BACKGROUND Brucellosis is endemic in India with seropositivity rates as high as 10%in children in the eastern states,yet the disease is not on the radar when a differential diagnosis of pyrexia of unknown origin(PUO)i...BACKGROUND Brucellosis is endemic in India with seropositivity rates as high as 10%in children in the eastern states,yet the disease is not on the radar when a differential diagnosis of pyrexia of unknown origin(PUO)is being considered,especially in children in urban set-up.This may be because of the non-specific multitude of systemic symptoms seen in this disease and the lack of awareness among clinicians.CASE SUMMARY We present a case of a 13-year-old boy,who came with a history of undulating fever for the past three and a half months,loss of appetite,and abdominal pain.The child had visited several pediatricians and was even admitted to a tertiary care hospital for PUO evaluation,but to no avail.He presented to us after three and half months of suffering and weight loss of more than 10%of body weight.His ultrasonography revealed thickening of the terminal ileum.His blood culture grew Brucella melitensis.A diagnosis of Brucellosis with terminal ileitis was made.Brucella serology by enzyme-linked immunoassay(ELISA)was positive for both IgG and IgM.He was treated with doxycycline and Rifampicin along with syrup multivitamin and zinc,for 6 wk.There was remarkable improvement with gain in 4 kg body weight within 2 mo of completing treatment.History revealed consumption of unpasteurized milk and contact with cattle.CONCLUSION Clinical suspicion,detailed history,appropriate laboratory investigations are the three pillars for diagnosing Brucellosis in patients presenting with vague symptoms.展开更多
Pyogenic liver abscess is a common entity in Indian subcontinent and is mostly caused by gram negative bacteria. Melioidosis is not commonly seen in India and only a few cases are reported. It can give rise to multipl...Pyogenic liver abscess is a common entity in Indian subcontinent and is mostly caused by gram negative bacteria. Melioidosis is not commonly seen in India and only a few cases are reported. It can give rise to multiple abscesses at different sites including liver. We report a case of isolated liver abscess caused by Burkholderia pseudomallei(B. pseudomallei) in a 29-yearold recently diagnosed diabetic, immunocompetent male. Diagnosis was made by imaging and culture of pus aspirated from the abscess and he was treated with percutaneous pigtail catheter drainage followed by antibiotics(meropenem and trimethoprim-sulphmethoxazole). Melioidosis is an emerging infection in India and has high mortality rate, so early diagnosis and promptmanagement is warranted which requires clinical vigilance and an intensive microbiological workup. Clinicians should be aware of isolated liver abscess caused by B. pseudomallei in appropriate clinical settings.展开更多
Background: Magnifying endoscopy is a promising modality for fine observation of minute surface structures and microvessel architecture in gastric lesions. Objective: To observe the response of microvessels to epineph...Background: Magnifying endoscopy is a promising modality for fine observation of minute surface structures and microvessel architecture in gastric lesions. Objective: To observe the response of microvessels to epinephrine stimulation in early gastric cancer tissues and to assess the usefulness of magnifying pharmacoendoscopy for histologic diagnosis. Design: This was a prospective pilot study. Setting: This study was conducted at an academic hospital. Patients: Twenty-nine patients with differentiated early gastric cancer were enrolled. Interventions: Microvessels in both the cancerous lesion and its adjacent non-neoplastic gastric mucosa were observed by magnifying endoscopy before and after focal spray with epinephrine solution (0.05 mg/mL).Main Outcome Measurements and Results: After epinephrine stimulation, noncancerous gastric mucosa surrounding the cancerous lesion showed a change in color from red to white; no microvessels were evident. On the other hand, all the cancerous lesions examined clearly showed enhancement of tumor microvessels. The rate of detection of tumor microvessels by magnifying pharmacoendoscopy (100%) was significantly higher than that by magnifying endoscopy alone (41.3%). Limitations: This was small pilot study. Conclusions: Magnifying pharmacoendoscopy with epinephrine is a powerful tool for assessing tumor vascularity and may contribute to the histologic diagnosis of differentiated early gastric cancers before endoscopic treatment.展开更多
Background:We hypothesized that magnetic resonance cholangiography(MRC) may have less accuracy for the diagnosis and the assessment of the severity of primary sclerosing cholangitis(PSC) than endoscopic retrograde cho...Background:We hypothesized that magnetic resonance cholangiography(MRC) may have less accuracy for the diagnosis and the assessment of the severity of primary sclerosing cholangitis(PSC) than endoscopic retrograde cholangiography(ERC) .Objective:The aim of this study was to determine the diagnostic accuracy and interobserver agreement of both ERC and MRC in PSC.Design:A case-control study.Setting:University Hospital.Patients:ERCs and MRCs of 36 patients with PSC and 51 controls(normal/other biliary tract diseases) were read in an independent,blinded,and random fashion by 2 magnetic resonance radiologists and 2 interventional endoscopists by using a