BACKGROUND Since fat does not transmit electrical energy well,delayed perforation and postpolypectomy syndrome due to electrical thermal injury are concerns in the endoscopic removal of colonic lipoma.The endoscopic s...BACKGROUND Since fat does not transmit electrical energy well,delayed perforation and postpolypectomy syndrome due to electrical thermal injury are concerns in the endoscopic removal of colonic lipoma.The endoscopic submucosal dissection(ESD)technique concentrates electrical energy conducts to the submucosa,not the adipose tissue.This helps to minimize electrical thermal injury,especially in the case of large colonic lipomas.In rare cases,such as colonic lipomas accompanied by mucosal lesions,it is difficult for endoscopists to decide how to safely remove them.CASE SUMMARY A 78-year-old man underwent colonoscopy for colorectal cancer screening.During colonoscopy,a yellowish submucosal tumor with positive cushion sign was observed in the ascending colon measuring about 4.5 cm.A nodular mucosal lesion of about 2.5 cm was observed on the mucosal surface of the lipoma.The lipoma was so large that it occupied much of the inside of the colon,making it difficult to see the entire laterally spreading tumor(LST)at once.The LST was confined to the surface of the lipoma,which had a semipedunculated shape with a wide neck.The margin of the LST was not observed at the neck of the lipoma.ESD was performed and the colonic lipoma with the LST was successfully removed without complications.After 3 d of hospitalization,the patient was discharged without any symptoms.The final pathology report showed that the lesion consisted of submucosal lipoma and tubulovillous adenoma with lowgrade dysplasia.CONCLUSION ESD is effective and safe for treating a large colonic lipoma with an LST by minimizing electrical thermal injury.展开更多
Response surface method is used to study the reliability analysis of laterally loaded piles in sloping ground. A development load-displacement （p-y） curve for laterally loaded pile response in sloping ground is used...Response surface method is used to study the reliability analysis of laterally loaded piles in sloping ground. A development load-displacement （p-y） curve for laterally loaded pile response in sloping ground is used to model the pile-soil system, both the pile head displacement and the maximum bending moment of the piles are used as the performance criteria in this study. The reliability analysis method of the laterally loaded pile in sloping ground under the pile head displacement and the maximum bending moment failure modes is proposed, which is in good agreement with the Monte Carlo method. The influences on the probability index of failure by a number of parameters are discussed. It is shown that the variability of pile head displacement increases with the increase in the coefficients of variation of ultimate bearing capacity factor （Npu）, secant elastic modulus at 50%（E50） and level load （H）. A negative correlation between Npu and non-dimensional factor （λ） leads to less spread out probability density function （PDF） of the pile head displacement;in contrast, a positive correlation between Npu andλgives a great variation in the PDF of pile head displacement. As for bearing capacity factor on ground surface （Npo） and λ, both negative and positive correlations between them give a great variation in the PDF of pile head displacement, and a negative correlation will obviously increase the variability of the response.展开更多
AIM： To clarify differences in mucin phenotype, prolif- erative activity and oncogenetic alteration among sub- types of colorectal laterally spreading tumor （LST）. METHODS： LSTs, defined as superficial elevated le...AIM： To clarify differences in mucin phenotype, prolif- erative activity and oncogenetic alteration among sub- types of colorectal laterally spreading tumor （LST）. METHODS： LSTs, defined as superficial elevated lesions greater than 10 mm in diameter with a low vertical axis, were macroscopically classified into two subtypes： （1） a granular type （Gr-LST） composed of superficially spread- ing aggregates of nodules forming a fiat-based lesion with a granulonodular and uneven surface; and （2） a non-granular type （NGr-LST） with a flat smooth surface and an absence of granulonodular formation. A total of 69 LSTs, comprising 36 Gr-LSTs and 33 NGr-LSTs, were immunohistochemically stained with MUC2, MUC5AC, MUC6, CD10 （markers of gastrointestinal cell lineage）, p53, 13-catenin and Ki-67 antibodies, and examined for alteration in exon 1 of v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog （KRAS） and exon 15 of v-raf murine sarcoma viral oncogene homologue B1 （BRAF） by poly- merase chain reaction followed by direct sequencing. RESULTS： Histologically, 15 Gr-LST samples were ad- enomas with low-grade dysplasia （LGD）, 12 were high- grade dysplasia （HGD） and 9 were adenocarcinomas invading the submucosa （INV）, while 12 NGr-LSTs demonstrated LGD, 14 HGD and 7 INV. In the proximal colon, MUC5AC expression was significantly higher in the Gr-type than the NGr-type. MUC6 was expressed only in NGr-LST. MUC2 or CD10 did not differ. P53 ex- pression demonstrated a significant stepwise increment in progression through LGD-HGD-INV with both types of LST. Nuclear β-catenin expression was significantly higher in the NGr-type. Ki-67 expression was signifi- cantly higher in the Gr-type in the lower one third zone of the tumor. In proximal, but not distal colon tumors, the incidence of KRAS provided mutation was signifi- cantly higher in the Gr-type harboring a specific muta- tional pattern （G12V）. BRAF mutations （V600E） were detected only in two Gr-LSTs. CONCLUSION： The two subtypes of LST, especially in the proximal colon, have differing phenotypes of gastrointestinal cell lineage, proliferation and activa- tion of Wnt/β-catenin or RAS/RAF/extracellular signal- regulated kinase signaling.展开更多
We report a type-I Ga Sb-based laterally coupled distributed-feedback（LC-DFB） laser with shallow-etched gratings operating a continuous wave at room temperature without re-growth process. Second-order Bragg gratings...We report a type-I Ga Sb-based laterally coupled distributed-feedback（LC-DFB） laser with shallow-etched gratings operating a continuous wave at room temperature without re-growth process. Second-order Bragg gratings are fabricated alongside the ridge waveguide by interference lithography. Index-coupled LC-DFB laser with a cavity of 1500 μm achieves single longitudinal mode continuous-wave operation at 20℃ with side mode suppression ratio（SMSR） as high as 24 dB.The maximum single mode continuous-wave output power is about 10 mW at room temperature（uncoated facet）. A low threshold current density of 230 A/cm^2 is achieved with differential quantum efficiency estimated to be 93 mW/A. The laser shows a good wavelength stability against drive current and working temperature.展开更多
A developed stereo particle image velocimetry(stereo-PIV) system was proposed to measure three-dimensional(3D) soil deformation around a laterally loaded pile in sand.The stereo-PIV technique extended 2D measurement t...A developed stereo particle image velocimetry(stereo-PIV) system was proposed to measure three-dimensional(3D) soil deformation around a laterally loaded pile in sand.The stereo-PIV technique extended 2D measurement to 3D based on a binocular vision model,where two cameras with a well geometrical setting were utilized to image the same object simultaneously.This system utilized two open software packages and some simple programs in MATLAB,which can easily be adjusted to meet user needs at a low cost.The failure planes form an angle with the horizontal line,which are measured at 27°-29°,approximately three-fourths of the frictional angle of soil.The edge of the strain wedge formed in front of the pile is an arc,which is slightly different from the straight line reported in the literature.The active and passive influence zones are about twice and six times of the diameter of the pile,respectively.The test demonstrates the good performance and feasibility of this stereo-PIV system for more advanced geotechnical testing.展开更多
AIM: To prospectively investigate the detection rate of laterally spreading tumors (LSTs) of the colorectum by computed tomography (CT) colonography (CTC).
