Accumulated sand-belts refer to those formed along the oasis fringe,especially at the upwind location,due to the accumulation of sand blocked by farmland windbreak. In the 60 years since the foundation of new China,a ...Accumulated sand-belts refer to those formed along the oasis fringe,especially at the upwind location,due to the accumulation of sand blocked by farmland windbreak. In the 60 years since the foundation of new China,a lot of trees have been planted for desertification combating in northwest and north China,thus,accumulated sand-belts were formed at the upwind location. The formation and the ecological effects of the accumulated sand-belts along the oasis fringe is a new scientific concern. To study the formation causes of these belts in Hexi corridor,21 samples were selected,and the height / width of the belts,as well as the vegetation,soil,soil moisture and climatic factors were investigated. This paper analyzed the correlation between the height / width of the belts and the vegetation,soil,soil moisture and climatic factors using the methods of variance analysis,correlation analysis and canonical correlation analysis. The results indicate that: the accumulated sand-belts take a trend of being high and wide in the east whereas low and narrow in the west,and most of the parts tend to be stable; the species on the belts are dominated by Tamarix austromongolica,the vegetation cover and the pure vegetation cover of different dominant species on the leeward slope of the accumulated sand-belts vary significantly. The canonical correlation analysis shows that: the height and width of accumulated sand-belt is the interaction of precipitation,distance to the sand source,leeward vegetation cover and annual average wind speed. Moreover,the height of accumulated sand-belts are negatively correlated to the soil moisture at the depth of 30- 50 cm,air humidity and leeward vegetation cover,and the width of the belts is also negatively correlated with the distance to the sand source. The ecological effects of the accumulated sand-belts are both positive( stopping sands from moving into farmland,protective role as an obstacle)and negative( when the belts decay and activate one day,they will become the new sand sources). At present,there are no signs showing the negative effects of the belts. The ecological effects of the accumulated sand-belts are: firstly the protective role as an obstacle,and secondly to intercept and reduce the sands moving into farmlands.展开更多
Fabric-skin adhesion was objectively described by the indices of the maximum adhesion force F_(max) , the maximum separation distance L_(max) ,and adhesion work W as well as the adhesion force-separation distance curv...Fabric-skin adhesion was objectively described by the indices of the maximum adhesion force F_(max) , the maximum separation distance L_(max) ,and adhesion work W as well as the adhesion force-separation distance curve. Firstly,gray correlation analysis method was adopted to investigate the correlation levels between adhesion indices,and secondly the relative importance of fabric structural parameters to fabric-skin adhesion,as well as the correlation levels between skin adhesion, water absorption, and wicking properties of the fabric. The results prove that W exhibits clear correlations with both F_(max) and L_(max) , yet the relevance between F_(max) and L_(max) is weak. Fabric adhesion indices are most associated with fabric mass and least with fabric thickness,whereas fabric wicking and water absorption present closest correlation with fabric thickness. Therefore, it is concluded that the relevance between fabric wicking, water absorption, and skin-adhesion properties are rather comprehensive than straight.展开更多
In order to clarify the correlation between short-shoot Fuji apple tree structure and different factors under different trimming and pruning modes,we investigate the trunk taperingness of free-spindle short-shoot Fuji...In order to clarify the correlation between short-shoot Fuji apple tree structure and different factors under different trimming and pruning modes,we investigate the trunk taperingness of free-spindle short-shoot Fuji and slender-spindle short-shoot Fuji,respectively,as well as the total thickness,average thickness,total length and average length of small main branches in the standard demonstration apple garden in Xingtang County of Hebei Province. By SPSS analysis,we study the correlation between trunk taperingness of trees with different shapes and the growth indices of their small main branches. The results show that the trunk taperingness of free-spindle short-shoot Fuji apple is negatively correlated with the total thickness,average thickness,total length and average length of small main branches,but the correlation is not significant; the trunk taperingness of slender-spindle short-shoot Fuji apple is negatively correlated with the total thickness but positively correlated with other factors,and the correlation with average length reaches a significant level. The results of this study can provide a scientific basis for guiding the high-density dwarf rootstock short-shoot Fuji apple tree trimming technology.展开更多