previously validated classification system.Readers had no access to clinical history,laboratory results,or patient mix.Results:Extrahepatic ductal(EHD) and intrahepatic ductal(IHD) visualization was excellent in 64% of 66% of MRCs and 86% of 74% of ERCs.Sensitivity and specificity for diagnosis of PSC for readers 1 to 4 were 91% and 85%,88% and 90%,81% and 96%,and 83% and 96%.respectively.Receiver operating curve values were excellent for all readers(all >0.9) .Interobserver agreement(κ statistics) for the diagnosis of PSC(MRC,0.83;ERC,0.73) and for identifying the presence of IHD strictures(MRC,0.64;ERC,0.86) was good for both modalities,but only ERC(ERC,0.55;MRC,0.36) was good for the presence and the severity of EHD strictures.When assessment of disease severity was limited to the 36 patients with PSC,interobserver agreement was very poor for both MRC(0.23 and 0.07 for EHD and IHD,respectively) and ERC(0.24 and 0.34 for EHD and IHD,respectively) .Limitations:The retrospective case-control study made it difficult to assess the impact of the diagnosis on patient management.Conclusions:ERC and MRC were comparable for diagnosing PSC,with very good interobserver agreement for the diagnosis of PSC and IHD strictures.Only ERC had good agreement for EHD strictures.Interobserver agreement was very poor for both MRC and ERC when disease severity of PSC was assessed.展开更多
The Purkinje cell and their synaptic contacts have been described using(1)light microsocopy,(2)transmission and scanning electron microscopy,and freeze etching technique,(3)conventional and field emission scanning ele...The Purkinje cell and their synaptic contacts have been described using(1)light microsocopy,(2)transmission and scanning electron microscopy,and freeze etching technique,(3)conventional and field emission scanning electron microscopy and cryofracture methods,(4)confocal laser scanning microscopy using intravital stain FM64,and(5)immunocytochemical techniques for Synapsin-I,PSD9-5,GluR1 subunit of AMPA receptors,N-cadherin,and CamKII alpha.The outer surface and inner content of plasma membrane,cell organelles,cytoskeleton,nucleus,dendritic and axonal processes have been exposed and analyzed in a three-dimensional view.The intramembrane morphology,in bi-and three-dimensional views,and immunocytochemical labeling of synaptic contacts with parallel and climbing fibers,basket and stellate cell axons have been characterized.Freeze etching technique,field emission scanning microscopy and cryofracture methods,and GluR1 immunohistochemistry showed the morphology and localization of postsynaptic receptors.Purkinje cell shows N-cadherin and CamKII alpha immunoreactivity.The correlative microscopy approach provides a deeper understanding of structure and function of the Purkinje cell,a new three-dimensional outer and inner vision,a more detailed study of afferent and intrinsic synaptic junctions,and of intracortical circuits.展开更多
Thin Layer Activation is a nuclear technique that has key advantages over other wear measuring techniques for mechanical systems,especially for in site experiments on equipment important to safety in nuclear plants.St...Thin Layer Activation is a nuclear technique that has key advantages over other wear measuring techniques for mechanical systems,especially for in site experiments on equipment important to safety in nuclear plants.Still,it incurs radioactive dose and,thus,must be proved radiologically safe before use,otherwise,the utilization of this technique may be hindered inviable.Proving said technique is safe previous to any operational/monetary cost is key,providing a methodology for this early assertion is the main contribution of this work—here,only non-occupationally exposed individuals are considered.This work offers a methodology,through a case study,to ascertain the Thin Layer Activation parameters to obtain safe levels of radioactive dose while maintaining statistically reliable results.This methodology consists of using simulations,through the Monte Carlo Method,to obtain the floors and ceilings for the previously mentioned activation parameters based on operation and work conditions on site.展开更多
After my paper (Zeng, 1986b) was published and another (Zeng, 1989) was submitted to the journal, I found two papers written by Arnold (1966) and McIntyre et al. (1987) and received some reprints of Ripa’s papers (19...After my paper (Zeng, 1986b) was published and another (Zeng, 1989) was submitted to the journal, I found two papers written by Arnold (1966) and McIntyre et al. (1987) and received some reprints of Ripa’s papers (1983; 1984; 1987; 1988) in the same field. I thank Drs. Mu Mu and Pedro Ripa very much for showing and sending me these interesting papers.展开更多