BACKGROUND Colorectal mucosa-associated lymphoid tissue(MALT)lymphoma is a rare disease,and only a few cases have been reported to date.It has no specific clinical presentations and shows various endoscopic appearance...BACKGROUND Colorectal mucosa-associated lymphoid tissue(MALT)lymphoma is a rare disease,and only a few cases have been reported to date.It has no specific clinical presentations and shows various endoscopic appearances.There is no uniform consensus on its treatment.With the advancement of endoscopic technology,endoscopic treatment has achieved better results in individual case reports of early-stage patients.CASE SUMMARY We report a case of rectal MALT in a 57-year-old Chinese man with no symptoms who received endoscopy as part of a routine physical examination,which incidentally found a 25 mm×20 mm,laterally spreading tumor(LST)-like elevated lesion in the rectum.Therefore,he was referred to our hospital for further endoscopic treatment.Complete and curable removal of the tumor was performed by endoscopic submucosal dissection.We observed enlarged and dilated branch-like vessels similar to those of gastric MALT lymphoma on magnifying endoscopy with narrow-band imaging.And immunopathological staining showed hyperplastic capillaries in the mucosa.Histopathological findings revealed diffusely hyperplastic lymphoid tissue in the lamina propria,with a visible lymphoid follicle structure surrounded by a large number of diffusely infiltrated lymphoid cells that had a relatively simple morphology and clear cytoplasm.In addition,immunohistochemical analysis suggested strongly positive expression for CD20 and Bcl-2.Gene rearrangement results showed positivity for IGH-A,IGH-C,IGK-B,and IGL.Taking all the above findings together,we arrived at a diagnosis of extranodal marginal zone B-cell lymphoma of MALT lymphoma. Positron emission tomography-computed tomographyexamination showed no other lesions involved. The patient will be followed byperiodic endoscopic observation.CONCLUSIONIn conclusion, we report a case of rectal MALT with an LST-like appearancetreated by endoscopic submucosal dissection. Further studies will be needed toexplore the clinical behavior, endoscopic appearance, and treatment of rectalMALT.展开更多
BACKGROUND Colorectal laterally spreading tumors(LSTs)with malignant potential require en bloc resection by endoscopic submucosal dissection(ESD),but lesions with deep submucosal invasion(SMI)are endoscopically unrese...BACKGROUND Colorectal laterally spreading tumors(LSTs)with malignant potential require en bloc resection by endoscopic submucosal dissection(ESD),but lesions with deep submucosal invasion(SMI)are endoscopically unresectable.AIM To investigate the factors associated with high-grade dysplasia(HGD)/carcinoma and deep SMI in colorectal LSTs.METHODS The endoscopic and histological results of consecutive patients who underwent ESD for colorectal LSTs in our hospital from June 2013 to March 2019 were retrospectively analyzed.The characteristics of LST subtypes were compared.Risk factors for HGD/carcinoma and deep SMI(invasion depth≥1000μm)were determined using multivariate logistic regression.RESULTS A total of 323 patients with 341 colorectal LSTs were enrolled.Among the four subtypes,non-granular pseudodepressed(NG-PD)LSTs(85.5%)had the highest rate of HGD/carcinoma,followed by the granular nodular mixed(G-NM)(77.0%),granular homogenous(29.5%),and non-granular flat elevated(24.2%)subtypes.Deep SMI occurred commonly in NG-PD LSTs(12.9%).In the adjusted multivariate analysis,NG-PD[odds ratio(OR=16.8,P<0.001)and G-NM(OR=7.8,P<0.001)subtypes],size≥2 cm(OR=2.2,P=0.005),and positive non-lifting sign(OR=3.3,P=0.024)were independently associated with HGD/carcinoma.The NG-PD subtype(OR=13.3,P<0.001)and rectosigmoid location(OR=8.7,P=0.007)were independent risk factors for deep SMI.CONCLUSION Because of their increased risk for malignancy,it is highly recommended that NG-PD and G-NM LSTs are removed en bloc through ESD.Given their substantial risk for deep SMI,surgery needs to be considered for NG-PD LSTs located in the rectosigmoid,especially those with positive nonlifting signs.展开更多
BACKGROUND The management strategies for recurrent ampullary adenoma after endoscopic papillectomy are still controversial.Patients with the recurrent papillary lesions need to receive repetitive endoscopic interventi...BACKGROUND The management strategies for recurrent ampullary adenoma after endoscopic papillectomy are still controversial.Patients with the recurrent papillary lesions need to receive repetitive endoscopic interventions due to the limitations of conventional endoscopic techniques.AIM To assess the feasibility,efficacy,and safety of hybrid endoscopic submucosal dissection(ESD)by duodenoscope for recurrent,laterally spreading papillary lesions.METHODS We enrolled two patients with recurrent,laterally spreading,duodenal papillary adenomas with no intraductal extension confirmed by follow-up between March 2017 and September 2018.After marking the resection borders of the lesion using a dual knife,a submucosal cushion was created by injecting a mixture of saline solution,methylene blue,and adrenaline.A total circumferential incision and submucosal excision was performed by dual knife combined with insulated-tip diathermic knife,and then the lesion was ligated and resected using an electric snare.Endoscopic hemostasis was applied during the endoscopic procedures.Moreover,the endoscopic retrograde cholangiopancreatography(ERCP)procedures,including selective cannulation and stent implantation of biliary and pancreatic ducts,were performed.Additionally,we performed endoclip closure for mucosal defect after ESD.RESULTS Hybrid ESD using a duodenoscope and biliary and pancreatic stent placement were performed successfully in two patients.The endoscopic size of recurrent papillary lesions was no more than 2 cm.Generally,the average total procedure time was 95.5 min,and the procedure time of ESD and ERCP was 38.5 min and 15.5 min,respectively.No serious complications occurred during the intraoperative and postoperative periods.The histopathological examination revealed tubulovillous adenoma negative for neoplastic extension at the cut margin in both patients.The duodenoscopic follow-up and histopathology of biopsy specimens at 3 mo after ESD showed no residual or recurrent lesions in ampullary areas in both cases.Both cases have been followed up with no recurrence to June 2020.CONCLUSION Hybrid ESD by duodenoscope is technically challenging,and may be curative for recurrent,laterally spreading papillary adenomas<2 cm.It should be performed cautiously in selected patients by experienced endoscopists.展开更多
