Background Exposure to bisphenol A(BPA),an environmental pollutant known for its endocrine-disrupting properties,during gestation has been reported to increase the risk of fetal growth restriction(FGR)in an ovine mode...Background Exposure to bisphenol A(BPA),an environmental pollutant known for its endocrine-disrupting properties,during gestation has been reported to increase the risk of fetal growth restriction(FGR)in an ovine model of pregnancy.We hypothesized that the FGR results from the BPA-induced insufficiency and barrier dysfunction of the placenta,oxidative stress,inflammatory responses,autophagy and endoplasmic reticulum stress(ERS).However,precise mechanisms underlying the BPA-induced placental dysfunction,and subsequently,FGR,as well as the potential involvement of placental ERS in these complications,remain to be investigated.Methods In vivo experiment,16 twin-pregnant(from d 40 to 130 of gestation)Hu ewes were randomly distributed into two groups(8 ewes each).One group served as a control and received corn oil once a day,whereas the other group received BPA(5 mg/kg/d as a subcutaneous injection).In vitro study,ovine trophoblast cells(OTCs)were exposed to 4 treatments,6 replicates each.The OTCs were treated with 400μmol/L BPA,400μmol/L BPA+0.5μg/m L tunicamycin(Tm;ERS activator),400μmol/L BPA+1μmol/L 4-phenyl butyric acid(4-PBA;ERS antagonist)and DMEM/F12 complete medium(control),for 24 h.Results In vivo experiments,pregnant Hu ewes receiving the BPA from 40 to 130 days of pregnancy experienced a decrease in placental efficiency,progesterone(P4)level and fetal weight,and an increase in placental estrogen(E2)level,together with barrier dysfunctions,OS,inflammatory responses,autophagy and ERS in type A cotyledons.In vitro experiment,the OTCs exposed to BPA for 24 h showed an increase in the E2 level and related protein and gene expressions of autophagy,ERS,pro-apoptosis and inflammatory response,and a decrease in the P4 level and the related protein and gene expressions of antioxidant,anti-apoptosis and barrier function.Moreover,treating the OTCs with Tm aggravated BPA-induced dysfunction of barrier and endocrine(the increased E2 level and decreased P4 level),OS,inflammatory responses,autophagy,and ERS.However,treating the OTCs with 4-PBA reversed the counteracted effects of Tm mentioned above.Conclusions In general,the results reveal that BPA exposure can cause ERS in the ovine placenta and OTCs,and ERS induction might aggravate BPA-induced dysfunction of the placental barrier and endocrine,OS,inflammatory responses,and autophagy.These data offer novel mechanistic insights into whether ERS is involved in BPA-mediated placental dysfunction and fetal development.展开更多
A method is proposed to fuse the velocity data of the global navigation satellite system(GNSS) and leveling height via combined adjustment with constraints. First, stable GNSS-leveling points are uniformly selected, a...A method is proposed to fuse the velocity data of the global navigation satellite system(GNSS) and leveling height via combined adjustment with constraints. First, stable GNSS-leveling points are uniformly selected, and the constraints of the geodetic height change velocity and normal height change velocity are given. Then, the GNSS vertical velocities and leveling height difference are used as observations of combined adjustment, and robust least-squares estimation are used to estimate the velocities of the unknown points. Finally, a vertical movement model is established with the GNSS vertical velocities and leveling vertical velocities obtained via combined adjustment. Data from the second-order leveling network and GNSS control points in Shandong Province are taken as test data, and eight calculation schemes are used for discussion. One of the schemes, the bifactor robust combined adjustment method based on variance component estimation with two kinds of vertical velocity constraints achieves the optimal results. The method applied in the scheme can be recommended for data fusion of GNSS and leveling, further improving the reliability of vertical crustal movement in Shandong Province.展开更多
In this paper,a kind of wall fabric’s surface treatment agent modified with nonionic surfactant was reported.This surface treatment agent was prepared by using nano tourmaline powder dispersion in water with surfacta...In this paper,a kind of wall fabric’s surface treatment agent modified with nonionic surfactant was reported.This surface treatment agent was prepared by using nano tourmaline powder dispersion in water with surfactant as dispersants by sand milling.Under the influence of different dispersants,the negative ions releasing amount of functional wall fabrics,the milling process and the storage stability of nano tourmaline powder dispersion were discussed.The results showed that nano tourmaline powder dispersion achieved the smallest average diameter of 44 nm and had best storage stability that the average diameter maintained below 200 nm in 17 days when the addition amount of dispersant was 20 percent of the tourmaline powders’weight.What is more,the quantity of negative ion releasing achieved 6500 ion/cm3 when addition amount of dispersant was 30 percent.This technique could be used to strengthen productivity of nano tourmaline powder dispersion.展开更多