Background: Primary malignant tumors arising from bone are uncommon but important malignant neoplasms which account for 0.2% of all primary cancers in adults and approximately 5% of all childhood malignancies. Aim: No...Background: Primary malignant tumors arising from bone are uncommon but important malignant neoplasms which account for 0.2% of all primary cancers in adults and approximately 5% of all childhood malignancies. Aim: No comprehensive surveillance data about primary malignant bone tumors is available from this region of West Bengal in the literature. An attempt is undertaken to correlate clinicopathological findings, both histological & cytological features of primary bone tumours. Method: This observational study of clinical presentation was corroborated with cytology and histopathology of 67 cases of primary malignant bone tumors in 2005-2007 in a tertiary health care centre. Results: Among the primary malignant tumors, 39 cases (58.20%) were male and 28 (41.80%) were female. Sixty one lesions (91%) were located in the long bones and 6 (9%) involving flat and short bones. Osteosarcomas are found to be the predominant primary malignant bone tumors (44.77%), followed by Ewing’s sarcomas (20.89%), chondrosarcomas (13.43%), high grade giant cell tumor, and plasmacytoma (5.97%). Predilection for male (M: F 2:1) found in both osteosarcoma and chondrosarcoma, but it was reverse in cases of Ewing’s sarcomas. Conclusion: Osteosarcoma is the most common around knee joint and chondrosarcoma is frequent in long bones in this region. We made an attempt to correlate FNAC findings with the histopathology and it was seen that overall sensitivity of FNAC of primary malignant bone tumors was 56.71%.展开更多
The nasopharynx is an unusual site for extraosseous chordoma. The characteristic histology and immunohistochemistry confirmed the diagnosis. The behaviour of this tumour is locally aggressive. We report a case of naso...The nasopharynx is an unusual site for extraosseous chordoma. The characteristic histology and immunohistochemistry confirmed the diagnosis. The behaviour of this tumour is locally aggressive. We report a case of nasopharyngeal chordoma in an elderly patient with literature review.展开更多
1. Introduction The goal of the present study was to develop non-in-vasive techniques for the assessment of voice disorders andfor monitoring the effects of voice. However, before acous-tic algorithms can be used in c...1. Introduction The goal of the present study was to develop non-in-vasive techniques for the assessment of voice disorders andfor monitoring the effects of voice. However, before acous-tic algorithms can be used in clinical applications, it isimportant to understand the relationship between clinicalperceptions of voice quality and the acoustic measures ob-展开更多
This paper presents some results concerning applications of the coupled dynamical-radiational model of stratocumulus Ye developed (Ye, 1990, hereafter referred to as the DRS model). Basically, calculations involved he...This paper presents some results concerning applications of the coupled dynamical-radiational model of stratocumulus Ye developed (Ye, 1990, hereafter referred to as the DRS model). Basically, calculations involved here relate to the time-integration of the DRS model to estimate some time constants associated with the boundary layer and cloud developments. To obtain cloud lifetime (CLT), the time interval from its formation to its dissipation, different cloud instability criteria are compared, the mechanism for dissipating cloud are discussed, and thereby two new criteria for judging whether cloud can maintain are established. Following these criteria, the sensitivities of CLT to parameters such as the air-sea temperature difference, subsidence, and surface wind are estimated. The main interesting results about the sensitivities of the forming time (CFT) are a stable environment, such as cool sea, low wind, and strong subsidence, would prolong the existence of Sc, which has been predicted by the model calculations and strikingly tallies with statistical observations.Besides, with the DRS model and the CLT criteria, we follow a marine boundary layer, starting with clear sky, through the formation and development of clouds and rain, until their dissipation. On the whole, the model results fit the developing process of a typically stable marine boundary layer, and show some features Nicholls (1984) observed for daytime Sc.展开更多
Background:The detection of the mucosal morphology(ie,mucosal and vascular patterns) in Barrett’s esophagus(BE) by magnifying(chromo) endoscopy may improve the distinction of high-grade intraepithelial neoplasia(HGIN...Background:The detection of the mucosal morphology(ie,mucosal and vascular patterns) in Barrett’s esophagus(BE) by magnifying(chromo) endoscopy may improve the distinction of high-grade intraepithelial neoplasia(HGIN) from nondysplastic specialized intestinal metaplasia(SIM) .Narrow band imaging(NBI) is a new technique that uses optical filters to enhance the mucosal contrast without the need for chromoendoscopy.Objective:To use NBI for the characterization and the classification of the mucosal morphology in nondysplastic BE and in BE with HGIN.Design:Descriptive study.Setting:Single-center study in a tertiary referral center for the diagnosis and treatment of patients with BE.Patients:We used NBI with magnifying endoscopy to image and biopsy randomly selected areas in 63 patients with BE.A systematic image and a biopsy specimen evaluation process was followed,including unblinded assessment of an exploratory set of images and biopsy specimens,and blinded evaluation of learning and validation sets.Main Outcome Measurements:The relationship between the mucosal morphology and the presence of SIM and HGIN.Results:SIM was characterized by either villous/gyrus-forming patterns(80%) ,which were mostly regular and had regular vascular patterns,or a flat mucosa with regular normal-appearing long branching vessels(20%) .HGIN was characterized by 3 abnormalities:irregular/disrupted mucosal patterns,irregular vascular patterns,and abnormal blood vessels.All areas with HGIN had at least 1 abnormality,and 85% had 2 or more abnormalities.The frequency of abnormalities showed a significant rise with increasing grades of dysplasia.The magnified NBI images had a sensitivity of 94%,a specificity of 76%,a positive predictive value of 64%,and a negative predictive value of 98% for HGIN.Limitations:No data on observer agreement.Conclusions:NBI with magnification reveals the mucosalmorphology characteristics of nondysplastic BE and HGIN,without the need for staining and has a relatively high diagnostic value for HGIN when used for targeted detailed examination of areas of interest.展开更多
