Based on the obtained data of half-lives（t1/2） for 31 polychlorinated biphenyl congeners（PCBs）, 3D quantitative structure-activity relationship（QSAR） pharmacophore was used to establish a 3D QSAR model to predic...Based on the obtained data of half-lives（t1/2） for 31 polychlorinated biphenyl congeners（PCBs）, 3D quantitative structure-activity relationship（QSAR） pharmacophore was used to establish a 3D QSAR model to predict the t1/2 values of the remaining 178 PCBs, using the structural parameters as independent variables and lgt1/2 values as the dependent variable. Among this process, the whole data set（31 compounds） was divided into a training set（24 compounds） for model generation and a test set（7 compounds） for model validation. Then, the full factor experimental design was used to research the potential second-order interactional effect between different substituent positions, obtaining the final regulation scheme for PCB. At last, a 3D QSAR pharmacophore model was established to validate the reasonable regulation targeting typical PCB with respect to half-lives and thermostability. As a result, the cross-validation correlation coefficient（q2） obtained by the 3D QSAR model was 0.845（〉0.5） and the coefficient of determination（r2） obtained was 0.936（〉0.9）, indicating that the models were robust and predictive. CoMSIA analyses upon steric, electrostatic and hydrophobic fields were 0.7%, 85.9%, and 13.4%, respectively. The electrostatic field was determined to be a primary factor governing the tt/2. From CoMSIA contour maps, tl/2 increased when substi- tuents possessed electropositive groups at the 2＇-, 3-, Y-, 5- and 5＇- positions and electronegative groups at the 3-, 3＇-, 5-, 6- and 6＇- positions, which could increase the PCB stability in transformer insulation oil. Modification of two typical PCB congeners（PCB-77 and PCB-81） showed that the lgtl/2 for three selected modified compounds increased by 13%（average ratio） compared with that of each congener and the thermostability of them were higher, validating the reasonability of the regulatory scheme obtained from the 3D QSAR model. These results are expected to be beneficial in predicting tl/2 values of PCB homologues and derivatives and in providing a theoretical foundation for further elucidation of the stability of PCBs.展开更多
AIM: To investigate the possible relationship between the influencing factors occurring before and during birth in full-term infants and the outcome of retinopathy. METHODS: Totally 816 full-term infants admitted in t...AIM: To investigate the possible relationship between the influencing factors occurring before and during birth in full-term infants and the outcome of retinopathy. METHODS: Totally 816 full-term infants admitted in the neonate intensive unit of Boai Hospital of Zhongshan between 1 May, 2008 and 30 June, 2011 were included in the study. Fundus examination was performed and evaluated individually on them at the age of 48 hours after delivery, 2 weeks and 1 month. Some possible risk factors happening prenatally or during delivery such as pregnant related hypertension, placenta previa, placental abruption etc, as well as some neonatal risk factors such as neonatal asphyxia, hypoxic-ischemic encephalopathy (HIE), low birth weight etc, were recorded and evacuated. Then the effect of the risk factors of full-term infants on retinopathy was studied. RESULTS: The incidence of retinal hemorrhage of full-term infants with prenatal pregnant related hypertension (PRH) of the mother (43.6%) was significantly higher than that of full-term infants without (8.0%). (P<0.001). The incidence of retinal hemorrhage of full-term infants with neonatal asphyxia and /or hypoxic-ischemic encephalopathy (HIE)(29.3%) was significantly higher than that of those without (15.7%), but correlation was not found between the severity of retina hemorrhage and the degree of hypoxic disease. A pale color of optic disc was associated with a low birth weight of full-term infant. Full-term infants with birth weigh-less than 2500g had a significant higher incidence of retinopathy than those with birth weight equal or more than 2500g( P<0.001). CONCLUSION: The main influencing factors which lead to retinopathy of high risk full-term infants are prenatal factors such as PRH, and some neonatal risk factors such as asphyxia, hypoxic-ischemic encephalopathy, and low birth weight.展开更多
In order to answer a question motivated by constructing substitution boxes in block ciphers we will exhibit an infinite family of full-rank factorizations of elementary 2-groups into two factors having equal sizes.
