An optimal allocation of earth is of great significance to reduce the project cost and duration in the construction of rock-fill dams. The earth allocation is a dynamic system affected by various time-space constraint...An optimal allocation of earth is of great significance to reduce the project cost and duration in the construction of rock-fill dams. The earth allocation is a dynamic system affected by various time-space constraints. Based on previous studies, a new method of optimizing this dynamic system as a static one is presented. In order to build a generalized and flexible model of the problem, some man-made constraints were investigated in building the mathematic model. Linear programming and simplex method are introduced to solve the optimization problem of earth allocation. A case study in a large-scale rock-fill dam construction project is presented to demonstrate the proposed method and its successful application shows the feasibility and effectiveness of the method.展开更多
To understand the structure of GABAergic neurons in the VMP and "barrel", the distribution of GABAergic neurons in the two areas were studied through immunohistochemistry and Laser Scanning Confocal Microscope. The ...To understand the structure of GABAergic neurons in the VMP and "barrel", the distribution of GABAergic neurons in the two areas were studied through immunohistochemistry and Laser Scanning Confocal Microscope. The results show that the distribution of GABAergic neurons in VMP and barrel are different, and the coding of information transmission in the two areas are also dissimilar; GABAergic neurons mainly distribute among the lines asymmetrically in VMP, the somata, dendrite and axon of GABAergic neurons are restricted in the "barrel", rarely having synaptic connections with other "barrel" around. Therefore, VMP and barrel may have different roles in transmission and on processing of informatiton.展开更多
AIM: To compare the racial differences of anatomical distribution of colorectal cancer (CRC) and determine the association of age, gender and time with anatomical distribution between patients from America (white) and...AIM: To compare the racial differences of anatomical distribution of colorectal cancer (CRC) and determine the association of age, gender and time with anatomical distribution between patients from America (white) and China (oriental).METHODS: Data was collected from 690 consecutive patients in Cleveland Clinic Florida, U.S.A. and 870consecutive patients in Nan Fang Hospital affiliated to the First Military Medical University, China over the past 11years from 1990 to 2000. All patients had colorectal adenocarcinoma diagnosed by histology and underwent surgery.RESULTS: The anatomical subsite distribution of tumor,age and gender were significantly different between white and oriental patients. Lesions in the proximal colon (P<0.001) were found in 36.3 % of white vs 26.0 % of oriental patients and cancers located in the distal colon and rectum in 63.7 % of white and 74 % of oriental patients (P<0.001). There was a trend towards the redistribution from distal colon and rectum to proximal colon in white males over time, especially in older patients (>80 years).No significant change of anatomical distribution occurred in white women and Oriental patients. The mean age at diagnosis was 69.0 years in white patients and 48.3 years in Oriental patients (P<0.001).CONCLUSION: This is the first study comparing the anatomical distribution of colorectal cancers in whites and Chinese patients. White Americans have a higher risk of proximal CRC and this risk increased with time. The proportion of white males with CRC also increased with time.Chinese patients were more likely to have distal CRC and developed the disease at a significantly earlier age than white patients. These findings have enhanced our understanding of the disease process of colorectal cancer in these two races.展开更多
Inflammation of axial and/or peripheral joints is one of the most frequent extra-intestinal manifestations complicating the clinical course and therapeutic approach in inflammatory bowel diseases(IBD).The frequency of...Inflammation of axial and/or peripheral joints is one of the most frequent extra-intestinal manifestations complicating the clinical course and therapeutic approach in inflammatory bowel diseases(IBD).The frequency of these complications seems to be similar for both diseases, Crohn's disease and ulcerative colitis.Arthritis associated with IBD belongs to the category of spondyloarthropathies.Axial involvement ranges from isolated inflammatory back pain to ankylosing spondylitis, whereas peripheral arthritis is noted in pauciarticular and in polyarticular disease.Asymptomatic radiological involvement of the sacroiliac joints is reported to occur in up to 50% of patients.Other musculoskeletal manifestations such as buttock pain, dactylitis, calcaneal enthesitis, and thoracic pain are frequently underdiagnosed and, consequently, are not treated appropriately.Several diagnostic approaches and criteria have been proposed over the past 40 years in an attempt to correctly classify and diagnose such manifestations.The correct recognition of spondylarthropathies needs an integrated multidisciplinary approach in order to identify common therapeutic strategies, especially in the era of the new biologic therapies.展开更多
Abstract: The shortest path problem in a network G is to find shortest paths between some specified source vertices and terminal vertices when the lengths of edges are given. The structure of the optimal solutions se...Abstract: The shortest path problem in a network G is to find shortest paths between some specified source vertices and terminal vertices when the lengths of edges are given. The structure of the optimal solutions set on the shortest paths is studied in this paper. First, the conditions of having unique shortest path between two distinguished vertices 8 and t in a network G are discussed; Second, the structural properties of 2-transformation ^-G graph G on the shortest-paths for G are presented heavily.展开更多
