SYNTHESIS AND PHOTOELECTRIC PROPERTIES OF PERYLENE RED PIGMENTS

A series of N, N′ dialkyl (and aryl) perylene 3,4:9, 10 bis (dicarboximide) compounds were prepared and purified, and their photoelectric properties as organic photoconductors were explored. It is found that N, N′ dimethyl perylene 3,4:9, 10 bis (dicarboximide) and perylene 3,4:9,10 tetracarboxylic acid bisbenzimidazole show excellent photoconductivities, their charge acceptance reaches 700 V and 485 V, and the photosensitivity is 45 lx·s and 10 lx·s with dark decays 70 and 60 V/s respectively. The introduction of chlorine atoms can improve their photoelectric properties. SEM analyses also show that the dispersion of pigment in OPC could affect its photosensitivity.

十六字方针是统战工作的基本方针

新时期的爱国统一战线,是一个由不同阶级、阶层和社会集团组成的广泛的政治联盟,不可避免地会存在各种差别和矛盾。按正确的方针处理统一战线内部的各种矛盾,协调统一战线内部的关系,才能使新时期的统一战线得到巩固和扩大。胡耀邦同志在党的十二大报告中强调的“长期共存,互相监督”,“肝胆相照,荣辱与共”,就是党在新的历史时期正确处理各方面关系,做好统战工作的唯一正确方针。

Laparo-endoscopic “Rendezvous” to treat cholecysto-choledocolithiasis: Effective,safe and simplifies the endoscopist’s work

AIM: To investigate our clinical experience with combined laparo-endoscopic Rendezvous (RV) for the treatment of patients affected by gallstones and common bile duct (CBD) stones and especially to study the never evaluated opinion of the endoscopist concerning the difficulty of the intraoperative endoscopic procedure during the RV in comparison with standard endoscopic retrograde cholangio-pancreatography (ERCP). METHODS: Eighty consecutive patients affected by cholecystolithiasis and diagnosed or suspected CBD stones were treated with a standardized "tailored" RV. The relevant technical features, the feasibility, the effectiveness in stone clearance, the safety but also the simple evaluation of difficulty and agreement of the endoscopist were analyzed with a questionnaire. RESULTS: The feasibility was 97.5% and the effectiveness 100% concerning CBD clearance and solution of coexisting problems at the papilla. Minor morbidity was 3.3%, the operating time was prolonged by a mean of 14 min, the mean hospital stay was 3.8 d and only one stone’s recurrence occurred. The endoscopist evaluated the procedure to be simpler than standard ERCP-ES in 81.2% of the cases.CONCLUSION: Simultaneous RV carries higheffectiveness and safety at least comparable to those reported for other options. The endoscopist is very often satisfied with this approach because of the minimization of some steps of the endoscopic procedure and avoidance of relevant iatrogenic risk factors. If the mandatory collaboration between surgeons and endoscopists is guaranteed, this approach can often be preferable for the patient, the surgeon, the endoscopist and the hospital.

MRI and PET images fusion based on human retina model

The diagnostic potential of brain positron emission tomography （PET） imaging is limited by low spatial resolution. For solving this problem we propose a technique for the fusion of PET and MRI images. This fusion is a trade-off between the spectral information extracted from PET images and the spatial information extracted from high spatial resolution MRI. The proposed method can control this trade-off. To achieve this goal, it is necessary to build a multiscale fusion model, based on the retinal cell photoreceptors model. This paper introduces general prospects of this model, and its application in multispectral medical image fusion. Results showed that the proposed method preserves more spectral features with less spatial distortion. Comparing with hue-intensity-saturation （HIS）, discrete wavelet transform （DWT）, wavelet-based sharpening and wavelet-a trous transform methods, the best spectral and spatial quality is only achieved simultaneously with the proposed feature-based data fusion method. This method does not require resampling images, which is an advantage over the other methods, and can perform in any aspect ratio between the pixels of MRI and PET images.