Diversity in bacterial communities was investigated along a petroleum hydrocarbon content gradient(0-0.4043 g/g)in surface(5-10 cm)and subsurface(35-40 cm)petroleum-contaminated soil samples from the Dagang Oilfield,C...Diversity in bacterial communities was investigated along a petroleum hydrocarbon content gradient(0-0.4043 g/g)in surface(5-10 cm)and subsurface(35-40 cm)petroleum-contaminated soil samples from the Dagang Oilfield,China.Using 16S rRNA Illumina high-throughput sequencing technology and several statistical methods,the bacterial diversity of the soil was studied.Subsequently,the environmental parameters were measured to analyze its relationship with the community variation.Nonmetric multidimensional scaling and analysis of similarities indicated a significant difference in the structure of the bacterial community between the nonpetroleum-contaminated surface and subsurface soils,but no differences were observed in different depths of petroleum-contaminated soil.Meanwhile,many significant correlations were obtained between diversity in soil bacterial community and physicochemical properties.Total petroleum hydrocarbon,total organic carbon,and total nitrogen were the three important factors that had the greatest impacts on the bacterial community distribution in the long-term petroleum-contaminated soils.Our research has provided references for the bacterial community distribution along a petroleum gradient in both surface and subsurface petroleum-contaminated soils of oilfield areas.展开更多
The effects of three factors (i.e., drop height h, hopper outlet diameter do, and material temperature T] on the dust generation rate derived from a free falling particle stream were investigated via filll factorial ...The effects of three factors (i.e., drop height h, hopper outlet diameter do, and material temperature T] on the dust generation rate derived from a free falling particle stream were investigated via filll factorial experiments. The correlation between the three factors and dust generation rate was also analysed. Results show that Tand h affect the first fugitive dust rate largely, whereas the second fugitive dust rate is mainly dominated by h and do. Through analysing the first fugitive dust percentage data, it is found that h and T should be considered first for higher temperatures and lower flow rates, whereas h and do can be considered under contrasting conditions, and h should be controlled in the remaining two sets of conditions. Relationships between the influencing factors and total and first fugitive dust rates were developed via multiple regression to quantify the dust emission rates for different contact surfaces (rigid or water).展开更多
Experimental investigations were conducted on the process of combustion and explosion vent in a 200 mm (diame- ter)×400 mm (length) vertical cylindrical vessel. When CH4-air mixture gases were used and the vent d...Experimental investigations were conducted on the process of combustion and explosion vent in a 200 mm (diame- ter)×400 mm (length) vertical cylindrical vessel. When CH4-air mixture gases were used and the vent diameter was 55 mm, conditions of Φ (equivalent ratio)=0.8, Φ=1.0 and Φ=1.3 and two ignition positions (at the cylinder center and bottom) were selected. The venting processes and the correlated factors are discussed in this paper.展开更多
With correlation analysis and factor analysis methods, the effects of preceding Pacific SSTs on subtropical high indexes of main raining seasons are discussed. The results of correlation analysis show that the effects...With correlation analysis and factor analysis methods, the effects of preceding Pacific SSTs on subtropical high indexes of main raining seasons are discussed. The results of correlation analysis show that the effects of SSTs on five subtropical high indexes differ in seasons and regions. The variation of SSTs mostly affects the area and intensity indexes of the subtropical high, followed by the western ridge index, and the effect on the ridge line index is more remarkable than on the north boundary index. The results of factor analysis reveals that the first common factor of SST of each season reflected mainly the inverse relation of SSTs variation between the central and eastern part of equatorial Pacific and the western Pacific, which correlates better with the subtropical high indexes in the main raining seasons than other common factors of SST. The analysis of interdecadal variation indicated that the variation of SSTs was conducive to the emergence of the La Ni?a event before the end of 1970s, such that in the summer the subtropical high is likely to be weaker and smaller and located eastward and northward. After the 1980s, the opposite characteristics prevailed.展开更多
Objective To investigate whether correlation existsbetween quantitative perfusion parameters obtained from dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)and different prognostic factors or immunohistoch...Objective To investigate whether correlation existsbetween quantitative perfusion parameters obtained from dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)and different prognostic factors or immunohistochemical subtypes of breast cancers.Methods A retrospective analysis of DCE-MRI was performed in展开更多
