The Kaerqueka polymetallic deposit, Qinghai, China, is one of the typical skarn-type polymetallic ore deposits in the Qimantage metallogenic belt. The dynamic mechanism on the formation of the Kaerqueka polymetallic d...The Kaerqueka polymetallic deposit, Qinghai, China, is one of the typical skarn-type polymetallic ore deposits in the Qimantage metallogenic belt. The dynamic mechanism on the formation of the Kaerqueka polymetallic deposit is always an interesting topic of research. We used the finite difference method to model the mineralizing process of the chalcopyrite in this region with considering the field geological features, mineralogy and geochemistry. In particular, the modern mineralization theory was used to quantitatively estimate the related chemical reactions associated with the chalcopyrite formation in the Kaerqueka polymetallic deposit. The numerical results indicate that the hydrothermal fluid flow is a key controlling factor of mineralization in this area and the temperature gradient is the driving force of pore-fluid flow. The metallogenic temperature of chalcopyrite in the Kaerqueka polymetallic deposit is between 250 and 350 ℃. The corresponding computational results have been verified by the field observations. It has been further demonstrated that the simulation results of coupled models in the field of emerging computational geosciences can enhance our understanding of the ore-forming processes in this area.展开更多
The shapes of intrusive body and contact zone might influence the formation and distribution of orebodies in skarn deposit.By taking Xinwuli intrusive body in Fenghuangshan copper deposit,Tongling,Anhui,China,as the r...The shapes of intrusive body and contact zone might influence the formation and distribution of orebodies in skarn deposit.By taking Xinwuli intrusive body in Fenghuangshan copper deposit,Tongling,Anhui,China,as the research object,a new method was used to obtain the quantitative relationship between intrusion morphology and skarn mineralization.The first step of the method was to extract morphological characteristic parameters based on mathematical morphology and Euclidean distance transformation;then the quantitative relationship between the parameters and orebodies was analyzed;finally correlational analyses between the parameters and mineralization indices were conducted.The results show that morphological characteristic parameters can effectively indicate the location of concealed ore bodies in skarn deposit,with the following parts as advantageous positions of skarn mineralization:(1)the parts away from the1st trend surface in the range from?25to50m;(2)the convex parts about200m away from the2nd trend surface,around which the tangent plane of the intrusive body is approximately consistent with the trend surface;(3)the contact zones with angle between intrusive body original contact surface and trend contact surface ranging from35°to70°;(4)the parts with angle between intrusive body original contact surface and regional extruding far crustal stress ranging from50°to60°.These knowledge can be applied to more skarn deposits for future mineral exploration.展开更多
Objective To understand the perception for the use of cataract surgical services in a population acceptors and non-acceptors of cataract surgery in urban Beijing. Methods From a community-based screening program a to...Objective To understand the perception for the use of cataract surgical services in a population acceptors and non-acceptors of cataract surgery in urban Beijing. Methods From a community-based screening program a total of 158 patients with presenting visual acuity of less than 6/18 on either eye due to age-related cataract were informed about the possibility of surgical treatment. These patients were interviewed and re-examined 36 to 46 months after initial screening. The main reasons for not accepting surgery were obtained using a questionnaire. Vision function and vision-related quality of life scores were assessed in those who received and did not receive surgery. Results At the follow-up examination 116 of the 158 patients were available and 36 （31.0%） had undergone cataract surgery. Cases who chose surgery had higher education level than those who did not seek surgery （OR=2.64, 95% CI： 1.08-6.63, P=0.02）. There were no significant differences in vision function （P=0.11） or quality of life scores （P=0.16） between the surgery group and the non-surgery group. Main reasons for not having surgery included no perceived need （50.0%）, feeling of being ＂too old＂ （19.2%）, and worry about the quality of surgery （9.6%）. Cost was seeking surgery. cited by 1 （1.9%） subject as the main reason for not展开更多