Coincidence of hepatocelluar carcinoma and hepatic angiomyolipomas in tuberous sclerosis complex: A case report

Tuberous sclerosis complex (TSC) is a dominantly inherited disorder which characterized by the growth of harmatomatous in multiple organs. Unlike the common development of renal angiomyolipoma, hepatic angiomyolipoma rarely occur in patients with TSC. We report here a patient with hepatic angiomyolipomas and concurrent hepatocellular carcinoma in TSC. This represents the first reported case in English literature. In this patient, multiple hepatic angiomyolipomas were diagnosed with recognition of their fat components and typical clinical settings. Hepatocellular carcinoma in the left liver lobe was definitely diagnosed by US guided biopsy. In such clinical settings, fat containing lesions in liver can be reasonably treated as angiomyolipomas, but non fat containing lesions must be differentiated from hepatocellular carcinoma, imaging guided biopsy can be adopted to confirm the diagnosis.

Role of 18F-fluorodeoxyglucose positron emission tomography imaging in surgery for pancreatic cancer

AIM： To evaluate the role of positron emission tomography using 18F-fluorodeoxyglucose （FDG-PET） in the surgical management of patients with pancreatic cancer, including the diagnosis, staging, and selection of patients for the subsequent surgical treatment. METHODS： This study involved 53 patients with proven primary pancreatic cancer. The sensitivity of diagnosing the primary cancer was examined for FDG-PET CT, cytological examination of the bile or pancreatic juice, and the serum levels of carcinoembrionic antigens （CEA） and carbohydrate antigen 19-9 （CA29-9）. Next, the accuracy of staging was compared between FDG-PET and CT. Finally, FDG-PET was analyzed semiquantitatively using the standard uptake value （SUV）. The impact of the SUV on patient management was evaluated by examining the correlations between the SUV and the histological findings of cancer. RESULTS： The sensitivity of FDG-PET, CT, cytological examination of the bile or pancreatic juice, and the serum levels of CEA and CA19-9 were 92.5%, 88.7%, 46.4%, 37.7% and 69.8%, respectively. In staging, FDG-PET was superior to CT only in diagnosing distant disease （bone metastasis）. For local staging, the sensitivity of CT was better than that of FDG-PEr. The SUV did not correlate with the pTNM stage, grades, invasions to the vessels and nerve, or with the size of the tumor. However, there was a statistically significant difference （4.6 ± 2.9 vs 7.8 ± 4.5, P = 0.024） in the SUV between patients with respectable and unresectable disease. CONCLUSION： FDG-PET is thus considered to be useful in the diagnosis of pancreatic cancer. However, regarding the staging of the disease, FDG-PET is not considered to be a sufficiently accurate diagnostic modality. Although the SUV does not correlate with the patho-histological prognostic factors, it may be useful in selecting patients who should undergo subsequent surgical treatment.

Real-time continuous-wave imaging with a 1.63THz OPTL and a pyroelectric camera

Real-time continuous-wave terahertz imaging is demonstrated with a 1.63 THz （184.31 lam） optically-pumped terahertz laser （OPTL） and a 124 × 124 element room-temperature pyroelectric camera. Transmission-mode THz imaging is presented for the samples hidden in various wrapping materials. These experimental results reveal the possibility to construct a simple real-time THz imaging system applied to nondestructive inspection.

Significance of scintigraphy for the localisation of obscure gastrointestinal bleedings

AIM： To determine the role of scintigraphy in patients with gastrointestinal （GI） bleeding of unknown Iocalisation. METHODS： We performed retrospective analyses on 92 patients receiving scintigraphies from 1993 to 2000 in the University of Regensburg hospital, which were done for Iocalisation of GI bleeding as a diagnostic step after an unsuccessful endoscopy. In addition to the scintigraphies, further diagnostic steps such as endoscopy, angiography or operations were performed. In some of the scintigraphies with negative results, a provocation test for bleeding with heparinisation was carried out. RESULTS： 73% of all scintigraphies showed a positive result. In 4.5% of the positive results, the source was located in the stomach, in 37% the source was the small bowel, in 25% the source was the right colon, in 4.5% the source was the left colon, and in 20% no clear Iocalisation was possible. Only 4% of all scintigraphies were false positive. A reliable positive scintigraphy was independent of the age of the examined patient. A provocation test for bleeding with heparin resulted in an additional 46% of positive scintigraphies with a reliable Iocalisation in primary negative scintigraphies. CONCLUSION- Our results show that scintigraphy and scintigraphy with heparin provocation tests are reliable procedures. They enable a reliable Iocalisation in about half of the obscure GI-bleeding cases. Scintigraphy is superior to angiography in locating a bleeding. It is shown that even in the age of video capsule endoscopy and double-balloon enteroscopy, scintigraphy provides a reliable and directed localization of GI bleeding and offers carefully targeted guidance for other procedures.