Background:Video-autofluorescence imaging(AFI) and narrow band imaging(NBI) are new endoscopic techniques that may improve the detection of high-grade intraepithelial neoplasia(HGIN) in Barrett’s esophagus(BE) .AFI i...Background:Video-autofluorescence imaging(AFI) and narrow band imaging(NBI) are new endoscopic techniques that may improve the detection of high-grade intraepithelial neoplasia(HGIN) in Barrett’s esophagus(BE) .AFI improves the detection of lesions but may give false-positive findings.NBI allows for detailed inspection of the mucosal and(micro) vascular patterns,which are related to HGIN.Objective:A proof-of-principle study to combine AFI and NBI to improve the detection of HGIN and to reduce false-positive findings.Design:Cross-sectional study of consecutive eligible patients.Setting:Single-center.Patients:Twenty patients with BE with suspected or endoscopically treated HGIN were investigated with 2 prototype imaging systems:AFI(inspection with high-resolution videoendoscopy and autofluorescence imaging for detection of lesions) and NBI(for detailed inspection of mucosal and vascular patterns of identified lesions) .Lesions were sampled for histopathologic evaluation.Main Outcome Measurements:The positive predictive value of AFI alone and of AFI-NBI for detecting HGIN and the reduction of falsepositive findings because of the use of NBI.Results:All of the 28 lesions with HGIN were identified with AFI.Seventeen were identified with white light(61%) .Forty-seven suspicious lesions were detected with AFI:28 contained HGIN(60%) and 19 were false positive(40%) .With NBI,25 of the true-positive lesions had definitely suspicious patterns,and 3 had dubiously suspicious patterns.Of the 19 false positives,14 were not suspicious on NBI.The false-positive rate,therefore,was reduced from 40% to 10%.Low-grade dysplasia was found in 4 of the remaining 5 false positives.All of the 14 patients with HGIN were identified by AFI-NBI(sensitivity 100%) .Limitations:Uncontrolled study in high-risk patients.Conclusions:This proof-of-principle study confirms that AFI can be used as a red-flag technique to detect suspicious lesions.With NBI,detailed inspection of the surface patterns can be performed.This combination may increase the accuracy of detecting HGIN in BE.展开更多
Based on the DRS model (one coupled dynamical-radiational model of stratocumulus), though extended to take advection into account, several calculations have been made to estimate its contributions to the thermodynamic...Based on the DRS model (one coupled dynamical-radiational model of stratocumulus), though extended to take advection into account, several calculations have been made to estimate its contributions to the thermodynamical structure of the PBL (planetary boundary layer). Advection various calculations show does affect the development of :he PBL, particularly in cloud forming and evolving. One of the intriguing findings which accords well with observations demonstrates that cold currents create strong convective weather, while warm currents bring about stable weather: produce prolonged low clouds or fogs.展开更多
In this paper,the optimal control of a class of general affine nonlinear discrete-time(DT) systems is undertaken by solving the Hamilton Jacobi-Bellman(HJB) equation online and forward in time.The proposed approach,re...In this paper,the optimal control of a class of general affine nonlinear discrete-time(DT) systems is undertaken by solving the Hamilton Jacobi-Bellman(HJB) equation online and forward in time.The proposed approach,referred normally as adaptive or approximate dynamic programming(ADP),uses online approximators(OLAs) to solve the infinite horizon optimal regulation and tracking control problems for affine nonlinear DT systems in the presence of unknown internal dynamics.Both the regulation and tracking controllers are designed using OLAs to obtain the optimal feedback control signal and its associated cost function.Additionally,the tracking controller design entails a feedforward portion that is derived and approximated using an additional OLA for steady state conditions.Novel update laws for tuning the unknown parameters of the OLAs online are derived.Lyapunov techniques are used to show that all signals are uniformly ultimately bounded and that the approximated control signals approach the optimal control inputs with small bounded error.In the absence of OLA reconstruction errors,an optimal control is demonstrated.Simulation results verify that all OLA parameter estimates remain bounded,and the proposed OLA-based optimal control scheme tunes itself to reduce the cost HJB equation.展开更多