Background:This study aimed to determine the prevalence and predictive factors of prolonged grief disorder(PGD)among those bereaved by the Wenchuan earthquake in Southwestern China seven years after the event.Methods:...Background:This study aimed to determine the prevalence and predictive factors of prolonged grief disorder(PGD)among those bereaved by the Wenchuan earthquake in Southwestern China seven years after the event.Methods:A cross-sectional survey based on census tracts was conducted on the bereaved earthquake survivors.Responses to the questionnaire regarding PGD and its potential associated factors were obtained either through face-to-face or telephone interview.PGD was screened by a validated Chinese version of the PGD questionnaire-13(PG-13).Bivariate and multivariate regression analyses were used to determine the prevalence and associated risk factors of PGD.Results:A total of 1464 bereaved earthquake survivors,with a response rate of 97.6%,were included in the study.Of the 1464 respondents studied,124(8.47%)were diagnosed with PGD.Multivariate regression analysis demonstrated that PGD in the bereaved earthquake individuals was significantly associated with several factors,including age,economic burden,close kinship with the deceased,and living with the deceased before the loss.Wenchuan earthquake bereaved aged 41e60 years were more likely to develop PGD compared to those aged younger than 40 or older than 60(OR=2.075,95%CI=1.297e3.319).Those who had a close kinship with the deceased had a higher tendency to develop PGD(OR=5.144,95%CI=2.716e9.740).The odds of PGD among the earthquake bereaved with economic burdens were higher relative to those who did not experience an economic burden(OR=8.123,95%CI=2.657e24.831).Those who living with the deceased before loss also had a higher tendency to develop PGD(OR=0.179,95%CI=0.053e0.602).Conclusions:This study revealed that a significantly high proportion(8.47%)of the Wenchuan earthquake-bereaved remain grieving seven years after the event.Those diagnosed with PGD should receive appropriate interventions from clinical psychologists.The risk factors identified in this study are crucial for the early screening and prevention of PGD in future nursing and psycho-clinical practices.展开更多
To explore the influence of substituent groups on thermally induced curing,eight new bio-based benzoxazines containing different substituent groups with different electron negativity and volumes were synthesized.The t...To explore the influence of substituent groups on thermally induced curing,eight new bio-based benzoxazines containing different substituent groups with different electron negativity and volumes were synthesized.The thermal curing of these bio-based benzoxazines was studied in detail.Combined with the curing reaction kinetics,simulation and calculation of Highest Occupied Molecular and Lowest Unoccupied Molecular values,the spatial and electronic effects of different substituent groups on the curing of benzoxazine was explored.It was found that when the substituent was located at the position directly connected to the N atom,the steric hindrance effect of the group was dominant.When the substituent group was located on the benzene ring connected to the O atom,both the electronic effect and the spatial effect influenced the curing of benzoxazine.When an electron-withdrawing group was connected ortho position to the O atom,the curing reaction was promoted due to the decreased electron cloud density of O-on the oxazine ring,making the C-O bond easier to break.When an electron-donating group was connected to the meta position of the O atom it also promoted the curing reaction,possibly because it increased the electron cloud density of the+CH2 reaction site and thereby facilitated electrophilic substitution via attack of+CH2 on the cross linking reaction centre.This work provides a deeper understanding of how spatial and electronic effects of substituents affect the curing of benzoxazine.展开更多
Redox potential has principal influences on formation and attribute of soils and it is necessary to research the measurement of soil redox potential. The self-made potentiometer and two indigenous FJA-5 potentiometers...Redox potential has principal influences on formation and attribute of soils and it is necessary to research the measurement of soil redox potential. The self-made potentiometer and two indigenous FJA-5 potentiometers were employed to measure the Eh values of fir forest soils in situ, which lied in Savage Sea Beauty Spot in Sichuan Province. Simultaneously fresh soils in situ were collected and made into suspensions with various soil-water ratios and standing time to measure Eh values. The results demonstrated that the total tendency of Eh values measured by the self-made potentiometer was gradually falling with soil-water ratios increasing and standing time prolonging. There is a great difference between Eh values measured in laboratory and in situ. Only in situ may the measured Eh values show realistic oxidation-reduction conditions and formation characteristics of forest soil. The self-made potentiometer has a preferable performance than indigenous FJA-5 potentiometers and it can be applied to measuring forest soil Eh in situ.展开更多
