AIM： Prednisone and azathioprine represent the standard treatment for autoimmune hepatitis （AIH）. However, only 65% of the patients enter complete histological remission. Recently, budesonide （BUD） was reported t...AIM： Prednisone and azathioprine represent the standard treatment for autoimmune hepatitis （AIH）. However, only 65% of the patients enter complete histological remission. Recently, budesonide （BUD） was reported to be a promising alternative. In this study we assessed the efficacy and safety of BUD in AIH. METHODS： Eighteen patients （12 women, 6 men; mean age 45.4±21 years） with AIH were treated with BUD （Budenofalk） 3 mg thrice daily and followed up for at least 24 wk. Seven patients also had features of primary biliary cirrhosis （n = 5） or primary sclerosing cholangitis （n = 2）. Advanced liver fibrosis or cirrhosis was present in RESULTS： Fifteen （83%） patients had a complete clinical and biochemical remission. Ten patients, including five with acute hepatitis, were given BUD as first-line therapy, of which seven enter remission. Three patients, two with liver cirrhosis, did not improve. All patients with second-line therapy experienced long-term remission. A histological remission was also seen in three patients. Clinically relevant BUD-induced side effects were recorded only in patients with liver cirrhosis （n = 4）. CONCLUSION： BUD is effective in remission induction in the majority of our patients with AIH. Side effects and treatment failure was mainly observed in patients with liver cirrhosis.展开更多
In order to improve the security and reliability for autonomous underwater vehicle （AUV） navigation, an H∞ robust fault-tolerant controller was designed after analyzing variations in state-feedback gain Operating c...In order to improve the security and reliability for autonomous underwater vehicle （AUV） navigation, an H∞ robust fault-tolerant controller was designed after analyzing variations in state-feedback gain Operating conditions and the design method were then analyzed so that the control problem could be expressed as a mathematical optimization problem. This permitted the use of linear matrix inequalities （LMI） to solve for the Hv controller for the system. When considering different actuator failures, these conditions were then also mathematically expressed, allowing the H∞ robust controller to solve for these events and thus be fault-tolerant. Finally, simulation results showed that the H∞ robust fault-tolerant controller could provide precise AUV navigation control with strong robustness.展开更多
S surface controllers have been proven to provide effective motion control for an autonomous underwater vehicle (AUV).However, it is difficult to adjust their control parameters manually.Choosing the optimum parameter...S surface controllers have been proven to provide effective motion control for an autonomous underwater vehicle (AUV).However, it is difficult to adjust their control parameters manually.Choosing the optimum parameters for the controller of a particular AUV is a significant challenge.To automate the process, a modified particle swarm optimization (MPSO) algorithm was proposed.It was based on immune theory, and used a nonlinear regression strategy for inertia weight to optimize AUV control parameters.A semi-physical simulation system for the AUV was developed as a platform to verify the proposed control method, and its structure was considered.The simulation results indicated that the semi-physical simulation platform was helpful, the optimization algorithm has good local and global searching abilities, and the method can be reliably used for an AUV.展开更多
The control system of an autonomous underwater vehicle （AUV） is introduced. According to control requirements of the AUV, a simple but practical adaptive PID control method is designed The semi-physical simulation ...The control system of an autonomous underwater vehicle （AUV） is introduced. According to control requirements of the AUV, a simple but practical adaptive PID control method is designed The semi-physical simulation is done to test the feasibility of the control system. The neural network idea and the structure of PID controller are referred to design the adaptive PID controller. An intelligent integral is introduced to improve control precision. Compaed with traditional PID con- trollers, the adaptive PID controller has simple structure, good online adjusting ability, fast convergence and good robustness. The simulation experiments also show that the adaptive PID control system has high precision and fine antijamming ability.展开更多