In this study we systematically investigate the effects of laterally inhomogeneous crustal structure with planar dipping interfaces on the teleseismic receiver function. For this purpose the synthetic receiver functio...In this study we systematically investigate the effects of laterally inhomogeneous crustal structure with planar dipping interfaces on the teleseismic receiver function. For this purpose the synthetic receiver functions in the 3-D laterally inhomogeneous media are computed using the Maslov asymptotic ray method (CHEN, LIU, 1999). Our results demonstrate that the symmetric and asymmetric variations above the sources azimuths appear on the radial and transverse components of the receiver function, respectively. The dipping direction and dipping angle of the interface beneath the station can be estimated from these features. But, when several different dipping interfaces exist within the crust, only an apparent dipping direction can be inferred from the waveform variations of the receiver function over different azimuths at a single station. By analyzing our observational data it is shown that the planar dipping interface is a well first-order approximation for investigating the crustal lateral inhomogeneity, when only data recorded at a single station are used. And our results given in this study are consistent with those given by seismic array study.展开更多
Micromachined comb-drive electrostatic resonators with folded-cantilever beams were designed and fabricated. A combination of Rayleigh＇s method and finite-element analysis was used to calculate the resonant frequency...Micromachined comb-drive electrostatic resonators with folded-cantilever beams were designed and fabricated. A combination of Rayleigh＇s method and finite-element analysis was used to calculate the resonant frequency drift as we adjusted the device geometry and material parameters. Three micromachined lateral resonant resonators with different beam widths were fabricated. Their resonant frequencies were experimentally measured to be 64.5,147.2, and 255.5kHz, respectively, which are in good agreement with the simulated resonant frequency. It is shown that an improved frequency performance could be obtained on the poly 3C-SiC based device structural material systems with high Young＇s modulus.展开更多
Due to the advent of the screening programs for colorectal cancer and the era of quality assurance colonoscopy the number the polyps that can be considered difficult,including large(>20 mm)laterally spreading tumor...Due to the advent of the screening programs for colorectal cancer and the era of quality assurance colonoscopy the number the polyps that can be considered difficult,including large(>20 mm)laterally spreading tumors(LSTs),has increased in the last decade.All LSTs should be assessed carefully,looking for suspicious areas of submucosal invasion(SMI),such as nodules or depressed areas,describing the morphology according to the Paris classification,the pit pattern,and vascular pattern.The simplest,most appropriate and safest endoscopic treatment with curative intent should be selected.For LST-granular homogeneous type,piecemeal endoscopic mucosal resection should be the first option due to its biological low risk of SMI.LST-nongranular pseudodepressed type has an increased risk of SMI,and en bloc resection should be mandatory.Underwater endoscopic mucosal resection is useful in situations where submucosal injection alters the operative field,e.g.,for the resection of scar lesions,with no lifting,adjacent tattoo,incomplete resection attempts,lesions into a colonic diverticulum,in ileocecal valve and lesions with intra-appendicular involvement.Endoscopic full thickness resection is very useful for the treatment of difficult to resect lesions of less than 20 up to 25 mm.Among the indications,we highlight the treatment of polyps with suspected malignancy because the acquired tissue allows an exact histologic risk stratification to assign patients individually to the best treatment and avoid surgery for low-risk lesions.Endoscopic submucosal dissection is the only endoscopic procedure that allows completes en bloc resection regardless of the size of the lesion.It should therefore be indicated in the treatment of lesions with risk of SMI.展开更多
Well known for their good performance,thin film transistors (TFTs) with active layers which were nickel induced laterally crystallized,are fabricated by conventional process of dual gate CMOS.The influence of pre h...Well known for their good performance,thin film transistors (TFTs) with active layers which were nickel induced laterally crystallized,are fabricated by conventional process of dual gate CMOS.The influence of pre high temperature treatment of device fabrication on the performance of TFTs is also investigated.The experiment shows that the high temperature treatment affects the performance of the devices strongly.The best performance is obtained by adopting pre treatment of 1000℃.The mobility of 314cm 2/(V·s) is obtained at NMOS TFTs with pre treatment of 1000℃,which is 10% and 22% higher than that treated at 1100℃ and without pre high temperature treatment,respectively.A maximum on/off current ratio of 3×10 8 is also obtained at 1000℃.Further investigation of uniformity verifies that the result is reliable.展开更多
The capability of piles to withstand horizontal loads is a major design issue.The current research work aims to investigate numerically the responses of laterally loaded piles at working load employing the concept of ...The capability of piles to withstand horizontal loads is a major design issue.The current research work aims to investigate numerically the responses of laterally loaded piles at working load employing the concept of a beam-on-Winkler-foundation model.The governing differential equation for a laterally loaded pile on elastic subgrade is derived.Based on LegendreGalerkin method and Runge-Kutta formulas of order four and five,the flexural equation of long piles embedded in homogeneous sandy soils with modulus of subgrade reaction linearly variable with depth is solved for both free-and fixed-headed piles.Mathematica,as one of the world’s leading computational software,was employed for the implementation of solutions.The proposed numerical techniques provide the responses for the entire pile length under the applied lateral load.The utilized numerical approaches are validated against experimental and analytical results of previously published works showing a more accurate estimation of the response of laterally loaded piles.Therefore,the proposed approaches can maintain both mathematical simplicity and comparable accuracy with the experimental results.展开更多
