An appropriate optimal number of market segments(ONS)estimation is essential for an enterprise to achieve successful market segmentation,but at present,there is a serious lack of attention to this issue in market segm...An appropriate optimal number of market segments(ONS)estimation is essential for an enterprise to achieve successful market segmentation,but at present,there is a serious lack of attention to this issue in market segmentation.In our study,an independent adaptive ONS estimation method BWCON-NSDK-means++is proposed by integrating a newinternal validity index(IVI)Between-Within-Connectivity(BWCON)and a newstable clustering algorithmNatural-SDK-means++(NSDK-means++)in a novel way.First,to complete the evaluation dimensions of the existing IVIs,we designed a connectivity formula based on the neighbor relationship and proposed the BWCON by integrating the connectivity with other two commonly considered measures of compactness and separation.Then,considering the stability,number of parameters and clustering performance,we proposed the NSDK-means++to participate in the integrationwhere the natural neighbor was used to optimize the initial cluster centers(ICCs)determination strategy in the SDK-means++.At last,to ensure the objectivity of the estimatedONS,we designed a BWCON-based ONS estimation framework that does not require the user to set any parameters in advance and integrated the NSDK-means++into this framework forming a practical ONS estimation tool BWCON-NSDK-means++.The final experimental results showthat the proposed BWCONand NSDK-means++are significantlymore suitable than their respective existing models to participate in the integration for determining theONS,and the proposed BWCON-NSDK-means++is demonstrably superior to the BWCON-KMA,BWCONMBK,BWCON-KM++,BWCON-RKM++,BWCON-SDKM++,BWCON-Single linkage,BWCON-Complete linkage,BWCON-Average linkage and BWCON-Ward linkage in terms of the ONS estimation.Moreover,as an independentmarket segmentation tool,the BWCON-NSDK-means++also outperforms the existing models with respect to the inter-market differentiation and sub-market size.展开更多
BACKGROUND It remains unclear whether laparoscopic multisegmental resection and ana-stomosis(LMRA)is safe and advantageous over traditional open multisegmental resection and anastomosis(OMRA)for treating synchronous c...BACKGROUND It remains unclear whether laparoscopic multisegmental resection and ana-stomosis(LMRA)is safe and advantageous over traditional open multisegmental resection and anastomosis(OMRA)for treating synchronous colorectal cancer(SCRC)located in separate segments.AIM To compare the short-term efficacy and long-term prognosis of OMRA as well as LMRA for SCRC located in separate segments.METHODS Patients with SCRC who underwent surgery between January 2010 and December 2021 at the Cancer Hospital,Chinese Academy of Medical Sciences and the Peking University First Hospital were retrospectively recruited.In accordance with the RESULTS LMRA patients showed markedly less intraoperative blood loss than OMRA patients(100 vs 200 mL,P=0.006).Compared to OMRA patients,LMRA patients exhibited markedly shorter postoperative first exhaust time(2 vs 3 d,P=0.001),postoperative first fluid intake time(3 vs 4 d,P=0.012),and postoperative hospital stay(9 vs 12 d,P=0.002).The incidence of total postoperative complications(Clavien-Dindo grade:≥II)was 2.9%and 17.1%(P=0.025)in the LMRA and OMRA groups,respectively,while the incidence of anastomotic leakage was 2.9%and 7.3%(P=0.558)in the LMRA and OMRA groups,respectively.Furthermore,the LMRA group had a higher mean number of lymph nodes dissected than the OMRA group(45.2 vs 37.3,P=0.020).The 5-year overall survival(OS)and disease-free survival(DFS)rates in OMRA patients were 82.9%and 78.3%,respectively,while these rates in LMRA patients were 78.2%and 72.8%,respectively.Multivariate prognostic analysis revealed that N stage[OS:HR hazard ratio(HR)=10.161,P=0.026;DFS:HR=13.017,P=0.013],but not the surgical method(LMRA/OMRA)(OS:HR=0.834,P=0.749;DFS:HR=0.812,P=0.712),was the independent influencing factor in the OS and DFS of patients with SCRC.CONCLUSION LMRA is safe and feasible for patients with SCRC located in separate segments.Compared to OMRA,the LMRA approach has more advantages related to short-term efficacy.展开更多
Trabecular bone disconnection “hotspots” of real termini (ReTm) previously mapped as loci of weakness in the female aging spine and hip may be a source of free-floating cancellous segments found in the medullary spa...Trabecular bone disconnection “hotspots” of real termini (ReTm) previously mapped as loci of weakness in the female aging spine and hip may be a source of free-floating cancellous segments found in the medullary space using a bespoke, thick slice histological method for identifying ReTm. A factor in their origin is apparently microdamage proliferation (differentiated by en bloc silver staining) with occasional callus moderation. Validation of similar “floating segments” (FS) in the ex-breeder rat suggested a pilot model for a potentially common phenomenon. Following marrow elution and density fractionation of the isolated floating segments from the whole proximal rat femora, scanning electron microscopy (SEM) and elemental microanalysis (EDS) was performed. The eluent contained numbers of vertically truncated, laterally branched floating segments (acute severance of sequential tensile cross-struts, causing chronic compression overload of axial-struts, with ii) inadequate stabilising callus, facilitating ReTm stacking into predetermined, substructural “crumple zones” of force containment, spheroidal attrition and particulate dissociation. As a catabolic outcome of altered tensile and hormonal influence, FS number may add a novel variable to cancellous bone kinetics particularly in women of relevance to fracture predisposition.展开更多