Autoimmune hepatitis(AIH),initially known as chronic active or active chronic hepatitis(and by various other names),first came under clinical notice in the late 1940s.However,quite likely,chronic active hepatitis(CAH)...Autoimmune hepatitis(AIH),initially known as chronic active or active chronic hepatitis(and by various other names),first came under clinical notice in the late 1940s.However,quite likely,chronic active hepatitis(CAH) had been observed prior to this and was attributed to a persistently destructive virus infection of the liver.An earlier(and controversial) designation in 1956 as lupoid hepatitis was derived from associated L.E.cell test positivity and emphasized accompanying multisystem features and immunological aberrations.Young women featured prominently in early descriptions of CAH.AIH was first applied in 1965 as a descriptive term.Disease-characteristic autoantibodies were defined from the early 1960s,notably antinuclear antibody(ANA),smooth muscle antibody(SMA) and liver-kidney microsomal(LKM) antibody.These are still widely used diagnostically but their relationship to pathogenesis is still not evident.A liver and disease specific autoantigen has long been searched for but unsuccessfully.Prolonged immunosuppressive therapy with predisolone and azathioprine in the 1960s proved beneficial and remains standard therapy today.AIH like many other autoimmune diseases is associated with particular HLA alleles especially with the "ancestral" B8,DR3 haplotype,and also with DR4.Looking forwards,AIH is one of the several enigmatic autoimmune diseases that,despite being(relatively) organ specific,are marked by autoimmune reactivities with non-organ-specific autoantigens.New paradigms are needed to explain the occurrence,expressions and pathogenesis of such diseases.展开更多
The natural ventilation widely used in greenhouses has advantages of saving energy and reducing expense. In order to provide information for climate control of greenhouse, a model was developed to predict the variatio...The natural ventilation widely used in greenhouses has advantages of saving energy and reducing expense. In order to provide information for climate control of greenhouse, a model was developed to predict the variation of air temperature in the naturally ventilated greenhouse equipped with insect-proof screen. Roof ventilation and combined roof and sidewall ventilation were considered in the model. This model was validated against the results of experiments conducted in the greenhouse when the wind was parallel to the gutters. The model parameters were determined by the least squares method. In the used model, effects of wind speed and window opening height on the air temperature variation were analyzed. Comparison between two types of ventilation showed that there existed a necessary ventilation rate which results in air temperature decrease in natural ventilation under special climatic conditions. In our experiments when wind speed was less than 3.2 ms?1, wind had a more gradual effect on greenhouse temperature for roof ventilation, compared with combined roof and sidewall ventilation, which had greater air temperature decrease than roof ventilation only.展开更多
In this case report we describe for the first time an association between autoimmune hepatitis （AIH） and uveitis, without any doubts about other possible etiologies, such as HCV, since all the old reports describe t...In this case report we describe for the first time an association between autoimmune hepatitis （AIH） and uveitis, without any doubts about other possible etiologies, such as HCV, since all the old reports describe the association of AIH with iridocyclitis before tests for HCV-related hepatitis could be available. A 38-year-old businessman with abnormal liver function tests and hyperemia of the bulbar conjunctiva was admitted to the hospital. Six years before admission, the patient presented with persistent fever, arthralgias, conjunctival hyperemia, leukocytosis and increased ESR, referred to acute rheumatic fever. The presence of systemic diseases, most commonly associated with uveitis, was investigated without results and the patient was then treated with topical corticosteroids. His symptoms resolved. A test for anti-nuclear antibodies was positive, at a titre of 1：320, with a speckled and nucleolar staining pattern. Liver ultrasound showed mild hepatomegaly with an increased echostructure of the liver. Percutaneous liver biopsy was performed under ultrasound assistance. Histological examination showed necroinflammation over the portal, periportal and Iobular areas, fibrotic portal tracts, with periportal fibrosis and occasional portal-to-portal bridgings, but intact hepatic architecture. Some hepatocytes showed barely discernible granules of hemosiderin in the Iobular area. Bile ductules had not any significant morphological alterations. METAVIR score was A2-F3, according to the modified HAI grading/fibrosis staging. The patient was diagnosed to have AIH with mild activity and fibrosis and was discharged on 25 mg prednisone, entering clinical and biochemical remission, further confirming diagnosis. After discharge the patient continued to have treatment with corticosteroids as an outpatient at a dose of 5 mg. On January 2002 the patient was readmitted to the hospital. A test for anti-nuclear antibodies was positive, at a titre of 1：320, with a speckled and nucleolar staining pattern. Anti-smooth muscle antibody test was also positive （1：160）, while anti-LKM antibodies were negative. Ophthalmologic examination revealed inflammatory cells and proteinaceous flare in the anterior chamber of the left eye, and a stromal lesion in the cornea. He was maintained on immunosuppressive therapy （5 mg prednisone plus topical antibiotic therapy for two weeks） and then discharged. A complete remission of the symptoms was registered on follow-up. At present （July 2005）, the patient is on prednisone （5 rag） and has no symptoms. Liver function tests are also within the normal range.展开更多
