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Biological culture is of great significance to the conservation of biodiversity. The formation and development of botanical gardens have reflected the plant culture which formed by human beings due to material and spiritual needs in history. Modern botanical gardens have made outstanding achievements in plant ex-situ protection, while the plant culture construction is still a little insufficient. In the process of global biodiversity conservation, the important roles of traditional culture in biodiversity conservation and sustainable use of biological resources have been increasingly valued. At this background, this study emphasized the close connection and co-evolution relationship between biocultural diversity and biodiversity, and reviewed the implication of plant culture in early botanical gardens and Chinese classical gardens. And through the analysis of the main functions of 3 085 modern botanical gardens around the world, we found that only 7.36% of botanical gardens carried out ethnobotanical research, while 11.18% carried out conservation biology research, and 17.18% worked out a plant conservation programme, which revealed the improvement of the protection function and the weakening of the cultural function of modern botanical gardens. Based on the demand for the construction of plant culture in the effective protection of plant diversity in the current botanical garden, this study further analyzed the deficiencies of plant culture construction in botanical gardens in China, including: (1) insufficient plant culture information data in plant species diversity information; (2) lack of consideration of benefit-sharing of traditional knowledge in biodiversity conservation; (3) lack of theme parks that display plant diversity with culture. Focused on the goal of plant diversity conservation and management in the China national botanical garden, we put forward the following suggestions on plant culture construction in the China national botanical garden system from three aspects, in order to provide a reference for the construction of a national botanical garden system with the characteristics of Chinese ecological civilization. Plant diversity protection and utilization: to strengthen the consideration of plant culture in the construction of plant diversity information and germplasm resource bank, encourage ethnobotanical research. Benefit-sharing: to establish access and benefit-sharing (ABS) standard procedures covering traditional knowledge to ensure fair and equitable benefit-sharing. Public participation: to consider display the regionality and uniqueness in China national botanical garden, and add ethnic plant culture theme parks or exhibition halls.

Objective To investigate the causal relationship between gut microbiota and insomnia by two-sample Mendelian randomization analysis. Methods The summary statistics of gut microbiota came from a meta-analysis of the largest genome-wide association study conducted by the MiBioGen Alliance. The summary statistics for insomnia came from the genome-wide association study of insomnia measurement. Inverse variance weighted, MR -Egger, weighted median, simple mode method, and weighted mode method were used to study the causal relationship between gut microbiota and insomnia. The stability of the results was evaluated by a series of sensitivity analyses. Results MR analysis showed that soft membrane Mollicutes RF9 [β-0.86, OR(95% CI): 0.42(0.25-0.71)] and unknown family [β=-0.86, OR(95% CI): 0.42(0.25-0.71)] had protective effect on insomnia. In addition, 14 other groups were found to be potentially causally associated with insomnia in this study including Oxalobacteraceae (F=170.153, P=0.034), Marvinbryantia (F=162.702, P=0.006), Ruminococcaceae UCG002 (F=298.323, P=0.046), Subdoligranulum(F=198.442, P=0.045), Anaerostipes(F=222.074, P=0.032), Gammaproteobacteria(F= 91.816, P= 0.006), Pasteurellales (F=231.141, P=0.010), Lachnospiraceae UCG010 (F=138.761, P=0.045), Peptococcus (F= 287.210, P=0.036), Ruminococcus gnavus group (F=162.913, P=0.031), Dorea (F=112.086, P=0.049), Flavonifractor (F= 95.307, P=0.020), and unknown genus (F=89.189, P=0.001). No significant heterogeneity or pleiotropy was detected. Conclusion Mendelian randomization shows that the flexurales, unknown families, and 14 other taxa are causally related to in-somnia. The gut microbiota may be one of the treatments to improve insomnia. [ABSTRACT FROM AUTHOR]

