Wound size and location affect the prognosis of penetrating ocular injury.

BACKGROUND: Ocular trauma is a leading cause of vision loss. Penetrating ocular injury is a major type of open globe injury(OGI), while its epidemiology and clinical characteristics are still uncertain. The aim of this study is to reveal the prevalence and prognostic factors of penetrating ocular injury in the Shandong province. METHODS: A retrospective study of penetrating ocular injury was performed at the Second Hospital of Shandong University, from January 2010 to December 2019. Demographic information, injury causes, ocular trauma types, and initial and final visual acuity(VA) were analyzed. To obtain more precise characteristics of penetrating injury, the eye global was divided into three zones and analyzed. RESULTS: Among 210 OGI, there are 83 penetrating injuries which account for 39.5% of all. In addition, the final VA of 59 penetrating injuries recovered to 0.1 or better, which possesses the highest frequency among OGI. In order to research the relationship between the wound location and the final VA, we took 74 cases of penetrating injuries without retina or optic nerve damage for analysis. Results show that 62 were male and 12 were female. The average age was 36.01 ± 14.15. The most frequent occupation is the worker followed by the peasant. Statistics show that there is an obvious deviation in the Ocular trauma score (OTS) predicting the final VA and the actual final VA in the 45-65 score group (p < 0.05). Results suggest that the commonest penetrating injury zone is zone III (32 cases, 43.8%). Zone III, which is farthest from the center of the visual axis, has the largest improvement of the final VA (p = 0.0001). On the contrary, there is no statistical difference in the visual improvement in zone I and zone I + II that involves the injury of the central visual axis. CONCLUSION: This study describes the epidemiology and clinical characteristics of patients hospitalized for penetrating ocular injury without retina damage in Shandong province. It can be concluded that larger size and closer location to the visual axis of damage are accompanied by worse prognosis improvement. The study provides a better understanding of the disease and enlightenment for the prediction of visual prognosis.

LiCl induces apoptosis via CHOP/NOXA/Mcl-1 axis in human choroidal melanoma cells.

BACKGROUND: Choroidal melanoma is the most common primary intraocular malignancy that occurs in adults. Lithium Chloride Promotes Apoptosis in Human Leukemia NB4 Cells by Inhibiting Glycogen Synthase Kinase-3 Beta. In this study, we aimed to understand whether LiCl exerts anticancer effects on choroidal melanoma cells and elucidate the underlying molecular mechanisms. METHODS: Human choroidal melanoma cells were treated with LiCl, and cell survival was assessed with MTT assays. Cell reproductive viability was measured by plate colony formation assays. Cell apoptosis was evaluated using flow cytometry, and proteins were detected using western blotting. A human choroidal melanoma xenograft model was established to demonstrate the effect of LiCl on human choroidal melanoma in vivo. RESULTS: We found that LiCl inhibited cell survival and clonogenic potential and induced apoptosis in human choroidal melanoma cells. LiCl also reduced the proliferation of choroidal melanoma cells in vivo. Moreover, the upregulation of NOXA and downregulation of Mcl-1 were responsible for LiCl-induced apoptosis. Mcl-1 overexpression obviously impaired LiCl-induced apoptosis and cleavage of caspase8, caspase9, caspase3 and PARP. Moreover, the protein expression of endoplasmic reticulum stress markers, including IRE1α, Bip, p-eIF2α, ATF4 and CHOP, were upregulated following treatment with LiCl. When CHOP expression was knocked down and cells were treated with LiCl, the protein level of NOXA was partially increased, and Mcl-1 expression was increased, while the cleavage of caspase8, caspase9, caspase3 and PARP that was induced by the LiCl was reduced compared with the vehicle treated group. Prolonged ER stress results in the activation of the apoptotic pathway. CONCLUSIONS: In summary, LiCl induced an endoplasmic reticulum stress response while activating intrinsic apoptosis. Furthermore, the CHOP/NOXA/Mcl-1 axis contributed to LiCl-induced apoptosis both in vitro and in vivo. The present study provides important mechanistic insight into potential cancer treatments involving LiCl and enhances the understanding of human choroidal melanoma.