The natural history of Barrett's esophagus (BE) is difficult to quantify because,by definition,it should describe the course of the condition if left untreated.Pragmatically,we assume that patients with BE will re...The natural history of Barrett's esophagus (BE) is difficult to quantify because,by definition,it should describe the course of the condition if left untreated.Pragmatically,we assume that patients with BE will receive symptomatic treatment with acid suppression,usually a proton pump inhibitor,to treat their heartburn.This paper describes the development of complications of stricture,ulcer,dysplasia and adenocarcinoma from this standpoint.Controversies over the definition of BE and its implications in clinical practice are presented.The presence of intestinal metaplasia and its relevance to cancer risk is discussed,and the need to measure the extent of the Barrett's epithelium (long and short segments) using the Prague guidelines is emphasized.Guidelines and international consensus over the diagnosis and management of BE are being regularly updated.The need for expert consensus is important due to the lack of randomized trials in this area.After searching the literature,we have tried to collate the important studies regarding progression of Barrett's to dysplasia and adenocarcinoma.No therapeutic studies yet reported show a clear reduction in the development of cancer in BE.The effect of pharmacological and surgical intervention on the natural history of Barrett's is a subject of ongoing research,including the Barrett's Oesophagus Surveillance Study and the aspirin and esomeprazole cancer chemoprevention trial with interesting results.The geographical variation and the wide range of outcomes highlight the difficulty of providing an individualized risk profile to patients with BE.Future studies on the interaction of genome wide abnormalities in Barrett's and their interaction with environmental factors may allow individualization of the risk of cancer developing in BE.展开更多
The TanDEM-X mission is a scientific and commercial Earth observation mission comprising two satellites flying in close formation. The formation maintenance can be advantageously performed by an onboard autonomous sys...The TanDEM-X mission is a scientific and commercial Earth observation mission comprising two satellites flying in close formation. The formation maintenance can be advantageously performed by an onboard autonomous system, which reduces the operational efforts, provides a shorter reaction time in case of contingencies and increases the control performance. The TanDEM-X Autonomous Formation Flying （TAFF） system has been developed for this purpose and is intended to replace the ground-based formation keeping activities during routine operations. TAFF has been activated for the first time in October 2010 for commissioning, during which the autonomous usage of thrusters was prohibited. Afterwards, a closed-loop campaign was successfully conducted in March 2011, demonstrating the capability of TAFF to maintain autonomously the formation. After a brief technical description of the system, the paper presents the key results gained during the commissioning phase and the closed-loop campaign,展开更多
文摘AIM： Prednisone and azathioprine represent the standard treatment for autoimmune hepatitis （AIH）. However, only 65% of the patients enter complete histological remission. Recently, budesonide （BUD） was reported to be a promising alternative. In this study we assessed the efficacy and safety of BUD in AIH. METHODS： Eighteen patients （12 women, 6 men; mean age 45.4±21 years） with AIH were treated with BUD （Budenofalk） 3 mg thrice daily and followed up for at least 24 wk. Seven patients also had features of primary biliary cirrhosis （n = 5） or primary sclerosing cholangitis （n = 2）. Advanced liver fibrosis or cirrhosis was present in RESULTS： Fifteen （83%） patients had a complete clinical and biochemical remission. Ten patients, including five with acute hepatitis, were given BUD as first-line therapy, of which seven enter remission. Three patients, two with liver cirrhosis, did not improve. All patients with second-line therapy experienced long-term remission. A histological remission was also seen in three patients. Clinically relevant BUD-induced side effects were recorded only in patients with liver cirrhosis （n = 4）. CONCLUSION： BUD is effective in remission induction in the majority of our patients with AIH. Side effects and treatment failure was mainly observed in patients with liver cirrhosis.
