,4_D for 1 h, the MTS of the cortical cells in the zone of cell elongation became randomly oriented, and much more randomly when the roots were treated for 24 h.
文摘ObjectiveThe aim was to assess genetic and physiological toxicity of wastewater from a pharmaceutical factory using root tip micronucleus technology of Vicia faba. MethodThe pollution of wastewater from a pharmaceutical factory was detected by using root tip micronucleus technology of Vicia faba, and the genetic and physiological toxicity of the wastewater to Vicia faba was assessed. ResultNon-processed wastewater had an extremely high level of biological toxicity; the cells were unable to live with the wastewater at a high concentration; the cells were able to grow with the wastewater at a low concentration, though the micronucleus ratio was extremely high. The processed wastewater had no significant impact on cell growth, but the micronucleus ratio was extremely high, showing that the processed water also had a high pollution index. ConclusionThe research could provide scientific references for the national treatment of wastewater from a pharmaceutical factory.
基金supported by the National Natural Science Foundation of China (No. 50838005)the Program for Changjiang Scholars and Innovative Research Team inUniversity (No. IRT0853)the National Program of Water Pollution Control (No. 2008ZX07317-004)
文摘The freshwater luminescent bacteria Vibrio-qinghaiensis sp.-Q67 test and the Vicia faba root tip test associated with solid-phase extraction were applied for cytotoxicity and genotoxicity assessment of organic substances in three rivers, two lakes and effluent flows from two wastewater treatment plants （WWTPs） in Xi＇an, China. Although the most seriously polluted fiver with high chemical oxygen demand （COD） and total organic carbon （TOC） showed high cytotoxicity （expressed as TIIs0, the toxicity impact index） and genotoxicity （expressed as RMCN, the relative frequency of micronucleus）, no correlative relation was found between the ecotoxicity and organic content of the water samples. However, there was a linear correlative relation between TIIs0 and RMCN for most water samples except that from the Zaohe River, which receives discharge from WWTP and untreated industrial wastewaters. The ecotoxicity of the organic toxicants in the Chanhe River and Zaohe River indicated that cytotoxic and genotoxic effects were related to the pollutant source. The TII50 and RMCN were also found to correlate roughly to the dissolved oxygen concentration of the water. Sufficient dissolved oxygen in surface water is thus proved to be an indicator of a healthy water environmental condition.
基金National Natural Science Foundation of China,No.81801028Natural Science Foundation of Zhejiang Province,No.LQ19H140001.
文摘BACKGROUND Several previous studies have reported an unusual root formation in which a fractured apical fragment of an immature root continued to develop independent of the main root after trauma to an immature tooth.To date,there have been only rare reports of the continuing apical formation of the fractured root associated with dens evaginatus(DE).This paper presents a case of a separated root tip formation associated with a fractured tubercle of DE.CASE SUMMARY An 11-year-old boy was referred for gingival sinus on the buccal side of the right mandibular second premolar(tooth#45).Clinically,tooth#45 was free of caries,but there was a sign of a fractured tubercle of DE on the occlusal surface.Radiography showed that the root canal of tooth#45 was widely radiolucent.A separated root apex was found apically under the main root and was nearly completely formed with an apical orifice at the apical tip.Tooth#45 was diagnosed as tubular fracture of DE with chronic apical periodontitis.A revascularization technique was recommended to treat the tooth.At 3-mo and 1-yr follow-up,the patient remained asymptomatic.Periapical radiography revealed that the separated root tip distally drifted with closure of the apex.However,the root length and thickness of the main root did not increased.CONCLUSION Clinicians should be aware that even if tubercle of DE is fractured in an immature tooth,the root tip may be separated from the main root and completely formed.
基金the Director IICT, Hyderabad for providing funds and facility to execute this study
文摘Allium cepa bioassay had been used from decades for the assessment of toxicants and their harmful effects on environment as well as human health. Magnesium oxide（MgO） particles are being utilized in different fields. However, reports on the adverse effects of MgO nanoparticles on the environment and mankind are scarce. Hence, the toxicity of MgO particles is of concern because of their increased utilization. In the current study, A. cepa was used as an indicator to assess the toxicological efficiency of MgO nano-and microparticles（NPs and MPs） at a range of exposure concentrations（12.5, 25, 50, and100 μg/m L）. The toxicity was evaluated by using various bioassays on A. cepa root tip cells such as comet assay, oxidative stress and their uptake/internalization profile. Results indicated a dose dependent increase in chromosomal aberrations and decrease in mitotic index（MI） when compared to control cells and the effect was more significant for NPs than MPs（at p 〈 0.05）. Comet analysis revealed that the Deoxyribonucleic acid（DNA） damage in terms of percent tail DNA ranged from 6.8–30.1 over 12.5–100 μg/m L concentrations of MgO NPs and was found to be significant at the exposed concentrations. A significant increase in generation of hydrogen peroxide and superoxide radicals was observed in accordance with the lipid peroxidation profile in both MgO NPs and MPs treated plants when compared with control. In conclusion, this investigation revealed that MgO NPs exposure exhibited greater toxicity on A. cepa than MPs.