Objective To assess the agreement between gonioscopy and ultrasound biomicroscopy(UBM) in detecting angle closure in Chinese patients with shallow anterior chamber. Methods An observational comparative study of the tw...Objective To assess the agreement between gonioscopy and ultrasound biomicroscopy(UBM) in detecting angle closure in Chinese patients with shallow anterior chamber. Methods An observational comparative study of the two different examination methods was conducted. Patients with normal intraocular pressure and temporal peripheral anterior chamber depth less than a quarter of corneal thickness based on slit lamp examination were included in this study from December 2007 to May 2009 in the outpatient clinic of First Hospital of Tsinghua University. Gonioscopy was performed with a Goldman goniolens in dark room first and followed by full beam light and indentation. If the filtering trabecular meshwork was invisible or any peripheral anterior synechia was found, that quadrant of the angle was considered closed. UBM was first undertaken in a darkened room then repeated with normal room lighting. If iridotrabecular apposition was showed, that quadrant of the angle was considered closed. The status of angle closure of each quadrant with different methods was recorded. Results 85 eyes of 46 patients were included in this study. The agreement between gonioscopy and UBM was poor(κ<0.4) with Kappa analysis in both dark and light conditions in each quadrant. The accordance of agreement between gonioscopy and UBM was hardly affected by age or sex, while in dark condition, eyes with deeper anterior chamber(P=0.005) or plateau iris configuration tended to produce different results(P=0.075) in the 2 methods. Conclusion Gonioscopy and UBM are both indispensable methods for detecting angle closure, neither can completely replace the other.展开更多
Objective To study the agreement between ophthalmologists and community health workers in detecting shallow anterior chamber with oblique flashlight test. Methods Totally 425 subjects were given an eye examination in ...Objective To study the agreement between ophthalmologists and community health workers in detecting shallow anterior chamber with oblique flashlight test. Methods Totally 425 subjects were given an eye examination in a community health center. The anterior chamber depth of each subject was examined by one ophthalmologist and two trained community health workers (one nurse and one non-professional health worker) using oblique flashlight test. Inter-observer agreement was determined using the weighted kappa statistic. Results Among the enrolled subjects,148 (35%) were male and 277 (65%) were female. Good agreement was noted in all the three observers. The comparison between the ophthalmologist and the nurse showed a kappa statistic of 0.42 for both eyes (P<0.001). The kappa statistic was 0.54 and 0.52 for right and left eyes respectively between the ophthalmologist and the non-professional health worker (P<0.001). As for agreement between the nurse and the non-professional health worker,the kappa statistic was 0.49 and 0.38 for right and left eyes,respectively (P<0.001). Conclusion The oblique flashlight test may be used as an applicable tool by trained community health workers for screening of shallow anterior chamber and play a role in blindness prevention in community.展开更多
AIM： To gain a better understanding of possible factors that may influence the decision of diabetes persons to participate in annual eye screening in an urban community setting of China.METHODS： A structured intervi...AIM： To gain a better understanding of possible factors that may influence the decision of diabetes persons to participate in annual eye screening in an urban community setting of China.METHODS： A structured interview including questions on attendance of eye screening, knowledge and awareness of diabetic retinopathy was conducted. The presence and degree of retinopathy were assessed using two field nonmydriatic retinal photography. RESULTS： Totally 720 diabetes persons were recruited and 519 were enrolled in this cross-sectional study. In this urban setting of Beijing, among diabetes patients of average of 10 y duration, 77% confirmed having undergone at least one eye examination and 61% reported having at least one eye examination with dilated pupil. As for the last 12 mo, the number decreased to 210（47%） and 131（30%） separately. Most of the participants（95%） were aware that diabetes could affect their vision and that regular eye examination was necessary. Very few of them（12%） however were aware that the early stages of diabetic retinopathy presented without symptoms of vision loss. Having attended patient education on diabetes was effective in building awareness about diabetic eye disease and was a significant positive predictor for attending eye screening [education in a year, Adj. OR=0.47（0.29-0.74）, P〈0.001, education years ago, Adj. OR=0.56（0.33-0.96）, P=0.036]. The duration of disease also increasedthe likelihood of having undergone eye screening（Adj. OR=0.96, P〈0.05）. CONCLUSION： Being exposed to education about the complications of diabetes increases the probability of attending diabetic eye screening. An appropriate patient knowledge building strategy should be made available to patients from the time of diagnosis.展开更多