Rhodium(III)-Catalyzed C-H Activation of Nitrones and Annulative Coupling with Nitroalkenes.

Rh(III)-catalyzed synthesis of nitro-functionalized indenes has been realized via C-H activation of arylnitrones and annulation with nitroolefins. The reaction proceeded in moderate to high yields with good functional group tolerance under ambient atmosphere.

Comparative Study on the Impact of Different Extraction Technologies on Structural Characteristics, Physicochemical Properties, and Biological Activities of Polysaccharides from Seedless Chestnut Rose (Rosa sterilis) Fruit.

Seedless chestnut rose (Rosa sterilis S. D. Shi, RS) is a fresh type of R. roxburghii Tratt with copious functional components in its fruit. Polysaccharides are recognized as one of the vital bioactive compounds in RS fruits, but their antioxidant and hypoglycemic properties have not been extensively explored. Hence, in this study, accelerated solvent extraction (RSP-W), citric acid (RSP-C), 5% sodium hydroxide/0.05% sodium borohydride (RSP-A), and 0.9% sodium chloride (RSP-S) solution extraction were individually utilized to obtain RS fruit polysaccharides. The physicochemical properties, structural characteristics, and biological activities were then compared. Results indicated that extraction methods had significant influences on the extraction yield, uronic acid content, monosaccharide composition, molecular weight, particle size, thermal stability, triple-helical structure, and surface morphology of RSPs apart from the major linkage bands and crystalline characteristics. The bioactivity tests showed that the RSP-S, which had the greatest amount of uronic acid and a comparatively lower molecular weight, exhibited more potent antioxidant and α-glucosidase inhibitory property. Furthermore, all RSPs inhibited α-glucosidase through a mixed-type manner and quenched their fluorescence predominantly via a static quenching mechanism, with RSP-S showing the highest binding efficiency. Our findings provide a theoretical basis for utilizing RSPs as functional ingredients in food industries.

Efficacy of venetoclax and rituximab in the treatment of concurrent acute myeloid leukemia and untreated chronic lymphocytic leukemia: A case report and literature review.

To date, few cases of concurrent acute myeloid leukemia (AML) and untreated chronic lymphocytic leukemia (CLL) have been reported. Due to the complexity of the pathogenesis and the absence of a uniform treatment regimen, the associated prognosis remains poor. The present study reports the case of a 58-year-old male with asymptomatic leukocytosis, who was previously healthy with no malignancies. Flow cytometry analysis revealed protocytosis, monocytosis and monoclonal B lymphocytosis in a bone marrow specimen. Results of a gene rearrangement assay demonstrated positive immunoglobulin heavy-chain variable region gene status in monoclonal B lymphocytes. Thus, the patient was diagnosed with AML with maturation (AML-M2) that co-existed with untreated CLL. The normative daunorubicin (40 mg/m2 on days 1-3) and cytarabine (80 mg/m2 on days 1-7) regimen combined with venetoclax (400 mg on days 1-7) and rituximab (375 mg/m2 on day 0) was used as induction chemotherapy. The patient achieved morphological complete remission in both AML and CLL following the first course of chemotherapy. In addition, the present study retrospectively analyzed the data of 22 patients with concurrent AML and untreated CLL, and the results demonstrated that the median age at the time of AML diagnosis was 69 years (range, 52-86 years). Moreover, the male:female ratio was 6.33:1 and AML-M2 was the most frequent subtype at diagnosis. The presence of a complex karyotype was associated with the poorest prognosis, and patients who received venetoclax often exhibited an improved prognosis. In conclusion, the combination of venetoclax and rituximab improves the prognosis of patients with concurrent AML and untreated CLL.

Optimizing rice yield, quality and nutrient use efficiency through combined application of nitrogen and potassium.