Locked segments are recognized as a critical role that controls the stability of rock slopes but remain an unclear and challenging problem with respect to their role incorporated into the failure mechanism.In order to...Locked segments are recognized as a critical role that controls the stability of rock slopes but remain an unclear and challenging problem with respect to their role incorporated into the failure mechanism.In order to study the effect of the locked segments on the initial failure process of rockslides,thirty-six groups of locked segment specimens with three different lithologies were prepared,direct shear tests were carried out to obtain the accelerations caused by brittle failure of the locked segment specimens.Experiment results showed that the maximum accelerations caused by the brittle failure of locked segment specimens was 2.91 g in the horizontal direction,and 3.18 g in the vertical direction.We took the Wangjiayan rockslide in 2008 Wenchuan earthquake as an example,the critical balance condition of the sliding mass under combined effect of gravity and accelerations induced by brittle failure of locked segment was analyzed,which indicated that the initial failure process of the Wangjiayan rockslides was notably influenced by the existence of the locked segment.The departure acceleration and direction of the Wangjiayan rockslide were proposed.The study results can provide a new insight into the understanding of the initial failure mechanism of rockslides with locked segments.展开更多
To explore the stress and deformation responses,as well as the failure characteristics of the shield tunnel segment of Hangzhou Metro under the influences of pit excavation and other surrounding projects,a self-develo...To explore the stress and deformation responses,as well as the failure characteristics of the shield tunnel segment of Hangzhou Metro under the influences of pit excavation and other surrounding projects,a self-developed“shield tunnel segment hydraulic loading system”was used to carry out full-scale loading tests on the three-ring staggered assembled segments.The structural performances and failure process of the tunnel segment under step-by-step asymmetric unloading were studied.A safety index was proposed to describe the bearing capacity of the segment.Next,a finite element model(FEM)was established to analyze the bearing capacity of segment using the test results.Finally,the effect of reinforcement with a steel plate on the deformation and bearing capacity of the segment was analyzed.The results showed that under asymmetric unloading,the peak value and amplitude of the bending moment on the near unloading side converged with a greater value than those on the far side.The concrete internal force exhibited a directional transformation at different load stages.Cracks first appeared at the 180inner arc surface of the bottom standard block and then expanded to both sides,while the rate of crack propagation of the outer arc surface was relatively lower.The bearing capacity of the segments can be evaluated by the combination of the factors,e.g.the residual bearing capacity coefficient,moment transfer coefficient,and characterization coefficient.The segments approaching failure can facilitate the increase in the residual bearing capacity coefficient by more than 50%.This can provide guidance for the service assessment of metro tunnel operations.展开更多
Spatial linear features are often represented as a series of line segments joined by measured endpoints in surveying and geographic information science.There are not only the measuring errors of the endpoints but also...Spatial linear features are often represented as a series of line segments joined by measured endpoints in surveying and geographic information science.There are not only the measuring errors of the endpoints but also the modeling errors between the line segments and the actual geographical features.This paper presents a Brownian bridge error model for line segments combining both the modeling and measuring errors.First,the Brownian bridge is used to establish the position distribution of the actual geographic feature represented by the line segment.Second,an error propagation model with the constraints of the measuring error distribution of the endpoints is proposed.Third,a comprehensive error band of the line segment is constructed,wherein both the modeling and measuring errors are contained.The proposed error model can be used to evaluate line segments’overall accuracy and trustability influenced by modeling and measuring errors,and provides a comprehensive quality indicator for the geospatial data.展开更多
Tmnsmembrane（TM） protein plays an important role in the life activity of the cells, and the prediction of transmembrane helical segments （TMHs） is an important subject in the bioinformatics research. Thus far, sev...Tmnsmembrane（TM） protein plays an important role in the life activity of the cells, and the prediction of transmembrane helical segments （TMHs） is an important subject in the bioinformatics research. Thus far, several prediction methods have been reported, but there are some deficiencies in prediction accuracy and adaptability in these methods. In this paper, a method based on discrete wavelet transform （DWT） was developed to predict the TMHs. Two sets of test data sets containing total 60 protein sequences were utilized to access the effect of the method. Compared with the prediction results of TMHMM2.0 and MEMSAT, the obtained results indicate that the presented method has high prediction accuracy.展开更多
Two series of polyurethanes based on mixed polychloromethyl methyl siloxane and poly-tetramethylene oxide in different weight fractions were synthesized. The phase separation ofsamples was studied using DSC and dynami...Two series of polyurethanes based on mixed polychloromethyl methyl siloxane and poly-tetramethylene oxide in different weight fractions were synthesized. The phase separation ofsamples was studied using DSC and dynamic mechanical property analysis. The results showedthat the introduction of chloromethyl group into polysiloxane increased its polarity and henceimproved the miscibilities with polytetramethylene oxide and polyurethane hard segment.Particularly, in the case of N-methyldiethanolamine extended materials, the surface and tensileproperties of these samples can be adjusted by various ratios of two soft segments.展开更多