Objective:To explore the effect of comprehensive nxirsing on patients with cervical cancer.Methods:A total of 100 cervical cancer patients,treated in Weihai Central Hospital from May 2020 to May 2021,were included in ...Objective:To explore the effect of comprehensive nxirsing on patients with cervical cancer.Methods:A total of 100 cervical cancer patients,treated in Weihai Central Hospital from May 2020 to May 2021,were included in this study.The patients were cared for by different methods.They were divided into two groups,the control group and the experimental group,in which routine nursing and comprehensive nursing were given,respectively.The effect of the two different nursing methods on the patients were compared and analyzed.Results:After nursing intervention,the incidence of complications and the scores of depression and anxiety of the experimental group were significantly lower compared with the control group,P<0.05.Conclusion:The application of comprehensive nursing among patients with cervical cancer has a positive significance on their recovery.It reduces the incidence of adverse reactions,improve patients5 negative emotions,and improve their satisfaction.展开更多
Objective:To explore the clinical significance of strengthening nurse patient communication in oncology department.Methods:The study was carried out in our hospital.Taking 100 patients selected from May 2020 to May 20...Objective:To explore the clinical significance of strengthening nurse patient communication in oncology department.Methods:The study was carried out in our hospital.Taking 100 patients selected from May 2020 to May 2021 as an example,all patients were cancer patients.When they were treated,they cooperated with nursing,carried out grouping experiments,adopted different nursing methods,and compared and analyzed the recovery of patients under different nursing interventions.Results:There were significant differences in nursing satisfaction and compliance between the experimental group and the control group,expressed as P<0.05.In contrast,the experimental group had higher satisfaction,better compliance and better effect.Conclusion:Strengthening nurse patient communication in oncology patients is helpful to improve patients’understanding,improve patients’bad mood and promote patients’compliance.It has positive significance and remarkable effect on patients.展开更多
Antimony(Sb)in natural water has long-term effects on both the ecological environment and human health.Iron mineral phase transformation(IMPT)is a prominent process for removing Sb(V)from natural water.However,the imp...Antimony(Sb)in natural water has long-term effects on both the ecological environment and human health.Iron mineral phase transformation(IMPT)is a prominent process for removing Sb(V)from natural water.However,the importance of IMPT in eliminating Sb remains uncertain.This study examined the various Sb–Fe binding mechanisms found in different IMPT pathways in natural water,shedding light on the underlying mechanisms.The study revealed that the presence of goethite(Goe),hematite(Hem),and magnetite(Mag)significantly affected the concentration of Sb(V)in natural water.Elevated pH levels facilitated higher Fe content in iron solids but impeded the process of removing Sb(V).To further our understanding,polluted natural water samples were collected from various locations surrounding Sb smelter sites.Results confirmed that converting ferrihydrite(Fhy)to Goe significantly reduced Sb levels(<5μg/L)in natural water.The emergence of secondary iron phases resulted in greater electrostatic attraction and stabilized surface complexes,which was the most likely cause of the decline of Sb concentration in natural water.The comprehensive findings offer new insights into the factors governing IMPT as well as the Sb(V)behavior control.展开更多
This study aimed to investigate the effects of dietary supplementation of underfed Hu ewes from d 35 to110 of gestation with either rumen-protected L-arginine(RP-Arg)or N-carbamylglutamate(NCG)on placental amino acid(...This study aimed to investigate the effects of dietary supplementation of underfed Hu ewes from d 35 to110 of gestation with either rumen-protected L-arginine(RP-Arg)or N-carbamylglutamate(NCG)on placental amino acid(AA)transport,angiogenic gene expression,and steroid anabolism.On d 35 of gestation,32 Hu ewes carrying twin fetuses were randomly divided into four treatment groups,each consisting of eight ewes,and were fed the following diets:A diet providing 100%of NRC’s nutrient requirements for pregnant ewes(CON);A diet providing 50%of NRC’s nutrient requirements for pregnant ewes(RES);RES diet plus 5 g/d NCG(RES+NCG);or RES diet plus 20 g/d RP-Arg(RES+ARG).On the d 110 of pregnancy,blood samples were taken from the mother,and samples were collected from type A cotyledons(COT;the fetal portions of the placenta).The levels of 17β-estradiol and progesterone in the maternal serum and both the capillary area density(CAD)and capillary surface density(CSD)in type A COT were decreased in response to Arg or NCG supplementation when compared to the RES group.The concentrations of arginine,leucine,putrescine and spermidine in type A COT were higher(P<0.05)in the RES+ARG or RES+NCG group than in the RES group.The mRNA expression levels of inducible nitric oxide synthase(iNOS)and solute carrier family 15,member 1(SLC15A1)were increased(P<0.05)while those of progesterone receptor(PGR)and fibroblast growth factor 2(FGF2)were decreased in type A COT by supplementation with either NCG or RP-Arg compared to the RES group.The results suggest that providing underfed pregnant ewes from d 35 to 110 of gestation with a diet supplemented with NCG or RP-Arg improves placental AA transport,and reduces the expression of angiogenic growth factor genes and steroid anabolism,leading to better fetal development.展开更多