Reasonable nitrogen (N) and potassium (K) application rates can effectively improve fertilizer use efficiency, rice yield and quality. A two-year field experiment was conducted with combined application of three N rates (135, 180, and 225 kg ha-1, denoted as N1-N3) and four K rates (0, 90, 135, and 180 kg ha-1, denoted as K0-K3) using super indica hybrid rice cultivar Yixiangyou (YXY) 2115 to explore the effects of co-application of N and K on rice growth and development. The results indicated that the combined application of N and K had significantly interactive effects on dry matter (DM) accumulation, nutrients absorption, N harvest index (NHI), K harvest index (KHI), spikelets per panicle and most rice quality indexes. The highest total DM accumulation (17998.17-19432.47 kg ha-1) at maturity stage was obtained under N3K2. The effect of co-application of N and K on nutrients absorption and utilization varied between the two years and within each year. The highest total N and K accumulations at maturity stage were observed under N3K1 and N3K2, respectively, while the highest N recovery efficiency (NRE) and K recovery efficiency (KRE) were observed under N1K3. High expression levels of N and K metabolism-related genes in rice grains were observed under N3K2 or N3K3, consistent with N and K uptake. Co-application of N and K increased rice yield significantly and the highest yield (6745.02-7010.27 kg ha-1) was obtained under N2K2. As more N was gradually applied, rice appearance quality improved but milling, cooking and eating quality decreased. Although appropriate application of K could improve rice milling, cooking and eating quality, it reduced appearance quality. The optimal milling, cooking and eating quality were obtained under N1K2, while the best appearance quality was obtained under N3K0. Overall, a combination of 135-210 kg ha-1 N and 115-137 kg ha-1 K application rates was recommended for achieving relatively higher yield and better quality in rice production.

Responses of Yield and Photosynthetic Characteristics of Rice to Climate Resources under Different Crop Rotation Patterns and Planting Methods.

Climate is the most important environmental factor influencing yield during rice growth and development. To investigate the relationships between climate and yield under different crop rotation patterns and planting methods, three typical rotation patterns (vegetable-rice (V), rape-rice (R), and wheat-rice (W)) and two mechanical planting methods (mechanical transplanting (T1) and mechanical direct seeding (T2)) were established. The results showed that compared to the V rotation pattern, the average daily temperature (ADT) during the sowing to heading stage increased under both R and W rotation patterns, which significantly shortened the growth period. Thus, the effective accumulated temperature (EAT), photosynthetic capacity, effective panicle (EP), and spikelet per panicle (SP) under R and W rotation patterns significantly decreased, leading to reductions in grain yield (GY). VT2 had a higher ratio of productive tillers (RPT), relative chlorophyll content (SPAD), leaf area index (LAI), and net photosynthetic rate (Pn) than those of VT1, which significantly increased panicle dry matter accumulation (DMA), resulting in an increase in GY. Although RT2 and WT2 had a higher RPT than those of RT1 and WT1, the GY of RT1 and WT1 decreased due to the significant reductions in EAT and photosynthetic capacity. Principal component analysis (PCA) showed that the comprehensive score for different rotation patterns followed the order of V > R > T with VT2 ranking first. The structural equation model (SEM) showed that EAT and ADT were the most important climate factors affecting yield, with total effects of 0.520 and -0.446, respectively. In conclusion, mechanical direct seeding under vegetable-rice rotation pattern and mechanical transplanting under rape-rice or wheat-rice rotation pattern were the rice-planting methods that optimized the climate resources in southwest China.

Phylogenetic placement of eight poorly known spiders of Microdipoena (Araneae, Mysmenidae), with descriptions of five new species.