Architecture singularity of a parallel mechanism with five degrees of freedom (DOF) is analyzed. Such mechanism consists of a movable platform connected to the base by five active limbs. Four of them are identical 6-D...Architecture singularity of a parallel mechanism with five degrees of freedom (DOF) is analyzed. Such mechanism consists of a movable platform connected to the base by five active limbs. Four of them are identical 6-DOF limbs and the last one has the same DOF as the specified DOF of the movable platform. Based on the kinematics analysis, two categories of architecture singularities for such mechanism are proposed. Then the sufficient condition for each singularity is researched. Results show that the mechanism is singular when it employs each category of the proposed architecture, provided that it satisfies the corresponding sufficient condition. It can be concluded that the proposed two categories of architecture singularities should be avoided with the following dimensional synthesis of such mechanism.展开更多
In order to obtain the principle of Pantadome lifting process and make theoretical foundation for practical applications, the core idea of Pantadome was introduced, which is to make a structure become a mechanism by t...In order to obtain the principle of Pantadome lifting process and make theoretical foundation for practical applications, the core idea of Pantadome was introduced, which is to make a structure become a mechanism by temporarily removing some members during the process of construction.The Abstract motion model was built. By determining the change of the coordinates of the hinge joint and that of each point of the structure, simulative analysis of the mechanical motion of Pantadome was realized. Then general program that simulates the lifting process of Pantadome was developed based on AutoCAD environment by Auto Lisp language. By completing the theoretical analysis of the lifting process of Pantadome, three-dimensional simulation of the lifting process of Pantadome was realized. And it is successfully applied to bidding work of practical engineering.展开更多
A meshiess local discontinuous Petrov-Galerkin (MLDPG) method based on the local symmetric weak form (LSWF) is presented with the application to blasting problems. The derivation is similar to that of mesh-based R...A meshiess local discontinuous Petrov-Galerkin (MLDPG) method based on the local symmetric weak form (LSWF) is presented with the application to blasting problems. The derivation is similar to that of mesh-based Runge-Kutta Discontinuous Galerkin (RKDG) method. The solutions are reproduced in a set of overlapped spherical sub-domains, and the test functions are employed from a partition of unity of the local basis functions. There is no need of any traditional nonoverlapping mesh either for local approximation purpose or for Galerkin integration purpose in the presented method. The resulting MLDPG method is a meshless, stable, high-order accurate and highly parallelizable scheme which inherits both the advantages of RKDG and meshless method (MM), and it can handle the problems with extremely complicated physics and geometries easily. Three numerical examples of the one-dimensional Sod shock-tube problem, the blast-wave problem and the Woodward-Colella interacting shock wave problem are given. All the numerical results are in good agreement with the closed solutions. The higher-order MLDPG schemes can reproduce more accurate solution than the lower-order schemes.展开更多
Objective: The aim of our study was to evaluate the pathological features of posterior echo attenuation of papillary thyroid microcarcinoma (PTMC) and cystic degeneration of cervical lymph node metastasis. Methods: We...Objective: The aim of our study was to evaluate the pathological features of posterior echo attenuation of papillary thyroid microcarcinoma (PTMC) and cystic degeneration of cervical lymph node metastasis. Methods: We retrospectively evaluated the ultrasound results from 36 cases of PTMC with 20 nodules of cystic degeneration of cervical lymph node metastasis and correlated the results with the histopathologic findings. Results: The preliminary study indicated certain correlation between histopathologic findings and ultrasound results of posterior echo attenuation of papillary thyroid microcarcinoma and cystic degeneration of cervical lymph node metastasis. Conclusion: Posterior echo attenuation detected by ultrasound was associated with fibrous structures in PTMC nodules, while cystic degeneration and papillary changes of cervical lymph node metastasis in PTMC showed liquefactive necrosis, degenerative changes and enlarged follicular of nodular structures.展开更多
