BACKGROUND Root canal retreatment is common after root canal therapy in clinical situations.Especially,completing the retreatment of variant root canals can be challenging.This is particularly true for the molars loca...BACKGROUND Root canal retreatment is common after root canal therapy in clinical situations.Especially,completing the retreatment of variant root canals can be challenging.This is particularly true for the molars located at the end of the dental arch.However,advancements in digital dental diagnosis and treatment techniques can solve these problems.Here,we describe a case of a maxillary second molar with a variant distobuccal root canal treated via a novel“inlay-guided endodontics”technique based on improved computer-generated programs.CASE SUMMARY A 63-year-old man complained of a defect in the maxillary left second molar.The tooth,diagnosed with post-treatment endodontic disease,was initially treated by conventional methods,which were ineffective.Our“inlay-guided endodontics”technique was subsequently adopted,with the establishment of a precise integrated three-dimensional(3D)plate model of cone-beam computed tomography data and a digital impression of the dentition.An optimal root canal approach was generated for the“virtual file”in the 3D model.The plate data were imported into a 3D printer and printed.With the help of the guide plate,the file was accurately placed into the cervical third of the distal root canal.The root canal and prosthodontic treatments successfully proceeded subsequently.CONCLUSION Our newly developed inlay guide plates may facilitate individualized and minimally invasive root canal treatment.展开更多
We present a case of a patient with rare anatomy of a maxillary second molar with three mesiobuccal root canals and a maxillary third molar with four separate roots, identified using multi-slice computed topography ...We present a case of a patient with rare anatomy of a maxillary second molar with three mesiobuccal root canals and a maxillary third molar with four separate roots, identified using multi-slice computed topography （CT） and three-dimensional reconstruction techniques. The described case enriched/might enrich our knowledge about possible anatomical aberrations of maxillary molars. In addition, we demonstrate the role of multi-slice CT as an objective tool for confirmatory diagnosis and successful endodontic management.展开更多
[Objectives]This study was conducted to improve the propagation efficiency of Gardenia jasminoides Ellis and improve the quality of plantlets.[Methods]A G.jasminoides cutting experiment was carried out with three diff...[Objectives]This study was conducted to improve the propagation efficiency of Gardenia jasminoides Ellis and improve the quality of plantlets.[Methods]A G.jasminoides cutting experiment was carried out with three different cuttage modes and two cutting treatment methods,and the rooting time,rooting rate,root amount and plantlet growth were measured and analyzed.[Results]The three-dimensional cutting model of CL1 could not only shorten the nursery cycle and promote root development,but also effectively improve the quality of plantlets and increase the yield of plantlets per unit area.It is an ideal way to improve the quality and efficiency of cutting plantlets.[Conclusions]This study has a positive role in promoting the healthy development of the nursery stock industry.展开更多
The static drill rooted nodular pile is a new type of pile foundation consisting of precast nodular pile and the surrounding cemented soil.This composite pile has a relatively high bearing capacity and the mud polluti...The static drill rooted nodular pile is a new type of pile foundation consisting of precast nodular pile and the surrounding cemented soil.This composite pile has a relatively high bearing capacity and the mud pollution will be largely reduced during the construction process by using this type of pile.In order to investigate the bearing capacity and load transfer mechanism of this pile,a group of experiments were conducted to provide a comparison between this new pile and the bored pile.The axial force of a precast nodular pile was also measured by the strain gauges installed on the pile to analyze the distribution of the axial force of the nodular pile and the skin friction supported by the surrounding soil,then 3D models were built by using the ABAQUS finite element program to investigate the load transfer mechanism of this composite pile in detail.By combining the results of field tests and the finite element method,the outcome showed that the bearing capacity of a static drill rooted nodular pile is higher than the bored pile,and that this composite pile will form a double stress dispersion system which will not only confirm the strength of the pile,but also make the skin friction to be fully mobilized.The settlement of this composite pile is mainly controlled by the precast nodular pile;meanwhile,the nodular pile and the surrounding cemented soil can be considered as deformation compatibility during the loading process.The nodes on the nodular pile play an important role during the load transfer process,the shear strength of the interface between the cemented soil and the soil of the static drill rooted pile is larger than that of the bored pile.展开更多