Ten species of the spider genus Microdipoena Banks, 1895 are reported from China, Laos, Indonesia, Georgia, and Seychelles. DNA sequences of the eight species are obtained to confirm their correct identification. The molecular phylogenetic analysis based on five gene fragments (16S, 18S, 28S, COI, and H3) were used to test the relationships and taxonomic placements of eight Microdipoena species, of which five species are documented as new to science: i.e., M.huisunsp. nov. (♀, China), M.lisusp. nov. (♀, China), M.shenyangsp. nov. (♂♀, China), M.thatitousp. nov. (♀, Laos), and M.zhulinsp. nov. (♂♀, China). Five known species are redescribed: M.elsae Saaristo, 1978 (♂♀, Seychelles), M.gongi (Yin, Peng & Bao, 2004) (♂♀, China), M.menglunensis (Lin & Li, 2008) (♂♀, China), M.jobi (Kraus, 1967) (♂♀, Georgia), and M.yinae (Lin & Li, 2013) (♂♀, China). All but M.menglunensis are diagnosed and illustrated. The family Mysmenidae is also the first recorded from Laos and Georgia.

Diversity of endosymbionts in camellia spiny whitefly, Aleurocanthus camelliae (Hemiptera: Aleyrodidae), estimated by 16S rRNA analysis and their biological implications.

Camellia spiny whitefly, Aleurocanthus camelliae (Hemiptera: Aleyrodidae), is a major pest in tea, which poses a serious threat to tea production. Similar to many insects, various bacterial symbioses inside A. camelliae may participate in the reproduction, metabolism, and detoxification of the host. However, few reports included research on the microbial composition and influence on A. camelliae growth. We first applied high-throughput sequencing of the V4 region in the 16S rRNA of symbiotic bacteria to study its component and effect on the biological trait of A. camelliae by comparing it with the antibiotic treatment group. The population parameters, survival rate, and fecundity rate of A. camelliae were also analyzed using the age-stage two-sex life table. Our results demonstrated that phylum Proteobacteria (higher than 96.15%) dominated the whole life cycle of A. camelliae. It unveiled the presence of Candidatus Portiera (primary endosymbiont) (67.15-73.33%), Arsenophonus (5.58-22.89%), Wolbachia (4.53-11.58%), Rickettsia (0.75-2.59%), and Pseudomonas (0.99-1.88%) genus. Antibiotic treatment caused a significant decrease in the endosymbiont, which negatively affected the host's biological properties and life process. For example, 1.5% rifampicin treatment caused a longer preadult stage in the offspring generation (55.92 d) compared to the control (49.75d) and a lower survival rate (0.36) than the control (0.60). The decreased intrinsic rate of increase (r), net reproductive rate (R 0), and prolonged mean generation time (T) were signs of all disadvantageous effects associated with symbiotic reduction. Our findings confirmed the composition and richness of symbiotic bacteria in larva and adult of A. camelliae by an Illumina NovaSeq 6000 analysis and their influence on the development of the host by demographic research. Together, the results suggested that symbiotic bacteria play an important role in manipulating the biological development of their hosts, which might help us for developing new pest control agents and technologies for better management of A. camelliae.

Effects of water stress on starch synthesis and accumulation of two rice cultivars at different growth stages.

Rice is a water intensive crop and soil water conditions affect rice yield and quality. However, there is limited research on the starch synthesis and accumulation of rice under different soil water conditions at different growth stages. Thus, a pot experiment was conducted to explore the effects of IR72 (indica) and Nanjing (NJ) 9108 (japonica) rice cultivars under flood-irrigated treatment (CK, 0 kPa), light water stress treatment (L, -20 ± 5 kPa), moderate water stress treatment (M, -40 ± 5 kPa) and severe water stress treatment (S, -60 ± 5 kPa) on the starch synthesis and accumulation and rice yield at booting stage (T1), flowering stage (T2) and filling stage (T3), respectively. Under LT treatment, the total soluble sugar and sucrose contents of both cultivars decreased while the amylose and total starch contents increased. Starch synthesis-related enzyme activities and their peak activities at mid-late growth stage increased as well. However, applying MT and ST treatments produced the opposite effects. The 1000-grain weight of both cultivars increased under LT treatment while the seed setting rate increased only under LT3 treatment. Compared with CK, water stress at booting stage decreased grain yield. The principal component analysis (PCA) showed that LT3 got the highest comprehensive score while ST1 got lowest for both cultivars. Furthermore, the comprehensive score of both cultivars under the same water stress treatment followed the trend of T3 > T2 > T1, and NJ 9108 had a better drought-resistant ability than IR72. Compared with CK, the grain yield under LT3 increased by 11.59% for IR72 and 16.01% for NJ 9108, respectively. Overall, these results suggested that light water stress at filling stage could be an effective method to enhance starch synthesis-related enzyme activities, promote starch synthesis and accumulation and increase grain yield.