A novel thermo-responsive hydrogel column, featured with both ends of linear poly（N- isopropylacrylarnide） （PNIPAM） chains being grafted onto cross-linked PNIPAM chains, was reported. The laterally sandwich-typed ...A novel thermo-responsive hydrogel column, featured with both ends of linear poly（N- isopropylacrylarnide） （PNIPAM） chains being grafted onto cross-linked PNIPAM chains, was reported. The laterally sandwich-typed hydrogel columns were fabricated by radical polymerization in a three-step process using a method of ice-melting synthesis. The initiating path, morphology and thermoresponsive characteristics of the prepared hydrogel columns were experimentally studied. The results show that the hydrogel column obtained by the initiator inside part has more quick swelling and deswelling rates responsing to temperature cycling than other hydrogels owing to linear PNIPAM chains to form supermacroporous structure. The proposed hydrogel structure provide a new mode of the phase transition behavior for thermo-sensitive ＂smart＂ or ＂intelligent＂ monodisperse micro-actuators, which is highly attractive for targeting drug delivery systems, chemical separations, and sensors and so on.展开更多
Colorectal laterally spreading tumor (LST) is a flat protuberant lesion originating from the colorectal mucosa, which is mainly charactherized by lateral superficial diffusion, and rarely vertically invades the deep w...Colorectal laterally spreading tumor (LST) is a flat protuberant lesion originating from the colorectal mucosa, which is mainly charactherized by lateral superficial diffusion, and rarely vertically invades the deep wall of the intestine. LST is closely related to the occurrence and development of colorectal cancer, but its pathological morphology and molecular mechanism are different from those of general adenoma, and it has some particularity. At present, the related research on LST in China has just started, but we find that its incidence is not low. Therefore, the research progress of epidemiology, molecular biology as well as clinical diagnosis and treatment of this disease is reviewed.展开更多
Lateral spread of frozen ground crust over liquefied soil has caused extensive bridge foundation damage in the past winter earthquakes.A shake table experiment was conducted to investigate the performance of a model p...Lateral spread of frozen ground crust over liquefied soil has caused extensive bridge foundation damage in the past winter earthquakes.A shake table experiment was conducted to investigate the performance of a model pile in this scenario and revealed unique pile failure mechanisms.The modelling results provided valuable data for validating numerical models.This paper presents analyses and results of this experiment using two numerical modeling approaches： solid-fluid coupled finite element（FE） modeling and the beam-on-nonlinear-Winkler-foundation（BNWF） method.A FE model was constructed based on the experiment configuration and subjected to earthquake loading.Soil and pile response results were presented and compared with experimental results to validate this model.The BNWF method was used to predict the pile response and failure mechanism.A p-y curve was presented for modelling the frozen ground crust with the free-field displacement from the experiment as loading.Pile responses were presented and compared with those of the experiment and FE model.It was concluded that the coupled FE model was effective in predicting formation of three plastic hinges at ground surface,ground crust-liquefiable soil interface and within the medium dense sand layer,while the BNWF method was only able to predict the latter two.展开更多
Naturally deposited clay is usually characterized by strength anisotropy; however, the effect of anisotropy on the capacity of a suction caisson was seldom investigated. The conventional Hill yield surface includes un...Naturally deposited clay is usually characterized by strength anisotropy; however, the effect of anisotropy on the capacity of a suction caisson was seldom investigated. The conventional Hill yield surface includes undrained strengths in triaxial shear, simple shear and pressuremeter shear simultaneously but it can not specify differences in respect to the mode of loading for a given shearing mode. A new technique of updating strength is integrated into incremental finite element （FE） calculation to consider the mode of loading, which is applied to the study of variation of capacity with the aspect ratio of suction caissons in anisotropic clay. Compared with the upper bound limit analysis, FE simulation is capable of offering the lateral capacity of short caissons. In the normal range of anisotropic strength properties, the Mises yield surface with simple shear strength predicts the horizontal capacity of which the error is less than 10% for rough caissons and 15% for smooth caissons. It is also found that the friction of caisson affects the capacity significantly.展开更多
An analytical model is developed to study the crushing behavior and energy absorption capability of a single elliptical tube impacted by two parallel rigid plates, with and without consideration of the strain hardenin...An analytical model is developed to study the crushing behavior and energy absorption capability of a single elliptical tube impacted by two parallel rigid plates, with and without consideration of the strain hardening effect. The four-hinge collapse mechanism is used, and the governing equation is derived from Lagrange equations of the second kind. The numerical simulation of the dynamic response of the elliptical tube under impact using the finite element explicit code LS-DYNA is performed. The reaction force-displacement curve and displacement-time curve of the plate obtained from the two methods are in good agreement.展开更多
Up to now,the DNA molecule adsorbed on a surface was believed to always preserve its native structure.This belief implies a negligible contribution of lateral surface forces during and after DNA adsorption although th...Up to now,the DNA molecule adsorbed on a surface was believed to always preserve its native structure.This belief implies a negligible contribution of lateral surface forces during and after DNA adsorption although their impact has never been elucidated.High-resolution atomic force microscopy was used to observe that stiff DNA molecules kinetically trapped on monomolecular films comprising one-dimensional periodically charged lamellar templates as a single layer or as a sublayer are oversaturated by sharp discontinuous kinks and can also be locally melted and supercoiled.We argue that kink/anti-kink pairs are induced by an overcritical lateral bending stress(>30 pNnm)inevitable for the highly anisotropic 1D-1D electrostatic interaction of DNA and underlying rows of positive surface charges.In addition,the unexpected kink-inducing mechanical instability in the shape of the template-directed DNA confined between the positively charged lamellar sides is observed indicating the strong impact of helicity.The previously reported anomalously low values of the persistence length of the surface-adsorbed DNA are explained by the impact of the surface-induced low-scale bending.The sites of the local melting and supercoiling are convincingly introduced as other lateral stress-induced structural DNA anomalies by establishing a link with DNA high-force mechanics.The results open up the study in the completely unexplored area of the principally anomalous kinetically trapped DNA surface conformations in which the DNA local mechanical response to the surface-induced spatially modulated lateral electrostatic stress is essentially nonlinear.The underlying rich and complex in-plane nonlinear physics acts at the nanoscale beyond the scope of applicability of the worm-like chain approximation.展开更多