Ignition within gas burner ejectors can lead to off design conditions and has significant influence on the burner behavior.Thus ignition in the ejector should be prevented.In the present study the influence of combust...Ignition within gas burner ejectors can lead to off design conditions and has significant influence on the burner behavior.Thus ignition in the ejector should be prevented.In the present study the influence of combustion reactions on the performance of gas burner injectors is investigated.To investigate if ignition is possible,simulated ignition delay times,using a detailed reaction mechanism,are compared to predicted mean residence times of the gas in the ejector.Gas burner ejectors are designed using one dimensional analytic equations,based on energy and momentum conservation equations and conventional isentropic equations.1D results are compared to 2D computational fluid dynamics(CFD)simulations,to take into account non-ideal mixing effects along the ejector.Results are validated with experiments with air at room temperature.1D results show very good agreement not only with CFD simulations for the case of non-reactive flows,but also with performed experiments.It is shown that the assumption of ideal mixing along the ejector and thus the comparison of the ignition delay time to the gas mean residence time,to predict ignition in the ejector,is not valid.Ignition in the ejector is possible,even if the ignition delay time is more than thirty times higher than the mean residence time.In addition to that,it is shown,that ignition and the choice of reaction mechanism have significant influence on the predicted gas burner ejector performance.Thus,the accurate prediction of ignition delay time and the use of a detailed reaction kinetic are mandatory to correctly predict the burner ejector behavior.展开更多
文摘BACKGROUND Brucellosis is endemic in India with seropositivity rates as high as 10%in children in the eastern states,yet the disease is not on the radar when a differential diagnosis of pyrexia of unknown origin(PUO)is being considered,especially in children in urban set-up.This may be because of the non-specific multitude of systemic symptoms seen in this disease and the lack of awareness among clinicians.CASE SUMMARY We present a case of a 13-year-old boy,who came with a history of undulating fever for the past three and a half months,loss of appetite,and abdominal pain.The child had visited several pediatricians and was even admitted to a tertiary care hospital for PUO evaluation,but to no avail.He presented to us after three and half months of suffering and weight loss of more than 10%of body weight.His ultrasonography revealed thickening of the terminal ileum.His blood culture grew Brucella melitensis.A diagnosis of Brucellosis with terminal ileitis was made.Brucella serology by enzyme-linked immunoassay(ELISA)was positive for both IgG and IgM.He was treated with doxycycline and Rifampicin along with syrup multivitamin and zinc,for 6 wk.There was remarkable improvement with gain in 4 kg body weight within 2 mo of completing treatment.History revealed consumption of unpasteurized milk and contact with cattle.CONCLUSION Clinical suspicion,detailed history,appropriate laboratory investigations are the three pillars for diagnosing Brucellosis in patients presenting with vague symptoms.
文摘Pyogenic liver abscess is a common entity in Indian subcontinent and is mostly caused by gram negative bacteria. Melioidosis is not commonly seen in India and only a few cases are reported. It can give rise to multiple abscesses at different sites including liver. We report a case of isolated liver abscess caused by Burkholderia pseudomallei(B. pseudomallei) in a 29-yearold recently diagnosed diabetic, immunocompetent male. Diagnosis was made by imaging and culture of pus aspirated from the abscess and he was treated with percutaneous pigtail catheter drainage followed by antibiotics(meropenem and trimethoprim-sulphmethoxazole). Melioidosis is an emerging infection in India and has high mortality rate, so early diagnosis and promptmanagement is warranted which requires clinical vigilance and an intensive microbiological workup. Clinicians should be aware of isolated liver abscess caused by B. pseudomallei in appropriate clinical settings.
文摘Background: Magnifying endoscopy is a promising modality for fine observation of minute surface structures and microvessel architecture in gastric lesions. Objective: To observe the response of microvessels to epinephrine stimulation in early gastric cancer tissues and to assess the usefulness of magnifying pharmacoendoscopy for histologic diagnosis. Design: This was a prospective pilot study. Setting: This study was conducted at an academic hospital. Patients: Twenty-nine patients with differentiated early gastric cancer were enrolled. Interventions: Microvessels in both the cancerous lesion and its adjacent non-neoplastic gastric mucosa were observed by magnifying endoscopy before and after focal spray with epinephrine solution (0.05 mg/mL).Main Outcome Measurements and Results: After epinephrine stimulation, noncancerous gastric mucosa surrounding the cancerous lesion showed a change in color from red to white; no microvessels were evident. On the other hand, all the cancerous lesions examined clearly showed enhancement of tumor microvessels. The rate of detection of tumor microvessels by magnifying pharmacoendoscopy (100%) was significantly higher than that by magnifying endoscopy alone (41.3%). Limitations: This was small pilot study. Conclusions: Magnifying pharmacoendoscopy with epinephrine is a powerful tool for assessing tumor vascularity and may contribute to the histologic diagnosis of differentiated early gastric cancers before endoscopic treatment.