AIM:To evaluate the clinical,radiological and microbiological properties of abdominal tuberculosis (TB) and to discuss methods needed to get the diagnosis. METHODS:Thirty-one patients diagnosed as abdominal TB between...AIM:To evaluate the clinical,radiological and microbiological properties of abdominal tuberculosis (TB) and to discuss methods needed to get the diagnosis. METHODS:Thirty-one patients diagnosed as abdominal TB between March 1998 and December 2001 at the Gastroenterology Department of Kartal State Hospital, Istanbul,Turkey were evaluated prospectively.Complete physical examination,medical and family history,blood count erythrocyte sedimentation rate,routine biochemical tests, Mantoux skin test,chest X-ray and abdominal ultrasonography (USG) were performed in all cases,whereas microbiological examination of ascites,upper gastrointestinal endoscopy,colonoscopy or barium enema,abdominal tomography,mediastinoscopy,laparoscopy or laparotomy were done when needed. RESULTS:The median age of patients (14 females,17 males) was 34.2 years (range 15-65 years).The most frequent symptoms were abdominal pain and weight loss. Eleven patients had active pulmonary TB.The most common abdominal USG findings were ascites and hepatomegaly.Ascitic fluid analysis performed in 13 patients was found to be exudative and acid resistant bacilli were present in smear and cultured only in one patient with BacTec (3.2%).Upper gastrointestinal endoscopy yielded nonspecific findings in 16 patients.Colonoscopy performed in 20 patients showed ulcers in 9 (45%),nodules in 2 (10%) and,stricture,polypoid lesions,granulomatous findings in terminal ileum and rectal fistula each in one patient (5%). Laparoscopy on 4 patients showed dilated bowel loops, thickening in the mesentery,multiple ulcers and tubercles on the peritoneum.Patients with abdominal TB were divided into three groups according to the type of involvement. Fifteen patients (48%) had intestinal TB,11 patients (35.2%) had tuberculous peritonitis and 5 (16.8%) tuberculous lymphadenitis.The diagnosis of abdominal TB was confirmed microbiologically in 5 (16%) and histo- pathologically in 19 patients (60.8%).The remaining nine patients (28.8%) had been diagnosed by a positive response to antituberculous treatment. CONCLUSION:Neither clinical signs,laboratory,radiological and endoscopic methods nor bacteriological and histopathological findings provide a gold standard by themselves in the diagnosis of abdominal TB.However,an algorithm of these diagnostic methods leads to considerably higher precision in the diagnosis of this insidious disease which primarily necessitate a clinical awareness of this serious health problem.展开更多
The visual inspection is an economical and effective method for welding. For measuring the feature sizes of grooves,a method based on line structured light is presented. Firstly,an adaptive algorithm to extract the su...The visual inspection is an economical and effective method for welding. For measuring the feature sizes of grooves,a method based on line structured light is presented. Firstly,an adaptive algorithm to extract the subpixel centerline of structured light stripes is introduced to deal with the uneven width and grayscale distributions of laser stripes,which is based on the quadratic weighted grayscale centroid. By means of region-of-interest(ROI)division and image difference,an image preprocessing algorithm is developed for filtering noise and improving image quality. Furthermore,to acquire geometrical dimensions of various grooves and groove types precisely,the subpixel feature point extraction algorithm of grooves is designed. Finally, experimental results of feature size measuring show that the absolute error of measurement is 0.031—0.176 mm,and the relative error of measurement is 0.2%—3.6%.展开更多
AIM:To investigate differences in clinical features between diffuse-and focal-type autoimmune pancreatitis(AIP).METHODS:Based on radiological findings by computed tomography and/or magnetic resonance imaging,we divide...AIM:To investigate differences in clinical features between diffuse-and focal-type autoimmune pancreatitis(AIP).METHODS:Based on radiological findings by computed tomography and/or magnetic resonance imaging,we divided 67 AIP patients into diffuse type(D type) and focal type(F type).We further divided F type into head type(H type) and body and/or tail type(B/T type) according to the location of enlargement.Finally,we classified the 67 AIP patients into three groups:D type,H type and B/T type.We compared the three types of AIP in terms of clinical,laboratory,radiological,functional and histological findings and clinical course.RESULTS:There were 34 patients with D-type,19 with H-type and 14 with B/T-type AIP.Although obstructive jaundice was frequently detected in D-typepatients(88%) and H-type patients(68%),no B/T-type patients showed jaundice as an initial symptom(P < 0.001).There were no differences in frequency of abdominal pain,but acute pancreatitis was associated more frequently in B/T-type patients(36%) than in D-type patients(3%)(P = 0.017).Serum immunoglobulin G(IgG)4 levels were significantly higher in D-type patients(median 309 mg/dL) than in B/T-type patients(133.5 mg/dL)(P = 0.042).Serum amylase levels in B/T-type patients(median:114 IU/L) were significantly greater than in H-type patients(72 IU/L)(P = 0.049).Lymphoplasmacytic sclerosing pancreatitis(LPSP) was histologically confirmed in 6 D-type,7 H-type and 4 B/T-type patients;idiopathic duct-centric pancreatitis was observed in no patients.Marked fibrosis and abundant infiltration of CD20-positive B lymphocytes with few IgG4-positive plasma cells were detected in 2 B/T-type patients.Steroid therapy was effective in all 50 patients(31 D type,13 H type and 6 B/T type).Although AIP relapsed during tapering or after stopping steroids in 3 D-type and 3 H-type patients,no patients relapsed in B/T type.During follow-up,radiological features of 6 B/T-type patients were not changed and 1 B/T-type patient improved naturally.CONCLUSION:Clinical features of H-type AIP were similar to those of D-type,but B/T-type differed from D and H types.B/T-type may involve diseases other than LPSP.展开更多
