AIM To determine the usefulness of assigning narrow-band imaging(NBI) scores for predicting tumor grade and invasion depth in colorectal tumors.METHODS A total of 161 colorectal lesions were analyzed from138 patients ...AIM To determine the usefulness of assigning narrow-band imaging(NBI) scores for predicting tumor grade and invasion depth in colorectal tumors.METHODS A total of 161 colorectal lesions were analyzed from138 patients who underwent endoscopic or surgical resection after conventional colonoscopy and magnifying endoscopy with NBI. The relationships between the surface and vascular patterns of the lesions, as visualized with NBI, and the tumor grade and depth of submucosa(SM) invasion were determined histopathologically.Scores were assigned to distinct features of the surface microstructures of tubular and papillary-type lesions.Using a multivariate analysis, a model was developed for predicting the tumor grade and depth of invasion based on NBI-finding scores.RESULTS NBI findings that correlated with a high tumor grade were associated with the "regular/irregular"(P < 0.0001)surface patterns and the "avascular area" pattern(P =0.0600). The vascular patterns of "disrupted vessels"(P = 0.0714) and "thick vessels"(P = 0.0133) but none of the surface patterns were associated with a depth of invasion of ≥ 1000 μm. In our model, a total NBIfinding score ≥ 1 was indicative of a high tumor grade(sensitivity: 0.97; specificity: 0.24), and a total NBIfinding score ≥ 9(sensitivity: 0.56; specificity: 1.0) was predictive of a SM invasion depth ≥ 1000 μm. Scores less than these cutoff values signified adenomas and a SM invasion depth < 1000 μm, respectively. Associations were also noted between selected NBI findings and tumor tissue architecture and histopathology.CONCLUSION Our multivariate statistical model for predicting tumor grades and invasion depths from NBI-finding scores may help standardize the diagnosis of colorectal lesions and inform therapeutic strategies.展开更多
The Maximum Effective Moment(MEM)criterion predicts that the initial orientation of ductile shear zones and shear bands is^55°relative to the maximum principal stress axis(σ1)and that the kinematic vorticity num...The Maximum Effective Moment(MEM)criterion predicts that the initial orientation of ductile shear zones and shear bands is^55°relative to the maximum principal stress axis(σ1)and that the kinematic vorticity number(Wk)is^0.94.These preferred orientations should be reflected in the pattern of quartz<c>-fabrics in shear zones and shear bands.Common quartz<c>-fabrics in plane strain can be divided into low-temperature(L)and high-temperature(H)fabrics,with each group showing three patterns.A steady flow with a constant value of Wk≈0.94 gives rise to L-1 and H-1 patterns,which are commonly characterized by a single<c>axis girdle normal to the shear zone and a single<c>-point maximum parallel to the shear zone.Once the conjugate set develops,L-1 and H-1 have opening angles of^70°and^110°,respectively.L-2 and H-2 are asymmetric patterns associated with variable deformation partitioning and vorticity values of0<Wk<0.94.In contrast,L-3 and H-3 are symmetric patterns associated with 100%deformation partitioning and Wk=0.The opening angle in quartz<c>-fabrics is implicitly linked to the temperature during deformation.The opening angle is^70°at low temperature and^110°at high temperature.However,a linear correction between the opening angle and the temperature cannot be established.During deformation partitioning,synthetic shear bands form earlier than antithetic bands and are more easily developed.This may result in opening angles of<70°for low-temperature fabrics and of>110°for high-temperature fabrics.The following criteria can be used to recognize reworked shear zones that have experienced multiple orogenic phases and changes in the stress state:1)the initial Wk is larger or smaller than^0.94;2)the change in Wk is abrupt,rather than progressive;3)inconsistent shear senses are inferred for the different phases of deformation;and4)a negative value of Wk is found in reworked shear zones.展开更多