基金Project(2017YFC0601503)supported by the National Key R&D Program of ChinaProjects(41872249,41472302,41772348)supported by the National Natural Science Foundation of China
文摘The Kaerqueka polymetallic deposit, Qinghai, China, is one of the typical skarn-type polymetallic ore deposits in the Qimantage metallogenic belt. The dynamic mechanism on the formation of the Kaerqueka polymetallic deposit is always an interesting topic of research. We used the finite difference method to model the mineralizing process of the chalcopyrite in this region with considering the field geological features, mineralogy and geochemistry. In particular, the modern mineralization theory was used to quantitatively estimate the related chemical reactions associated with the chalcopyrite formation in the Kaerqueka polymetallic deposit. The numerical results indicate that the hydrothermal fluid flow is a key controlling factor of mineralization in this area and the temperature gradient is the driving force of pore-fluid flow. The metallogenic temperature of chalcopyrite in the Kaerqueka polymetallic deposit is between 250 and 350 ℃. The corresponding computational results have been verified by the field observations. It has been further demonstrated that the simulation results of coupled models in the field of emerging computational geosciences can enhance our understanding of the ore-forming processes in this area.
基金Projects(41472301,41472302) supported by the National Natural Science Foundation of China
文摘The shapes of intrusive body and contact zone might influence the formation and distribution of orebodies in skarn deposit.By taking Xinwuli intrusive body in Fenghuangshan copper deposit,Tongling,Anhui,China,as the research object,a new method was used to obtain the quantitative relationship between intrusion morphology and skarn mineralization.The first step of the method was to extract morphological characteristic parameters based on mathematical morphology and Euclidean distance transformation;then the quantitative relationship between the parameters and orebodies was analyzed;finally correlational analyses between the parameters and mineralization indices were conducted.The results show that morphological characteristic parameters can effectively indicate the location of concealed ore bodies in skarn deposit,with the following parts as advantageous positions of skarn mineralization:(1)the parts away from the1st trend surface in the range from?25to50m;(2)the convex parts about200m away from the2nd trend surface,around which the tangent plane of the intrusive body is approximately consistent with the trend surface;(3)the contact zones with angle between intrusive body original contact surface and trend contact surface ranging from35°to70°;(4)the parts with angle between intrusive body original contact surface and regional extruding far crustal stress ranging from50°to60°.These knowledge can be applied to more skarn deposits for future mineral exploration.
文摘Objective To understand the perception for the use of cataract surgical services in a population acceptors and non-acceptors of cataract surgery in urban Beijing. Methods From a community-based screening program a total of 158 patients with presenting visual acuity of less than 6/18 on either eye due to age-related cataract were informed about the possibility of surgical treatment. These patients were interviewed and re-examined 36 to 46 months after initial screening. The main reasons for not accepting surgery were obtained using a questionnaire. Vision function and vision-related quality of life scores were assessed in those who received and did not receive surgery. Results At the follow-up examination 116 of the 158 patients were available and 36 （31.0%） had undergone cataract surgery. Cases who chose surgery had higher education level than those who did not seek surgery （OR=2.64, 95% CI： 1.08-6.63, P=0.02）. There were no significant differences in vision function （P=0.11） or quality of life scores （P=0.16） between the surgery group and the non-surgery group. Main reasons for not having surgery included no perceived need （50.0%）, feeling of being ＂too old＂ （19.2%）, and worry about the quality of surgery （9.6%）. Cost was seeking surgery. cited by 1 （1.9%） subject as the main reason for not
基金Supported by Capital Medical Development Sciences Fund(2009-2034)Tsinghua-Yue-Yuen Medical Sciences Fund(20240000564)