AIM: To investigate the efficacy of Ferrara rings (FR) implantation in the treatment of keratoconus.METHODS: It was a retrospective case series descriptive study. The sample was comprised of 50 patients 79 eyes diagno...AIM: To investigate the efficacy of Ferrara rings (FR) implantation in the treatment of keratoconus.METHODS: It was a retrospective case series descriptive study. The sample was comprised of 50 patients 79 eyes diagnosed with progressive keratoconus. This included 24 (48%) males and 26 (52%) females between the age of 13 and 44 years. All participants underwent surgical implantation of FR in the period between January 2009 and September 2010 at Jordan University Hospital. Thorough ophthalmologic examinations were applied to measure vital variables for each pathological condition before and after surgery. RESULTS: Findings indicated an overall significant postoperative improvement in both uncorrected visual acuity (UCVA) and best spectacle corrected visual acuity (BSCVA) throughout follow up visits. Moreover, results illustrated a significant decrease in spherical equivalent (SE) and keratometric readings (lower, higher and the average). CONCLUSION: Surgical intervention strategies are being frequently developed to meet the needs of patients with keratoconus. The implantation of Ferrara rings has proven to be a safe and feasible alternative procedure for the treatment of mild-moderate keratoconus especially for patients with contact lenses intolerance. We have found that this procedure has improved visual outcomes in all eyes studied. Nevertheless, further research is needed to investigate long term outcomes.展开更多
AIM:To evaluate the clinical outcomes after Ferrara intrastromal corneal ring segments(ICRS)reoperation in patients with keratoconus.METHODS:A total of 37 keratoconus eyes implanted with intrastromal corneal ring segm...AIM:To evaluate the clinical outcomes after Ferrara intrastromal corneal ring segments(ICRS)reoperation in patients with keratoconus.METHODS:A total of 37 keratoconus eyes implanted with intrastromal corneal ring segments,which had an ICRS exchange,addition,reposition or removal were evaluated.Uncorrected visual acuity(UCVA),best corrected visual acuity(BCVA),keratometry(K),asphericity(Q)and pachymetry at the thinnest point(PTP)of the cornea were evaluated using a corneal tomography(Oculus Pentacam,USA)RESULTS:The mean follow-up time after the reoperation was 30.5±9.7 months.The mean UCVA improved from 20/300 to 20/80(P=0.005);the mean BCVA improved from 20/160 to 20/50(P=0.0002),the mean keratometry reduced from 49.33±4.19D to 46.16±3.90D(P=0.0001),the mean pachymetry at the thinnest point increased from 450±42.9μm to 469±40.8μm(P=0.0001).The asphericity increased from-0.84±0.74 to-0.35±0.81(P=0.15)and the spherical equivalent reduced from-4.64±4.87D to-3.04±3.45D(P=0.137).The changes in the asphericity and spherical equivalent were not statistically significant.CONCLUSION:Ferrara ICRS implantation showed to be a reversible and readjustable surgical procedure for keratoconus treatment.Good outcomes can be obtained even after removal,addition,reposition or exchange of ICRS.展开更多
BACKGROUND Liver resection and radiofrequency ablation are considered curative options for hepatocellular carcinoma.The choice between these techniques is still controversial especially in cases of hepatocellular carc...BACKGROUND Liver resection and radiofrequency ablation are considered curative options for hepatocellular carcinoma.The choice between these techniques is still controversial especially in cases of hepatocellular carcinoma affecting posterosuperior segments in elderly patients.AIM To compare post-operative outcomes between liver resection and radiofrequency ablation in elderly with single hepatocellular carcinoma located in posterosuperior segments.METHODS A retrospective multicentric study was performed enrolling 77 patients age≥70-years-old with single hepatocellular carcinoma(≤30 mm),located in posterosuperior segments(4a,7,8).Patients were divided into liver resection and radiofrequency ablation groups and preoperative,peri-operative and long-term outcomes were retrospectively analyzed and compared using a 1:1 propensity score matching.RESULTS After propensity score matching,twenty-six patients were included in each group.Operative time and overall postoperative complications were higher in the resection group compared to the ablation group(165 min vs 20 min,P<0.01;54%vs 19%P=0.02 respectively).A median hospital stay was significantly longer in the resection group than in the ablation group(7.5 d vs 3 d,P<0.01).Ninety-day mortality was comparable between the two groups.There were no significant differences between resection and ablation group in terms of overall survival and disease free survival at 1,3,and 5 years.CONCLUSION Radiofrequency ablation in posterosuperior segments in elderly is safe and feasible and ensures a short hospital stay,better quality of life and does not modify the overall and disease-free survival.展开更多
Hydrangea bretschneideri Dipp is a highly popular ornamental plant for garden decoration.Genetic engineering technology has been successfully used in many plant species,but it is limited in Hydrangea.Here we establish...Hydrangea bretschneideri Dipp is a highly popular ornamental plant for garden decoration.Genetic engineering technology has been successfully used in many plant species,but it is limited in Hydrangea.Here we established an efficient regeneration system by using stem segments as explants for the first time.In our study,the plant growth regulators(PGRs)were evaluated at the different regeneration processes,including axillary shoots regeneration and root induction.We found that the optimal concentration for axillary buds’induction was 2.0 mgL^(-1)6-BA and 0.5 mgL^(-1)1 IAA,its highest induction rate was 70%.Moreover,the highest axillary shoots proliferation coefficient was 10.7 on the Murashige and Skoog(MS)medium with 2.0 mgL^(-1)6-benzyladenine(BA),0.2 mgL^(-1)indole-3-butyric acid(IBA),and 1.0 mgL^(-1)gibberellin A3(GA3).The highest frequency of root induction was 80.0±0.06%by culturing the elongated shoots in 1/2 MS medium containing 0.1 mgL^(-1)IBA.In summary,our study will provide an effective technology for large-scale propagation and important pathway for promoting the popularization and application of Hydrangea bretschneideri Dipp.展开更多