The root morphology of erect type peanut in deep soil was studied in this paper. In the experiment, erect type peanut showed as most as five-order lateral roots with 13 227 pieces of lateral roots. At the seedling sta...The root morphology of erect type peanut in deep soil was studied in this paper. In the experiment, erect type peanut showed as most as five-order lateral roots with 13 227 pieces of lateral roots. At the seedling stage, the root system of erect type peanut was handstand cone-typed with lateral roots at various orders distributed around the taproot, and among the roots, the taproot was longest. During the late seedling stage to mature stage, the upper part of the root system of erect type peanut was blunt cone-typed, the middle part was three-dimensional network typed, while the lower part was cyUnder-like. The longest first-order lateral root was the longest root. At the mature stage, the taproot was not always the deepest root.展开更多
Background Although three-dimensional MRI （3D-MRI） of short T1 inversion recovery turbo spin-echo （STIR TSE） has showed superior to two-dimensional MRI （2D-MRI） in showing the spinal cord and lumbar nerve roots,...Background Although three-dimensional MRI （3D-MRI） of short T1 inversion recovery turbo spin-echo （STIR TSE） has showed superior to two-dimensional MRI （2D-MRI） in showing the spinal cord and lumbar nerve roots, it remains difficult in demonstrating radicular vein at present. We have found that short T1 inversion recovery long time echo （STIR LONG TE） was better in showing radicular vein. To further study the methods and character of the 3D-MRI of lumbar nerve root, ganglions and radicular vein in normal and lumbar disc herniation （LDH） adults, in the present study, we evaluated two 3D-MRI techniques, STIR TSE and STIR LONG TE for demonstrating lumbar nerve roots and especial radicular vein in normal and LDH adults. Methods Twelve normal adult persons and 19 LDH patients were included in this study; special oblique coronal location was adopted. STIR TSE and STIR LONG TE were performed in all participants, and the detection rates of radicular vein and nerve root of L3, L4, L5,S1 were calculated. The grading system was used in grading compromise of the intraspinal extradural lumbar nerve root, ganglion and radicular vein in LDH patients, and all the grading injury of nerve root, ganglion and radicular vein had been evaluated. Results The definite rate of radicular vein （DRRV） of 3D-MRI of STIR LONG TE was significantly different from that of STIR TSE. DRRV of STIR LONG TE was L3, 91.7%, L4, 100%, L5, 100%, $1, 100% and that of STIR TSE was L3, 33.3%, L4, 37.5%, L5, 58.3%, $1,45.8% in normal adults. It showed no difference between STIR LONG TE and STIR TSE in the detection rate of nerve root. The different patho-injuries of nerve root, ganglion and radicular vein could be seen in all LDH patients by the 3D-MRI of STIR LONG TE. The mean score of Japanese Orthopaedic Association （JOA） was 16.16, and 29 nerve roots were calculated in all the study. The mean grading injury of nerve root was 2.17, that of nerve root ganglion was 1.28, that of radicular vein was 1.83, and the mean co-grading injury of nerve root, ganglion and radicular vein was 5.31. The correlation coefficient was 0.478 （P=0.010） between the score of JOA and that of radicular vein. Conclusion The 3D-MRI of STIR LONG TE is superior to STIR TSE for not only detecting the lumbar nerve root, ganglion and especial radicular vein in normal adults, but also displaying their patho-injuries degree in LDH patients.展开更多
The quantification and effects of system pH value on the interactions between Pb（II） and the biopolymer in activated sludge were investigated. The biopolymer had two protein-like fluorescence peaks （Ex/Em = 280 nm1...The quantification and effects of system pH value on the interactions between Pb（II） and the biopolymer in activated sludge were investigated. The biopolymer had two protein-like fluorescence peaks （Ex/Em = 280 nm1326-338 nm for peak A; Ex/Em = 220-230 nm/324-338 nm for peak B）. The fluorescence intensities of peak B were higher than those of peak A. The fluorophores of both peaks could be largely quenched by Pb（ll）, and the quencher dose for peak B was about half of that for peak A. The modified Stern-Volmer equation well depicted the fluorescence quenching titration. The quenching constant （Ka） values for both peaks decreased with rising system pH value, and then sharply decreased under alkaline conditions. It could be attributed to that the alkaline conditions caused the reduction of available Pb（II） due to the occurrence of Pb（OH）2 sediments. The Ka values of peak B were bigger than those for peak A at the same system pH values. Accordingly, the aromatic proteins （peak B） played a key role in the interactions between metal ions and the biopolymer.展开更多
Root systems are a black box obscuring a comprehensive understanding of plant function,from the ecosystem scale down to the individual. In particular,a lack of knowledge about the genetic mechanisms and environmental ...Root systems are a black box obscuring a comprehensive understanding of plant function,from the ecosystem scale down to the individual. In particular,a lack of knowledge about the genetic mechanisms and environmental effects that condition root system growth hinders our ability to develop the next generation of crop plants for improved agricultural productivity and sustainability. We discuss how the methods and metrics we use to quantify root systems can affect our ability to understand them,how we can bridge knowledge gaps and accelerate the derivation of structurefunction relationships for roots,and why a detailed mechanistic understanding of root growth and function will be important for future agricultural gains.展开更多