Principle of Coordinates Acquisition Based on Single Camera

The principle and accuracy of 3-D coordinates acquisition using one single camera and the Aided Measuring Probe(AMP) are discussed in this paper. Using one single camera and one AMP which has several embedded targets and one tip with known coordinates, the single camera′s orientation and location can be calculated. After orientation, the global coordinate system is obtained. During measurement, the camera is fixed firstly, then the AMP is held and the feature point is touched.The camera is triggered lastly. The position and orientation of the AMP are therefore calculated from the size and position of its image on the sensor. Since the tip point of AMP has known relation with the embedded targets, the feature point can be measured. Tests show that the accuracy of length measurement is 0.2 mm and accuracy for flatness measurement in XSY-plane is 0.1 mm.

Color compensation for multi-view video coding based on diversity of cameras

A novel color compensation method for multi-view video coding (MVC) is proposed, which efficiently exploits the inter-view dependencies between views with the existence of color mismatch caused by the diversity of cameras. A color compensation model is developed in RGB channels and then extended to YCbCr channels for practical use. A modified inter-view reference picture is constructed based on the color compensation model, which is more similar to the coding picture than the original inter-view reference picture. Moreover, the color compensation factors can be derived in both encoder and decoder, therefore no additional data need to be transmitted to the decoder. The experimental results show that the proposed method improves the coding efficiency of MVC and maintains good subjective quality.

STUDY ON MODERATORS OF SMALL－SIZE NEUTRON RADIOGRAPHY INSTALLATIONS WITH NEUTRON TUBE AS SOURCE

Calculation of moderator analogues for 14 MeV neutrons as source were made at a IBM/PC AT computer using TAMAKER-ANISN program and 46 groups (25 neutron groups, 21 photon groups) UW cross section data. The intensifying effect of lead and natural uranium for moderating 14 MeV neutrons is confirmed. Adopting proper structure of the moderator, the intensifying factor M (times) may be larger than 3. Using lead and natural uranium in sub-critical assemblies (or call boosters),with 14 MeV neutrons as source, with the same dimension as that of above, the intensifying effect is also condrmed. With a proper structure of sub-critical assembly,the intensifying factor M may be close to or eved larger than (1 - k)-1 where k isthe effective multiplication factor.

Clinical study of digital mammography,contrast-enhanced MRI as well as their combination in the diagnosis of breast cancer

Objective： To compare the effectiveness of digital mammography and MRI in the detection and diagnosis of breast cancer and to assess the value of these modalities as well as the combination of the two. Methods： Sixty-seven patients with surgery and pathology proved breast lesion （malignant, n = 32; benign, n = 46） underwent digital mammography and MRI, the pulse sequences included T1WI, T2WI, diffuse weighted imaging （DWI）, and dynamic contrast-enhanced MRI before surgery. Of the results of these two modalities, all lesions were classified into 5 groups according to BI-RADS classification, and the imaging findings were correlated to histopathology. The sensitivity and specificity of each modality as well as the combination of the two were calculated. Results： Of these 78 breasts lesions, The sensitivity was 78.13%% （25/32） for digital mammography and 93.75% （30/32） for MRI （P 〉 0.05）. The specificity was 73.91%% （34/46） and 89.13% （41/46） accordingly （P 〈 0.05）, both of them showed statistical difference. The sensitivity and specificity was 98.63% and 97.16% respectively as these two modalities were used in combination. Conclusion： Digital mammography in combination with MRI is helpful in the diagnosis of breast cancer, the sensitivity and specificity was enhanced when compared to that of single modality.

Development of a Three-Dimensional Measuring System for Neonates' Head and Facial Morphology

A web camera based multi-camera convergent close-range photogrammetric system is developed to obtain the neonates＇ head and facial morphology. The data will then be used to develop a secure and good-fitting eye-patch protector for neonates, particularly whoa they are exposed to bright lights such as phototherapy light. Measurements obtained by the system are evaluated and validated against data obtained from optical scanning. Results show that the photogrammetric system meets the requirements of measuring accuracy and safety for neonate in the neonatal units.