Objective Assess whether local health facilities can adequately support the performance of general practitioners(GPs)trained by China’s national compulsory services programme(CSP).Design Prospective cohort study.Sett...Objective Assess whether local health facilities can adequately support the performance of general practitioners(GPs)trained by China’s national compulsory services programme(CSP).Design Prospective cohort study.Setting Health facilities in middle and western rural areas in China,2015–2022.Participants Cohorts of CSP graduates from 2015 to 2019 in four major medical universities.Main outcomes Job performance measured by a 12-item Job Performance Scale;productivity measured by outpatient volume per day;turnover measured by ever changing jobs within the past year.Results 91.2%,92.0%and 90.5%GPs working in township health centres reported inadequate medication,equipment and external assistance from higher level hospitals,while CSP graduates working in secondary or tertiary hospitals reported a lower rate of less than 60%.The top three tests reported as lacking were blood gases(67.7%),microbiology(61.6%)and cancer biomarkers(49.7%);the top three lacked procedures were CT scan(64.8%),MRI scan(58.1%)and ambulatory BP monitoring(55.8%);and the top three lacked drugs were drugs for cardiovascular diseases(23.3%),systematic hormonal preparations(17.7%)and traditional Chinese medicines(13.0%).Multivariable analysis showed that facility support was positively associated with job performance—adequate medication increased job performance by 2.2 points(95%CI 0.7to 3.8),and adequate external assistance increased job performance by 3.3 points(95%CI 1.8to 4.8).Facility support was also positively associated with productivity—adequate medication increased outpatients seen per day by 20%(95%CI 0.1to 0.3),and adequate equipment increased outpatients seen per day by 12%(95%CI 0.0to 0.2).Facility support did not have significant impact on turnover,but GPs who changed jobs in the past year were 1.9–2.3 times more likely to report adequate facility support.Conclusion GPs in township health centres experienced a high prevalence of shortage in facility support.The identification of a positive association between facility support and performance and productivity has implications for future research and resources deployment in primary healthcare.展开更多
The climatic warming and humidification observed in the arid region of Northwest China(ARNC) and their impacts on the ecological environment have become an issue of concern. The associated multi-scale characteristics ...The climatic warming and humidification observed in the arid region of Northwest China(ARNC) and their impacts on the ecological environment have become an issue of concern. The associated multi-scale characteristics and environmental responses are currently poorly understood. Using data from satellite remote sensing, field observations, and the Coupled Model Intercomparison Project phase 6, this paper systematically analyzes the process and scale characteristics of the climatic warming and humidification in the ARNC and their impacts on ecological vegetation. The results show that not only have temperature and precipitation increased significantly in the ARNC over the past 60 years, but the increasing trend of precipitation is also obviously intensifying. The dryness index, which comprehensively considers the effects of precipitation and temperature, has clearly decreased, and the trend in humidification has increased. Spatially, the trend of temperature increase has occurred over the entire region, while 93.4% of the region has experienced an increase in precipitation, suggesting a spatially consistent climatic warming and humidification throughout the ARNC. Long-term trends and interannual changes in temperature and precipitation dominate the changes in climatic warming and humidification. Compared to interannual variations in temperature, the trend change of temperature contributes more to the overall temperature change. However, the contribution of interannual variations in precipitation is greater than that of the precipitation trend to the overall precipitation change. The current climatic warming and humidification generally promote the growth of ecological vegetation. Since the 1980 s,82.4% of the regional vegetation has thrived. The vegetation index has a significant positive correlation with precipitation and temperature. However, it responds more significantly to interannual precipitation variation, although the vegetation response varies significantly under different types of land use. The warming and humidification of the climate in the ARNC are probably related to intensifications of the westerly wind circulation and ascending air motions.They are expected to continue in the future, although the strength of the changes will probably be insufficient to significantly change the basic climate pattern in the ARNC. The results of this study provide helpful information for decision making related to China's "Belt and Road" development strategies.展开更多
This article uses multivariate regression and decomposition analyses to assess household income mobility determinants and their contributions to income mobility in rural China from 1989 to 2006. The findings indicate ...This article uses multivariate regression and decomposition analyses to assess household income mobility determinants and their contributions to income mobility in rural China from 1989 to 2006. The findings indicate that households with lower initial income level, higher share of wage income, higher educational level of household members, larger number of non-agricultural employed household members and younger heads are more mobile. Moreover, besides initial income, change in the share of wage income, change in the share of non-agricultural employed household members, and change in average year of education of household members are the most important factors that account for income mobility. These findings necessitate more emphasis on policies that promote non-agricultural employment and education to enhance household income mobility in rural China.展开更多