文摘BACKGROUND Since fat does not transmit electrical energy well,delayed perforation and postpolypectomy syndrome due to electrical thermal injury are concerns in the endoscopic removal of colonic lipoma.The endoscopic submucosal dissection(ESD)technique concentrates electrical energy conducts to the submucosa,not the adipose tissue.This helps to minimize electrical thermal injury,especially in the case of large colonic lipomas.In rare cases,such as colonic lipomas accompanied by mucosal lesions,it is difficult for endoscopists to decide how to safely remove them.CASE SUMMARY A 78-year-old man underwent colonoscopy for colorectal cancer screening.During colonoscopy,a yellowish submucosal tumor with positive cushion sign was observed in the ascending colon measuring about 4.5 cm.A nodular mucosal lesion of about 2.5 cm was observed on the mucosal surface of the lipoma.The lipoma was so large that it occupied much of the inside of the colon,making it difficult to see the entire laterally spreading tumor(LST)at once.The LST was confined to the surface of the lipoma,which had a semipedunculated shape with a wide neck.The margin of the LST was not observed at the neck of the lipoma.ESD was performed and the colonic lipoma with the LST was successfully removed without complications.After 3 d of hospitalization,the patient was discharged without any symptoms.The final pathology report showed that the lesion consisted of submucosal lipoma and tubulovillous adenoma with lowgrade dysplasia.CONCLUSION ESD is effective and safe for treating a large colonic lipoma with an LST by minimizing electrical thermal injury.
基金Projects(5147847951322403)supported by the National Natural Science Foundation of China+3 种基金Project(2015CX005)supported by Innovation Driven Plan of Central South University,ChinaProject(14JJ4003)supported by Hunan Provincial Natural Science Foundation,ChinaProject(SKLGP2014K008)supported by Opening Fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,ChinaProject(2015CB060200)supported by the National Basic Research Program of China
文摘Response surface method is used to study the reliability analysis of laterally loaded piles in sloping ground. A development load-displacement （p-y） curve for laterally loaded pile response in sloping ground is used to model the pile-soil system, both the pile head displacement and the maximum bending moment of the piles are used as the performance criteria in this study. The reliability analysis method of the laterally loaded pile in sloping ground under the pile head displacement and the maximum bending moment failure modes is proposed, which is in good agreement with the Monte Carlo method. The influences on the probability index of failure by a number of parameters are discussed. It is shown that the variability of pile head displacement increases with the increase in the coefficients of variation of ultimate bearing capacity factor （Npu）, secant elastic modulus at 50%（E50） and level load （H）. A negative correlation between Npu and non-dimensional factor （λ） leads to less spread out probability density function （PDF） of the pile head displacement;in contrast, a positive correlation between Npu andλgives a great variation in the PDF of pile head displacement. As for bearing capacity factor on ground surface （Npo） and λ, both negative and positive correlations between them give a great variation in the PDF of pile head displacement, and a negative correlation will obviously increase the variability of the response.
基金Supported by A grant-in-aid for General Scientific Research from the Ministry of Education, Science, Sports and Culture to Hiroyuki Mitomi, No. 21590394to Tsuyoshi Saito, No. 23590434, To-kyo, Japan
文摘AIM： To clarify differences in mucin phenotype, prolif- erative activity and oncogenetic alteration among sub- types of colorectal laterally spreading tumor （LST）. METHODS： LSTs, defined as superficial elevated lesions greater than 10 mm in diameter with a low vertical axis, were macroscopically classified into two subtypes： （1） a granular type （Gr-LST） composed of superficially spread- ing aggregates of nodules forming a fiat-based lesion with a granulonodular and uneven surface; and （2） a non-granular type （NGr-LST） with a flat smooth surface and an absence of granulonodular formation. A total of 69 LSTs, comprising 36 Gr-LSTs and 33 NGr-LSTs, were immunohistochemically stained with MUC2, MUC5AC, MUC6, CD10 （markers of gastrointestinal cell lineage）, p53, 13-catenin and Ki-67 antibodies, and examined for alteration in exon 1 of v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog （KRAS） and exon 15 of v-raf murine sarcoma viral oncogene homologue B1 （BRAF） by poly- merase chain reaction followed by direct sequencing. RESULTS： Histologically, 15 Gr-LST samples were ad- enomas with low-grade dysplasia （LGD）, 12 were high- grade dysplasia （HGD） and 9 were adenocarcinomas invading the submucosa （INV）, while 12 NGr-LSTs demonstrated LGD, 14 HGD and 7 INV. In the proximal colon, MUC5AC expression was significantly higher in the Gr-type than the NGr-type. MUC6 was expressed only in NGr-LST. MUC2 or CD10 did not differ. P53 ex- pression demonstrated a significant stepwise increment in progression through LGD-HGD-INV with both types of LST. Nuclear β-catenin expression was significantly higher in the NGr-type. Ki-67 expression was signifi- cantly higher in the Gr-type in the lower one third zone of the tumor. In proximal, but not distal colon tumors, the incidence of KRAS provided mutation was signifi- cantly higher in the Gr-type harboring a specific muta- tional pattern （G12V）. BRAF mutations （V600E） were detected only in two Gr-LSTs. CONCLUSION： The two subtypes of LST, especially in the proximal colon, have differing phenotypes of gastrointestinal cell lineage, proliferation and activa- tion of Wnt/β-catenin or RAS/RAF/extracellular signal- regulated kinase signaling.