AIM: To investigate and evaluate the pathological features and diagnostic value of focal nodular hyperplasia (FNH) with multiection spiral computed tomography (MSCT) and postprocessing. METHODS: A total of 25 pa...AIM: To investigate and evaluate the pathological features and diagnostic value of focal nodular hyperplasia (FNH) with multiection spiral computed tomography (MSCT) and postprocessing. METHODS: A total of 25 patients with FNH who had undergone MSCT and postprocessing were included in the investigation. All patients had been pathologically or clinically confirmed with FNH. A number of 75 cases of hepatic carcinomas, hemangiomas and adenomas were randomly selected at a same period for a comparative study. RESULTS: There was a single focus in 22 cases and multiple foci in 3 cases. On the plain scan, 17 lesions showed hypodensity, 7 isodensity and 4 hyperdensity (the case with fatty liver). With contrast, 28 lesions were enhanced evenly or in the nodules in the arterial phase; 13 lesions still showed hyperdensity, 11 lesions isodensity and 4 lesions hypodensity in the parenchymatous phase; in the delayed phase only 5 lesions showed hyperdensity but 9 lesions showed isodensity or slight hypodensity and 14 lesions showed hypodensity. Twelve lesions of 28 had central asteroid scars. Thickened feeding arteries in postprocessing were seen in 24 lesions, and were integrated into the parenchymatous lesions with a gradual and smooth course. On the contrary, there were no artery penetrated into the lesion found in any of comparative hepatic tumors. CONCLUSION: Doctors could make a correct diagnosis and differentiation of FNH on evaluation of the characteristic appearance on MSCT with postprocessing,展开更多
Objective To investigate the clinical characteristics and treatment strategy of lower extremity arterial occlusive disease in patients with Crohn's disease (CD). Methods Clinical information of 9 cases suffering f...Objective To investigate the clinical characteristics and treatment strategy of lower extremity arterial occlusive disease in patients with Crohn's disease (CD). Methods Clinical information of 9 cases suffering from lower extremity arterial occlusion and CD was investigated retrospectively. Results All the cases were less than 50 years old and the most were females (8/9). Arterial occlusions occurred in either active (5/9) or inactive (4/9) stage of CD. Besides the arteries of lower extremities, other arteries could also be involved such as aorta, iliac artery, renal artery or mesentery artery. Seven cases had atherosclerotic imaging findings (4 had aortic plaques and 6 had iliac artery stenoses). Embolectomy or thromboendarterectomy were mostly performed. Four (44.4%) cases had recurrent lower limb ischemia. Conclusions Arterial occlusive disease is a rare extraintestinal manifestation of CD. A thorough inspection of aorta is necessary. Embolectomy is mostly preferred. Anticoagulation treatment is highly recommended after the operation.展开更多
Arch is a typical complex structure comparing with beam and plate in bridge system. This paper investigates the damage characteristic combining the crack location with the crack intensity in arch. Initially, the first...Arch is a typical complex structure comparing with beam and plate in bridge system. This paper investigates the damage characteristic combining the crack location with the crack intensity in arch. Initially, the first four displacement modes of intact and different damaged arch are simulated and the displacement mode changes are obtained. Next, the wavelet transformation is applied to the displacement mode changes in arch and wavelet coefficients at damage loci are picked. Finally, the damage index including damage location and damage intensity in arch is provided and plotted. The results show that wavelet coefficient module maximum of mode changes can be the damage indicator and is influenced by damage location and damage intensity. The damage indicator is proportional to the damage intensity and present monotonic trend according to damage location which depend on the mode order. At the same time, the large modulus maximum corresponds to small damage combination of location and intensity in the first four modes.展开更多
Fiumara d'arte is an open-air museum of sculpture and contemporary art. Among the art-works of Fiumara d'arte, the Pyramid is the last one in order of time. It is a monumental sculpture made of COR-TEN steel, by the...Fiumara d'arte is an open-air museum of sculpture and contemporary art. Among the art-works of Fiumara d'arte, the Pyramid is the last one in order of time. It is a monumental sculpture made of COR-TEN steel, by the artist Mauro Staccioli and it is located on one specific point of the 38th parallel of latitude, on a hill of the northern mountains of Sicily. In this study the architectural and engineering features of land art-works built in this particular plein-air park are examined and discussed. After a general description of Fiumara d'Arte and its significance in the territory, the case of the Pyramid on the 38th parallel is focalized and a discussion of its architectural, artistic and environmental values is reported. Moreover the structural implications in its design and construction are explained, while the worst effects of external actions are underlined by showing the results of the analysis performed on a finite element model of the whole structure.展开更多
