23 research outputs found

    Unified Singularity Modeling and Reconfiguration of 3rT Metamorphic Parallel Mechanisms with Parallel Constraint Screws

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    This paper presents a unified singularity modeling and reconfiguration analysis of variable topologies of a class of metamorphic parallel mechanisms with parallel constraint screws. The new parallel mechanisms consist of three reconfigurable rT PS limbs that have two working phases stemming from the reconfigurable Hooke (rT) joint. While one phase has full mobility, the other supplies a constraint force to the platform. Based on these, the platform constraint screw systems show that the new metamorphic parallel mechanisms have four topologies by altering the limb phases with mobility change among 1R2T (one rotation with two translations), 2R2T, and 3R2T and mobility 6. Geometric conditions of the mechanism design are investigated with some special topologies illustrated considering the limb arrangement. Following this and the actuation scheme analysis, a unified Jacobian matrix is formed using screw theory to include the change between geometric constraints and actuation constraints in the topology reconfiguration. Various singular configurations are identified by analyzing screw dependency in the Jacobian matrix. The work in this paper provides basis for singularity-free workspace analysis and optimal design of the class of metamorphic parallel mechanisms with parallel constraint screws which shows simple geometric constraints with potential simple kinematics and dynamics properties

    Table_1_Fine Mapping and Candidate Gene Identification for Wax Biosynthesis Locus, BoWax1 in Brassica oleracea L. var. capitata.DOC

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    <p>Cuticular waxes play important roles in plant protection against various biotic and abiotic environmental stresses. The cuticular wax covering gives normal cabbage a glaucous appearance, but the appearance of waxless mutant is glossy green. Based on the present study, inheritance of the glossy green character of mutant HUAYOU2 follows a simple recessive pattern. Genetic analysis of an F<sub>2</sub> population comprising 808 recessive individuals derived from HUAYOU2 (P<sub>1</sub>, maternal parent) and M36 (P<sub>2</sub>, paternal parent) revealed that a single recessive locus, BoWax1 (Brassica oleracea Wax 1), controls glossy green trait in B. oleracea. This locus was mapped to a region of 158.5 kb on chromosome C01. Based on nucleotide sequence analysis, Bol013612 was identified as the candidate gene for BoWax1. Sequencing results demonstrated that there is a deletion mutation of two nucleotides in the cDNA of Bol013612 of HUAYOU2, which may account for its glossy green trait. These results lay the foundation for functional analysis of BoWax1 and may accelerate research on wax metabolism in cabbage.</p

    The trends of mortality and years of life lost of cancers in urban and rural areas in China, 1990‐2017

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    Abstract Background With the rapid development of the socioeconomic status, the mortality of several cancers has been changed in China during the past 30 years. We aimed to estimate the trends of mortality and years of life lost (YLLs) of various cancers in urban and rural areas of China from 1990 to 2017. Methods The mortality data were collected from Chinese yearbooks and the age structure of population from the Chinese sixth population census were used as reference to calculate age‐standardized mortality rates (ASMRs) and YLLs rates. Joinpoint regression analysis was implemented to calculate the annual percent change (APC) of mortality rates and YLL rates for cancers. YLLs owing to premature death were calculated as age‐specific cancer deaths multiplied by the reference life expectancy at birth of 80 years for male and 82.5 years for female. Results The ASMRs of all cancers showed significant decreasing trends for urban residents from 1990 to 2017, such downward trend without significance was also observed among rural residents. Interestingly, ASMRs of lung cancer and breast cancer have raised continuously in rural areas since 1990. The age‐standardized YYL rates for urban and rural residents decreased with 1.02% and 0.85% per year, respectively. YLLs in rural areas were higher than those in urban areas, whereas YLLs of urban outstripped those of rural finally with the increasing in YLLs of urban areas (216.71% for men and 207.87% for women). Conclusion The ASMRs and YLL rates of all cancers have declined in urban and rural areas from 1990 to 2017. YLLs increased in urban areas and remained higher level in rural areas after 2014 year. Preventive measures should be strengthened to against cancer, especially for lung cancer

    Enhanced expression of transient receptor potential channel 3 in uterine smooth muscle tissues of lipopolysaccharide-induced preterm delivery mice

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    Objective(s): We aimed to investigate the influence of transient receptor potential channel 3 (TRPC3) on lipopolysaccharide-induced (LPS) preterm delivery mice. Materials and Methods: Mice were randomly assigned to the four groups: an unpregnant group, a mid-pregnancy group (E15), a term delivery group, and an LPS-induced preterm delivery group (intraperitoneal injection LPS at 15 days). Uterine smooth muscles were obtained through caesarean section; TRPC3 expression was measured by real-time PCR, western blotting, and immunohistochemistry. A specific inhibitor of TRPC3 (SKF96365) was injected into the LPS-induced preterm delivery group to determine whether the delivery interval was prolonged. Results: TRPC3 was primarily expressed in the uterine smooth muscle layer. In addition, the LPS-induced preterm delivery group had an obviously higher expression level of TRPC3 mRNA and protein compared with the unpregnant and E15 groups, which were close to term delivery. More importantly, SKF96365 prolongs the delivery interval of LPS-induced preterm delivery mice. Conclusion: Enhanced expression of TRPC3 may be associated with LPS-induced preterm delivery in mice. The specific inhibitor of TRPC3 (SKF96365) may be helpful for clinical treatment of preterm delivery