文摘Background:We hypothesized that magnetic resonance cholangiography(MRC) may have less accuracy for the diagnosis and the assessment of the severity of primary sclerosing cholangitis(PSC) than endoscopic retrograde cholangiography(ERC) .Objective:The aim of this study was to determine the diagnostic accuracy and interobserver agreement of both ERC and MRC in PSC.Design:A case-control study.Setting:University Hospital.Patients:ERCs and MRCs of 36 patients with PSC and 51 controls(normal/other biliary tract diseases) were read in an independent,blinded,and random fashion by 2 magnetic resonance radiologists and 2 interventional endoscopists by using a previously validated classification system.Readers had no access to clinical history,laboratory results,or patient mix.Results:Extrahepatic ductal(EHD) and intrahepatic ductal(IHD) visualization was excellent in 64% of 66% of MRCs and 86% of 74% of ERCs.Sensitivity and specificity for diagnosis of PSC for readers 1 to 4 were 91% and 85%,88% and 90%,81% and 96%,and 83% and 96%.respectively.Receiver operating curve values were excellent for all readers(all >0.9) .Interobserver agreement(κ statistics) for the diagnosis of PSC(MRC,0.83;ERC,0.73) and for identifying the presence of IHD strictures(MRC,0.64;ERC,0.86) was good for both modalities,but only ERC(ERC,0.55;MRC,0.36) was good for the presence and the severity of EHD strictures.When assessment of disease severity was limited to the 36 patients with PSC,interobserver agreement was very poor for both MRC(0.23 and 0.07 for EHD and IHD,respectively) and ERC(0.24 and 0.34 for EHD and IHD,respectively) .Limitations:The retrospective case-control study made it difficult to assess the impact of the diagnosis on patient management.Conclusions:ERC and MRC were comparable for diagnosing PSC,with very good interobserver agreement for the diagnosis of PSC and IHD strictures.Only ERC had good agreement for EHD strictures.Interobserver agreement was very poor for both MRC and ERC when disease severity of PSC was assessed.
文摘The Purkinje cell and their synaptic contacts have been described using(1)light microsocopy,(2)transmission and scanning electron microscopy,and freeze etching technique,(3)conventional and field emission scanning electron microscopy and cryofracture methods,(4)confocal laser scanning microscopy using intravital stain FM64,and(5)immunocytochemical techniques for Synapsin-I,PSD9-5,GluR1 subunit of AMPA receptors,N-cadherin,and CamKII alpha.The outer surface and inner content of plasma membrane,cell organelles,cytoskeleton,nucleus,dendritic and axonal processes have been exposed and analyzed in a three-dimensional view.The intramembrane morphology,in bi-and three-dimensional views,and immunocytochemical labeling of synaptic contacts with parallel and climbing fibers,basket and stellate cell axons have been characterized.Freeze etching technique,field emission scanning microscopy and cryofracture methods,and GluR1 immunohistochemistry showed the morphology and localization of postsynaptic receptors.Purkinje cell shows N-cadherin and CamKII alpha immunoreactivity.The correlative microscopy approach provides a deeper understanding of structure and function of the Purkinje cell,a new three-dimensional outer and inner vision,a more detailed study of afferent and intrinsic synaptic junctions,and of intracortical circuits.
基金the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for financially supporting one of the authors (M.A.F.)the Instituto de Engenharia Nuclear (IENCNEN)+1 种基金Programa de Engenharia Mecanica (PEM-COPPE/UFRJ)for their invaluable help for the development of the research
文摘Thin Layer Activation is a nuclear technique that has key advantages over other wear measuring techniques for mechanical systems,especially for in site experiments on equipment important to safety in nuclear plants.Still,it incurs radioactive dose and,thus,must be proved radiologically safe before use,otherwise,the utilization of this technique may be hindered inviable.Proving said technique is safe previous to any operational/monetary cost is key,providing a methodology for this early assertion is the main contribution of this work—here,only non-occupationally exposed individuals are considered.This work offers a methodology,through a case study,to ascertain the Thin Layer Activation parameters to obtain safe levels of radioactive dose while maintaining statistically reliable results.This methodology consists of using simulations,through the Monte Carlo Method,to obtain the floors and ceilings for the previously mentioned activation parameters based on operation and work conditions on site.
文摘After my paper (Zeng, 1986b) was published and another (Zeng, 1989) was submitted to the journal, I found two papers written by Arnold (1966) and McIntyre et al. (1987) and received some reprints of Ripa’s papers (1983; 1984; 1987; 1988) in the same field. I thank Drs. Mu Mu and Pedro Ripa very much for showing and sending me these interesting papers.