[Objective] The aim was to study the conditions of tissue culture regeneration seedling by using the stem segments of Euphorbia tirucalli and determine the optimum culture condition of each culture stage,so as to prov...[Objective] The aim was to study the conditions of tissue culture regeneration seedling by using the stem segments of Euphorbia tirucalli and determine the optimum culture condition of each culture stage,so as to provide references for the factory production and relative study of tissue culture seedling of E. tirucalli. [Method] Taking the stem segments of E. tirucalli as explants,the effects of various mediums on germination rate,multiplication coefficient and rooting rate were studied. [Result] The optimum induction medium of germination culture was 1/2MS＋NAA 0.02 mg/L＋6-BA 1.0 mg/L,with differentiation rate of 89.7%; the best subculture medium was 1/2MS＋NAA 0.02 mg/L＋6-BA 0.60 mg/L＋AD 3.0 mg/L,with multiplication coefficient of 5.70; the optimum rooting culture medium was 1/2MS＋NAA 0.40 mg/L＋IBA 0.4 mg/L,with rooting rate of 100% and transplanting survival rate of 80%. [Conclusion] The tissue culture conditions of stem segments of E. tirucalli were determined primarily.展开更多
By computing and classifying the data of gully offset obtained from field surveys along the Tianjingshan fault zone and estimating the ages of three types of gullies,the strike-slip rates along the fault zone are disc...By computing and classifying the data of gully offset obtained from field surveys along the Tianjingshan fault zone and estimating the ages of three types of gullies,the strike-slip rates along the fault zone are discussed in different time intervals and fault segments.The results suggest that the intensity of activity along the fault zone is not strong,but the differences between different time intervals and fault segments since the late Pleistocene have been obvious.The average rates range from 0.23 mm/a to 1.62 mm/a.The largest average rate is 1.40 mm/a,which occurred in the early and middle of late Pleistocene along the western segment of the fault zone.Since the late stage of the late Pleistocene,the center of faulting activity of the fault zone has shifted to the middle segment,and the average slip rates range have changed from 1.30 mm/a to 1.63 mm/a.展开更多
We investigate global temperature data produced by the Climate Research Unit at the University of East Anglia (CRU) and the Berkeley Earth Surface Temperature consortium (BEST). We first fit the 1850-2010 data with po...We investigate global temperature data produced by the Climate Research Unit at the University of East Anglia (CRU) and the Berkeley Earth Surface Temperature consortium (BEST). We first fit the 1850-2010 data with polynomials of degrees 1 to 9. A significant ~60-yr oscillation is accounted for as soon as degree 4 is reached. This oscillation is even better modeled as a broken line, more precisely a series of ~30-yr long linear segments, with slope breaks (singularities) in ~1904, ~1940, and ~1974 (±3 yr), and a possible recent occurrence at the turn of the 20th century. Oceanic indices PDO (Pacific Decadal Oscillation) and AMO (Atlantic Multidecadal Oscillation) have undergone major changes (respectively of sign and slope) roughly at the same times as the temperature slope breaks. This can be interpreted with a system of oceanic non-linear coupled oscillators with abrupt mode shifts. Thus, the Earth’s climate may have entered a new mode (a new ~30-yr episode) near the turn of the 20th century: no further temperature increase, a dominantly negative PDO index and a decreasing AMO index might be expected for the next decade or two.展开更多
Based on the vector diffraction theory, the effect of complex phase filters on intensity distribution of a radially polarized multi Gaussian beam in the focal region of high NA lens is theoretically investigated. It i...Based on the vector diffraction theory, the effect of complex phase filters on intensity distribution of a radially polarized multi Gaussian beam in the focal region of high NA lens is theoretically investigated. It is observed that a properly designed multi belt complex phase filter can generate subwavelength novel focal patterns including splitting of focal spots and generation of multiple focal spot segments such as eight, six and four focal spots along the optical axis are obtained. We expect that such an investigation is useful for optical manipulation and material processing, multiple high refractive index particle trapping technologies.展开更多
Depending on the excitability of the medium, a propagating wave segment will either contract or expand to fill the medium with spiral waves. This paper aims to introduce a simple mechanism of feedback control to stabi...Depending on the excitability of the medium, a propagating wave segment will either contract or expand to fill the medium with spiral waves. This paper aims to introduce a simple mechanism of feedback control to stabilize such an expansion or contraction. To do this, we lay out a feedback control system in a block diagram and reduce it into a bare, universal formula. Analytical and experimental findings are compared through a series of numerical simulations of the Barkley model.展开更多
The liver has eight segments, which are referred to by numbers or by names. The numbering of the segments is done in a counterclockwise manner with the liver being viewed from the inferior surface, starting from Segme...The liver has eight segments, which are referred to by numbers or by names. The numbering of the segments is done in a counterclockwise manner with the liver being viewed from the inferior surface, starting from Segment Ⅰ(the caudate lobe). Standard anatomical description of the liver segments is available by computed tomographic scan and ultrasonography. Endoscopic ultrasound(EUS) has been used for a detailed imaging of many intra-abdominal organs and for the assessment of intra-abdominal vasculature. A stepwise evaluation of the liver segments by EUS has not been described. In this article, we have described a stepwise evaluation of the liver segments by EUS. This information can be useful for planning successful radical surgeries, preparing for biopsy, portal vein embolization, transjugular intrahepatic portosystemic shunt, tumour resection or partial hepatectomy, and for planning EUS guided diagnostic and therapeutic procedures.展开更多
基金supported by the earmarked fund for CARS-29 and the open funds of the Key Laboratory of Viticulture and Enology,Ministry of Agriculture,China.