基金Project supported by the National Key Basic Research Program of China(Grant Nos.2014CB643903 and 2013CB932904)the National Special Funds for the Development of Major Research Equipment and Instruments,China(Grant No.2012YQ140005)+1 种基金the National Natural Science Foundation of China(Grant Nos.61435012,61274013,61306088,and 61290303)the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB01010200)
文摘We report a type-I Ga Sb-based laterally coupled distributed-feedback（LC-DFB） laser with shallow-etched gratings operating a continuous wave at room temperature without re-growth process. Second-order Bragg gratings are fabricated alongside the ridge waveguide by interference lithography. Index-coupled LC-DFB laser with a cavity of 1500 μm achieves single longitudinal mode continuous-wave operation at 20℃ with side mode suppression ratio（SMSR） as high as 24 dB.The maximum single mode continuous-wave output power is about 10 mW at room temperature（uncoated facet）. A low threshold current density of 230 A/cm^2 is achieved with differential quantum efficiency estimated to be 93 mW/A. The laser shows a good wavelength stability against drive current and working temperature.
基金Project(104244) supported by the Natural Sciences and Engineering Research Council of Canada
文摘A developed stereo particle image velocimetry(stereo-PIV) system was proposed to measure three-dimensional(3D) soil deformation around a laterally loaded pile in sand.The stereo-PIV technique extended 2D measurement to 3D based on a binocular vision model,where two cameras with a well geometrical setting were utilized to image the same object simultaneously.This system utilized two open software packages and some simple programs in MATLAB,which can easily be adjusted to meet user needs at a low cost.The failure planes form an angle with the horizontal line,which are measured at 27°-29°,approximately three-fourths of the frictional angle of soil.The edge of the strain wedge formed in front of the pile is an arc,which is slightly different from the straight line reported in the literature.The active and passive influence zones are about twice and six times of the diameter of the pile,respectively.The test demonstrates the good performance and feasibility of this stereo-PIV system for more advanced geotechnical testing.
文摘AIM: To prospectively investigate the detection rate of laterally spreading tumors (LSTs) of the colorectum by computed tomography (CT) colonography (CTC).
文摘BACKGROUND Colorectal mucosa-associated lymphoid tissue(MALT)lymphoma is a rare disease,and only a few cases have been reported to date.It has no specific clinical presentations and shows various endoscopic appearances.There is no uniform consensus on its treatment.With the advancement of endoscopic technology,endoscopic treatment has achieved better results in individual case reports of early-stage patients.CASE SUMMARY We report a case of rectal MALT in a 57-year-old Chinese man with no symptoms who received endoscopy as part of a routine physical examination,which incidentally found a 25 mm×20 mm,laterally spreading tumor(LST)-like elevated lesion in the rectum.Therefore,he was referred to our hospital for further endoscopic treatment.Complete and curable removal of the tumor was performed by endoscopic submucosal dissection.We observed enlarged and dilated branch-like vessels similar to those of gastric MALT lymphoma on magnifying endoscopy with narrow-band imaging.And immunopathological staining showed hyperplastic capillaries in the mucosa.Histopathological findings revealed diffusely hyperplastic lymphoid tissue in the lamina propria,with a visible lymphoid follicle structure surrounded by a large number of diffusely infiltrated lymphoid cells that had a relatively simple morphology and clear cytoplasm.In addition,immunohistochemical analysis suggested strongly positive expression for CD20 and Bcl-2.Gene rearrangement results showed positivity for IGH-A,IGH-C,IGK-B,and IGL.Taking all the above findings together,we arrived at a diagnosis of extranodal marginal zone B-cell lymphoma of MALT lymphoma. Positron emission tomography-computed tomographyexamination showed no other lesions involved. The patient will be followed byperiodic endoscopic observation.CONCLUSIONIn conclusion, we report a case of rectal MALT with an LST-like appearancetreated by endoscopic submucosal dissection. Further studies will be needed toexplore the clinical behavior, endoscopic appearance, and treatment of rectalMALT.
基金Supported by Beijing Nova Program,No.Z201100006820147Beijing Municipal Administration of Hospitals’Youth Program,No.QML20180102。
文摘BACKGROUND Colorectal laterally spreading tumors(LSTs)with malignant potential require en bloc resection by endoscopic submucosal dissection(ESD),but lesions with deep submucosal invasion(SMI)are endoscopically unresectable.AIM To investigate the factors associated with high-grade dysplasia(HGD)/carcinoma and deep SMI in colorectal LSTs.METHODS The endoscopic and histological results of consecutive patients who underwent ESD for colorectal LSTs in our hospital from June 2013 to March 2019 were retrospectively analyzed.The characteristics of LST subtypes were compared.Risk factors for HGD/carcinoma and deep SMI(invasion depth≥1000μm)were determined using multivariate logistic regression.RESULTS A total of 323 patients with 341 colorectal LSTs were enrolled.Among the four subtypes,non-granular pseudodepressed(NG-PD)LSTs(85.5%)had the highest rate of HGD/carcinoma,followed by the granular nodular mixed(G-NM)(77.0%),granular homogenous(29.5%),and non-granular flat elevated(24.2%)subtypes.Deep SMI occurred commonly in NG-PD LSTs(12.9%).In the adjusted multivariate analysis,NG-PD[odds ratio(OR=16.8,P<0.001)and G-NM(OR=7.8,P<0.001)subtypes],size≥2 cm(OR=2.2,P=0.005),and positive non-lifting sign(OR=3.3,P=0.024)were independently associated with HGD/carcinoma.The NG-PD subtype(OR=13.3,P<0.001)and rectosigmoid location(OR=8.7,P=0.007)were independent risk factors for deep SMI.CONCLUSION Because of their increased risk for malignancy,it is highly recommended that NG-PD and G-NM LSTs are removed en bloc through ESD.Given their substantial risk for deep SMI,surgery needs to be considered for NG-PD LSTs located in the rectosigmoid,especially those with positive nonlifting signs.