A Target-Orientated Marker Image Binarization Method for Orthopaedic Surgical Navigation System

Camera calibration is the key technique in a C-arm based orthopaedic surgical navigation system. The extraction of marker location information is a necessary step in the calibration process. Ideal marker images should possess uniform background and contain marker shadow only, but in fact marker images always possess nonuniform background and are contaminated by noise and unwanted anatomic information, making the extraction very difficult. A target-orientated marker shadow extraction method was proposed. With this method a proper threshold for marker image binarization can be determined.

Highly metabolic thrombus of the portal vein:^(18)F fluorodeoxyglucose positron emission tomography/computer tomography demonstration and clinical significance in hepatocellular carcinoma

AIM： To assess the ability of ^18F-fluorodeoxyglucose positron emission tomography/computer tomography （^18F-FDG PET/CT） to differentiate between benign and malignant portal vein thrombosis in hepatocellular carcinoma （HCC） patients.METHODS： Five consecutive patients who had HBV cirrhosis, biopsy-proven HCC, and thrombosis of the main portal vein and/or left/right portal vein on ultrasound （US）, computer tomography （CT） or magnetic resonance imaging （MRI） were studied with ^18F-FDG PET/CT. The presence or absence of a highly metabolic thrombus on ^18F-FDG PET/CT was considered diagnostic for malignant or benign portal vein thrombosis, respectively. All patients were followed-up monthly with US, CT or MRI. Shrinkage of the thrombus or recanalization of the vessels on US, CT or MRI during follow-up was considered to be definitive evidence of the benign nature of the thrombosis, whereas enlargement of the thrombus, disruption of the vessel wall, and parenchymal infiltration over follow-up were considered to be consistent with malignancy. ^18SF-FDG PET/CT, and US, CT or MRI results were compared.RESULTS： Follow-up （1 to 10 mo） showed signs of malignant thrombosis in 4 of the 5 patients. US, CT or MRI produced a true-positive result for malignancy in 4 of the patients, and a false-positive result in 1. ^18F-FDG PET/CT showed a highly metabolic thrombus in 4 of the 5 patients. ^18F-FDG PET/CT achieved a true-positive result in all 4 of these patients, and a true-negative result in the other patient. No false-positive result was observed using ^18F-FDG PET/CT.CONCLUSION： ^18F-FDG PET/CT may be helpful in discriminating between benign and malignant portal vein thrombi. Patients may benefit from ^18F-FDG PET/CT when portal vein thrombi can not be diagnosed exactly by US, CT or MRI.

Investigating the role of^(99m)Tc-TRODAT-1 SPECT imaging in idiopathic Parkinson's disease

Objective:To investigate the role of ^(99m)Tc-TRODAT-1 SPECT in diagnosis and assessing severity of idiopathicParkinson's disease(PD).Methods:Thirty-eight patients with primary,tentative diagnosis of PD and eighteen age-matchednormal controls were studied with ^(99m)Tc-TRODAT-1 SPECT imaging.The regions of interests(ROIs)were drawn manually oncerebellum(CB),occipital cortex(OC)and three transverse plane slice-views of striatums,the semiquantitative BG(back-ground)/[(OC+CB)/2]were then calculated.Results:A lower uptake of ^(99m)Tc-TRODAT-1 in striatums were displayed inthirty-six out of thirty-eight PD patients by visual inspection,compared to controls.In twenty-four PD cases with HYS(Hoehn andYahr scale)stage Ⅰ,a greater loss of DAT uptake was found in striatum and its subregions contralateral striatum to the affectedlimbs than in the same regions of the controls,although the striatal uptake was bilaterally reduced.Using Spearman correlationanalysis showed that the reduction of the uptake ratios significantly correlated with the UPDRS in striatum and all its subregions inthe PD group(P<0.05),a similar change was also found in the putamen by using the rating scale of Hoehn and Yahr (P<0.05).However,analysis of variance(ANOVA)did not show any relationship between the decreasing uptake of ^(99m)Tc-TRODAT-1 andincreasing severity of PD patients,although the specific uptake of ^(99m)Tc-TRODAT-1 was continuously decreased in the striatumby visual inspection with the progress of PD from HYS stage Ⅰ to Ⅲ.Conclusion:^(99m)Tc-TRODAT-1 SPECT imaging may serve asa useful method for improving the correct diagnosis of PD.In assessing the role of ^(99m)Tc-TRODAT-1 SPECT in disease severity ofPD,UPDRS can offer a comprehensive index,although the Hoehn and Yahr assessment may be available in part.