文摘Objective To assess the agreement between gonioscopy and ultrasound biomicroscopy(UBM) in detecting angle closure in Chinese patients with shallow anterior chamber. Methods An observational comparative study of the two different examination methods was conducted. Patients with normal intraocular pressure and temporal peripheral anterior chamber depth less than a quarter of corneal thickness based on slit lamp examination were included in this study from December 2007 to May 2009 in the outpatient clinic of First Hospital of Tsinghua University. Gonioscopy was performed with a Goldman goniolens in dark room first and followed by full beam light and indentation. If the filtering trabecular meshwork was invisible or any peripheral anterior synechia was found, that quadrant of the angle was considered closed. UBM was first undertaken in a darkened room then repeated with normal room lighting. If iridotrabecular apposition was showed, that quadrant of the angle was considered closed. The status of angle closure of each quadrant with different methods was recorded. Results 85 eyes of 46 patients were included in this study. The agreement between gonioscopy and UBM was poor(κ<0.4) with Kappa analysis in both dark and light conditions in each quadrant. The accordance of agreement between gonioscopy and UBM was hardly affected by age or sex, while in dark condition, eyes with deeper anterior chamber(P=0.005) or plateau iris configuration tended to produce different results(P=0.075) in the 2 methods. Conclusion Gonioscopy and UBM are both indispensable methods for detecting angle closure, neither can completely replace the other.
基金Supported by Tsinghua-Yue-Yuen Medical Sciences Fund (20240000564) and Norwegian Fredskorpset Exchange Program
文摘Objective To study the agreement between ophthalmologists and community health workers in detecting shallow anterior chamber with oblique flashlight test. Methods Totally 425 subjects were given an eye examination in a community health center. The anterior chamber depth of each subject was examined by one ophthalmologist and two trained community health workers (one nurse and one non-professional health worker) using oblique flashlight test. Inter-observer agreement was determined using the weighted kappa statistic. Results Among the enrolled subjects,148 (35%) were male and 277 (65%) were female. Good agreement was noted in all the three observers. The comparison between the ophthalmologist and the nurse showed a kappa statistic of 0.42 for both eyes (P<0.001). The kappa statistic was 0.54 and 0.52 for right and left eyes respectively between the ophthalmologist and the non-professional health worker (P<0.001). As for agreement between the nurse and the non-professional health worker,the kappa statistic was 0.49 and 0.38 for right and left eyes,respectively (P<0.001). Conclusion The oblique flashlight test may be used as an applicable tool by trained community health workers for screening of shallow anterior chamber and play a role in blindness prevention in community.
基金Supported by the National Natural Science Foundation of China(No.81273159)Capital Medical Development Research Fund(No.2009-2034)
文摘AIM： To gain a better understanding of possible factors that may influence the decision of diabetes persons to participate in annual eye screening in an urban community setting of China.METHODS： A structured interview including questions on attendance of eye screening, knowledge and awareness of diabetic retinopathy was conducted. The presence and degree of retinopathy were assessed using two field nonmydriatic retinal photography. RESULTS： Totally 720 diabetes persons were recruited and 519 were enrolled in this cross-sectional study. In this urban setting of Beijing, among diabetes patients of average of 10 y duration, 77% confirmed having undergone at least one eye examination and 61% reported having at least one eye examination with dilated pupil. As for the last 12 mo, the number decreased to 210（47%） and 131（30%） separately. Most of the participants（95%） were aware that diabetes could affect their vision and that regular eye examination was necessary. Very few of them（12%） however were aware that the early stages of diabetic retinopathy presented without symptoms of vision loss. Having attended patient education on diabetes was effective in building awareness about diabetic eye disease and was a significant positive predictor for attending eye screening [education in a year, Adj. OR=0.47（0.29-0.74）, P〈0.001, education years ago, Adj. OR=0.56（0.33-0.96）, P=0.036]. The duration of disease also increasedthe likelihood of having undergone eye screening（Adj. OR=0.96, P〈0.05）. CONCLUSION： Being exposed to education about the complications of diabetes increases the probability of attending diabetic eye screening. An appropriate patient knowledge building strategy should be made available to patients from the time of diagnosis.