基金supported by the fund for the National 14th Five-Year Plan Key Research and Development Program(2021YFD1600702)XPCC Agricultural Science and Technology Innovation Project(NCG202232)the Top Talents Award Plan of Yangzhou University(2020)。
文摘Background Exposure to bisphenol A(BPA),an environmental pollutant known for its endocrine-disrupting properties,during gestation has been reported to increase the risk of fetal growth restriction(FGR)in an ovine model of pregnancy.We hypothesized that the FGR results from the BPA-induced insufficiency and barrier dysfunction of the placenta,oxidative stress,inflammatory responses,autophagy and endoplasmic reticulum stress(ERS).However,precise mechanisms underlying the BPA-induced placental dysfunction,and subsequently,FGR,as well as the potential involvement of placental ERS in these complications,remain to be investigated.Methods In vivo experiment,16 twin-pregnant(from d 40 to 130 of gestation)Hu ewes were randomly distributed into two groups(8 ewes each).One group served as a control and received corn oil once a day,whereas the other group received BPA(5 mg/kg/d as a subcutaneous injection).In vitro study,ovine trophoblast cells(OTCs)were exposed to 4 treatments,6 replicates each.The OTCs were treated with 400μmol/L BPA,400μmol/L BPA+0.5μg/m L tunicamycin(Tm;ERS activator),400μmol/L BPA+1μmol/L 4-phenyl butyric acid(4-PBA;ERS antagonist)and DMEM/F12 complete medium(control),for 24 h.Results In vivo experiments,pregnant Hu ewes receiving the BPA from 40 to 130 days of pregnancy experienced a decrease in placental efficiency,progesterone(P4)level and fetal weight,and an increase in placental estrogen(E2)level,together with barrier dysfunctions,OS,inflammatory responses,autophagy and ERS in type A cotyledons.In vitro experiment,the OTCs exposed to BPA for 24 h showed an increase in the E2 level and related protein and gene expressions of autophagy,ERS,pro-apoptosis and inflammatory response,and a decrease in the P4 level and the related protein and gene expressions of antioxidant,anti-apoptosis and barrier function.Moreover,treating the OTCs with Tm aggravated BPA-induced dysfunction of barrier and endocrine(the increased E2 level and decreased P4 level),OS,inflammatory responses,autophagy,and ERS.However,treating the OTCs with 4-PBA reversed the counteracted effects of Tm mentioned above.Conclusions In general,the results reveal that BPA exposure can cause ERS in the ovine placenta and OTCs,and ERS induction might aggravate BPA-induced dysfunction of the placental barrier and endocrine,OS,inflammatory responses,and autophagy.These data offer novel mechanistic insights into whether ERS is involved in BPA-mediated placental dysfunction and fetal development.
基金supported by the National Natural Science Foundation of China(41774004,41904040)the Technological Innovation of SHASG(SCK2020-11).
文摘A method is proposed to fuse the velocity data of the global navigation satellite system(GNSS) and leveling height via combined adjustment with constraints. First, stable GNSS-leveling points are uniformly selected, and the constraints of the geodetic height change velocity and normal height change velocity are given. Then, the GNSS vertical velocities and leveling height difference are used as observations of combined adjustment, and robust least-squares estimation are used to estimate the velocities of the unknown points. Finally, a vertical movement model is established with the GNSS vertical velocities and leveling vertical velocities obtained via combined adjustment. Data from the second-order leveling network and GNSS control points in Shandong Province are taken as test data, and eight calculation schemes are used for discussion. One of the schemes, the bifactor robust combined adjustment method based on variance component estimation with two kinds of vertical velocity constraints achieves the optimal results. The method applied in the scheme can be recommended for data fusion of GNSS and leveling, further improving the reliability of vertical crustal movement in Shandong Province.
文摘In this paper,a kind of wall fabric’s surface treatment agent modified with nonionic surfactant was reported.This surface treatment agent was prepared by using nano tourmaline powder dispersion in water with surfactant as dispersants by sand milling.Under the influence of different dispersants,the negative ions releasing amount of functional wall fabrics,the milling process and the storage stability of nano tourmaline powder dispersion were discussed.The results showed that nano tourmaline powder dispersion achieved the smallest average diameter of 44 nm and had best storage stability that the average diameter maintained below 200 nm in 17 days when the addition amount of dispersant was 20 percent of the tourmaline powders’weight.What is more,the quantity of negative ion releasing achieved 6500 ion/cm3 when addition amount of dispersant was 30 percent.This technique could be used to strengthen productivity of nano tourmaline powder dispersion.