Narrow band imaging(NBI) endoscopy is an optical image enhancing technology that allows a detailed inspection of vascular and mucosal patterns, providing the ability to predict histology during real-time endoscopy. By...Narrow band imaging(NBI) endoscopy is an optical image enhancing technology that allows a detailed inspection of vascular and mucosal patterns, providing the ability to predict histology during real-time endoscopy. By combining NBI with magnification endoscopy(NBI-ME), the accurate assessment of lesions in the gastrointestinal tract can be achieved, as well as the early detection of neoplasia by emphasizing neovascularization. Promising results of the method in the diagnosis of premalignant and malignant lesions of gastrointestinal tract have been reported in clinical studies. The usefulness of NBI-ME as an adjunct to endoscopic therapy in clinical practice, the potential to improve diagnostic accuracy, surveillance strategies and cost-saving strategies based on this method are summarized in this review. Various classification systems of mucosal and vascular patterns used to differentiate preneoplastic and neoplastic lesions have been reviewed. We concluded that the clinical applicability of NBI-ME has increased, but standardization of endoscopic criteria and classification systems, validation in randomized multicenter trials and training programs to improve the diagnostic performance are all needed before the widespread acceptance of the method in routine practice. However, published data regarding the usefulness of NBI endoscopy are relevant in order to recommend the method as a reliable tool in diagnostic and therapy, even for less experienced endoscopists.展开更多
This paper presents the design and the experimental characterization of a new multi-band antenna consisting of three folded monopoles dedicated to mobile communication systems. The originality of this paper is to get ...This paper presents the design and the experimental characterization of a new multi-band antenna consisting of three folded monopoles dedicated to mobile communication systems. The originality of this paper is to get the PMR (Professional or Private Mobile Radio) band with the GSM (Global System for Mobile Communications), DCS (Digital Cellular System) and UMTS (Universal Mobile Telecommunications System) bands. The main lobe of the antenna radiates in the zenith direction with a linear polarization over all bands. It is interesting to design the proposed antenna in order to obtain better performances in terms of directive radiation pattern (especially in the PMR band) in comparison with the already existing antenna systems in the wireless market for similar purposes. The prototype was studied with the software CST-MWS (Micro wave studio 2012). The antenna has been designed and successfully measured.展开更多
文摘AIM To determine the usefulness of assigning narrow-band imaging(NBI) scores for predicting tumor grade and invasion depth in colorectal tumors.METHODS A total of 161 colorectal lesions were analyzed from138 patients who underwent endoscopic or surgical resection after conventional colonoscopy and magnifying endoscopy with NBI. The relationships between the surface and vascular patterns of the lesions, as visualized with NBI, and the tumor grade and depth of submucosa(SM) invasion were determined histopathologically.Scores were assigned to distinct features of the surface microstructures of tubular and papillary-type lesions.Using a multivariate analysis, a model was developed for predicting the tumor grade and depth of invasion based on NBI-finding scores.RESULTS NBI findings that correlated with a high tumor grade were associated with the "regular/irregular"(P < 0.0001)surface patterns and the "avascular area" pattern(P =0.0600). The vascular patterns of "disrupted vessels"(P = 0.0714) and "thick vessels"(P = 0.0133) but none of the surface patterns were associated with a depth of invasion of ≥ 1000 μm. In our model, a total NBIfinding score ≥ 1 was indicative of a high tumor grade(sensitivity: 0.97; specificity: 0.24), and a total NBIfinding score ≥ 9(sensitivity: 0.56; specificity: 1.0) was predictive of a SM invasion depth ≥ 1000 μm. Scores less than these cutoff values signified adenomas and a SM invasion depth < 1000 μm, respectively. Associations were also noted between selected NBI findings and tumor tissue architecture and histopathology.CONCLUSION Our multivariate statistical model for predicting tumor grades and invasion depths from NBI-finding scores may help standardize the diagnosis of colorectal lesions and inform therapeutic strategies.