文摘BACKGROUND The management strategies for recurrent ampullary adenoma after endoscopic papillectomy are still controversial.Patients with the recurrent papillary lesions need to receive repetitive endoscopic interventions due to the limitations of conventional endoscopic techniques.AIM To assess the feasibility,efficacy,and safety of hybrid endoscopic submucosal dissection(ESD)by duodenoscope for recurrent,laterally spreading papillary lesions.METHODS We enrolled two patients with recurrent,laterally spreading,duodenal papillary adenomas with no intraductal extension confirmed by follow-up between March 2017 and September 2018.After marking the resection borders of the lesion using a dual knife,a submucosal cushion was created by injecting a mixture of saline solution,methylene blue,and adrenaline.A total circumferential incision and submucosal excision was performed by dual knife combined with insulated-tip diathermic knife,and then the lesion was ligated and resected using an electric snare.Endoscopic hemostasis was applied during the endoscopic procedures.Moreover,the endoscopic retrograde cholangiopancreatography(ERCP)procedures,including selective cannulation and stent implantation of biliary and pancreatic ducts,were performed.Additionally,we performed endoclip closure for mucosal defect after ESD.RESULTS Hybrid ESD using a duodenoscope and biliary and pancreatic stent placement were performed successfully in two patients.The endoscopic size of recurrent papillary lesions was no more than 2 cm.Generally,the average total procedure time was 95.5 min,and the procedure time of ESD and ERCP was 38.5 min and 15.5 min,respectively.No serious complications occurred during the intraoperative and postoperative periods.The histopathological examination revealed tubulovillous adenoma negative for neoplastic extension at the cut margin in both patients.The duodenoscopic follow-up and histopathology of biopsy specimens at 3 mo after ESD showed no residual or recurrent lesions in ampullary areas in both cases.Both cases have been followed up with no recurrence to June 2020.CONCLUSION Hybrid ESD by duodenoscope is technically challenging,and may be curative for recurrent,laterally spreading papillary adenomas<2 cm.It should be performed cautiously in selected patients by experienced endoscopists.
基金State National Natural Science Foundation (49674213).
文摘In this study we systematically investigate the effects of laterally inhomogeneous crustal structure with planar dipping interfaces on the teleseismic receiver function. For this purpose the synthetic receiver functions in the 3-D laterally inhomogeneous media are computed using the Maslov asymptotic ray method (CHEN, LIU, 1999). Our results demonstrate that the symmetric and asymmetric variations above the sources azimuths appear on the radial and transverse components of the receiver function, respectively. The dipping direction and dipping angle of the interface beneath the station can be estimated from these features. But, when several different dipping interfaces exist within the crust, only an apparent dipping direction can be inferred from the waveform variations of the receiver function over different azimuths at a single station. By analyzing our observational data it is shown that the planar dipping interface is a well first-order approximation for investigating the crustal lateral inhomogeneity, when only data recorded at a single station are used. And our results given in this study are consistent with those given by seismic array study.
文摘Micromachined comb-drive electrostatic resonators with folded-cantilever beams were designed and fabricated. A combination of Rayleigh＇s method and finite-element analysis was used to calculate the resonant frequency drift as we adjusted the device geometry and material parameters. Three micromachined lateral resonant resonators with different beam widths were fabricated. Their resonant frequencies were experimentally measured to be 64.5,147.2, and 255.5kHz, respectively, which are in good agreement with the simulated resonant frequency. It is shown that an improved frequency performance could be obtained on the poly 3C-SiC based device structural material systems with high Young＇s modulus.
文摘Due to the advent of the screening programs for colorectal cancer and the era of quality assurance colonoscopy the number the polyps that can be considered difficult,including large(>20 mm)laterally spreading tumors(LSTs),has increased in the last decade.All LSTs should be assessed carefully,looking for suspicious areas of submucosal invasion(SMI),such as nodules or depressed areas,describing the morphology according to the Paris classification,the pit pattern,and vascular pattern.The simplest,most appropriate and safest endoscopic treatment with curative intent should be selected.For LST-granular homogeneous type,piecemeal endoscopic mucosal resection should be the first option due to its biological low risk of SMI.LST-nongranular pseudodepressed type has an increased risk of SMI,and en bloc resection should be mandatory.Underwater endoscopic mucosal resection is useful in situations where submucosal injection alters the operative field,e.g.,for the resection of scar lesions,with no lifting,adjacent tattoo,incomplete resection attempts,lesions into a colonic diverticulum,in ileocecal valve and lesions with intra-appendicular involvement.Endoscopic full thickness resection is very useful for the treatment of difficult to resect lesions of less than 20 up to 25 mm.Among the indications,we highlight the treatment of polyps with suspected malignancy because the acquired tissue allows an exact histologic risk stratification to assign patients individually to the best treatment and avoid surgery for low-risk lesions.Endoscopic submucosal dissection is the only endoscopic procedure that allows completes en bloc resection regardless of the size of the lesion.It should therefore be indicated in the treatment of lesions with risk of SMI.
文摘Well known for their good performance,thin film transistors (TFTs) with active layers which were nickel induced laterally crystallized,are fabricated by conventional process of dual gate CMOS.The influence of pre high temperature treatment of device fabrication on the performance of TFTs is also investigated.The experiment shows that the high temperature treatment affects the performance of the devices strongly.The best performance is obtained by adopting pre treatment of 1000℃.The mobility of 314cm 2/(V·s) is obtained at NMOS TFTs with pre treatment of 1000℃,which is 10% and 22% higher than that treated at 1100℃ and without pre high temperature treatment,respectively.A maximum on/off current ratio of 3×10 8 is also obtained at 1000℃.Further investigation of uniformity verifies that the result is reliable.
文摘The capability of piles to withstand horizontal loads is a major design issue.The current research work aims to investigate numerically the responses of laterally loaded piles at working load employing the concept of a beam-on-Winkler-foundation model.The governing differential equation for a laterally loaded pile on elastic subgrade is derived.Based on LegendreGalerkin method and Runge-Kutta formulas of order four and five,the flexural equation of long piles embedded in homogeneous sandy soils with modulus of subgrade reaction linearly variable with depth is solved for both free-and fixed-headed piles.Mathematica,as one of the world’s leading computational software,was employed for the implementation of solutions.The proposed numerical techniques provide the responses for the entire pile length under the applied lateral load.The utilized numerical approaches are validated against experimental and analytical results of previously published works showing a more accurate estimation of the response of laterally loaded piles.Therefore,the proposed approaches can maintain both mathematical simplicity and comparable accuracy with the experimental results.