Taxonomic study on Mysmenidae spiders (Mysmenidae, Araneae) from Xishuangbanna of Yunnan, China.

Thirteen spider species belonging to the family Mysmenidae Petrunkevitch, 1928 are reported from Xishuangbanna Tropical Botanical Garden (XTBG), Menglun Township, Mengla County, Yunnan Province of China. One genus and five species are documented as new to science: Mengmenabanna gen. nov. et. sp. nov. (♂♀), Mengmenayulin sp. nov. (♀), Mosuheguomu sp. nov. (♂♀), Mysmenaluosuo sp. nov. (♂♀), and Mysmenadai sp. nov. (♀). One species is proposed as a new combination: Mosuzhengi (Lin & Li, 2008) comb. nov. (♂♀, ex Mysmena Simon, 1894). The females of Microdipoenamenglunensis (Lin & Li, 2008), Mysmenaarcilonga Lin & Li, 2008, Mysmenafurca Lin & Li, 2008, and Mysmenarostella Lin & Li, 2008 are described for the first time. Three known species are re-examined and photographed: Gaoligongataeniata Lin & Li, 2014, Mysmenabiangulata (Lin & Li, 2008), and Mysmenacornigera (Lin & Li, 2008). Morphological diagnoses and illustrations are provided for these thirteen mysmenid species.

Response of yield and quality of giant embryo rice to nitrogen application and analysis of lipid-lowering effect.

Giant embryo rice is known as a highly nutritious functional rice because it is rich in gamma-aminobutyric acid (GABA), which has various regulatory functions in the human body. To study the response of giant embryo rice yield and quality to nitrogen (N) application, and to verify the effect of giant embryo brown rice on alleviating hyperlipidemia in rats. In this study, field experiments were conducted in 2020 and 2021 using the giant embryo rice varietiers J20 (japonica) and Koshihikari (japonica) rice as experimental materials and five N levels, 0 (N0), 90 (N1), 135 (N2), 180 (N3) and 225 (N4) kg ha-1. The results showed that the yield of both varieties increased with increasing N and the maximum values were observed under the N2 treatment. As more N was gradually applied, the brown rice rate, milled rice rate, head rice rate and GABA content of both varieties first increased and then decreased, while the chalky grain rate and chalkiness showed the opposite trend. The optimal values of these indexes were observed under the N2 treatment. The peak viscosity and breakdown value of J20 decreased, while its setback value and pasting temperature increased with increasing N. In contrast, Koshihikari showed the opposite trend. The protein content and protein component contents of both varieties showed an increasing trend with increasing N, among which gliadin was the most sensitive protein component to N fertilizer. Animal experiments results showed that J20 brown rice could significantly slow the rate of weight gain of rats, reduce serum total cholesterol and triglyceride levels and increase high-density lipoprotein cholesterol levels. Therefore, increasing N could effectively enhance J20 yield and improve processing, appearance and nutritional quality but decrease cooking and eating quality. The brown rice J20 had the effect of slowing the rate of weight gain and reducing the hyperlipidemia level of rats, the optimal N application rate for achieving high yield, high quality and good functional characteristics in the giant embryo rice J20 was 135 kg ha-1. These findings will provide a theoretical and technical foundation for the popularization and application of giant embryo rice in the future.

Evaluation of Eleven Plant Species as Potential Banker Plants to Support Predatory Orius sauteri in Tea Plant Systems.