基金This work was supported by funding from the Chengdu University of Traditional Chinese Medicine(Grant no:RWQN1410).
文摘Background:This study aimed to determine the prevalence and predictive factors of prolonged grief disorder(PGD)among those bereaved by the Wenchuan earthquake in Southwestern China seven years after the event.Methods:A cross-sectional survey based on census tracts was conducted on the bereaved earthquake survivors.Responses to the questionnaire regarding PGD and its potential associated factors were obtained either through face-to-face or telephone interview.PGD was screened by a validated Chinese version of the PGD questionnaire-13(PG-13).Bivariate and multivariate regression analyses were used to determine the prevalence and associated risk factors of PGD.Results:A total of 1464 bereaved earthquake survivors,with a response rate of 97.6%,were included in the study.Of the 1464 respondents studied,124(8.47%)were diagnosed with PGD.Multivariate regression analysis demonstrated that PGD in the bereaved earthquake individuals was significantly associated with several factors,including age,economic burden,close kinship with the deceased,and living with the deceased before the loss.Wenchuan earthquake bereaved aged 41e60 years were more likely to develop PGD compared to those aged younger than 40 or older than 60(OR=2.075,95%CI=1.297e3.319).Those who had a close kinship with the deceased had a higher tendency to develop PGD(OR=5.144,95%CI=2.716e9.740).The odds of PGD among the earthquake bereaved with economic burdens were higher relative to those who did not experience an economic burden(OR=8.123,95%CI=2.657e24.831).Those who living with the deceased before loss also had a higher tendency to develop PGD(OR=0.179,95%CI=0.053e0.602).Conclusions:This study revealed that a significantly high proportion(8.47%)of the Wenchuan earthquake-bereaved remain grieving seven years after the event.Those diagnosed with PGD should receive appropriate interventions from clinical psychologists.The risk factors identified in this study are crucial for the early screening and prevention of PGD in future nursing and psycho-clinical practices.
基金This work was partially supported by the National Natural Science Foundation of China(51773060,and 52073091)Shanghai Natural Science Foundation(20ZR1414600)+1 种基金Shanghai Aerospace Science and Technology Innovation Fund(SAST2020-087)the Fundamental Research Funds for the Central Universities(50321042017001).
文摘To explore the influence of substituent groups on thermally induced curing,eight new bio-based benzoxazines containing different substituent groups with different electron negativity and volumes were synthesized.The thermal curing of these bio-based benzoxazines was studied in detail.Combined with the curing reaction kinetics,simulation and calculation of Highest Occupied Molecular and Lowest Unoccupied Molecular values,the spatial and electronic effects of different substituent groups on the curing of benzoxazine was explored.It was found that when the substituent was located at the position directly connected to the N atom,the steric hindrance effect of the group was dominant.When the substituent group was located on the benzene ring connected to the O atom,both the electronic effect and the spatial effect influenced the curing of benzoxazine.When an electron-withdrawing group was connected ortho position to the O atom,the curing reaction was promoted due to the decreased electron cloud density of O-on the oxazine ring,making the C-O bond easier to break.When an electron-donating group was connected to the meta position of the O atom it also promoted the curing reaction,possibly because it increased the electron cloud density of the+CH2 reaction site and thereby facilitated electrophilic substitution via attack of+CH2 on the cross linking reaction centre.This work provides a deeper understanding of how spatial and electronic effects of substituents affect the curing of benzoxazine.
文摘Redox potential has principal influences on formation and attribute of soils and it is necessary to research the measurement of soil redox potential. The self-made potentiometer and two indigenous FJA-5 potentiometers were employed to measure the Eh values of fir forest soils in situ, which lied in Savage Sea Beauty Spot in Sichuan Province. Simultaneously fresh soils in situ were collected and made into suspensions with various soil-water ratios and standing time to measure Eh values. The results demonstrated that the total tendency of Eh values measured by the self-made potentiometer was gradually falling with soil-water ratios increasing and standing time prolonging. There is a great difference between Eh values measured in laboratory and in situ. Only in situ may the measured Eh values show realistic oxidation-reduction conditions and formation characteristics of forest soil. The self-made potentiometer has a preferable performance than indigenous FJA-5 potentiometers and it can be applied to measuring forest soil Eh in situ.