This paper studies the factors that affect the safe full heading of machine-transplanted rice seedlings in the temperate and cool ricegrowing areas,and explores the influence of machine-transplanted rice seedling vari...This paper studies the factors that affect the safe full heading of machine-transplanted rice seedlings in the temperate and cool ricegrowing areas,and explores the influence of machine-transplanted rice seedling varieties,seedling age,nitrogen fertilizer application rate and management on the safe full heading of machine-transplanted rice seedlings. Results show that for the mechanized production in the temperate and cool rice-growing areas,we should select the mid-early maturity cold-resistant varieties with growth period of not exceeding 180 d,control the seedling age to be 30- 35 d and total amount of pure nitrogen to be not more than 300 kg / ha,and moderately reduce the nitrogen fertilizer postponing ratio. Under this condition,we can achieve safe full heading of machine-transplanted rice seedlings and ensure the yield.展开更多
BACKGROUND The treatment of heart failure not only needs to relieve the clinical symptoms and improve the quality of life for patients but also needs to select scientific and reasonable ways to prevent or delay the pr...BACKGROUND The treatment of heart failure not only needs to relieve the clinical symptoms and improve the quality of life for patients but also needs to select scientific and reasonable ways to prevent or delay the progression of the disease,thus reducing the mortality and hospitalization rate.Although the previous regimen can effectively relieve symptoms in the early stage of treatment,long-term use may cause adverse events,such as arrhythmia,and even increase mortality.Therefore,conventional treatment cannot meet the actual health needs of patients,and scientific nursing intervention is very necessary.AIM To investigate the application of self-care based on full-course individualized health education (FCIHE) and its influencing factors in patients with chronic heart failure (CHF).METHODS We enrolled CHF patients who were admitted to our center between September 2015 and June 2016 and divided them into an intervention group (n = 50) and control group (n = 50) using a random number table.Routine nursing care was applied to the control group,and FCIHE was offered to the intervention group.The self-care behavior,6-min walking distance (6MWD),and 36-item short form health survey (SF-36) scores were compared between the two groups.The influencing factors of the self-care were also analyzed.RESULTS The 6MWD was not significantly different between the two groups at admission (P > 0.05);however,at 3 and 6 mo after discharge,6MWD was significantly increased,and it was significantly longer in the intervention group (P < 0.05).The scores for self-care behavior showed no significant difference at admission between the two groups (P > 0.05);however,at 3 and 6 mo after discharge,the total scores for self-care maintenance,management,confidence,and behavior of the intervention group were significantly higher than those of the control group (P < 0.05).There were no significant differences in the SF-36 scores at admission (P > 0.05);however,at 3 mo and 6 mo after discharge,the scores for all eight subscales,including physical functioning,role limitations due to physical problems,bodily pain,general health perceptions,vitality,social functioning,role-limitations due to emotional problems,and mental health,were significantly higher in the intervention group (P < 0.05).As shown by logistic regression analysis,the influencing factors of self-care mainly included age,cardiac function class,and education background (odds ratio > 1;all P < 0.05).CONCLUSION FCIHE improved self-care behavior and cardiac function in CHF patients.Age,cardiac function,and education level affected the implementation of self-care among CHF patients.展开更多
文摘Based on the obtained data of half-lives（t1/2） for 31 polychlorinated biphenyl congeners（PCBs）, 3D quantitative structure-activity relationship（QSAR） pharmacophore was used to establish a 3D QSAR model to predict the t1/2 values of the remaining 178 PCBs, using the structural parameters as independent variables and lgt1/2 values as the dependent variable. Among this process, the whole data set（31 compounds） was divided into a training set（24 compounds） for model generation and a test set（7 compounds） for model validation. Then, the full factor experimental design was used to research the potential second-order interactional effect between different substituent positions, obtaining the final regulation scheme for PCB. At last, a 3D QSAR pharmacophore model was established to validate the reasonable regulation targeting typical PCB with respect to half-lives and thermostability. As a result, the cross-validation correlation coefficient（q2） obtained by the 3D QSAR model was 0.845（〉0.5） and the coefficient of determination（r2） obtained was 0.936（〉0.9）, indicating that the models were robust and predictive. CoMSIA analyses upon steric, electrostatic and hydrophobic fields were 0.7%, 85.9%, and 13.4%, respectively. The electrostatic field was determined to be a primary factor governing the tt/2. From CoMSIA contour maps, tl/2 increased when substi- tuents possessed electropositive groups at the 2＇-, 3-, Y-, 5- and 5＇- positions and electronegative groups at the 3-, 3＇-, 5-, 6- and 6＇- positions, which could increase the PCB stability in transformer insulation oil. Modification of two typical PCB congeners（PCB-77 and PCB-81） showed that the lgtl/2 for three selected modified compounds increased by 13%（average ratio） compared with that of each congener and the thermostability of them were higher, validating the reasonability of the regulatory scheme obtained from the 3D QSAR model. These results are expected to be beneficial in predicting tl/2 values of PCB homologues and derivatives and in providing a theoretical foundation for further elucidation of the stability of PCBs.