文摘An appropriate optimal number of market segments(ONS)estimation is essential for an enterprise to achieve successful market segmentation,but at present,there is a serious lack of attention to this issue in market segmentation.In our study,an independent adaptive ONS estimation method BWCON-NSDK-means++is proposed by integrating a newinternal validity index(IVI)Between-Within-Connectivity(BWCON)and a newstable clustering algorithmNatural-SDK-means++(NSDK-means++)in a novel way.First,to complete the evaluation dimensions of the existing IVIs,we designed a connectivity formula based on the neighbor relationship and proposed the BWCON by integrating the connectivity with other two commonly considered measures of compactness and separation.Then,considering the stability,number of parameters and clustering performance,we proposed the NSDK-means++to participate in the integrationwhere the natural neighbor was used to optimize the initial cluster centers(ICCs)determination strategy in the SDK-means++.At last,to ensure the objectivity of the estimatedONS,we designed a BWCON-based ONS estimation framework that does not require the user to set any parameters in advance and integrated the NSDK-means++into this framework forming a practical ONS estimation tool BWCON-NSDK-means++.The final experimental results showthat the proposed BWCONand NSDK-means++are significantlymore suitable than their respective existing models to participate in the integration for determining theONS,and the proposed BWCON-NSDK-means++is demonstrably superior to the BWCON-KMA,BWCONMBK,BWCON-KM++,BWCON-RKM++,BWCON-SDKM++,BWCON-Single linkage,BWCON-Complete linkage,BWCON-Average linkage and BWCON-Ward linkage in terms of the ONS estimation.Moreover,as an independentmarket segmentation tool,the BWCON-NSDK-means++also outperforms the existing models with respect to the inter-market differentiation and sub-market size.
文摘BACKGROUND It remains unclear whether laparoscopic multisegmental resection and ana-stomosis(LMRA)is safe and advantageous over traditional open multisegmental resection and anastomosis(OMRA)for treating synchronous colorectal cancer(SCRC)located in separate segments.AIM To compare the short-term efficacy and long-term prognosis of OMRA as well as LMRA for SCRC located in separate segments.METHODS Patients with SCRC who underwent surgery between January 2010 and December 2021 at the Cancer Hospital,Chinese Academy of Medical Sciences and the Peking University First Hospital were retrospectively recruited.In accordance with the RESULTS LMRA patients showed markedly less intraoperative blood loss than OMRA patients(100 vs 200 mL,P=0.006).Compared to OMRA patients,LMRA patients exhibited markedly shorter postoperative first exhaust time(2 vs 3 d,P=0.001),postoperative first fluid intake time(3 vs 4 d,P=0.012),and postoperative hospital stay(9 vs 12 d,P=0.002).The incidence of total postoperative complications(Clavien-Dindo grade:≥II)was 2.9%and 17.1%(P=0.025)in the LMRA and OMRA groups,respectively,while the incidence of anastomotic leakage was 2.9%and 7.3%(P=0.558)in the LMRA and OMRA groups,respectively.Furthermore,the LMRA group had a higher mean number of lymph nodes dissected than the OMRA group(45.2 vs 37.3,P=0.020).The 5-year overall survival(OS)and disease-free survival(DFS)rates in OMRA patients were 82.9%and 78.3%,respectively,while these rates in LMRA patients were 78.2%and 72.8%,respectively.Multivariate prognostic analysis revealed that N stage[OS:HR hazard ratio(HR)=10.161,P=0.026;DFS:HR=13.017,P=0.013],but not the surgical method(LMRA/OMRA)(OS:HR=0.834,P=0.749;DFS:HR=0.812,P=0.712),was the independent influencing factor in the OS and DFS of patients with SCRC.CONCLUSION LMRA is safe and feasible for patients with SCRC located in separate segments.Compared to OMRA,the LMRA approach has more advantages related to short-term efficacy.