Objective To evaluate the associations between serum level of trimethylamine oxide （TMAO） and vascular calcification and explore the risk factors of vascular calcification in patients with chronic kidney disease （CKD）. Methods A total of 118 CKD3-5 patients were assigned into two experimental groups of calcification and non-calcification according to whether or not there was calcification of abdominal aorta. And 60 healthy people with matching age and gender were selected as control group. Serum level of TMAO was determined by enzyme-linked immunosorbent assay （ELISA）. The clinical data of two groups were compared. Results TMAO（6.49 ± 0.76）μmol/L，serum phosphorus (1.73±0.62)μmol/L，calcium-phosphorus product(3.66±1.30)，parathyroid hormone （PTH）[232.90（96.90，521.60）ng/L]，alkaline phosphatase （ALP） [72.00（55.75，113.50）U/L]，serum creatinine （Scr）[684.50（511.25，921.00）μmol/L] and C-reactive protein （CRP）[5.00（1.28，21.88）mg/L] were higher in experimental group than those in control group （P＜0.05）. Serum calcium（Scr）(2.13±0.24)μmol/L，25-hydroxyvitamin D[23.67（16.84，30.06）μg/L]，albumin （Alb）(37.35±5.97)g/L and estimated glomerular filtration rate （eGFR）[6.02（4.70，8.50）mL·min-1·（1.73m2）-1] were lower in control group （P＜0.05）. TMAO(6.01±0.90)μmol/L，age(47.81±13.51)year，proportion of hemodialysis，serum calcium (2.07±0.21)μmol/L and CRP[4.70（0.80，19.44）mg/L] were higher in calcification group than that in non-calcification group （P＜0.05）. No statistically significant inter-group difference existed in gender，basic diseases （hypertension & diabetes mellitus），blood phosphorus，calcium-phosphorus product，PTH，ALP，Alb，total cholesterol （TC），triglyceride （TG），25 hydroxyvitamin D，Scr and eGFR （P＞0.05）. Vascular calcification was correlated positively with age （r = 0.446，P＜0.001），TMAO （r = 0.614，P＜0.001），serum calcium （r = 0.192，P = 0.038），CRP （r = 0.208，P = 0.024） and hemodialysis （r = 0.238，P = 0.009）. Logistic analysis revealed that age （OR = 1.069，95%CI: 1.025-1.115，P = 0.002） and TMAO （OR = 19.295，95%CI: 5.785-64.663，P＜0.001） were the independent risk factors for vascular calcification. ROC curve indicated that area under curve （AUC） of TMAO and serum calcium were 0.855 and 0.611 respectively for diagnosing vascular calcification. AUC of combination was 0.868 with a sensitivity of 85.2% and a specificity of 71.9%. Conclusion Serum level of TMAO is correlated with vascular calcification in CKD patients. And TMAO is expected to become an adjunct to diagnosing vascular calcification. Due to a low specificity，it should be combined with other risk factors for assessing vascular calcification. The common risk factors for vascular calcification include age，TMAO，serum calcium，CRP and hemodialysis. And age and serum level of TMAO are independent risk factors for vascular calcification in CKD patients.

Deep learning has achieved great success in various practical applications.How to effectively improve the model execution efficiency is one of the important research issues in this field.The existing deep learning frameworks usually model deep learning in the form of computational graphs,try to optimize computational graphs through subgraph substitution rules designed by experts and mainly use heuristic algorithms to search substitution sequences.Their shortcomings mainly include:1)the exis-ting subgraph substitution rules result in a large search space and the heuristic algorithms are not efficient;2)these algorithms are not scalable for large computation graphs;3)cannot utilize the history optimization results.In order to solve the above problem,we propose GSO,a graph neural network-based deep learning computation graph optimization framework.We transfer the graph substitution optimization problem as the subgraph matching problem.Based on the feature information from the operators and the computation graph topology,we utilize the graph neural network to predict the subgraph matching feasibility and positions.We implement the framework using Python,which is compatible with the mainstream deep learning systems.The experimental results show that:1)compared to the total graph substitution rules,the proposed rule can reduce the search space by up to 92%;2)compared to the existing heuristic algorithms,GSO can complete the subgraph replacement process of the computational graph 2 times faster.The optimized computation graph is up to 34% faster the original graph.