基金Supported by Science Council Grant of Zhongshan City, China (No. 20082A091)
文摘AIM: To investigate the possible relationship between the influencing factors occurring before and during birth in full-term infants and the outcome of retinopathy. METHODS: Totally 816 full-term infants admitted in the neonate intensive unit of Boai Hospital of Zhongshan between 1 May, 2008 and 30 June, 2011 were included in the study. Fundus examination was performed and evaluated individually on them at the age of 48 hours after delivery, 2 weeks and 1 month. Some possible risk factors happening prenatally or during delivery such as pregnant related hypertension, placenta previa, placental abruption etc, as well as some neonatal risk factors such as neonatal asphyxia, hypoxic-ischemic encephalopathy (HIE), low birth weight etc, were recorded and evacuated. Then the effect of the risk factors of full-term infants on retinopathy was studied. RESULTS: The incidence of retinal hemorrhage of full-term infants with prenatal pregnant related hypertension (PRH) of the mother (43.6%) was significantly higher than that of full-term infants without (8.0%). (P<0.001). The incidence of retinal hemorrhage of full-term infants with neonatal asphyxia and /or hypoxic-ischemic encephalopathy (HIE)(29.3%) was significantly higher than that of those without (15.7%), but correlation was not found between the severity of retina hemorrhage and the degree of hypoxic disease. A pale color of optic disc was associated with a low birth weight of full-term infant. Full-term infants with birth weigh-less than 2500g had a significant higher incidence of retinopathy than those with birth weight equal or more than 2500g( P<0.001). CONCLUSION: The main influencing factors which lead to retinopathy of high risk full-term infants are prenatal factors such as PRH, and some neonatal risk factors such as asphyxia, hypoxic-ischemic encephalopathy, and low birth weight.
文摘In order to answer a question motivated by constructing substitution boxes in block ciphers we will exhibit an infinite family of full-rank factorizations of elementary 2-groups into two factors having equal sizes.
文摘This paper studies the factors that affect the safe full heading of machine-transplanted rice seedlings in the temperate and cool ricegrowing areas,and explores the influence of machine-transplanted rice seedling varieties,seedling age,nitrogen fertilizer application rate and management on the safe full heading of machine-transplanted rice seedlings. Results show that for the mechanized production in the temperate and cool rice-growing areas,we should select the mid-early maturity cold-resistant varieties with growth period of not exceeding 180 d,control the seedling age to be 30- 35 d and total amount of pure nitrogen to be not more than 300 kg / ha,and moderately reduce the nitrogen fertilizer postponing ratio. Under this condition,we can achieve safe full heading of machine-transplanted rice seedlings and ensure the yield.
基金Supported by the Program of Qiqihar Science and Technology Plan,No.SFGG-201534
文摘BACKGROUND The treatment of heart failure not only needs to relieve the clinical symptoms and improve the quality of life for patients but also needs to select scientific and reasonable ways to prevent or delay the progression of the disease,thus reducing the mortality and hospitalization rate.Although the previous regimen can effectively relieve symptoms in the early stage of treatment,long-term use may cause adverse events,such as arrhythmia,and even increase mortality.Therefore,conventional treatment cannot meet the actual health needs of patients,and scientific nursing intervention is very necessary.AIM To investigate the application of self-care based on full-course individualized health education (FCIHE) and its influencing factors in patients with chronic heart failure (CHF).METHODS We enrolled CHF patients who were admitted to our center between September 2015 and June 2016 and divided them into an intervention group (n = 50) and control group (n = 50) using a random number table.Routine nursing care was applied to the control group,and FCIHE was offered to the intervention group.The self-care behavior,6-min walking distance (6MWD),and 36-item short form health survey (SF-36) scores were compared between the two groups.The influencing factors of the self-care were also analyzed.RESULTS The 6MWD was not significantly different between the two groups at admission (P > 0.05);however,at 3 and 6 mo after discharge,6MWD was significantly increased,and it was significantly longer in the intervention group (P < 0.05).The scores for self-care behavior showed no significant difference at admission between the two groups (P > 0.05);however,at 3 and 6 mo after discharge,the total scores for self-care maintenance,management,confidence,and behavior of the intervention group were significantly higher than those of the control group (P < 0.05).There were no significant differences in the SF-36 scores at admission (P > 0.05);however,at 3 mo and 6 mo after discharge,the scores for all eight subscales,including physical functioning,role limitations due to physical problems,bodily pain,general health perceptions,vitality,social functioning,role-limitations due to emotional problems,and mental health,were significantly higher in the intervention group (P < 0.05).As shown by logistic regression analysis,the influencing factors of self-care mainly included age,cardiac function class,and education background (odds ratio > 1;all P < 0.05).CONCLUSION FCIHE improved self-care behavior and cardiac function in CHF patients.Age,cardiac function,and education level affected the implementation of self-care among CHF patients.