文摘Trabecular bone disconnection “hotspots” of real termini (ReTm) previously mapped as loci of weakness in the female aging spine and hip may be a source of free-floating cancellous segments found in the medullary space using a bespoke, thick slice histological method for identifying ReTm. A factor in their origin is apparently microdamage proliferation (differentiated by en bloc silver staining) with occasional callus moderation. Validation of similar “floating segments” (FS) in the ex-breeder rat suggested a pilot model for a potentially common phenomenon. Following marrow elution and density fractionation of the isolated floating segments from the whole proximal rat femora, scanning electron microscopy (SEM) and elemental microanalysis (EDS) was performed. The eluent contained numbers of vertically truncated, laterally branched floating segments (acute severance of sequential tensile cross-struts, causing chronic compression overload of axial-struts, with ii) inadequate stabilising callus, facilitating ReTm stacking into predetermined, substructural “crumple zones” of force containment, spheroidal attrition and particulate dissociation. As a catabolic outcome of altered tensile and hormonal influence, FS number may add a novel variable to cancellous bone kinetics particularly in women of relevance to fracture predisposition.
基金supported by the National Natural Science Foundation of China (Grant No. 41672295)
文摘Locked segments are recognized as a critical role that controls the stability of rock slopes but remain an unclear and challenging problem with respect to their role incorporated into the failure mechanism.In order to study the effect of the locked segments on the initial failure process of rockslides,thirty-six groups of locked segment specimens with three different lithologies were prepared,direct shear tests were carried out to obtain the accelerations caused by brittle failure of the locked segment specimens.Experiment results showed that the maximum accelerations caused by the brittle failure of locked segment specimens was 2.91 g in the horizontal direction,and 3.18 g in the vertical direction.We took the Wangjiayan rockslide in 2008 Wenchuan earthquake as an example,the critical balance condition of the sliding mass under combined effect of gravity and accelerations induced by brittle failure of locked segment was analyzed,which indicated that the initial failure process of the Wangjiayan rockslides was notably influenced by the existence of the locked segment.The departure acceleration and direction of the Wangjiayan rockslide were proposed.The study results can provide a new insight into the understanding of the initial failure mechanism of rockslides with locked segments.
基金supported by the Basic Public Welfare Research Projects in Zhejiang Province,China(Grant No.LGF22E080012)General Scientific Research Projects for Agriculture and Social Development in Hangzhou,China(Grant No.20201203B127).
文摘To explore the stress and deformation responses,as well as the failure characteristics of the shield tunnel segment of Hangzhou Metro under the influences of pit excavation and other surrounding projects,a self-developed“shield tunnel segment hydraulic loading system”was used to carry out full-scale loading tests on the three-ring staggered assembled segments.The structural performances and failure process of the tunnel segment under step-by-step asymmetric unloading were studied.A safety index was proposed to describe the bearing capacity of the segment.Next,a finite element model(FEM)was established to analyze the bearing capacity of segment using the test results.Finally,the effect of reinforcement with a steel plate on the deformation and bearing capacity of the segment was analyzed.The results showed that under asymmetric unloading,the peak value and amplitude of the bending moment on the near unloading side converged with a greater value than those on the far side.The concrete internal force exhibited a directional transformation at different load stages.Cracks first appeared at the 180inner arc surface of the bottom standard block and then expanded to both sides,while the rate of crack propagation of the outer arc surface was relatively lower.The bearing capacity of the segments can be evaluated by the combination of the factors,e.g.the residual bearing capacity coefficient,moment transfer coefficient,and characterization coefficient.The segments approaching failure can facilitate the increase in the residual bearing capacity coefficient by more than 50%.This can provide guidance for the service assessment of metro tunnel operations.
基金National Natural Science Foundation of China(Nos.42071372,42221002)。
文摘Spatial linear features are often represented as a series of line segments joined by measured endpoints in surveying and geographic information science.There are not only the measuring errors of the endpoints but also the modeling errors between the line segments and the actual geographical features.This paper presents a Brownian bridge error model for line segments combining both the modeling and measuring errors.First,the Brownian bridge is used to establish the position distribution of the actual geographic feature represented by the line segment.Second,an error propagation model with the constraints of the measuring error distribution of the endpoints is proposed.Third,a comprehensive error band of the line segment is constructed,wherein both the modeling and measuring errors are contained.The proposed error model can be used to evaluate line segments’overall accuracy and trustability influenced by modeling and measuring errors,and provides a comprehensive quality indicator for the geospatial data.
基金Project supported by National High-Technology Research andDevelopment Program of China (Grant No .2002AA234021)
文摘Tmnsmembrane（TM） protein plays an important role in the life activity of the cells, and the prediction of transmembrane helical segments （TMHs） is an important subject in the bioinformatics research. Thus far, several prediction methods have been reported, but there are some deficiencies in prediction accuracy and adaptability in these methods. In this paper, a method based on discrete wavelet transform （DWT） was developed to predict the TMHs. Two sets of test data sets containing total 60 protein sequences were utilized to access the effect of the method. Compared with the prediction results of TMHMM2.0 and MEMSAT, the obtained results indicate that the presented method has high prediction accuracy.
文摘Two series of polyurethanes based on mixed polychloromethyl methyl siloxane and poly-tetramethylene oxide in different weight fractions were synthesized. The phase separation ofsamples was studied using DSC and dynamic mechanical property analysis. The results showedthat the introduction of chloromethyl group into polysiloxane increased its polarity and henceimproved the miscibilities with polytetramethylene oxide and polyurethane hard segment.Particularly, in the case of N-methyldiethanolamine extended materials, the surface and tensileproperties of these samples can be adjusted by various ratios of two soft segments.