基金Supported by the Heilongjiang Postdoctoral Foundation under Grant No. LH-04010
文摘In order to improve the security and reliability for autonomous underwater vehicle （AUV） navigation, an H∞ robust fault-tolerant controller was designed after analyzing variations in state-feedback gain Operating conditions and the design method were then analyzed so that the control problem could be expressed as a mathematical optimization problem. This permitted the use of linear matrix inequalities （LMI） to solve for the Hv controller for the system. When considering different actuator failures, these conditions were then also mathematically expressed, allowing the H∞ robust controller to solve for these events and thus be fault-tolerant. Finally, simulation results showed that the H∞ robust fault-tolerant controller could provide precise AUV navigation control with strong robustness.
基金Supported by the 863 Project under Grant No.2008AA092301the Fundamental Research Foundation of Harbin Engineering University under Grant No.2007001
文摘S surface controllers have been proven to provide effective motion control for an autonomous underwater vehicle (AUV).However, it is difficult to adjust their control parameters manually.Choosing the optimum parameters for the controller of a particular AUV is a significant challenge.To automate the process, a modified particle swarm optimization (MPSO) algorithm was proposed.It was based on immune theory, and used a nonlinear regression strategy for inertia weight to optimize AUV control parameters.A semi-physical simulation system for the AUV was developed as a platform to verify the proposed control method, and its structure was considered.The simulation results indicated that the semi-physical simulation platform was helpful, the optimization algorithm has good local and global searching abilities, and the method can be reliably used for an AUV.
文摘The control system of an autonomous underwater vehicle （AUV） is introduced. According to control requirements of the AUV, a simple but practical adaptive PID control method is designed The semi-physical simulation is done to test the feasibility of the control system. The neural network idea and the structure of PID controller are referred to design the adaptive PID controller. An intelligent integral is introduced to improve control precision. Compaed with traditional PID con- trollers, the adaptive PID controller has simple structure, good online adjusting ability, fast convergence and good robustness. The simulation experiments also show that the adaptive PID control system has high precision and fine antijamming ability.
文摘Autoimmune hepatitis(AIH),initially known as chronic active or active chronic hepatitis(and by various other names),first came under clinical notice in the late 1940s.However,quite likely,chronic active hepatitis(CAH) had been observed prior to this and was attributed to a persistently destructive virus infection of the liver.An earlier(and controversial) designation in 1956 as lupoid hepatitis was derived from associated L.E.cell test positivity and emphasized accompanying multisystem features and immunological aberrations.Young women featured prominently in early descriptions of CAH.AIH was first applied in 1965 as a descriptive term.Disease-characteristic autoantibodies were defined from the early 1960s,notably antinuclear antibody(ANA),smooth muscle antibody(SMA) and liver-kidney microsomal(LKM) antibody.These are still widely used diagnostically but their relationship to pathogenesis is still not evident.A liver and disease specific autoantigen has long been searched for but unsuccessfully.Prolonged immunosuppressive therapy with predisolone and azathioprine in the 1960s proved beneficial and remains standard therapy today.AIH like many other autoimmune diseases is associated with particular HLA alleles especially with the "ancestral" B8,DR3 haplotype,and also with DR4.Looking forwards,AIH is one of the several enigmatic autoimmune diseases that,despite being(relatively) organ specific,are marked by autoimmune reactivities with non-organ-specific autoantigens.New paradigms are needed to explain the occurrence,expressions and pathogenesis of such diseases.
基金Project (No. 50175101) supported by the National Natural ScienceFoundation of China
文摘The natural ventilation widely used in greenhouses has advantages of saving energy and reducing expense. In order to provide information for climate control of greenhouse, a model was developed to predict the variation of air temperature in the naturally ventilated greenhouse equipped with insect-proof screen. Roof ventilation and combined roof and sidewall ventilation were considered in the model. This model was validated against the results of experiments conducted in the greenhouse when the wind was parallel to the gutters. The model parameters were determined by the least squares method. In the used model, effects of wind speed and window opening height on the air temperature variation were analyzed. Comparison between two types of ventilation showed that there existed a necessary ventilation rate which results in air temperature decrease in natural ventilation under special climatic conditions. In our experiments when wind speed was less than 3.2 ms?1, wind had a more gradual effect on greenhouse temperature for roof ventilation, compared with combined roof and sidewall ventilation, which had greater air temperature decrease than roof ventilation only.