文摘Objective:To explore the effect of comprehensive nxirsing on patients with cervical cancer.Methods:A total of 100 cervical cancer patients,treated in Weihai Central Hospital from May 2020 to May 2021,were included in this study.The patients were cared for by different methods.They were divided into two groups,the control group and the experimental group,in which routine nursing and comprehensive nursing were given,respectively.The effect of the two different nursing methods on the patients were compared and analyzed.Results:After nursing intervention,the incidence of complications and the scores of depression and anxiety of the experimental group were significantly lower compared with the control group,P<0.05.Conclusion:The application of comprehensive nursing among patients with cervical cancer has a positive significance on their recovery.It reduces the incidence of adverse reactions,improve patients5 negative emotions,and improve their satisfaction.
文摘Objective:To explore the clinical significance of strengthening nurse patient communication in oncology department.Methods:The study was carried out in our hospital.Taking 100 patients selected from May 2020 to May 2021 as an example,all patients were cancer patients.When they were treated,they cooperated with nursing,carried out grouping experiments,adopted different nursing methods,and compared and analyzed the recovery of patients under different nursing interventions.Results:There were significant differences in nursing satisfaction and compliance between the experimental group and the control group,expressed as P<0.05.In contrast,the experimental group had higher satisfaction,better compliance and better effect.Conclusion:Strengthening nurse patient communication in oncology patients is helpful to improve patients’understanding,improve patients’bad mood and promote patients’compliance.It has positive significance and remarkable effect on patients.
基金financially supported by the National Key R&D Program of China(No.2022YFC3900200)Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52121004)+3 种基金Major program Natural Science Foundation of Hunan Province of China(No.2021JC0001)National Natural Science Foundation of China(No.22276218)key projects of Science and Technology of Hunan Province(No.2020SK2006)Science and Technology Innovation Program of Hunan Province(No.2021RC3013).
文摘Antimony(Sb)in natural water has long-term effects on both the ecological environment and human health.Iron mineral phase transformation(IMPT)is a prominent process for removing Sb(V)from natural water.However,the importance of IMPT in eliminating Sb remains uncertain.This study examined the various Sb–Fe binding mechanisms found in different IMPT pathways in natural water,shedding light on the underlying mechanisms.The study revealed that the presence of goethite(Goe),hematite(Hem),and magnetite(Mag)significantly affected the concentration of Sb(V)in natural water.Elevated pH levels facilitated higher Fe content in iron solids but impeded the process of removing Sb(V).To further our understanding,polluted natural water samples were collected from various locations surrounding Sb smelter sites.Results confirmed that converting ferrihydrite(Fhy)to Goe significantly reduced Sb levels(<5μg/L)in natural water.The emergence of secondary iron phases resulted in greater electrostatic attraction and stabilized surface complexes,which was the most likely cause of the decline of Sb concentration in natural water.The comprehensive findings offer new insights into the factors governing IMPT as well as the Sb(V)behavior control.
基金The research was supported by the fund for the Top Talents Award Plan of Yangzhou University(2020)the Cyanine Project of Yangzhou University(2020).
文摘This study aimed to investigate the effects of dietary supplementation of underfed Hu ewes from d 35 to110 of gestation with either rumen-protected L-arginine(RP-Arg)or N-carbamylglutamate(NCG)on placental amino acid(AA)transport,angiogenic gene expression,and steroid anabolism.On d 35 of gestation,32 Hu ewes carrying twin fetuses were randomly divided into four treatment groups,each consisting of eight ewes,and were fed the following diets:A diet providing 100%of NRC’s nutrient requirements for pregnant ewes(CON);A diet providing 50%of NRC’s nutrient requirements for pregnant ewes(RES);RES diet plus 5 g/d NCG(RES+NCG);or RES diet plus 20 g/d RP-Arg(RES+ARG).On the d 110 of pregnancy,blood samples were taken from the mother,and samples were collected from type A cotyledons(COT;the fetal portions of the placenta).The levels of 17β-estradiol and progesterone in the maternal serum and both the capillary area density(CAD)and capillary surface density(CSD)in type A COT were decreased in response to Arg or NCG supplementation when compared to the RES group.The concentrations of arginine,leucine,putrescine and spermidine in type A COT were higher(P<0.05)in the RES+ARG or RES+NCG group than in the RES group.The mRNA expression levels of inducible nitric oxide synthase(iNOS)and solute carrier family 15,member 1(SLC15A1)were increased(P<0.05)while those of progesterone receptor(PGR)and fibroblast growth factor 2(FGF2)were decreased in type A COT by supplementation with either NCG or RP-Arg compared to the RES group.The results suggest that providing underfed pregnant ewes from d 35 to 110 of gestation with a diet supplemented with NCG or RP-Arg improves placental AA transport,and reduces the expression of angiogenic growth factor genes and steroid anabolism,leading to better fetal development.