A practical iterative two-view metric reconstruction with uncalibrated cameras

This paper presents a practical iterative algorithm for two-view metric reconstruction without any prior knowledge about the scene and motion in a nonsingular geometry configuration. The principal point is assumed to locate at the image center with zero skew and the same aspect ratio, and the interior parameters are fixed, so the self-calibration becomes focal-length cali- bration. Existing focal length calibration methods are direct solutions of a quadric composed of fundamental matrix, which are sensitive to noise. A quaternion-based linear iterative Least-Square Method is proposed in this paper, and one-dimensional searching for optimal focal length in a constrained region instead of solving optimization problems with inequality constraints is applied to simplify the computation complexity, then unique rotational matrix and translate vector are recovered. Experiments with simulation data and real images are given to verify the algorithm.

New Measurement of Swaying Quantity and Multi-barrel Parallelism for Rocket Launcher

By analyzing the deficiencies of the method, a measurement system with the technologies of photoelectricity, laser and digital image processing to synthetically measure these two parameters has been developed. A traditional method to measure the swaying quantity and multi-barrel parallelism of rocket launcher is introduced. Meanwhile, the principle, executive plan and the accuracy analysis are also presented. The photoelectric measurement system has been applied in the swaying quantity and multi-barrel parallelism measurement for Φ122 mm and Φ302 mm rocket launcher. The metrical errors are both 16^th.

Mobile Robot Localization and Navigation System Based on Monocular Vision

A system for mobile robot localization and navigation was presented.With the proposed system,the robot can be located and navigated by a single landmark in a single image.And the navigation mode may be following-track,teaching and playback,or programming.The basic idea is that the system computes the differences between the expected and the recognized position at each time and then controls the robot in a direction to reduce those differences.To minimize the robot sensor equipment,only one omnidirectional camera was used.Experiments in disturbing environments show that the presented algorithm is robust and easy to implement,without camera rectification.The rootmean-square error(RMSE) of localization is 1.4,cm,and the navigation error in teaching and playback is within 10,cm.

Selection criteria for preoperative endoscopic retrograde cholangiopancreatography before laparoscopic cholecystectomy and endoscopic treatment of bile duct stones:Results of a retrospective,single center study between 1996-2002

AIM: The optimal treatment for bile duct stones (in terms of cost, complications and accuracy) is unclear. The aim of our study was to determine the predictive factors for preoperative endoscopic retrograde cholangiopancreatography (ERCP).METHODS: Patients undergoing preoperative ERCP (≤90 d before laparoscopic cholecystectomy) were evaluated in this retrospective study from the 1^st of January 1996 to the 31^st of December 2002. The indications for ERCP were elevated serum bilirubin, elevated liver function tests (LFT), dilated bile duct (≥8 mm) and/or stone at US examination, coexisting acute pancreatitis and/or acute pancreatitis or jaundice in patient's history. Suspected prognostic factors and the combination of factors were compared to the result of ERCRRESULTS: Two hundred and six preoperative ERCPs were performed during the observed period. The rate of successful cannulation for ERC was (97.1%). Bile duct stones were detected in 81 patients (39.3%), and successfully removed in 79 (97.5%). The number of prognostic factors correlated with the presence of bile duct stones. The positive predictive value for one prognostic factor was 1.2%, for two 43%,for three 72.5%, for four or more 91.4%.CONCLUSION: Based on our data preoperative ERCP is highly recommended in patients with three or more positive factors (high risk patients). In contrast, ERCP is not indicated in patients with zero or one factor (low risk patients).Preoperative ERCP should be offered to patients with two positive factors (moderate risk patients), however the practice should also be based on the local conditions (e.g.skill of the endoscopist, other diagnostic tools).