文摘In this case report we describe for the first time an association between autoimmune hepatitis （AIH） and uveitis, without any doubts about other possible etiologies, such as HCV, since all the old reports describe the association of AIH with iridocyclitis before tests for HCV-related hepatitis could be available. A 38-year-old businessman with abnormal liver function tests and hyperemia of the bulbar conjunctiva was admitted to the hospital. Six years before admission, the patient presented with persistent fever, arthralgias, conjunctival hyperemia, leukocytosis and increased ESR, referred to acute rheumatic fever. The presence of systemic diseases, most commonly associated with uveitis, was investigated without results and the patient was then treated with topical corticosteroids. His symptoms resolved. A test for anti-nuclear antibodies was positive, at a titre of 1：320, with a speckled and nucleolar staining pattern. Liver ultrasound showed mild hepatomegaly with an increased echostructure of the liver. Percutaneous liver biopsy was performed under ultrasound assistance. Histological examination showed necroinflammation over the portal, periportal and Iobular areas, fibrotic portal tracts, with periportal fibrosis and occasional portal-to-portal bridgings, but intact hepatic architecture. Some hepatocytes showed barely discernible granules of hemosiderin in the Iobular area. Bile ductules had not any significant morphological alterations. METAVIR score was A2-F3, according to the modified HAI grading/fibrosis staging. The patient was diagnosed to have AIH with mild activity and fibrosis and was discharged on 25 mg prednisone, entering clinical and biochemical remission, further confirming diagnosis. After discharge the patient continued to have treatment with corticosteroids as an outpatient at a dose of 5 mg. On January 2002 the patient was readmitted to the hospital. A test for anti-nuclear antibodies was positive, at a titre of 1：320, with a speckled and nucleolar staining pattern. Anti-smooth muscle antibody test was also positive （1：160）, while anti-LKM antibodies were negative. Ophthalmologic examination revealed inflammatory cells and proteinaceous flare in the anterior chamber of the left eye, and a stromal lesion in the cornea. He was maintained on immunosuppressive therapy （5 mg prednisone plus topical antibiotic therapy for two weeks） and then discharged. A complete remission of the symptoms was registered on follow-up. At present （July 2005）, the patient is on prednisone （5 rag） and has no symptoms. Liver function tests are also within the normal range.
文摘The natural history of Barrett's esophagus (BE) is difficult to quantify because,by definition,it should describe the course of the condition if left untreated.Pragmatically,we assume that patients with BE will receive symptomatic treatment with acid suppression,usually a proton pump inhibitor,to treat their heartburn.This paper describes the development of complications of stricture,ulcer,dysplasia and adenocarcinoma from this standpoint.Controversies over the definition of BE and its implications in clinical practice are presented.The presence of intestinal metaplasia and its relevance to cancer risk is discussed,and the need to measure the extent of the Barrett's epithelium (long and short segments) using the Prague guidelines is emphasized.Guidelines and international consensus over the diagnosis and management of BE are being regularly updated.The need for expert consensus is important due to the lack of randomized trials in this area.After searching the literature,we have tried to collate the important studies regarding progression of Barrett's to dysplasia and adenocarcinoma.No therapeutic studies yet reported show a clear reduction in the development of cancer in BE.The effect of pharmacological and surgical intervention on the natural history of Barrett's is a subject of ongoing research,including the Barrett's Oesophagus Surveillance Study and the aspirin and esomeprazole cancer chemoprevention trial with interesting results.The geographical variation and the wide range of outcomes highlight the difficulty of providing an individualized risk profile to patients with BE.Future studies on the interaction of genome wide abnormalities in Barrett's and their interaction with environmental factors may allow individualization of the risk of cancer developing in BE.
文摘The TanDEM-X mission is a scientific and commercial Earth observation mission comprising two satellites flying in close formation. The formation maintenance can be advantageously performed by an onboard autonomous system, which reduces the operational efforts, provides a shorter reaction time in case of contingencies and increases the control performance. The TanDEM-X Autonomous Formation Flying （TAFF） system has been developed for this purpose and is intended to replace the ground-based formation keeping activities during routine operations. TAFF has been activated for the first time in October 2010 for commissioning, during which the autonomous usage of thrusters was prohibited. Afterwards, a closed-loop campaign was successfully conducted in March 2011, demonstrating the capability of TAFF to maintain autonomously the formation. After a brief technical description of the system, the paper presents the key results gained during the commissioning phase and the closed-loop campaign,