We propose a robust blind watermarking algorithm for three-dimensional(3D)mesh models based on vertex curvature to maintain good robustness and improve visual masking in 3D mesh models.In the embedding process,by usin...We propose a robust blind watermarking algorithm for three-dimensional(3D)mesh models based on vertex curvature to maintain good robustness and improve visual masking in 3D mesh models.In the embedding process,by using the local window of vertex,the root mean square curvature is calculated for every vertex of the 3D mesh model and an ordered set of fluctuation values is obtained.According to the ordered fluctuation values,the vertices are separated into bins.In each bin the fluctuation values are normalized.Finally,the mean of the root mean square curvature fluctuation values of the vertices in each bin is modulated to embed watermark information.In watermark detection,the algorithm uses a blind watermark extraction technique to extract the watermark information.The experimental results show that the algorithm has a very good performance for visual masking of the embedded model and that it can resist a variety of common attacks such as vertex rearrangement,rotation,translating,uniform scaling,noise,smoothing,quantization,and simplification.展开更多
Background:The three-dimensional(3D)visualization model has ability to quantify the surgical anatomy of farlateral approach.This study was designed to disclose the relationship between surgical space and exposed tissu...Background:The three-dimensional(3D)visualization model has ability to quantify the surgical anatomy of farlateral approach.This study was designed to disclose the relationship between surgical space and exposed tissues in the far-lateral approach by the volumetric analysis of 3D model.Methods:The 3D skull base models were constructed using MRI and CT data of 15 patients(30 sides)with trigeminal neuralgia.Surgical corridors of the far-lateral approach were simulated by triangular pyramids to represent two surgical spaces exposing bony and neurovascular tissues.Volumetric comparison of surgical anatomy was performed using pair t test.Results:The morphometric results were almost the same in the two surgical spaces except the vagus nerve(CN X)exposed only in one corridor,whereas the volumetric comparison represented the statistical significant differences of surgical space and bony and neurovascular tissues involved in the two corridors(P<0.001).The differences of bony and neurovascular tissues failed to equal the difference of surgical space.Conclusions:For far-lateral approach,the increase of exposure for the bony and neurovascular tissues is not necessarily matched with the increase of surgical space.The volumetric comparative analysis is helpful to provide more detailed anatomical information in the surgical design.展开更多
基金the Youth Development Project of Army Military Medical University,No.2018XQN014the Clinical Innovation Project of Army Military Medical University,No.2019XLC2014the Science and Technology Foundation of Chongqing,China,No.cstc2014jcyjA10092.
文摘BACKGROUND Root canal retreatment is common after root canal therapy in clinical situations.Especially,completing the retreatment of variant root canals can be challenging.This is particularly true for the molars located at the end of the dental arch.However,advancements in digital dental diagnosis and treatment techniques can solve these problems.Here,we describe a case of a maxillary second molar with a variant distobuccal root canal treated via a novel“inlay-guided endodontics”technique based on improved computer-generated programs.CASE SUMMARY A 63-year-old man complained of a defect in the maxillary left second molar.The tooth,diagnosed with post-treatment endodontic disease,was initially treated by conventional methods,which were ineffective.Our“inlay-guided endodontics”technique was subsequently adopted,with the establishment of a precise integrated three-dimensional(3D)plate model of cone-beam computed tomography data and a digital impression of the dentition.An optimal root canal approach was generated for the“virtual file”in the 3D model.The plate data were imported into a 3D printer and printed.With the help of the guide plate,the file was accurately placed into the cervical third of the distal root canal.The root canal and prosthodontic treatments successfully proceeded subsequently.CONCLUSION Our newly developed inlay guide plates may facilitate individualized and minimally invasive root canal treatment.
文摘We present a case of a patient with rare anatomy of a maxillary second molar with three mesiobuccal root canals and a maxillary third molar with four separate roots, identified using multi-slice computed topography （CT） and three-dimensional reconstruction techniques. The described case enriched/might enrich our knowledge about possible anatomical aberrations of maxillary molars. In addition, we demonstrate the role of multi-slice CT as an objective tool for confirmatory diagnosis and successful endodontic management.