文摘Background: Primary malignant tumors arising from bone are uncommon but important malignant neoplasms which account for 0.2% of all primary cancers in adults and approximately 5% of all childhood malignancies. Aim: No comprehensive surveillance data about primary malignant bone tumors is available from this region of West Bengal in the literature. An attempt is undertaken to correlate clinicopathological findings, both histological & cytological features of primary bone tumours. Method: This observational study of clinical presentation was corroborated with cytology and histopathology of 67 cases of primary malignant bone tumors in 2005-2007 in a tertiary health care centre. Results: Among the primary malignant tumors, 39 cases (58.20%) were male and 28 (41.80%) were female. Sixty one lesions (91%) were located in the long bones and 6 (9%) involving flat and short bones. Osteosarcomas are found to be the predominant primary malignant bone tumors (44.77%), followed by Ewing’s sarcomas (20.89%), chondrosarcomas (13.43%), high grade giant cell tumor, and plasmacytoma (5.97%). Predilection for male (M: F 2:1) found in both osteosarcoma and chondrosarcoma, but it was reverse in cases of Ewing’s sarcomas. Conclusion: Osteosarcoma is the most common around knee joint and chondrosarcoma is frequent in long bones in this region. We made an attempt to correlate FNAC findings with the histopathology and it was seen that overall sensitivity of FNAC of primary malignant bone tumors was 56.71%.
文摘The nasopharynx is an unusual site for extraosseous chordoma. The characteristic histology and immunohistochemistry confirmed the diagnosis. The behaviour of this tumour is locally aggressive. We report a case of nasopharyngeal chordoma in an elderly patient with literature review.
文摘1. Introduction The goal of the present study was to develop non-in-vasive techniques for the assessment of voice disorders andfor monitoring the effects of voice. However, before acous-tic algorithms can be used in clinical applications, it isimportant to understand the relationship between clinicalperceptions of voice quality and the acoustic measures ob-
文摘This paper presents some results concerning applications of the coupled dynamical-radiational model of stratocumulus Ye developed (Ye, 1990, hereafter referred to as the DRS model). Basically, calculations involved here relate to the time-integration of the DRS model to estimate some time constants associated with the boundary layer and cloud developments. To obtain cloud lifetime (CLT), the time interval from its formation to its dissipation, different cloud instability criteria are compared, the mechanism for dissipating cloud are discussed, and thereby two new criteria for judging whether cloud can maintain are established. Following these criteria, the sensitivities of CLT to parameters such as the air-sea temperature difference, subsidence, and surface wind are estimated. The main interesting results about the sensitivities of the forming time (CFT) are a stable environment, such as cool sea, low wind, and strong subsidence, would prolong the existence of Sc, which has been predicted by the model calculations and strikingly tallies with statistical observations.Besides, with the DRS model and the CLT criteria, we follow a marine boundary layer, starting with clear sky, through the formation and development of clouds and rain, until their dissipation. On the whole, the model results fit the developing process of a typically stable marine boundary layer, and show some features Nicholls (1984) observed for daytime Sc.
文摘Background:The detection of the mucosal morphology(ie,mucosal and vascular patterns) in Barrett’s esophagus(BE) by magnifying(chromo) endoscopy may improve the distinction of high-grade intraepithelial neoplasia(HGIN) from nondysplastic specialized intestinal metaplasia(SIM) .Narrow band imaging(NBI) is a new technique that uses optical filters to enhance the mucosal contrast without the need for chromoendoscopy.Objective:To use NBI for the characterization and the classification of the mucosal morphology in nondysplastic BE and in BE with HGIN.Design:Descriptive study.Setting:Single-center study in a tertiary referral center for the diagnosis and treatment of patients with BE.Patients:We used NBI with magnifying endoscopy to image and biopsy randomly selected areas in 63 patients with BE.A systematic image and a biopsy specimen evaluation process was followed,including unblinded assessment of an exploratory set of images and biopsy specimens,and blinded evaluation of learning and validation sets.Main Outcome Measurements:The relationship between the mucosal morphology and the presence of SIM and HGIN.Results:SIM was characterized by either villous/gyrus-forming patterns(80%) ,which were mostly regular and had regular vascular patterns,or a flat mucosa with regular normal-appearing long branching vessels(20%) .HGIN was characterized by 3 abnormalities:irregular/disrupted mucosal patterns,irregular vascular patterns,and abnormal blood vessels.All areas with HGIN had at least 1 abnormality,and 85% had 2 or more abnormalities.The frequency of abnormalities showed a significant rise with increasing grades of dysplasia.The magnified NBI images had a sensitivity of 94%,a specificity of 76%,a positive predictive value of 64%,and a negative predictive value of 98% for HGIN.Limitations:No data on observer agreement.Conclusions:NBI with magnification reveals the mucosalmorphology characteristics of nondysplastic BE and HGIN,without the need for staining and has a relatively high diagnostic value for HGIN when used for targeted detailed examination of areas of interest.