基金This study involves human participants and was approved by Institutional Review Board of Peking University Health Science Center(PU IRB)(IRB00001052-15027).
文摘Objective Assess whether local health facilities can adequately support the performance of general practitioners(GPs)trained by China’s national compulsory services programme(CSP).Design Prospective cohort study.Setting Health facilities in middle and western rural areas in China,2015–2022.Participants Cohorts of CSP graduates from 2015 to 2019 in four major medical universities.Main outcomes Job performance measured by a 12-item Job Performance Scale;productivity measured by outpatient volume per day;turnover measured by ever changing jobs within the past year.Results 91.2%,92.0%and 90.5%GPs working in township health centres reported inadequate medication,equipment and external assistance from higher level hospitals,while CSP graduates working in secondary or tertiary hospitals reported a lower rate of less than 60%.The top three tests reported as lacking were blood gases(67.7%),microbiology(61.6%)and cancer biomarkers(49.7%);the top three lacked procedures were CT scan(64.8%),MRI scan(58.1%)and ambulatory BP monitoring(55.8%);and the top three lacked drugs were drugs for cardiovascular diseases(23.3%),systematic hormonal preparations(17.7%)and traditional Chinese medicines(13.0%).Multivariable analysis showed that facility support was positively associated with job performance—adequate medication increased job performance by 2.2 points(95%CI 0.7to 3.8),and adequate external assistance increased job performance by 3.3 points(95%CI 1.8to 4.8).Facility support was also positively associated with productivity—adequate medication increased outpatients seen per day by 20%(95%CI 0.1to 0.3),and adequate equipment increased outpatients seen per day by 12%(95%CI 0.0to 0.2).Facility support did not have significant impact on turnover,but GPs who changed jobs in the past year were 1.9–2.3 times more likely to report adequate facility support.Conclusion GPs in township health centres experienced a high prevalence of shortage in facility support.The identification of a positive association between facility support and performance and productivity has implications for future research and resources deployment in primary healthcare.
基金Supported by the National Natural Science Foundation of China (41630426 and 41975016)Climate Change Special Project of the China Meteorological Administration (CCSF201913 and CCSF202010)。
文摘The climatic warming and humidification observed in the arid region of Northwest China(ARNC) and their impacts on the ecological environment have become an issue of concern. The associated multi-scale characteristics and environmental responses are currently poorly understood. Using data from satellite remote sensing, field observations, and the Coupled Model Intercomparison Project phase 6, this paper systematically analyzes the process and scale characteristics of the climatic warming and humidification in the ARNC and their impacts on ecological vegetation. The results show that not only have temperature and precipitation increased significantly in the ARNC over the past 60 years, but the increasing trend of precipitation is also obviously intensifying. The dryness index, which comprehensively considers the effects of precipitation and temperature, has clearly decreased, and the trend in humidification has increased. Spatially, the trend of temperature increase has occurred over the entire region, while 93.4% of the region has experienced an increase in precipitation, suggesting a spatially consistent climatic warming and humidification throughout the ARNC. Long-term trends and interannual changes in temperature and precipitation dominate the changes in climatic warming and humidification. Compared to interannual variations in temperature, the trend change of temperature contributes more to the overall temperature change. However, the contribution of interannual variations in precipitation is greater than that of the precipitation trend to the overall precipitation change. The current climatic warming and humidification generally promote the growth of ecological vegetation. Since the 1980 s,82.4% of the regional vegetation has thrived. The vegetation index has a significant positive correlation with precipitation and temperature. However, it responds more significantly to interannual precipitation variation, although the vegetation response varies significantly under different types of land use. The warming and humidification of the climate in the ARNC are probably related to intensifications of the westerly wind circulation and ascending air motions.They are expected to continue in the future, although the strength of the changes will probably be insufficient to significantly change the basic climate pattern in the ARNC. The results of this study provide helpful information for decision making related to China's "Belt and Road" development strategies.
基金funded by the National Institute of Health(R01-HD30880,DK056350,and R01-HD38700)
文摘This article uses multivariate regression and decomposition analyses to assess household income mobility determinants and their contributions to income mobility in rural China from 1989 to 2006. The findings indicate that households with lower initial income level, higher share of wage income, higher educational level of household members, larger number of non-agricultural employed household members and younger heads are more mobile. Moreover, besides initial income, change in the share of wage income, change in the share of non-agricultural employed household members, and change in average year of education of household members are the most important factors that account for income mobility. These findings necessitate more emphasis on policies that promote non-agricultural employment and education to enhance household income mobility in rural China.