Objective: To analyze the clinical characteristics and medical treatment of hospitalized patients with chronic heartfailure, and provide medication for the patients. Methods: According to medical records of inpatien...Objective: To analyze the clinical characteristics and medical treatment of hospitalized patients with chronic heartfailure, and provide medication for the patients. Methods: According to medical records of inpatients, demographicinformation, etiology, clinical features and treatment information were collected. Results: A total of 610 cases withheart failure from our hospital between July 2010 and June 2016 were analyzed. The average age of all the patientswas 63. Males accounted for 50.49%. There were 82.7% patients with NYHA functional classification at III-IV.31.3% patients with coronary artery disease, 28.4% with rheumatic heart diseases and 21.8% with expansion ofheart disease. 27.4 percent of the patients with the left ventricular ejection fraction lower than 40%. There were78.9% patients received aldosterone antagonist treatment, 63.4% received ACEI/ARB, 62.1% received digoxin,59.8% received beta blockers, and 75.4% patients received decoction, and 80.8% received Chinese patent medicine.Conclusion: The study has shown that high utilization of traditional Chinese medicine is to highlight theadvantages of the combination of traditional Chinese and western medicine in the treatment of heart failure. Theusage of spironolactone, ACEI/ARB, beta blockers in our hospital was lower than the ratio reported, higher thanthat of the national average. However, the use of diureticis is lower than that of national average, which may relateto the use of damp-clearing herbs. Clinicians should pay attention to the high utilization rate of digoxin. Patientswith the left ventricular ejection fraction 〉 50% accounted for 61.1%, which required more attention should be paidto the diagnosis and treatment of patients with heart failure of the ejection fraction remains.展开更多
文摘An optimal allocation of earth is of great significance to reduce the project cost and duration in the construction of rock-fill dams. The earth allocation is a dynamic system affected by various time-space constraints. Based on previous studies, a new method of optimizing this dynamic system as a static one is presented. In order to build a generalized and flexible model of the problem, some man-made constraints were investigated in building the mathematic model. Linear programming and simplex method are introduced to solve the optimization problem of earth allocation. A case study in a large-scale rock-fill dam construction project is presented to demonstrate the proposed method and its successful application shows the feasibility and effectiveness of the method.
基金Supported by National Natural Science Fund(30670230)~~
文摘To understand the structure of GABAergic neurons in the VMP and "barrel", the distribution of GABAergic neurons in the two areas were studied through immunohistochemistry and Laser Scanning Confocal Microscope. The results show that the distribution of GABAergic neurons in VMP and barrel are different, and the coding of information transmission in the two areas are also dissimilar; GABAergic neurons mainly distribute among the lines asymmetrically in VMP, the somata, dendrite and axon of GABAergic neurons are restricted in the "barrel", rarely having synaptic connections with other "barrel" around. Therefore, VMP and barrel may have different roles in transmission and on processing of informatiton.
文摘AIM: To compare the racial differences of anatomical distribution of colorectal cancer (CRC) and determine the association of age, gender and time with anatomical distribution between patients from America (white) and China (oriental).METHODS: Data was collected from 690 consecutive patients in Cleveland Clinic Florida, U.S.A. and 870consecutive patients in Nan Fang Hospital affiliated to the First Military Medical University, China over the past 11years from 1990 to 2000. All patients had colorectal adenocarcinoma diagnosed by histology and underwent surgery.RESULTS: The anatomical subsite distribution of tumor,age and gender were significantly different between white and oriental patients. Lesions in the proximal colon (P<0.001) were found in 36.3 % of white vs 26.0 % of oriental patients and cancers located in the distal colon and rectum in 63.7 % of white and 74 % of oriental patients (P<0.001). There was a trend towards the redistribution from distal colon and rectum to proximal colon in white males over time, especially in older patients (>80 years).No significant change of anatomical distribution occurred in white women and Oriental patients. The mean age at diagnosis was 69.0 years in white patients and 48.3 years in Oriental patients (P<0.001).CONCLUSION: This is the first study comparing the anatomical distribution of colorectal cancers in whites and Chinese patients. White Americans have a higher risk of proximal CRC and this risk increased with time. The proportion of white males with CRC also increased with time.Chinese patients were more likely to have distal CRC and developed the disease at a significantly earlier age than white patients. These findings have enhanced our understanding of the disease process of colorectal cancer in these two races.
文摘Inflammation of axial and/or peripheral joints is one of the most frequent extra-intestinal manifestations complicating the clinical course and therapeutic approach in inflammatory bowel diseases(IBD).The frequency of these complications seems to be similar for both diseases, Crohn's disease and ulcerative colitis.Arthritis associated with IBD belongs to the category of spondyloarthropathies.Axial involvement ranges from isolated inflammatory back pain to ankylosing spondylitis, whereas peripheral arthritis is noted in pauciarticular and in polyarticular disease.Asymptomatic radiological involvement of the sacroiliac joints is reported to occur in up to 50% of patients.Other musculoskeletal manifestations such as buttock pain, dactylitis, calcaneal enthesitis, and thoracic pain are frequently underdiagnosed and, consequently, are not treated appropriately.Several diagnostic approaches and criteria have been proposed over the past 40 years in an attempt to correctly classify and diagnose such manifestations.The correct recognition of spondylarthropathies needs an integrated multidisciplinary approach in order to identify common therapeutic strategies, especially in the era of the new biologic therapies.