Tea green leafhoppers and thrips are key pests in tea plantations and have widely invaded those of Asian origin. Pesticides are currently a favorable control method but not desirable for frequent use on tea plants. To meet Integrated Pest Management (IPM) demand, biological control with a natural enemy is viewed as the most promising way. Orius sauteri are slated to be a natural enemy to tea pests. However, more knowledge of rearing O. sauteri and selecting banker plant systems is strongly needed. The reproductive biology evaluation of the egg oviposition and population life parameters of O. sauteri under laboratory conditions were examined, and the supporting ability of 11 plant species-motherwort, white clover, red bean, mung bean, peanut, soybean, kidney bean, herba violae, bush vetch, smooth vetch, and common vetch-in a greenhouse was assessed. Most of the selected plants, except for herba violae, performed relatively well with high oviposition quantity and survival. The mean fecundity per female on red bean and motherwort was 148.75 eggs and 148.25 eggs, respectively, and 90.20 eggs for tea plants (the smallest); there also were significant differences. In an experiment to determine the life parameters of O. sauteri, all the tested plants, except herba violae, were found to be able to complete the growth and development of the life cycle; there also were significant differences. The intrinsic rate of increase of motherwort and red bean was 1.18 and 1.17, respectively, and higher compared to that of the other plants, including tea plants (1.13). This result of the O. sauteri population development index was also confirmed in a greenhouse with the number of motherwort and red beans being as high as 113.33 and 112.67. Since motherwort was found to be susceptible to aphids and powdery mildew in each trial, it cannot be used for intercropping in tea gardens. Among the 11 plants, red bean was found to be the most suitable to support O. sauteri in tea plantations.

Functional Response and Control Potential of Orius sauteri (Hemiptera: Anthocoridae) on Tea Thrips (Dendrothrips minowai Priesner).

This study aimed to clarify the functional response and control potential of O. sauteri in relation to tea thrips. The functional response, interference response, and control potential of O. sauteri on adult tea thrips, in different insect stages and environment temperatures, were studied. The results showed that the predation of O. sauteri against tea thrips was positively correlated with prey density, while the effects of searching for O. sauteri on the adult tea thrips were negatively correlated with prey density. The predation effects of O. sauteri on tea thrips were also influenced by prey density, which indicated that there was an intra-specific interference response from predators to tea thrips. The population density of tea thrips was significantly decreased, and O. sauteri showed a remarkable ability to control them when the benefit-to-harm ratio was 3:100.

LOX-1 Regulates Neutrophil Apoptosis and Fungal Load in A. Fumigatus Keratitis.

PURPOSE: To determine whether LOX-1 regulates neutrophil apoptosis and fungal load in A. fumigatus keratitis. METHODS: Fas, FasL, CASP3, CASP8, CASP9 and BCL2 were tested in normal and infected corneas of C57BL/6 mice. Mice corneas were infected with A. fumigatus with or without pretreatment of LOX-1 neutralizing antibody or inhibitor (Poly I). Clinical score was recored and HE staining was tested. Fungal load in mice corneas was observed by plate counting. Poly morphonuclear neutrophilic leukocytes (PMNs) were stimulated with 75% ethanol-killed A. fumigatus with or without pretreatment of LOX-1 neutralizing antibody or Poly I. PCR, western blot and immunostaining tested expression of Fas, FasL, CASP3, CASP8, CASP9, BCL2 and cleaved caspase-3. PMNs infiltration and TUNEL-positive cells were assessed by immunofluorescent staining. Flow cytometry assay tested the percentage of apoptosis neutrophils. RESULTS: Fas, Fas ligand, caspase-8, caspase-9 and caspase-3 mRNA levels were significantly higher in C57BL/6 mice corneas infected with A. fumigatus than normal corneas. Poly I treatment alleviated the severity and decreased clinical score at 3, 5 and 7 days post infecrion (p.i.). HE staining showed less infiltration in corneal tissue after LOX-1 inhibition. Plate counting experiment showed that number of viable fungus in corneas of Poly I treated group was significantly less than control group. LOX-1 neutralizing antibody or Poly I treatment significantly decreased neutrophil infiltration, the quantity of TUNEL-positive cells, the expression of Fas, Fas ligand, caspase-8, caspase-9, caspase-3, cleaved caspase-3 and the percentage of apoptosis neutrophils compared with control corneas. LOX-1 neutralizing antibody treatment significantly decreased Fas, FasL, CASP3, CASP8, CASP9 and cleaved caspase-3 expression in neutrophils. CONCLUSION: LOX-1 inhibition decrease neutrophil apoptosis and fungal load in A. fumigatus keratitis.