Objective To investigate the training, career development and mental status of anesthesia postgraduates during the pandemic of COVID-19. Methods A self-designed questionnaire was distributed through WeChat platform to anesthesia postgraduates in Beijing, Shanghai and Chengdu. The data were recorded automatically. Results A total of 222 anesthesia postgraduates participated in the survey. Among them, 52.7% of the students were contented with outcomes of online learning, 37.84% of the students considered their graduation were negatively affected by the pandemic, 76.92% of the students thought they were more used to interview in real life than online interview, and 54.95% of the students had psychological counseling service provided by school experts during the pandemic. Conclusions During the COVID-19 pandemic, medical school endeavored to guarantee the study, career development and mental health of postgraduates.

Objective: To investigate the changes of serum anti-schistosome antibody titers in schistosomiasis japonica patients after treatment, in order to provide the evidence for formulating the schistosomiasis surveillance program in marshland and lake regions., Methods: Upon prospective cohort study, the stool examination positive schistosomiasis patients and blood examination positive suspected patients (the titer was more than 1:80, including 1:80) were selected as the research objects in Jiangling County in 2014, and they received the 2-day praziquantel therapy. Half year, one year and two years after the treatment, their blood samples and fecal samples were collected for IHA anti-schistosome antibody detections and schistosome egg and miracidium detections., Results: In 2014, the stool examination positives were 251, and the majority of them were over 41 years old, accounting for 93.23% (234/251) ; 581 cases of high antibody titers were detected by the IHA method, and the majority of them were over 41 years old, accounting for 89.16% (518/581) . Half year, one year and two years after the treatment, among the stool examination positives, the negative conversion rates of stool positives were 99.60% (250/251), 100% (239/239) and 100% (234/234) respectively and the negative conversion rates of antibody positives were 21.91% (55/251), 64.11% (156/239) and 76.89% (193/234) respectively. In the high antibody titer positives, the negative conversion rates were 38.04% (221/581), 64.11% (359/560), and 77.86% (429/551) respectively, Half year, one year and two years after the treatment. There were statistically significant differences among the antibody negative conversion rates by χ 2 test ( χ 2 = 77.538, 183.412, 25.469 respectively, all P < 0.001) . The geometric mean values of antibody titers of different durations between 2 groups were analyzed by 2-independent-samples T test, and the geometric mean values of antibody titers between the 2 groups were different before the treatment ( t = 23.576, P < 0.01), but the geometric mean values of antibody titers between the 2 groups were not different 6 months, 1 year and 2 years after the treatment ( t = -0.046, 1.165, -0.132, P = 0.964, 0.245, 0.895 respectively)., Conclusions: The levels of serum anti-schistosome antibody degrade slowly in schistosomiasis japonica patients after the treatment, and the results of IHA tests cannot distinguish the current schistosome infection from previous schistosome infection. Therefore, it is necessary to develop the specific diagnostic technology for schistosome infection in order to meet the need of monitoring.