文摘Abstract: The shortest path problem in a network G is to find shortest paths between some specified source vertices and terminal vertices when the lengths of edges are given. The structure of the optimal solutions set on the shortest paths is studied in this paper. First, the conditions of having unique shortest path between two distinguished vertices 8 and t in a network G are discussed; Second, the structural properties of 2-transformation ^-G graph G on the shortest-paths for G are presented heavily.
文摘Architecture singularity of a parallel mechanism with five degrees of freedom (DOF) is analyzed. Such mechanism consists of a movable platform connected to the base by five active limbs. Four of them are identical 6-DOF limbs and the last one has the same DOF as the specified DOF of the movable platform. Based on the kinematics analysis, two categories of architecture singularities for such mechanism are proposed. Then the sufficient condition for each singularity is researched. Results show that the mechanism is singular when it employs each category of the proposed architecture, provided that it satisfies the corresponding sufficient condition. It can be concluded that the proposed two categories of architecture singularities should be avoided with the following dimensional synthesis of such mechanism.
文摘In order to obtain the principle of Pantadome lifting process and make theoretical foundation for practical applications, the core idea of Pantadome was introduced, which is to make a structure become a mechanism by temporarily removing some members during the process of construction.The Abstract motion model was built. By determining the change of the coordinates of the hinge joint and that of each point of the structure, simulative analysis of the mechanical motion of Pantadome was realized. Then general program that simulates the lifting process of Pantadome was developed based on AutoCAD environment by Auto Lisp language. By completing the theoretical analysis of the lifting process of Pantadome, three-dimensional simulation of the lifting process of Pantadome was realized. And it is successfully applied to bidding work of practical engineering.
基金Supported by New Century Excellent Talents in University in China(NCET),National"973" Program(No.61338)Innovative Research Project of Xi'an Hi-Tech Institute(EPXY0806)
文摘A meshiess local discontinuous Petrov-Galerkin (MLDPG) method based on the local symmetric weak form (LSWF) is presented with the application to blasting problems. The derivation is similar to that of mesh-based Runge-Kutta Discontinuous Galerkin (RKDG) method. The solutions are reproduced in a set of overlapped spherical sub-domains, and the test functions are employed from a partition of unity of the local basis functions. There is no need of any traditional nonoverlapping mesh either for local approximation purpose or for Galerkin integration purpose in the presented method. The resulting MLDPG method is a meshless, stable, high-order accurate and highly parallelizable scheme which inherits both the advantages of RKDG and meshless method (MM), and it can handle the problems with extremely complicated physics and geometries easily. Three numerical examples of the one-dimensional Sod shock-tube problem, the blast-wave problem and the Woodward-Colella interacting shock wave problem are given. All the numerical results are in good agreement with the closed solutions. The higher-order MLDPG schemes can reproduce more accurate solution than the lower-order schemes.
文摘Objective: The aim of our study was to evaluate the pathological features of posterior echo attenuation of papillary thyroid microcarcinoma (PTMC) and cystic degeneration of cervical lymph node metastasis. Methods: We retrospectively evaluated the ultrasound results from 36 cases of PTMC with 20 nodules of cystic degeneration of cervical lymph node metastasis and correlated the results with the histopathologic findings. Results: The preliminary study indicated certain correlation between histopathologic findings and ultrasound results of posterior echo attenuation of papillary thyroid microcarcinoma and cystic degeneration of cervical lymph node metastasis. Conclusion: Posterior echo attenuation detected by ultrasound was associated with fibrous structures in PTMC nodules, while cystic degeneration and papillary changes of cervical lymph node metastasis in PTMC showed liquefactive necrosis, degenerative changes and enlarged follicular of nodular structures.
