Objective:To monitor the pathological alterations in pancreas of rat during experimental fluorosis. Methods:Sixty Sprague Dawley albino rats of both sexes were divided into 12 experimental groups and one control group...Objective:To monitor the pathological alterations in pancreas of rat during experimental fluorosis. Methods:Sixty Sprague Dawley albino rats of both sexes were divided into 12 experimental groups and one control group.The rats of control group were administered subcutaneously double distilled water 1 mL/kg bw daily.The experimental groups were injected with 30,45,and 75 mg NaF/kg bw/day.The experimental period was divided into 4 phases at interval of 15,22,30,and 36 days.Animals were sacrificed from each group at the end of 16,23,31,and 37 days.Results: The following changes were observed in this study:(1) Pathological examination of pancreas after 15 days of fluoride treatment revealed:hypertrophy of acini,leucocytes infilteration and pycnouc nuclei due to necrosis of acini in group 1;uremic alterations,invulsion and infoldings of reticular layer of islets of Langerhans in group 2;and a decrease in number of acini and interlobular connective tissues resulted in an increase in intercellular spaces in pancreas of rats in group 3.(2)Hyalinization and hypertrophy in the lobules of acini and hyperplasia and hypertrophy in intercalated duct with mucinous secretion in pancreas of rat of group 4;squamous metaplasia of pancreatic duct,adenoma of pancreas,hemorrhagic necrosis in group 5;and hyperplasia of acini and reduction in number of pancreatic islets in group 6.(3) Disorganization and atrophy of pancreatic lobules and presence of vacuoles in a group of six were visible in pancreas of rats in group 7;acute pancreatic and lamellated inflammatory cells in test rats of group 8;and islet adenoma and decrease in number of islets cells,and exudation in acini were noticed in experimental rats of group 9.(4) In the last phase of experimentation,atrophic alterations in pancreatic acini,invulsions,and necrosis was prominent in group 10,deep inflammation and proliferation of connective tissue of pancreas in experimental group 11,and periodical fibrosis, hyperplasia of acini,degenerative changes in pancreas of rats in group 12.Conclusion:The histopathological examination of pancreas of fluoridated rats exhibited structural alterations in the exocrine glands.The acini revealed hypertrophy,pyknotic nucleus,necrosis and uremic alterations.Acini became lobulated and reveal increased pigmentation.展开更多
The group Ⅲ nitrides are an important class of materials with aplications in UV and visible optoelectronics,high temperature electronics,cold cathodes and solar blind detectors.In recent years,with the realisation of...The group Ⅲ nitrides are an important class of materials with aplications in UV and visible optoelectronics,high temperature electronics,cold cathodes and solar blind detectors.In recent years,with the realisation of nitride based LEDs,the use of GaN IED has the potential to compete with 1raditional filament and discharge lamps,for the provision of white lighting,and there has been an explosion of interest in the MOCVD growth of GaN based materials with an increasing focus on large area multiwafer reactors and wafer uniforrmity.This paper will review the design philosophy and characteristics of close-coupled showerhead reactors,relating these to the requirements of group Ⅲ-nitride growth,and will present a selection of data resulting from the operation of such equipment.These results suggest that the close coupled showerhead style of reactor is very suitable for the growth of GaN based structures in both research and production environments.展开更多
Aims.To estimate the incidence of ac ute-onset presumed infectious endophthalmitis(PIE)following cataract surgery in the UK and provide epidemiologica l data on the pre-sentation,management,microbiolo gy,and outcome o...Aims.To estimate the incidence of ac ute-onset presumed infectious endophthalmitis(PIE)following cataract surgery in the UK and provide epidemiologica l data on the pre-sentation,management,microbiolo gy,and outcome of cases of endophthalmitis.Methods.Cases were identified prospectively by active surveillan ce through the British Ophthalmological Surveillance Uni t reporting card system,for the 12-month period October 1999to September 2000inclusive.Questionnaire data were obtained from ophthal-mologists throughout the UK at baseline and 6months after diagnosis.Under-reporting was estimated by independently contacting units with infection databases.Results.Data were available on 213patients at baseline and 201patients at follow-up.The minimum estimated incidence of PIE was0.086per 100cataract extractions a nd the corrected inci-dence was 0.14per 100cataract extra ctions.For the management of PIE,96%of patients re ceived intravitreal,30%subconjunctival,65%oral,and 17%intravenous antibiotics.In all,17%of patients received intravitreal steroid.From the intraocular sampl es taken for microbio-logical analysis,56%were culture p ositive.At follow-up,48%of patients achieved visual acui ty of 6/12or better and 66%achieved better than 6/60.13%of patients were unable to perceive light or had evisc eration of the globe.Conclusions.The incidence of PIE after cataract surgery in the UK is comparable to that of other s tudies.Approxi-mately 50%of patients achieved a vis ual acuity close to the driving standard.展开更多