Objective: To investigate the effects and cost of four formulations of niclosamide ethanolamine salt in Oncomelania hupensis snail control in the field in marshland and lake regions, so as to provide the evidence for drawing up the plan of molluscicide using in schistosomiasis endemic areas., Methods: One drainage channel and one channel without water in the same area with snails in Jiangling County, Jingzhou City were selected as the research fields. The drainage channel was divided into 9 sections, except one section as a blank control group where the natural death rate of snails was observed only, and the remaining 8 sections were taken as the observation groups, where different dosages of 4% niclosamide ethanolamine salt powder, 5% niclosamide ethanolamine salt granules, 25% niclosamide ethanolamine salt suspending agent, 26% metaldehyde and niclosamide ethanolamine salt suspending agent, and 50% niclosamide ethanolamine salt wettable powder were used respectively. The channel without water were divided into 4 sections, except one section as a blank control group, the other 3 segments were taken as the observation groups, where 4% niclosamide ethanolamine salt powder, 5% niclosamide ethanolamine salt granules, and 50% niclosamide ethanolamine salt wettable powder were used respectively. Before and after spraying molluscicide for 7 days and 15 days, the system sampling method was used to observe the effects of snail control. Meanwhile, the unit cost method was used to calculate the costs of the different mulluscicide formulations abovementioned in unit area (1 m 2 )., Results: In the field at the drainage channel, the snail mortality rates of the groups spraying 4% niclosamide ethanolamine salt powder (50 g/m 2 ), 5% niclosamide ethanolamine salt granules (40 g/m 2 ), 25% niclosamide ethanolamine suspending agent, 26% metaldehyde and niclosamide ethanolamine salt suspending agent, and 50% niclosamide ethanolamine salt wettable powder (2 g/m 2 and 4 g/m 2 ) for 7 days were 79.52%97.87%, while the rates after spraying for 15 days were 71.00%-96.30%, and compared with those before spraying, the differences were statistically significant (all P < 0.01). For the groups spraying with 2 g/m 2 or 4 g/m 2 suspending agent as well as wettable powder for 7 days, the snail mortality rates were significantly different (both P < 0.05). In the field at the channel without water, the snail mortality rates of the 3 observation groups after spraying molluscicide for 7 days were 97.14%-100%, while for 15 days were 94.32 %-100%, and compared with the rates before spraying, all the differences were statistically significant (all P < 0.01). The unit costs per 1 m 2 of the molluscicide abovementioned were ranged from 0.280 Yuan to 0.416 Yuan., Conclusions: In marshland area inside embankment, the molluscicide formulations of the powder and granule are suitable for the environments without water or with instability water level, while the molluscicide formulations of the suspended agents and wettable powder are suitable for the water environment. Though the unit cost of powder is the lowest, the molluscicide in this formulation flies away seriously.

Objective: To understand the spatial distribution characteristics of wild feces in schistosomiasis endemic areas of Jiangling County, Hubei Province and further explore the source of infection efficiently, so as to provide the evidence for the development of corresponding monitoring and response technology., Methods: In 2011, the fresh wild feces were investigated every two months in the selected 15 villages by the severity of historical endemic in Jiangling County. The schistosome miracidium hatching method was used to test the schistosome infection of the wild feces. The descriptive analysis and spatial analysis were used for the description of the spatial distribution of the wild feces., Results: Totally 701 wild feces samples were collected with the average density of 0.055 6/100 m 2 , and the positive rate of the wild feces was 11.70% (82/701). The results of the regression analysis showed a positive spatial correlation between the positive rate of wild feces and the rate of human infection, the area with infected Oncomelania hupensis and the number of fenced cattle, and the corrected R 2 of the model was 0.58., Conclusions: The infection rate of wild feces is positively correlated with the rate of human infection, area with infected O. hupensis and number of fenced cattle in space in Jiangling County, so the prevention and control measures could be conducted according to the spatial distribution of the positive wild feces.