文摘AIM:To evaluate the clinical,radiological and microbiological properties of abdominal tuberculosis (TB) and to discuss methods needed to get the diagnosis. METHODS:Thirty-one patients diagnosed as abdominal TB between March 1998 and December 2001 at the Gastroenterology Department of Kartal State Hospital, Istanbul,Turkey were evaluated prospectively.Complete physical examination,medical and family history,blood count erythrocyte sedimentation rate,routine biochemical tests, Mantoux skin test,chest X-ray and abdominal ultrasonography (USG) were performed in all cases,whereas microbiological examination of ascites,upper gastrointestinal endoscopy,colonoscopy or barium enema,abdominal tomography,mediastinoscopy,laparoscopy or laparotomy were done when needed. RESULTS:The median age of patients (14 females,17 males) was 34.2 years (range 15-65 years).The most frequent symptoms were abdominal pain and weight loss. Eleven patients had active pulmonary TB.The most common abdominal USG findings were ascites and hepatomegaly.Ascitic fluid analysis performed in 13 patients was found to be exudative and acid resistant bacilli were present in smear and cultured only in one patient with BacTec (3.2%).Upper gastrointestinal endoscopy yielded nonspecific findings in 16 patients.Colonoscopy performed in 20 patients showed ulcers in 9 (45%),nodules in 2 (10%) and,stricture,polypoid lesions,granulomatous findings in terminal ileum and rectal fistula each in one patient (5%). Laparoscopy on 4 patients showed dilated bowel loops, thickening in the mesentery,multiple ulcers and tubercles on the peritoneum.Patients with abdominal TB were divided into three groups according to the type of involvement. Fifteen patients (48%) had intestinal TB,11 patients (35.2%) had tuberculous peritonitis and 5 (16.8%) tuberculous lymphadenitis.The diagnosis of abdominal TB was confirmed microbiologically in 5 (16%) and histo- pathologically in 19 patients (60.8%).The remaining nine patients (28.8%) had been diagnosed by a positive response to antituberculous treatment. CONCLUSION:Neither clinical signs,laboratory,radiological and endoscopic methods nor bacteriological and histopathological findings provide a gold standard by themselves in the diagnosis of abdominal TB.However,an algorithm of these diagnostic methods leads to considerably higher precision in the diagnosis of this insidious disease which primarily necessitate a clinical awareness of this serious health problem.
基金supported by the National Natural Science Foundation of China(No. 51975293)the Aeronautical Science Foundation of China (No. 2019ZD052010)。
文摘The visual inspection is an economical and effective method for welding. For measuring the feature sizes of grooves,a method based on line structured light is presented. Firstly,an adaptive algorithm to extract the subpixel centerline of structured light stripes is introduced to deal with the uneven width and grayscale distributions of laser stripes,which is based on the quadratic weighted grayscale centroid. By means of region-of-interest(ROI)division and image difference,an image preprocessing algorithm is developed for filtering noise and improving image quality. Furthermore,to acquire geometrical dimensions of various grooves and groove types precisely,the subpixel feature point extraction algorithm of grooves is designed. Finally, experimental results of feature size measuring show that the absolute error of measurement is 0.031—0.176 mm,and the relative error of measurement is 0.2%—3.6%.
基金Supported by The Research Committee of Intractable Pancreatic Diseases (Principal investigatorTooru Shimosegawa) provided by the Ministry of Health, Labour and Welfare of Japan
文摘AIM:To investigate differences in clinical features between diffuse-and focal-type autoimmune pancreatitis(AIP).METHODS:Based on radiological findings by computed tomography and/or magnetic resonance imaging,we divided 67 AIP patients into diffuse type(D type) and focal type(F type).We further divided F type into head type(H type) and body and/or tail type(B/T type) according to the location of enlargement.Finally,we classified the 67 AIP patients into three groups:D type,H type and B/T type.We compared the three types of AIP in terms of clinical,laboratory,radiological,functional and histological findings and clinical course.RESULTS:There were 34 patients with D-type,19 with H-type and 14 with B/T-type AIP.Although obstructive jaundice was frequently detected in D-typepatients(88%) and H-type patients(68%),no B/T-type patients showed jaundice as an initial symptom(P < 0.001).There were no differences in frequency of abdominal pain,but acute pancreatitis was associated more frequently in B/T-type patients(36%) than in D-type patients(3%)(P = 0.017).Serum immunoglobulin G(IgG)4 levels were significantly higher in D-type patients(median 309 mg/dL) than in B/T-type patients(133.5 mg/dL)(P = 0.042).Serum amylase levels in B/T-type patients(median:114 IU/L) were significantly greater than in H-type patients(72 IU/L)(P = 0.049).Lymphoplasmacytic sclerosing pancreatitis(LPSP) was histologically confirmed in 6 D-type,7 H-type and 4 B/T-type patients;idiopathic duct-centric pancreatitis was observed in no patients.Marked fibrosis and abundant infiltration of CD20-positive B lymphocytes with few IgG4-positive plasma cells were detected in 2 B/T-type patients.Steroid therapy was effective in all 50 patients(31 D type,13 H type and 6 B/T type).Although AIP relapsed during tapering or after stopping steroids in 3 D-type and 3 H-type patients,no patients relapsed in B/T type.During follow-up,radiological features of 6 B/T-type patients were not changed and 1 B/T-type patient improved naturally.CONCLUSION:Clinical features of H-type AIP were similar to those of D-type,but B/T-type differed from D and H types.B/T-type may involve diseases other than LPSP.