基金the National Natural Science Foundation of China (No.20976202)the Natural Science Foundation of Hubei Province (No.2009CDB161)
文摘A novel thermo-responsive hydrogel column, featured with both ends of linear poly（N- isopropylacrylarnide） （PNIPAM） chains being grafted onto cross-linked PNIPAM chains, was reported. The laterally sandwich-typed hydrogel columns were fabricated by radical polymerization in a three-step process using a method of ice-melting synthesis. The initiating path, morphology and thermoresponsive characteristics of the prepared hydrogel columns were experimentally studied. The results show that the hydrogel column obtained by the initiator inside part has more quick swelling and deswelling rates responsing to temperature cycling than other hydrogels owing to linear PNIPAM chains to form supermacroporous structure. The proposed hydrogel structure provide a new mode of the phase transition behavior for thermo-sensitive ＂smart＂ or ＂intelligent＂ monodisperse micro-actuators, which is highly attractive for targeting drug delivery systems, chemical separations, and sensors and so on.
文摘Colorectal laterally spreading tumor (LST) is a flat protuberant lesion originating from the colorectal mucosa, which is mainly charactherized by lateral superficial diffusion, and rarely vertically invades the deep wall of the intestine. LST is closely related to the occurrence and development of colorectal cancer, but its pathological morphology and molecular mechanism are different from those of general adenoma, and it has some particularity. At present, the related research on LST in China has just started, but we find that its incidence is not low. Therefore, the research progress of epidemiology, molecular biology as well as clinical diagnosis and treatment of this disease is reviewed.
基金US Department of Transportation through Alaska University Transportation Centerthe State of Alaska Department of Transportation and Public Facilities(AK DOT&PF)under Project AUTC#410015
文摘Lateral spread of frozen ground crust over liquefied soil has caused extensive bridge foundation damage in the past winter earthquakes.A shake table experiment was conducted to investigate the performance of a model pile in this scenario and revealed unique pile failure mechanisms.The modelling results provided valuable data for validating numerical models.This paper presents analyses and results of this experiment using two numerical modeling approaches： solid-fluid coupled finite element（FE） modeling and the beam-on-nonlinear-Winkler-foundation（BNWF） method.A FE model was constructed based on the experiment configuration and subjected to earthquake loading.Soil and pile response results were presented and compared with experimental results to validate this model.The BNWF method was used to predict the pile response and failure mechanism.A p-y curve was presented for modelling the frozen ground crust with the free-field displacement from the experiment as loading.Pile responses were presented and compared with those of the experiment and FE model.It was concluded that the coupled FE model was effective in predicting formation of three plastic hinges at ground surface,ground crust-liquefiable soil interface and within the medium dense sand layer,while the BNWF method was only able to predict the latter two.
基金This project was financially supported by the National Natural Science Foundation of China (Grant No.50309001)Young Teacher Foundation of Dalian University of Technology (2003)
文摘Naturally deposited clay is usually characterized by strength anisotropy; however, the effect of anisotropy on the capacity of a suction caisson was seldom investigated. The conventional Hill yield surface includes undrained strengths in triaxial shear, simple shear and pressuremeter shear simultaneously but it can not specify differences in respect to the mode of loading for a given shearing mode. A new technique of updating strength is integrated into incremental finite element （FE） calculation to consider the mode of loading, which is applied to the study of variation of capacity with the aspect ratio of suction caissons in anisotropic clay. Compared with the upper bound limit analysis, FE simulation is capable of offering the lateral capacity of short caissons. In the normal range of anisotropic strength properties, the Mises yield surface with simple shear strength predicts the horizontal capacity of which the error is less than 10% for rough caissons and 15% for smooth caissons. It is also found that the friction of caisson affects the capacity significantly.
基金Project supported by the National Natural Science Foundation of China(No.11032001)
文摘An analytical model is developed to study the crushing behavior and energy absorption capability of a single elliptical tube impacted by two parallel rigid plates, with and without consideration of the strain hardening effect. The four-hinge collapse mechanism is used, and the governing equation is derived from Lagrange equations of the second kind. The numerical simulation of the dynamic response of the elliptical tube under impact using the finite element explicit code LS-DYNA is performed. The reaction force-displacement curve and displacement-time curve of the plate obtained from the two methods are in good agreement.
基金This work was supported in part by a grant from Russian Scientific Foundation(Project No.17-75-30064).
文摘Up to now,the DNA molecule adsorbed on a surface was believed to always preserve its native structure.This belief implies a negligible contribution of lateral surface forces during and after DNA adsorption although their impact has never been elucidated.High-resolution atomic force microscopy was used to observe that stiff DNA molecules kinetically trapped on monomolecular films comprising one-dimensional periodically charged lamellar templates as a single layer or as a sublayer are oversaturated by sharp discontinuous kinks and can also be locally melted and supercoiled.We argue that kink/anti-kink pairs are induced by an overcritical lateral bending stress(>30 pNnm)inevitable for the highly anisotropic 1D-1D electrostatic interaction of DNA and underlying rows of positive surface charges.In addition,the unexpected kink-inducing mechanical instability in the shape of the template-directed DNA confined between the positively charged lamellar sides is observed indicating the strong impact of helicity.The previously reported anomalously low values of the persistence length of the surface-adsorbed DNA are explained by the impact of the surface-induced low-scale bending.The sites of the local melting and supercoiling are convincingly introduced as other lateral stress-induced structural DNA anomalies by establishing a link with DNA high-force mechanics.The results open up the study in the completely unexplored area of the principally anomalous kinetically trapped DNA surface conformations in which the DNA local mechanical response to the surface-induced spatially modulated lateral electrostatic stress is essentially nonlinear.The underlying rich and complex in-plane nonlinear physics acts at the nanoscale beyond the scope of applicability of the worm-like chain approximation.