Objective: To implement a two-level community-based health education pattern of schistosomiasis in residents of endemic areas in marshland and lake regions, so as to explore the suitable pattern of health education under hypo-endemic situation., Methods: Two schistosomiasis endemic villages in Jiangling County, Hubei Province were collected as study areas, and among which, one village was treated as an intervention group, where the two-level community-based health education pattern as well as regular control measures was implemented; the other village was a control group, where only regular control measures were implemented. The awareness rates on schistosomiasis control, the rates of correct behavior and the compliance rates of examination, treatment and chemotherapy of the two groups before and after the intervention were compared., Results: According to the results of the baseline survey in 2014, the awareness rates of schistosomiasis control of the intervention and control groups were 84.00% and 77.45%, respectively, the correct rates of behavior of the two groups were 72.00% and 63.73%, respectively, and the compliance rates of the treatment were 80.36% and 82.28%, respectively, there were no statistically significant differences between all the above rates of the two groups (all P > 0.05). After the intervention of the two-level community-based health education, the correct rates of behavior, and the compliance rates of examination and chemotherapy of the two groups were 92.31% and 80.37%, 95.11% and 82.55%, 84.13% and 63.64%, respectively, and the differences between all the rates above of the two groups were statistically significant (all P < 0.05). When compared to those before intervention, the growing rates of the compliance rates of examination, treatment and chemotherapy of the intervention group were 20.97%, 15.33% and 23.29%, respectively, while those of control group were 14.27%, 4.17%, -3.77%, respectively, the growing rates of the intervention groups were higher than those of the control groups., Conclusions: Through the two-level community-based pattern of health education, the compliance rates of examination and treatment of the residents have improved, and therefore, the pattern is suitable for popularization and application in marshland and lake regions.

Objective: To observe the Oncomelania hupensis snail control effects of molluscicides with different formulations in the ditch with unstable water level in field of marshland and lake areas, so as to provide the evidence for formulating the prevention strategies., Methods: A drainage channel with O. hupensis snails in Jiangling County, Jingzhou City were selected as the study field, then it was divided into 6 segments, except 1 segment was treated as the blank control group for observing the natural mortality rate of the snails, the other 5 segments were treated as observation groups, where 4% niclosamide ethanolamine salt powder, 5% niclosamide ethanolamine salt granule, 25% suspension concentrate of niclosamide ethanolamine salt, 26% suspension concentrate of metaldehyde and niclosamide ethanolamine salt, 50% niclosamide ethanolamine salt wettable powder were applied respectively. Before and after the mollusciciding, the snail surveys were carried out through the systematic sampling method, and the short- and long-term effects of snail control were observed, and the mortality rates of the snails on the slope above the water level and those below the water level were compared., Results: When 7 d and 15 d after mullusciciding, the mortality rates of snails on the slope above the water level in each observation group were 79.52%-97.87% and 90.43%-96.30%, respectively, when compared with those before mollusciciding, all the differences were statistically significant (all P < 0.01). When 7 d after mullusciciding, the mortality rates of snails below the water level in each observation group were 17.11%-50.00%, which were all lower than those of the snails on the slope above the water level in the corresponding groups (all P ＜ 0.05); when 15 d after mullusciciding, the rates were 9.43%-95.24%, and those in 25% suspension concentrate of niclosamide ethanolamine salt, 26% suspension concentrate of metaldehyde and niclosamide ethanolamine salt, 50% niclosamide ethanolamine salt wettable powder groups were all lower than those of the snails on the slope above the water level in the corresponding groups (all P ＜ 0.01). Compared with the densities of living snails before mollusciciding, those 6 months after mollusciciding in each observation group decreased by 70.21%-78.98%., Conclusions: The molluscicides in the formulation of powders and granule are suitable for both the snail environment with or without water, while those in the formulation of suspension agents and wettable powders are suitable only for environments with water.

Objective: To establish more efficient method to isolate of dermal papilla cells (DPCs) from back skin of SD rats, and then to study the growth ability and characteristics of SD rat dermal papilla cells in vitro., Method: DPCs were separated from back skin of SD rats according to the modified method of two-step enzymatic digestion. The DPCs morphological observation under inverted microscope, the growth kinetics by cells number, the cell cycle analysis by flow cytometry analysis and determine the surface epitopes by immunohistochemical staining and flow cytometry analysis., Result: Cultured DPCs were similar to fibroblasts in appearance, but generally and periodically exhibited an aggregative growth pattern. The growth kinetics showed that the number of DPCs presented progressive increase in a logarithm mode in the first 3 days and entered into plateau after 9 days, P1, P3, P5 multiplication time was 68 h, 52 h and 36 h, respectively. The flow cytometrical analysis showed that DPCs of P1, P3, P5 G0/G1 stage were (90.21 +/- 5.13)%, (81.23 +/- 1.85)% and (75.16 +/- 5.32)%, respectively. G0/G1 stage cells became less following passage subculture and elongation of culture time, but most of the DPCs stayed resting stage still. The cultivated dermal papilla cells expression of alpha-smooth muscle and CD44 on cell surface was positive, CK and CD34 were negative., Conclusion: DPCs can be separated by the modified method of two-step enzymatic digestion successfully. The cultivated dermal papilla cells vitro show the feature of stem cells and has important potentially as a new seed cell source for cell engineering.