    Assessment of the Nutrient Removal Potential of Floating Native and Exotic Aquatic Macrophytes Cultured in Swine Manure Wastewater

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    Although eutrophication and biological invasion have caused serious harm to aquatic ecosystems, exotic and even invasive plants have been used extensively in phytoremediation water systems in China. To identify native aquatic plants with excellent water restoration potential, two representative native floating aquatic plants from Guangdong Province, namely Ludwigia adscendens (PL) and Trapa natans (PT), were selected, with Eichhornia crassipes as a control, to study their growth status, adaptability, and nutrient removal potentials in swine manure wastewater. The results demonstrated that the two native plants offered greater advantages than E. crassipes in water restoration. Within 60 days, PL and PT exhibited excellent growth statuses, and their net biomass growth rates were 539.8% and 385.9%, respectively, but the E. crassipes decayed and died with an increasing HRT (hydraulic retention time). The PL and PT could adjust the pH of the wastewater, improve the dissolved oxygen and oxidation-reduction potential, and reduce the electrical conductivity value. The removal rates of NH4+&ndash;N, NO3&minus;&ndash;N, NO2&minus;&ndash;N, total nitrogen, total phosphorus, chemical oxygen demand (COD), and Chl-a in the PL group reached 98.67%, 64.83%, 26.35%, 79.30%, 95.90%, 69.62%, and 92.23%, respectively; those in the PT group reached 99.47%, 95.83%, 85.17%, 83.73%, 88.72%, 75.06%, and 91.55%, respectively. The absorption contribution rates of total nitrogen (TN) and total phosphorus (TP) in the PL group were 40.6% and 43.5%, respectively, while those in the PT group were 36.9% and 34.5%, respectively. The results indicated that L. adscendens and T. natans are both promising aquatic plants for application to the restoration of swine manure wastewater in subtropical areas

    The variable codons of H5N1 avian influenza A virus haemagglutinin genes

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    We investigated the selection pressures on the haemagglutinin genes of H5N1 avian influenza viruses using fixed effects likelihood models. We found evidence of positive selection in the sequences from isolates from 1997 to 2007, except viruses from 2000

    Purification Efficiency of Three Combinations of Native Aquatic Macrophytes in Artificial Wastewater in Autumn

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    Water pollution caused by excessive nutrient and biological invasion is increasingly widespread in China, which can lead to problems with drinking water as well as serious damage to the ecosystem if not be properly treated. Aquatic plant restoration (phytoremediation) has become a promising and increasingly popular solution. In this study, eight native species of low-temperature-tolerant aquatic macrophytes were chosen to construct three combinations of aquatic macrophytes to study their purification efficiency on eutrophic water in large open tanks during autumn in Guangzhou City. The total nitrogen (TN) removal rates of group A (Vallisneria natans + Ludwigia adscendens + Monochoria vaginalis + Saururus chinensis), group B (V. natans + Ipomoea aquatica + Acorus calamus + Typha orientalis), and group C (V. natans + L. adscendens + Schoenoplectus juncoides + T. orientalis) were 79.10%, 46.39%, and 67.46%, respectively. The total phosphorus (TP) removal rates were 89.39%, 88.37%, and 91.96% in groups A, B, and C, respectively, while the chemical oxygen demand (COD) removal rates were 93.91%, 96.48%, and 92.78%, respectively. In the control group (CK), the removal rates of TN, TP, and COD were 70.42%, 86.59%, and 87.94%, respectively. The overall removal rates of TN, TP, and COD in the plant groups were only slightly higher than that in CK group, which did not show a significant advantage. This may be related to the leaf decay of some aquatic plants during the experiment, whereby the decay of V. natans was the most obvious. The results suggest that a proper amount of plant residue will not lead to a significant deterioration of water quality

    The association of metabolic syndrome components and diabetes mellitus: evidence from China National Stroke Screening and Prevention Project

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    Abstract Background The metabolic syndrome (MetS) is related with cardiovascular disease. However, its relationship with diabetes mellitus (DM) has not been examined in Chinese population with a larger sample. We aimed to assess the relationship between metabolic syndrome (MetS) and its components, and DM, and to determine the best one from the available definitions of Mets when assessing the risk of DM. Methods This was a cross-sectional survey in a nationally representative sample of 109,551 Chinese adults aged ≥40 years in 2014–15. MetS was defined according to three criteria including the updated International Diabetes Federation (IDF) criterion, the National Cholesterol Education Program Third Adult Treatment Panel (NCEP ATP III) criterion and American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) criterion. Logistic regression models were used to estimate the odds of DM. Results MetS as defined by three criteria including IDF, NCEP ATP III,and AHA/NHLBI all increased the prevalence of DM, and the adjusted ORs with 95% CI was more higher using NCEP ATP III (3.65, 3.52–3.79) than IDF (2.50, 2.41–2.60) and AHA/NHLBI (3.03, 2.92–3.24). The odds of DM was highest in hyperglycemia with cut-off glucose≥6.1 mmol/L (14.55, 13.97–15.16), and other components were also associated significantly with DM. There was heterogeneity for OR of DM associated with various trait combinations. Conclusions The NCEP ATPIII MetS definition may be more suitable for assessment of DM risk in Chinese population. Hyperglycemia, as previous study reported, are important risk factors of DM. Besides, other traits of Mets are also significantly associated with DM and should therefore be of greater concern
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