文摘Background:Video-autofluorescence imaging(AFI) and narrow band imaging(NBI) are new endoscopic techniques that may improve the detection of high-grade intraepithelial neoplasia(HGIN) in Barrett’s esophagus(BE) .AFI improves the detection of lesions but may give false-positive findings.NBI allows for detailed inspection of the mucosal and(micro) vascular patterns,which are related to HGIN.Objective:A proof-of-principle study to combine AFI and NBI to improve the detection of HGIN and to reduce false-positive findings.Design:Cross-sectional study of consecutive eligible patients.Setting:Single-center.Patients:Twenty patients with BE with suspected or endoscopically treated HGIN were investigated with 2 prototype imaging systems:AFI(inspection with high-resolution videoendoscopy and autofluorescence imaging for detection of lesions) and NBI(for detailed inspection of mucosal and vascular patterns of identified lesions) .Lesions were sampled for histopathologic evaluation.Main Outcome Measurements:The positive predictive value of AFI alone and of AFI-NBI for detecting HGIN and the reduction of falsepositive findings because of the use of NBI.Results:All of the 28 lesions with HGIN were identified with AFI.Seventeen were identified with white light(61%) .Forty-seven suspicious lesions were detected with AFI:28 contained HGIN(60%) and 19 were false positive(40%) .With NBI,25 of the true-positive lesions had definitely suspicious patterns,and 3 had dubiously suspicious patterns.Of the 19 false positives,14 were not suspicious on NBI.The false-positive rate,therefore,was reduced from 40% to 10%.Low-grade dysplasia was found in 4 of the remaining 5 false positives.All of the 14 patients with HGIN were identified by AFI-NBI(sensitivity 100%) .Limitations:Uncontrolled study in high-risk patients.Conclusions:This proof-of-principle study confirms that AFI can be used as a red-flag technique to detect suspicious lesions.With NBI,detailed inspection of the surface patterns can be performed.This combination may increase the accuracy of detecting HGIN in BE.
文摘Based on the DRS model (one coupled dynamical-radiational model of stratocumulus), though extended to take advection into account, several calculations have been made to estimate its contributions to the thermodynamical structure of the PBL (planetary boundary layer). Advection various calculations show does affect the development of :he PBL, particularly in cloud forming and evolving. One of the intriguing findings which accords well with observations demonstrates that cold currents create strong convective weather, while warm currents bring about stable weather: produce prolonged low clouds or fogs.
基金partly supported by the National Science Foundation (No.ECCS#0621924,ECCS-#0901562)the Intelligent Systems Center
文摘In this paper,the optimal control of a class of general affine nonlinear discrete-time(DT) systems is undertaken by solving the Hamilton Jacobi-Bellman(HJB) equation online and forward in time.The proposed approach,referred normally as adaptive or approximate dynamic programming(ADP),uses online approximators(OLAs) to solve the infinite horizon optimal regulation and tracking control problems for affine nonlinear DT systems in the presence of unknown internal dynamics.Both the regulation and tracking controllers are designed using OLAs to obtain the optimal feedback control signal and its associated cost function.Additionally,the tracking controller design entails a feedforward portion that is derived and approximated using an additional OLA for steady state conditions.Novel update laws for tuning the unknown parameters of the OLAs online are derived.Lyapunov techniques are used to show that all signals are uniformly ultimately bounded and that the approximated control signals approach the optimal control inputs with small bounded error.In the absence of OLA reconstruction errors,an optimal control is demonstrated.Simulation results verify that all OLA parameter estimates remain bounded,and the proposed OLA-based optimal control scheme tunes itself to reduce the cost HJB equation.
基金Financial support was provided by the Austrian research funding association(FFG)within the research project“Entwicklung eines innovativen Tunnelofen-Energiekonzeptes mit Reingasbrennern und Energieeffizienter Prozesstechnik(TOREtech)”(FFG project#865020).
文摘Ignition within gas burner ejectors can lead to off design conditions and has significant influence on the burner behavior.Thus ignition in the ejector should be prevented.In the present study the influence of combustion reactions on the performance of gas burner injectors is investigated.To investigate if ignition is possible,simulated ignition delay times,using a detailed reaction mechanism,are compared to predicted mean residence times of the gas in the ejector.Gas burner ejectors are designed using one dimensional analytic equations,based on energy and momentum conservation equations and conventional isentropic equations.1D results are compared to 2D computational fluid dynamics(CFD)simulations,to take into account non-ideal mixing effects along the ejector.Results are validated with experiments with air at room temperature.1D results show very good agreement not only with CFD simulations for the case of non-reactive flows,but also with performed experiments.It is shown that the assumption of ideal mixing along the ejector and thus the comparison of the ignition delay time to the gas mean residence time,to predict ignition in the ejector,is not valid.Ignition in the ejector is possible,even if the ignition delay time is more than thirty times higher than the mean residence time.In addition to that,it is shown,that ignition and the choice of reaction mechanism have significant influence on the predicted gas burner ejector performance.Thus,the accurate prediction of ignition delay time and the use of a detailed reaction kinetic are mandatory to correctly predict the burner ejector behavior.