文摘AIM: To investigate and evaluate the pathological features and diagnostic value of focal nodular hyperplasia (FNH) with multiection spiral computed tomography (MSCT) and postprocessing. METHODS: A total of 25 patients with FNH who had undergone MSCT and postprocessing were included in the investigation. All patients had been pathologically or clinically confirmed with FNH. A number of 75 cases of hepatic carcinomas, hemangiomas and adenomas were randomly selected at a same period for a comparative study. RESULTS: There was a single focus in 22 cases and multiple foci in 3 cases. On the plain scan, 17 lesions showed hypodensity, 7 isodensity and 4 hyperdensity (the case with fatty liver). With contrast, 28 lesions were enhanced evenly or in the nodules in the arterial phase; 13 lesions still showed hyperdensity, 11 lesions isodensity and 4 lesions hypodensity in the parenchymatous phase; in the delayed phase only 5 lesions showed hyperdensity but 9 lesions showed isodensity or slight hypodensity and 14 lesions showed hypodensity. Twelve lesions of 28 had central asteroid scars. Thickened feeding arteries in postprocessing were seen in 24 lesions, and were integrated into the parenchymatous lesions with a gradual and smooth course. On the contrary, there were no artery penetrated into the lesion found in any of comparative hepatic tumors. CONCLUSION: Doctors could make a correct diagnosis and differentiation of FNH on evaluation of the characteristic appearance on MSCT with postprocessing,
文摘Objective To investigate the clinical characteristics and treatment strategy of lower extremity arterial occlusive disease in patients with Crohn's disease (CD). Methods Clinical information of 9 cases suffering from lower extremity arterial occlusion and CD was investigated retrospectively. Results All the cases were less than 50 years old and the most were females (8/9). Arterial occlusions occurred in either active (5/9) or inactive (4/9) stage of CD. Besides the arteries of lower extremities, other arteries could also be involved such as aorta, iliac artery, renal artery or mesentery artery. Seven cases had atherosclerotic imaging findings (4 had aortic plaques and 6 had iliac artery stenoses). Embolectomy or thromboendarterectomy were mostly performed. Four (44.4%) cases had recurrent lower limb ischemia. Conclusions Arterial occlusive disease is a rare extraintestinal manifestation of CD. A thorough inspection of aorta is necessary. Embolectomy is mostly preferred. Anticoagulation treatment is highly recommended after the operation.
文摘Arch is a typical complex structure comparing with beam and plate in bridge system. This paper investigates the damage characteristic combining the crack location with the crack intensity in arch. Initially, the first four displacement modes of intact and different damaged arch are simulated and the displacement mode changes are obtained. Next, the wavelet transformation is applied to the displacement mode changes in arch and wavelet coefficients at damage loci are picked. Finally, the damage index including damage location and damage intensity in arch is provided and plotted. The results show that wavelet coefficient module maximum of mode changes can be the damage indicator and is influenced by damage location and damage intensity. The damage indicator is proportional to the damage intensity and present monotonic trend according to damage location which depend on the mode order. At the same time, the large modulus maximum corresponds to small damage combination of location and intensity in the first four modes.
文摘Fiumara d'arte is an open-air museum of sculpture and contemporary art. Among the art-works of Fiumara d'arte, the Pyramid is the last one in order of time. It is a monumental sculpture made of COR-TEN steel, by the artist Mauro Staccioli and it is located on one specific point of the 38th parallel of latitude, on a hill of the northern mountains of Sicily. In this study the architectural and engineering features of land art-works built in this particular plein-air park are examined and discussed. After a general description of Fiumara d'Arte and its significance in the territory, the case of the Pyramid on the 38th parallel is focalized and a discussion of its architectural, artistic and environmental values is reported. Moreover the structural implications in its design and construction are explained, while the worst effects of external actions are underlined by showing the results of the analysis performed on a finite element model of the whole structure.
文摘Objective: To analyze the clinical characteristics and medical treatment of hospitalized patients with chronic heartfailure, and provide medication for the patients. Methods: According to medical records of inpatients, demographicinformation, etiology, clinical features and treatment information were collected. Results: A total of 610 cases withheart failure from our hospital between July 2010 and June 2016 were analyzed. The average age of all the patientswas 63. Males accounted for 50.49%. There were 82.7% patients with NYHA functional classification at III-IV.31.3% patients with coronary artery disease, 28.4% with rheumatic heart diseases and 21.8% with expansion ofheart disease. 27.4 percent of the patients with the left ventricular ejection fraction lower than 40%. There were78.9% patients received aldosterone antagonist treatment, 63.4% received ACEI/ARB, 62.1% received digoxin,59.8% received beta blockers, and 75.4% patients received decoction, and 80.8% received Chinese patent medicine.Conclusion: The study has shown that high utilization of traditional Chinese medicine is to highlight theadvantages of the combination of traditional Chinese and western medicine in the treatment of heart failure. Theusage of spironolactone, ACEI/ARB, beta blockers in our hospital was lower than the ratio reported, higher thanthat of the national average. However, the use of diureticis is lower than that of national average, which may relateto the use of damp-clearing herbs. Clinicians should pay attention to the high utilization rate of digoxin. Patientswith the left ventricular ejection fraction 〉 50% accounted for 61.1%, which required more attention should be paidto the diagnosis and treatment of patients with heart failure of the ejection fraction remains.