基金Supported by Changsha Science and Technology Planning Project (kq1801028)Major Landmark Innovation Demonstration Project (2019XK2002)
文摘[Objectives]This study was conducted to improve the propagation efficiency of Gardenia jasminoides Ellis and improve the quality of plantlets.[Methods]A G.jasminoides cutting experiment was carried out with three different cuttage modes and two cutting treatment methods,and the rooting time,rooting rate,root amount and plantlet growth were measured and analyzed.[Results]The three-dimensional cutting model of CL1 could not only shorten the nursery cycle and promote root development,but also effectively improve the quality of plantlets and increase the yield of plantlets per unit area.It is an ideal way to improve the quality and efficiency of cutting plantlets.[Conclusions]This study has a positive role in promoting the healthy development of the nursery stock industry.
文摘The static drill rooted nodular pile is a new type of pile foundation consisting of precast nodular pile and the surrounding cemented soil.This composite pile has a relatively high bearing capacity and the mud pollution will be largely reduced during the construction process by using this type of pile.In order to investigate the bearing capacity and load transfer mechanism of this pile,a group of experiments were conducted to provide a comparison between this new pile and the bored pile.The axial force of a precast nodular pile was also measured by the strain gauges installed on the pile to analyze the distribution of the axial force of the nodular pile and the skin friction supported by the surrounding soil,then 3D models were built by using the ABAQUS finite element program to investigate the load transfer mechanism of this composite pile in detail.By combining the results of field tests and the finite element method,the outcome showed that the bearing capacity of a static drill rooted nodular pile is higher than the bored pile,and that this composite pile will form a double stress dispersion system which will not only confirm the strength of the pile,but also make the skin friction to be fully mobilized.The settlement of this composite pile is mainly controlled by the precast nodular pile;meanwhile,the nodular pile and the surrounding cemented soil can be considered as deformation compatibility during the loading process.The nodes on the nodular pile play an important role during the load transfer process,the shear strength of the interface between the cemented soil and the soil of the static drill rooted pile is larger than that of the bored pile.
文摘The root morphology of erect type peanut in deep soil was studied in this paper. In the experiment, erect type peanut showed as most as five-order lateral roots with 13 227 pieces of lateral roots. At the seedling stage, the root system of erect type peanut was handstand cone-typed with lateral roots at various orders distributed around the taproot, and among the roots, the taproot was longest. During the late seedling stage to mature stage, the upper part of the root system of erect type peanut was blunt cone-typed, the middle part was three-dimensional network typed, while the lower part was cyUnder-like. The longest first-order lateral root was the longest root. At the mature stage, the taproot was not always the deepest root.
文摘Background Although three-dimensional MRI （3D-MRI） of short T1 inversion recovery turbo spin-echo （STIR TSE） has showed superior to two-dimensional MRI （2D-MRI） in showing the spinal cord and lumbar nerve roots, it remains difficult in demonstrating radicular vein at present. We have found that short T1 inversion recovery long time echo （STIR LONG TE） was better in showing radicular vein. To further study the methods and character of the 3D-MRI of lumbar nerve root, ganglions and radicular vein in normal and lumbar disc herniation （LDH） adults, in the present study, we evaluated two 3D-MRI techniques, STIR TSE and STIR LONG TE for demonstrating lumbar nerve roots and especial radicular vein in normal and LDH adults. Methods Twelve normal adult persons and 19 LDH patients were included in this study; special oblique coronal location was adopted. STIR TSE and STIR LONG TE were performed in all participants, and the detection rates of radicular vein and nerve root of L3, L4, L5,S1 were calculated. The grading system was used in grading compromise of the intraspinal extradural lumbar nerve root, ganglion and radicular vein in LDH patients, and all the grading injury of nerve root, ganglion and radicular vein had been evaluated. Results The definite rate of radicular vein （DRRV） of 3D-MRI of STIR LONG TE was significantly different from that of STIR TSE. DRRV of STIR LONG TE was L3, 91.7%, L4, 100%, L5, 100%, $1, 100% and that of STIR TSE was L3, 33.3%, L4, 37.5%, L5, 58.3%, $1,45.8% in normal adults. It showed no difference between STIR LONG TE and STIR TSE in the detection rate of nerve root. The different patho-injuries of nerve root, ganglion and radicular vein could be seen in all LDH patients by the 3D-MRI of STIR LONG TE. The mean score of Japanese Orthopaedic Association （JOA） was 16.16, and 29 nerve roots were calculated in all the study. The mean grading injury of nerve root was 2.17, that of nerve root ganglion was 1.28, that of radicular vein was 1.83, and the mean co-grading injury of nerve root, ganglion and radicular vein was 5.31. The correlation coefficient was 0.478 （P=0.010） between the score of JOA and that of radicular vein. Conclusion The 3D-MRI of STIR LONG TE is superior to STIR TSE for not only detecting the lumbar nerve root, ganglion and especial radicular vein in normal adults, but also displaying their patho-injuries degree in LDH patients.