基金Supported by Modern Agricultural Industry Technology System (CARS-2004B)
文摘[Objective] This study aimed to establish an effective detection technology for rapidly identifying Bt transgenic sugarcane, promptly removing non-Bt transgenic plants and increasing breeding efficiency of Bt transgenic plants, thereby improving breeding efficiency of insect-resistant sugarcane cultivars in China. [ Method] Approximately 1 mg of root tips and other materials were crushed, placed in the bottom of PCR tubes, added successively with solution I and mineral oil, headed at 95 ℃ for 15 rain, added with solution Ⅱ, and finally added with solution III containing GBt primer for PCR. After separated by using electrophoresis on agarese gel, amplification products were observed and photographed under a gel imaging system. [ Result] Various materials treated with different concentrations of solution led to different amplification results. Specifically, the appropriate concentration of NaOH in solution I was 0.1 -0.2 mol/L; the appropriate pH value of solution II was 2. No bands were amplified from mature leaves, tender leaves and old roots of Bt transgenic sugarcane, while root tips successfully amplified 545 bp target bands. The established method was used to identify and analyze 63 hybrid seedlings of YT 91 -976 × SBR216, results showed that a total of 17 samples exhibited 545 bp bands, accounting for approximately 27% of the total number of hybrid seedlings, indicating that these 17 seedlings were Bt transgenic sugarcane plants. [ Conclusion] The rapid detection method established in this study is conducive to identifying Bt transgenic sugarcane and improving breeding efficiency of insect-resistant sugarcane lines, which provides basis for screening of other transgenic materials.
文摘Seeds of japonica rice cv.Zhenuo 2 with twodifferent physiological states(dry seeds withwater content 13% and wet seeds soaked in thewater for 36 h)were irradiated by COlaser infour different power-densities and durations re-spectively.The treatment irradiated with 200GY ofCo γ-rays was considered as control.The flesh root tips were cut and fixed inCarnoy’s fluid for cytological examination.
基金supported by the National Natural Science Foundation of China(32071749)。
文摘Root tips are the main components of absorptive fine roots,but their seasonal dynamics and relationship to environmental factors remain unclear due to the difficulties in methodology.In this study,we explored the temporal patterns of root-tip production and mortality in monoculture plantations of five temperate tree species at a common site in northeastern China,and identified the general environmental controls on such processes.We made monthly in-situ assessments of root tip length(RTL)production and mortality in two hardwood and three coniferous species with a minirhizotron(MR)method during the growing seasons of 2008 and 2009.Air temperature,rainfall,soil temperature and water content at 10 cm depth were determined concurrently.RTL production in all species exhibited consistent peaks in summer(June–August)in two growing seasons.RTL mortality showed substantial interannual and interspecific variability,with peaks in autumn and winter in 2008,but various patterns in 2009.RTL production positively correlated with monthly soil and air temperature across all species,and with monthly rainfall in three coniferous species.However,there was no significant correlation between RTL production and soil water content.By contrast,RTL mortality was weakly related to environmental factors,showing positive correlations with soil temperature in Korean spruce,and with rainfall in Korean pine and Korean spruce.Our findings suggest that the seasonal patterns of RTL production are convergent across the five temperate tree species due to the overlapped distribution of heat and rainfall,which can conduce roots to maximizing the acquisition of nutrient resources in the soil.
文摘目的比较生物陶瓷材料iRoot BP Plus和无机三氧化物聚合物(MTA)形成根尖屏障修复根尖未发育完全恒牙的效果。方法回顾2018年1月至2022年8月医院牙体牙髓专家门诊收治的80例(80颗患牙)根尖未发育完全恒牙患者,按材料差异应用差异分为两组,A组40例:根尖屏障修复术中应用iRoot BP Plus材料;B组40例:术中应用MTA材料;对比两组修复效果。结果A组、B组效果评价比较(P>0.05)。A组充填操作时间(8.51±1.38)min,短于B组的(15.48±2.09)min,差异有统计学意义(P<0.05)。A组治疗6个月O-PAI评分低于B组,并发症发生率2.50%低于B组的20.00%(P<0.05)。结论iRoot BP Plus和MTA形成根尖屏障修复根尖未发育完全恒牙均有相似效果,但iRoot BP Plus充填时间短,并发症少,值得应用。