Objective: To study the influence of preoperative chemoradiotherapy, preoperative chemotherapy, and operation alone on the cellular immunity in patients with middle or lower rectal cancer., Methods: Ninety middle or lower rectal cancer patients were non-randomly divided into 3 equal groups: preoperative radiotherapy group, receiving conventional radiotherapy with a total dose of 30 Gy in 10 fractions completed within 2 weeks; preoperative chemoradiotherapy group, receiving 2 cycles of single-oral drug regimen (capecitabine 1000 mg/m(2) for 2 weeks as a cycle with an interval of 1 week) and then, i.e., 2 days later, receiving conventional radiotherapy as prescribed for the patients in the preoperative radiotherapy group; and operation alone group. Operation was performed on the patients of the former 2 groups 3 weeks after the completion of the relevant treatment. Blood samples were collected on the admission day, 1 day before operation, and 7 day and 1 month after operation. Flow cytometry was used to detect the levels of CD(3)(+), CD(4)(+), CD(8)(+), CD(4)(+)/CD(8)(+), and NK cells., Results: There were no significant differences in the levels of CD(3)(+), CD(4)(+), CD(8)(+), CD(4)(+)/CD(8)(+), and NK cells before and after radiotherapy between the preoperative chemoradiotherapy group and preoperative chemotherapy group (all P > 0.05). 7 days after operation, the levels of CD(3)(+), CD(4)(+), CD(4)(+)/CD(8)(+), and NK cells were degraded and the CD(8)(+) level was increased significantly (all P < 0.05) in all 3 groups. One month after operation, the levels of CD(3)(+), CD(4)(+), CD(4)(+)/CD(8)(+), and NK cells were all significantly higher and the CD(8)(+) level was significantly lower than those before operation and 7 days after operation (all P < 0.05)in all 3 groups. There were no significant differences in the T cell number and the proportions of different categories of cells at different time points in these 3 group (all P < 0.05)., Conclusion: Preoperative chemoradiotherapy and preoperative chemotherapy have no significant impact on the cellular immune function in the patients with rectal cancer.

Objective: To investigate the differences in the characteristics of optic nerve damage in patients with primary open angle glaucoma (POAG)and normal tension glaucoma (NTG)., Method: The optic disc parameters and retinal nerve fiber layer (RNFL) of 47 eyes of 39 subjects with POAG (IOP > 24 mmHg) and 38 eyes of 32 subjects with NTG (IOP < 21 mmHg) were measured by using a Heidelberg retina tomograph II, color stereo-optic disc photographs, and an Octopus automated perimetry., Results: (1) Rim area, rim/disc area ratios and three sectors except temporal quadrant of optic disc were significantly smaller, whereas C/D was significantly larger in patients with NTG than those of POAG. The mean RNFL thickness and RNFL cross-sectional areas at temporal/interior and temporal/superior in those with NTG were significantly (P < 0.05) smaller than those of POAG. The rim volume was significantly (P < 0.05) smaller and mean cup depth was significantly (P < 0.05) larger in patients with NTG than POAG. (2) The defect types of RNFL: RNFL diffuse loss and local defect ratio were 53.19% and 4.26% in POAG, respectively; while were 21.05% and 55.26% in NTG, respectively. The difference between the proportions of the defect type of RNFL in patients with POAG and those of NTG is statistically significant (P < 0.01)., Conclusions: Our results demonstrate that the varieties of C/D area ratio, rim area, RNFL thickness, and defect types of RNFL with NTG and POAG indicate that the different mechanisms are involved in optic nerve damage in the two types of glaucoma.