[Estimation of Health Risk and Enaction of Safety Standards of N-nitrosodimethylamine(NDMA) in Drinking Waters in China].

Nitrosamines such as nitrosodimethylamine(NDMA) in drinking water have recently attracted great attention because of their high carcinogenicity and high detection rate. Nitrosamines have also been repeatedly detected in drinking water in our country, leading to a lot of concerns about our drinking water safety. However, China has not yet formulated the relevant drinking water safety standards. In order to evaluate the health risks caused by NDMA in drinking water and to provide recommendations for the development of drinking water safety standards, the method of disability-adjusted life years(DALYs) and the two-stage disease model were used to estimate the health risk of liver cancer caused by intake of NDMA in drinking water. The data of this study were collected from two large-scale water quality surveys conducted in 35 cities in China from November 2009 to May 2012, and the detection conducted by Chen Chao et al. in 23 cities in China from 2012 to 2014, with a total of 146 water plants data. The results showed that mean(8.97 ng·L-1) and median(2.90 ng·L-1) NDMA concentrations were both not very high except in some special areas. The incidence of life-long cancer was 5.69×10-6 and 5.69 times as high as the negligible risk value(1×10-6) specified by the US EPA. The total disease burden of NDMA was 844.15 person-years, of which the death loss was 818.31 person-years, accounting for 96.9%. The incapacity loss was 25.84 person-years, accounting for 3.1% in comparison. Death loss was greater than the loss of incapacity. The disease burden was highest in the age group of 55-60 years(129.40 person-years), followed by 45-50 years(120.44 person-years). The burden of disease was higher in middle-aged and elderly people. The averaged loss was 6.27×10-7 DALYs per person per year in our country. Only considering the health risk factors, NDMA concentration safety standards should be 6.12 ng·L-1. According to the specific national conditions, the NDMA safety standard in the range of 6-40 ng·L-1 was recommended. On one hand, we can control the concentration of NDMA in drinking water, to reduce health risks as far as possible, and on the other hand, we can also ensure the effectiveness of disinfection of drinking water treatments. China's economic and water treatment technological level and other factors should also be taken into consideration in the near future. In view of potential health risks of NDMA, it's necessary to adopt more effective, economical and also environmental water treatment techniques and develop reasonable safety standards to ensure the quality of drinking water and people's health.

[Accumulated Health Risk Assessment of Arsenic in Drinking Water of Major Cities of China].

Based on the drinking water quality survey data of China's major cities, the existing disease burden calculation method was improved and disability-adjusted life years (DALYs) was taken as the end of evaluation to assess the health risk of arsenic contamination level. The results showed that the concentration of arsenic in drinking water of major cities in China was very low (0.53 µg·L-1), far below the national limit (10 µg·L-1) and the total lifetime cancer incidence was 1.76×10-5. The order of risks of different kinds of cancers was:skin cancer (1.53×10-5) > lung cancer (2.25×10-6) > liver cancer (2.30×10-8) > bladder cancer (1.34×10-10) and the average disease burden was 1.91×10-6 per person-year. Among them, skin cancer and lung cancer accounted for 70.2% and 29.0% respectively, and the disease burdens of bladder cancer and liver cancer were negligible, but the overall cancer risk was still higher than the recommended level of 10-6 per person-year by WHO. Although the arsenic level of drinking water in China was not high, the risk of cancer could not be ignored. Thus more effective and feasible measures should be taken to reduce arsenic concentration to protect people's drinking water safety in the future.