文摘AIM: To investigate the efficacy of Ferrara rings (FR) implantation in the treatment of keratoconus.METHODS: It was a retrospective case series descriptive study. The sample was comprised of 50 patients 79 eyes diagnosed with progressive keratoconus. This included 24 (48%) males and 26 (52%) females between the age of 13 and 44 years. All participants underwent surgical implantation of FR in the period between January 2009 and September 2010 at Jordan University Hospital. Thorough ophthalmologic examinations were applied to measure vital variables for each pathological condition before and after surgery. RESULTS: Findings indicated an overall significant postoperative improvement in both uncorrected visual acuity (UCVA) and best spectacle corrected visual acuity (BSCVA) throughout follow up visits. Moreover, results illustrated a significant decrease in spherical equivalent (SE) and keratometric readings (lower, higher and the average). CONCLUSION: Surgical intervention strategies are being frequently developed to meet the needs of patients with keratoconus. The implantation of Ferrara rings has proven to be a safe and feasible alternative procedure for the treatment of mild-moderate keratoconus especially for patients with contact lenses intolerance. We have found that this procedure has improved visual outcomes in all eyes studied. Nevertheless, further research is needed to investigate long term outcomes.
文摘AIM:To evaluate the clinical outcomes after Ferrara intrastromal corneal ring segments(ICRS)reoperation in patients with keratoconus.METHODS:A total of 37 keratoconus eyes implanted with intrastromal corneal ring segments,which had an ICRS exchange,addition,reposition or removal were evaluated.Uncorrected visual acuity(UCVA),best corrected visual acuity(BCVA),keratometry(K),asphericity(Q)and pachymetry at the thinnest point(PTP)of the cornea were evaluated using a corneal tomography(Oculus Pentacam,USA)RESULTS:The mean follow-up time after the reoperation was 30.5±9.7 months.The mean UCVA improved from 20/300 to 20/80(P=0.005);the mean BCVA improved from 20/160 to 20/50(P=0.0002),the mean keratometry reduced from 49.33±4.19D to 46.16±3.90D(P=0.0001),the mean pachymetry at the thinnest point increased from 450±42.9μm to 469±40.8μm(P=0.0001).The asphericity increased from-0.84±0.74 to-0.35±0.81(P=0.15)and the spherical equivalent reduced from-4.64±4.87D to-3.04±3.45D(P=0.137).The changes in the asphericity and spherical equivalent were not statistically significant.CONCLUSION:Ferrara ICRS implantation showed to be a reversible and readjustable surgical procedure for keratoconus treatment.Good outcomes can be obtained even after removal,addition,reposition or exchange of ICRS.
文摘BACKGROUND Liver resection and radiofrequency ablation are considered curative options for hepatocellular carcinoma.The choice between these techniques is still controversial especially in cases of hepatocellular carcinoma affecting posterosuperior segments in elderly patients.AIM To compare post-operative outcomes between liver resection and radiofrequency ablation in elderly with single hepatocellular carcinoma located in posterosuperior segments.METHODS A retrospective multicentric study was performed enrolling 77 patients age≥70-years-old with single hepatocellular carcinoma(≤30 mm),located in posterosuperior segments(4a,7,8).Patients were divided into liver resection and radiofrequency ablation groups and preoperative,peri-operative and long-term outcomes were retrospectively analyzed and compared using a 1:1 propensity score matching.RESULTS After propensity score matching,twenty-six patients were included in each group.Operative time and overall postoperative complications were higher in the resection group compared to the ablation group(165 min vs 20 min,P<0.01;54%vs 19%P=0.02 respectively).A median hospital stay was significantly longer in the resection group than in the ablation group(7.5 d vs 3 d,P<0.01).Ninety-day mortality was comparable between the two groups.There were no significant differences between resection and ablation group in terms of overall survival and disease free survival at 1,3,and 5 years.CONCLUSION Radiofrequency ablation in posterosuperior segments in elderly is safe and feasible and ensures a short hospital stay,better quality of life and does not modify the overall and disease-free survival.
基金This work is supported by the Grassland Talent Project:The Innovation Team of New Varieties Breeding at the Economic and Ecological Shrub,and the Evaluation of the Economic and Ecological Shrub Resources and New Variety Breeding in Inner Mongolia(No.201702077)。
文摘Hydrangea bretschneideri Dipp is a highly popular ornamental plant for garden decoration.Genetic engineering technology has been successfully used in many plant species,but it is limited in Hydrangea.Here we established an efficient regeneration system by using stem segments as explants for the first time.In our study,the plant growth regulators(PGRs)were evaluated at the different regeneration processes,including axillary shoots regeneration and root induction.We found that the optimal concentration for axillary buds’induction was 2.0 mgL^(-1)6-BA and 0.5 mgL^(-1)1 IAA,its highest induction rate was 70%.Moreover,the highest axillary shoots proliferation coefficient was 10.7 on the Murashige and Skoog(MS)medium with 2.0 mgL^(-1)6-benzyladenine(BA),0.2 mgL^(-1)indole-3-butyric acid(IBA),and 1.0 mgL^(-1)gibberellin A3(GA3).The highest frequency of root induction was 80.0±0.06%by culturing the elongated shoots in 1/2 MS medium containing 0.1 mgL^(-1)IBA.In summary,our study will provide an effective technology for large-scale propagation and important pathway for promoting the popularization and application of Hydrangea bretschneideri Dipp.