基金funded by the National Natural Science Foundation of China(Grant No.41772207)
文摘The Maximum Effective Moment(MEM)criterion predicts that the initial orientation of ductile shear zones and shear bands is^55°relative to the maximum principal stress axis(σ1)and that the kinematic vorticity number(Wk)is^0.94.These preferred orientations should be reflected in the pattern of quartz<c>-fabrics in shear zones and shear bands.Common quartz<c>-fabrics in plane strain can be divided into low-temperature(L)and high-temperature(H)fabrics,with each group showing three patterns.A steady flow with a constant value of Wk≈0.94 gives rise to L-1 and H-1 patterns,which are commonly characterized by a single<c>axis girdle normal to the shear zone and a single<c>-point maximum parallel to the shear zone.Once the conjugate set develops,L-1 and H-1 have opening angles of^70°and^110°,respectively.L-2 and H-2 are asymmetric patterns associated with variable deformation partitioning and vorticity values of0<Wk<0.94.In contrast,L-3 and H-3 are symmetric patterns associated with 100%deformation partitioning and Wk=0.The opening angle in quartz<c>-fabrics is implicitly linked to the temperature during deformation.The opening angle is^70°at low temperature and^110°at high temperature.However,a linear correction between the opening angle and the temperature cannot be established.During deformation partitioning,synthetic shear bands form earlier than antithetic bands and are more easily developed.This may result in opening angles of<70°for low-temperature fabrics and of>110°for high-temperature fabrics.The following criteria can be used to recognize reworked shear zones that have experienced multiple orogenic phases and changes in the stress state:1)the initial Wk is larger or smaller than^0.94;2)the change in Wk is abrupt,rather than progressive;3)inconsistent shear senses are inferred for the different phases of deformation;and4)a negative value of Wk is found in reworked shear zones.
文摘Narrow band imaging(NBI) endoscopy is an optical image enhancing technology that allows a detailed inspection of vascular and mucosal patterns, providing the ability to predict histology during real-time endoscopy. By combining NBI with magnification endoscopy(NBI-ME), the accurate assessment of lesions in the gastrointestinal tract can be achieved, as well as the early detection of neoplasia by emphasizing neovascularization. Promising results of the method in the diagnosis of premalignant and malignant lesions of gastrointestinal tract have been reported in clinical studies. The usefulness of NBI-ME as an adjunct to endoscopic therapy in clinical practice, the potential to improve diagnostic accuracy, surveillance strategies and cost-saving strategies based on this method are summarized in this review. Various classification systems of mucosal and vascular patterns used to differentiate preneoplastic and neoplastic lesions have been reviewed. We concluded that the clinical applicability of NBI-ME has increased, but standardization of endoscopic criteria and classification systems, validation in randomized multicenter trials and training programs to improve the diagnostic performance are all needed before the widespread acceptance of the method in routine practice. However, published data regarding the usefulness of NBI endoscopy are relevant in order to recommend the method as a reliable tool in diagnostic and therapy, even for less experienced endoscopists.
文摘This paper presents the design and the experimental characterization of a new multi-band antenna consisting of three folded monopoles dedicated to mobile communication systems. The originality of this paper is to get the PMR (Professional or Private Mobile Radio) band with the GSM (Global System for Mobile Communications), DCS (Digital Cellular System) and UMTS (Universal Mobile Telecommunications System) bands. The main lobe of the antenna radiates in the zenith direction with a linear polarization over all bands. It is interesting to design the proposed antenna in order to obtain better performances in terms of directive radiation pattern (especially in the PMR band) in comparison with the already existing antenna systems in the wireless market for similar purposes. The prototype was studied with the software CST-MWS (Micro wave studio 2012). The antenna has been designed and successfully measured.
文摘采用外周血淋巴细胞培养及G带染色体标本制作技术,研究和分析华南虎(Panthera tigris amoyensis)染色体的核型和带型。结果表明:华南虎二倍体染色体数为2n=38条,其中常染色体18对,性染色体1对。常染色体按相对长度从长到短依次编号为1~18。根据着丝粒指数可将华南虎染色体分为4组,即A组(m),包括2、5、13、18和X;B组(Sm),包括1、4、7、8、9、10、11、12、14、17和Y;C组(St),包括3、6;D组(t),包括15、16。核型公式为8(m)+20(Sm)+4(St)+4(t),XY(m,Sm)/XX(m,m)。本研究成功制备了华南虎染色体核型标本,初步建立了华南虎染色体G带核型模式图谱。经比对,发现华南虎与东北虎(P. t. altaica)染色体核型存在明显差异,可为虎亚种的分类研究提供依据,同时能为华南虎种群基因多样性及遗传学研究提供新的参考和开辟新的途径。