基金Acknowledgements This work was supported by the Foundation of State Key Laboratory of Pollution Control and Resource Reuse （Tongji University）, China （No. PCRRE16019）, the National Natural Science Foundation of China （Grant Nos. 51678422 and 51378368）, Sheng Yun- Fei College Students Scientific and Technological Innovation Fund, China Scholarship Council （No. 201506260022）, the National Science ＆ Technology Pillar Program （No. 2013BAD21B03）, and the higher school innovative engineering plan （111 Projec0.
文摘The quantification and effects of system pH value on the interactions between Pb（II） and the biopolymer in activated sludge were investigated. The biopolymer had two protein-like fluorescence peaks （Ex/Em = 280 nm1326-338 nm for peak A; Ex/Em = 220-230 nm/324-338 nm for peak B）. The fluorescence intensities of peak B were higher than those of peak A. The fluorophores of both peaks could be largely quenched by Pb（ll）, and the quencher dose for peak B was about half of that for peak A. The modified Stern-Volmer equation well depicted the fluorescence quenching titration. The quenching constant （Ka） values for both peaks decreased with rising system pH value, and then sharply decreased under alkaline conditions. It could be attributed to that the alkaline conditions caused the reduction of available Pb（II） due to the occurrence of Pb（OH）2 sediments. The Ka values of peak B were bigger than those for peak A at the same system pH values. Accordingly, the aromatic proteins （peak B） played a key role in the interactions between metal ions and the biopolymer.
基金supported by the Donald Danforth Plant Science Centerthe National Science Foundation under Award Number IIA-1355406
文摘Root systems are a black box obscuring a comprehensive understanding of plant function,from the ecosystem scale down to the individual. In particular,a lack of knowledge about the genetic mechanisms and environmental effects that condition root system growth hinders our ability to develop the next generation of crop plants for improved agricultural productivity and sustainability. We discuss how the methods and metrics we use to quantify root systems can affect our ability to understand them,how we can bridge knowledge gaps and accelerate the derivation of structurefunction relationships for roots,and why a detailed mechanistic understanding of root growth and function will be important for future agricultural gains.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20113227110021)
文摘We propose a robust blind watermarking algorithm for three-dimensional(3D)mesh models based on vertex curvature to maintain good robustness and improve visual masking in 3D mesh models.In the embedding process,by using the local window of vertex,the root mean square curvature is calculated for every vertex of the 3D mesh model and an ordered set of fluctuation values is obtained.According to the ordered fluctuation values,the vertices are separated into bins.In each bin the fluctuation values are normalized.Finally,the mean of the root mean square curvature fluctuation values of the vertices in each bin is modulated to embed watermark information.In watermark detection,the algorithm uses a blind watermark extraction technique to extract the watermark information.The experimental results show that the algorithm has a very good performance for visual masking of the embedded model and that it can resist a variety of common attacks such as vertex rearrangement,rotation,translating,uniform scaling,noise,smoothing,quantization,and simplification.
基金Capital health development research special fund(2014-4-5073)Educational science and technology projects for young and middle-aged teachers of Fujian Provincial Department of Education(JAY190824)
文摘Background:The three-dimensional(3D)visualization model has ability to quantify the surgical anatomy of farlateral approach.This study was designed to disclose the relationship between surgical space and exposed tissues in the far-lateral approach by the volumetric analysis of 3D model.Methods:The 3D skull base models were constructed using MRI and CT data of 15 patients(30 sides)with trigeminal neuralgia.Surgical corridors of the far-lateral approach were simulated by triangular pyramids to represent two surgical spaces exposing bony and neurovascular tissues.Volumetric comparison of surgical anatomy was performed using pair t test.Results:The morphometric results were almost the same in the two surgical spaces except the vagus nerve(CN X)exposed only in one corridor,whereas the volumetric comparison represented the statistical significant differences of surgical space and bony and neurovascular tissues involved in the two corridors(P<0.001).The differences of bony and neurovascular tissues failed to equal the difference of surgical space.Conclusions:For far-lateral approach,the increase of exposure for the bony and neurovascular tissues is not necessarily matched with the increase of surgical space.The volumetric comparative analysis is helpful to provide more detailed anatomical information in the surgical design.