基金Supported by Key Technologies R &D Program of Guangdong Province (2009B0203030092006B20201007)~~
文摘[Objective] The aim was to study the conditions of tissue culture regeneration seedling by using the stem segments of Euphorbia tirucalli and determine the optimum culture condition of each culture stage,so as to provide references for the factory production and relative study of tissue culture seedling of E. tirucalli. [Method] Taking the stem segments of E. tirucalli as explants,the effects of various mediums on germination rate,multiplication coefficient and rooting rate were studied. [Result] The optimum induction medium of germination culture was 1/2MS＋NAA 0.02 mg/L＋6-BA 1.0 mg/L,with differentiation rate of 89.7%; the best subculture medium was 1/2MS＋NAA 0.02 mg/L＋6-BA 0.60 mg/L＋AD 3.0 mg/L,with multiplication coefficient of 5.70; the optimum rooting culture medium was 1/2MS＋NAA 0.40 mg/L＋IBA 0.4 mg/L,with rooting rate of 100% and transplanting survival rate of 80%. [Conclusion] The tissue culture conditions of stem segments of E. tirucalli were determined primarily.
基金This project was sponsored by the State Seismological Bureau (85-02-3-3), China
文摘By computing and classifying the data of gully offset obtained from field surveys along the Tianjingshan fault zone and estimating the ages of three types of gullies,the strike-slip rates along the fault zone are discussed in different time intervals and fault segments.The results suggest that the intensity of activity along the fault zone is not strong,but the differences between different time intervals and fault segments since the late Pleistocene have been obvious.The average rates range from 0.23 mm/a to 1.62 mm/a.The largest average rate is 1.40 mm/a,which occurred in the early and middle of late Pleistocene along the western segment of the fault zone.Since the late stage of the late Pleistocene,the center of faulting activity of the fault zone has shifted to the middle segment,and the average slip rates range have changed from 1.30 mm/a to 1.63 mm/a.
基金financial support from IPGP as part of the IEPT RAS-IPGP cooperation.IPGP Contribution NS 3391.
文摘We investigate global temperature data produced by the Climate Research Unit at the University of East Anglia (CRU) and the Berkeley Earth Surface Temperature consortium (BEST). We first fit the 1850-2010 data with polynomials of degrees 1 to 9. A significant ~60-yr oscillation is accounted for as soon as degree 4 is reached. This oscillation is even better modeled as a broken line, more precisely a series of ~30-yr long linear segments, with slope breaks (singularities) in ~1904, ~1940, and ~1974 (±3 yr), and a possible recent occurrence at the turn of the 20th century. Oceanic indices PDO (Pacific Decadal Oscillation) and AMO (Atlantic Multidecadal Oscillation) have undergone major changes (respectively of sign and slope) roughly at the same times as the temperature slope breaks. This can be interpreted with a system of oceanic non-linear coupled oscillators with abrupt mode shifts. Thus, the Earth’s climate may have entered a new mode (a new ~30-yr episode) near the turn of the 20th century: no further temperature increase, a dominantly negative PDO index and a decreasing AMO index might be expected for the next decade or two.
文摘Based on the vector diffraction theory, the effect of complex phase filters on intensity distribution of a radially polarized multi Gaussian beam in the focal region of high NA lens is theoretically investigated. It is observed that a properly designed multi belt complex phase filter can generate subwavelength novel focal patterns including splitting of focal spots and generation of multiple focal spot segments such as eight, six and four focal spots along the optical axis are obtained. We expect that such an investigation is useful for optical manipulation and material processing, multiple high refractive index particle trapping technologies.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11105074 and 11005026)the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province, China (Grant Nos. 11KJB140004 and 11KJA110001)the Qing Lan Project of Jiangsu Province, China
文摘Depending on the excitability of the medium, a propagating wave segment will either contract or expand to fill the medium with spiral waves. This paper aims to introduce a simple mechanism of feedback control to stabilize such an expansion or contraction. To do this, we lay out a feedback control system in a block diagram and reduce it into a bare, universal formula. Analytical and experimental findings are compared through a series of numerical simulations of the Barkley model.
文摘The liver has eight segments, which are referred to by numbers or by names. The numbering of the segments is done in a counterclockwise manner with the liver being viewed from the inferior surface, starting from Segment Ⅰ(the caudate lobe). Standard anatomical description of the liver segments is available by computed tomographic scan and ultrasonography. Endoscopic ultrasound(EUS) has been used for a detailed imaging of many intra-abdominal organs and for the assessment of intra-abdominal vasculature. A stepwise evaluation of the liver segments by EUS has not been described. In this article, we have described a stepwise evaluation of the liver segments by EUS. This information can be useful for planning successful radical surgeries, preparing for biopsy, portal vein embolization, transjugular intrahepatic portosystemic shunt, tumour resection or partial hepatectomy, and for planning EUS guided diagnostic and therapeutic procedures.