文摘Objective:To monitor the pathological alterations in pancreas of rat during experimental fluorosis. Methods:Sixty Sprague Dawley albino rats of both sexes were divided into 12 experimental groups and one control group.The rats of control group were administered subcutaneously double distilled water 1 mL/kg bw daily.The experimental groups were injected with 30,45,and 75 mg NaF/kg bw/day.The experimental period was divided into 4 phases at interval of 15,22,30,and 36 days.Animals were sacrificed from each group at the end of 16,23,31,and 37 days.Results: The following changes were observed in this study:(1) Pathological examination of pancreas after 15 days of fluoride treatment revealed:hypertrophy of acini,leucocytes infilteration and pycnouc nuclei due to necrosis of acini in group 1;uremic alterations,invulsion and infoldings of reticular layer of islets of Langerhans in group 2;and a decrease in number of acini and interlobular connective tissues resulted in an increase in intercellular spaces in pancreas of rats in group 3.(2)Hyalinization and hypertrophy in the lobules of acini and hyperplasia and hypertrophy in intercalated duct with mucinous secretion in pancreas of rat of group 4;squamous metaplasia of pancreatic duct,adenoma of pancreas,hemorrhagic necrosis in group 5;and hyperplasia of acini and reduction in number of pancreatic islets in group 6.(3) Disorganization and atrophy of pancreatic lobules and presence of vacuoles in a group of six were visible in pancreas of rats in group 7;acute pancreatic and lamellated inflammatory cells in test rats of group 8;and islet adenoma and decrease in number of islets cells,and exudation in acini were noticed in experimental rats of group 9.(4) In the last phase of experimentation,atrophic alterations in pancreatic acini,invulsions,and necrosis was prominent in group 10,deep inflammation and proliferation of connective tissue of pancreas in experimental group 11,and periodical fibrosis, hyperplasia of acini,degenerative changes in pancreas of rats in group 12.Conclusion:The histopathological examination of pancreas of fluoridated rats exhibited structural alterations in the exocrine glands.The acini revealed hypertrophy,pyknotic nucleus,necrosis and uremic alterations.Acini became lobulated and reveal increased pigmentation.
文摘The group Ⅲ nitrides are an important class of materials with aplications in UV and visible optoelectronics,high temperature electronics,cold cathodes and solar blind detectors.In recent years,with the realisation of nitride based LEDs,the use of GaN IED has the potential to compete with 1raditional filament and discharge lamps,for the provision of white lighting,and there has been an explosion of interest in the MOCVD growth of GaN based materials with an increasing focus on large area multiwafer reactors and wafer uniforrmity.This paper will review the design philosophy and characteristics of close-coupled showerhead reactors,relating these to the requirements of group Ⅲ-nitride growth,and will present a selection of data resulting from the operation of such equipment.These results suggest that the close coupled showerhead style of reactor is very suitable for the growth of GaN based structures in both research and production environments.
文摘Aims.To estimate the incidence of ac ute-onset presumed infectious endophthalmitis(PIE)following cataract surgery in the UK and provide epidemiologica l data on the pre-sentation,management,microbiolo gy,and outcome of cases of endophthalmitis.Methods.Cases were identified prospectively by active surveillan ce through the British Ophthalmological Surveillance Uni t reporting card system,for the 12-month period October 1999to September 2000inclusive.Questionnaire data were obtained from ophthal-mologists throughout the UK at baseline and 6months after diagnosis.Under-reporting was estimated by independently contacting units with infection databases.Results.Data were available on 213patients at baseline and 201patients at follow-up.The minimum estimated incidence of PIE was0.086per 100cataract extractions a nd the corrected inci-dence was 0.14per 100cataract extra ctions.For the management of PIE,96%of patients re ceived intravitreal,30%subconjunctival,65%oral,and 17%intravenous antibiotics.In all,17%of patients received intravitreal steroid.From the intraocular sampl es taken for microbio-logical analysis,56%were culture p ositive.At follow-up,48%of patients achieved visual acui ty of 6/12or better and 66%achieved better than 6/60.13%of patients were unable to perceive light or had evisc eration of the globe.Conclusions.The incidence of PIE after cataract surgery in the UK is comparable to that of other s tudies.Approxi-mately 50%of patients achieved a vis ual acuity close to the driving standard.