Objective: To investigate the prevalence of primary angle-closure glaucoma (PACG) of urban and rural residents in Beijing, China. A quantitative comparison was made based on the data collected from this epidemiological survey. We also identify some of the most typical risk factors associated with PACG., Methods: Glaucomatous screening examination was applied to specific age group populations (aged 40 and older) in the defined district of Beijing and its remote rural county, from June to October, 2001. There are 4451 subjects in all, 1980 rural subjects and 2471 urban subjects, 1939 males and 2512 females. The screen and diagnostic methods used in this survey included van Herick methods and gonioscopy examination to estimate the peripheral depth of the anterior chamber, visual acuity, intraocular pressure, refraction status, stereoscopic fundus photography, and threshold-related visual field tests. Subjects regarded as suspected glaucoma and glaucoma patients are reexamined with standard glaucomatous examination., Results: The response rate of rural and urban population is 79.6% (1980/2488), 87.1% (2471/2836), respectively. The prevalence of PACG (in aged 40 years or older population) resulted from this survey was 1.2% (95% CI 0.9% - 1.5%). However, the prevalence was different between urban and rural residents, 1.1% (95% CI 0.8% - 1.4%) vs. 1.6% (95% CI 1.2% - 2.0%). The prevalence of PACG in female was more than that in male, 1.7% (95% CI 1.3% - 2.1%) vs.0.8% (95% CI 0.5% - 1.1%). A drastic increase in prevalence of PACG with age increase was identified in both survey sites, however, this increase in rural subjects (aged 60-69 years group) occurred ten years earlier than those from urban subjects (aged more than 70 years group). Compared to urban residents, rural residents showed higher prevalence of unilateral low vision (39.3% vs. 20.6%) and blindness (28.6% vs. 14.7%). This survey also confirmed that, as people aging, refraction status became hyperopia, the depth of peripheral anterior chamber became narrow. In the different age groups, female and male groups, the changes of refraction status and the depth of peripheral anterior chamber paralleled the prevalence of PACG., Conclusions: The prevalence of PACG was obviously different in different groups. This could due to several factors including gender, age, change of refraction status and chamber angle as well.

Objective: To investigate the prevalence and causes of low vision and blindness in Beijing residents aged 40 and over., Methods: 4,451 residents aged 40 and over in 3 rural communities and 5 urban communities in Beijing underwent eye examination, including examination of distant and near visual acuity (VA), best corrected distant and near VA, pinhole VA, and visual field, slit lamp biomicroscopy, and dilated ocular examination in the form of in-home survey by defined population-based sampling. The medical history was surveyed too. The data were analyzed based on the criteria of the World Health Organization., Results: The general prevalence rates of low vision and blindness were 0.99% (95% CI: 0.70-1.28) and 0.39% (95% CI: 0.21-0.57) respectively. The prevalence rate of low vision in females was 1.45%, 2.23 times that of males (0.65%) (OR: 1.97, 95% CI: 1.00-3.95). The prevalence rate of low vision of rural residents was 1.76%, 2.89 times that of urban residents (0.61%) (OR: 2.93, 95% CI: 1.43-6.11). The prevalence rate of blindness in females was 0.64% and 0.37% in males. The prevalence rate of blindness of rural residents was 1.06%, 2.04 times that of the urban residents (0.52%) (OR: 3.77, 95% CI: 1.41-10.62). The 3 major causes of blindness were cataract (37.50%), glaucoma (29.20%), and high myopic macular degeneration (8.30%). The prevalence of blindness increased with age., Conclusion: The prevalence rates of low vision and blindness are higher in the rural areas. Cataract, glaucoma, and high myopic macular degeneration are the major causes of blindness. The prevalence of low vision and blindness are influenced by age, sex; area, health care level, educational level, and environmental factors.