Objective: Neurosyphilis is challenging to diagnose, especially in patients with human immunodeficiency virus (HIV)/syphilis co-infection. The aim of this study was to profile the clinical features of neurosyphilis an...Objective: Neurosyphilis is challenging to diagnose, especially in patients with human immunodeficiency virus (HIV)/syphilis co-infection. The aim of this study was to profile the clinical features of neurosyphilis and evaluate the correlation between neurosyphilis and clinical or laboratory factors among patients with HIV/syphilis co-infection.Methods: We retrospectively analyzed the data of 479 HIV/syphilis co-infected patients examined between August 2009 and September 2018. A multivariate logistic regression model was used to identify factors correlated with neurosyphilis.Results: The overall prevalence of neurosyphilis was 21.7%. The prevalence of neurosyphilis differed among patients with primary (11.1%), secondary (20.1%), and latent syphilis (29.1%). The prevalences of neurosyphilis in patients with serological non-response and serofast patients were 26.1% and 6.3%, respectively, while 12.5% of patients with serological relapse had neurosyphilis. Patients with secondary and latent syphilis had serum rapid plasma reagin (RPR) titers (per unit) of 1.44-fold [95% confidence interval (CI): 1.08-1.93,P= 0.014] and 2.73-fold (95%CI: 1.49-5.00,P= 0.001), respectively, which increased the risk of confirmed neurosyphilis. Among patients with latent syphilis, a serum RPR titer of ≥1:32 and peripheral blood CD4 cell count of ≤350/mL were significantly associated with neurosyphilis, with adjusted odds ratios of 9.45 (95%CI: 1.86-48.03,P= 0.007) and 3.75 (95%CI: 1.11-12.66,P= 0.033), respectively.Conclusion: A serum RPR titer of ≥1:32 and a peripheral blood CD4 cell count of ≤350/mL have predictive value in screening for neurosyphilis among HIV-positive patients with latent syphilis.展开更多
The correlation between the wear behavior of a heavy commercial vehicle (HCV) brake liner tested under controlled laboratory conditions and that in actual field conditions is investigated.A brake liner study for frict...The correlation between the wear behavior of a heavy commercial vehicle (HCV) brake liner tested under controlled laboratory conditions and that in actual field conditions is investigated.A brake liner study for friction and wear is performed on an inertia brake dynamometer (IBD) at different temperatures (200 ℃,250 ℃,and 300 ℃) using 6000 brake actuations in a laboratory.The total wear loss of the brake liner at three different temperatures for 6000 brake actuations in IBD is found to be 1.12 mm.The actual field test is conducted on four different HCVs,namely,a city bus (CB),a high speed bus (HSB),a highway truck (HWT),and a tipper lorry (TL).These HCVs run at different terrain/traffic conditions and load conditions.When comparing the predicted life of the brake liner through the IBD test with the actual life of the brake liner in different HCVs,a vast difference is observed.Due to the large variation of liner life observed between the actual and predicted tests,an extensive field test is conducted.In the field test,the liner with identical formulation is fitted in the four types of HCVs.The predicted life of the liner using IBD is then correlated with the field test observation and a correlation factor is determined.Based on this correlation factor,the predicted life of the liner and the achieved life on the HCV are found to be fairly close.This study will be useful to design the friction material formulation and to predict the actual life of the brake liner for various HCVs.展开更多
Objective To analyze the correlative factors of peptic ulcer recurrence in the elderly.Methods From January to December 2009,169 elderly patients(≥60 years old)with peptic ulcer delected by edoscopy were enrolled,who...Objective To analyze the correlative factors of peptic ulcer recurrence in the elderly.Methods From January to December 2009,169 elderly patients(≥60 years old)with peptic ulcer delected by edoscopy were enrolled,whose treatment and usage of medication were analyzed.Data of treatment and recurrence in 3-year follow-up were recorded.Mann-Whitney rank sum test展开更多
Three-dimensional fluorescence excitation–emission matrix(EEM) coupled with parallel factor analysis(PARAFAC) was performed for a total of 18 water samples taken from three water sources(two lakes and one wastew...Three-dimensional fluorescence excitation–emission matrix(EEM) coupled with parallel factor analysis(PARAFAC) was performed for a total of 18 water samples taken from three water sources(two lakes and one wastewater treatment plant(WWTP) secondary effluent),with the purpose of identifying the major ultrafiltration(UF) membrane foulants in different water sources. Three fluorescent components(C1, C2 and C3) were identified,which represented terrestrially derived humic-like substances(C1), microbially derived humic-like substances(C2), and protein-like substances(C3). The correlations between the different fluorescent components and UF membrane fouling were analyzed. It was shown that for the WWTP secondary effluent, all three components(C1, C2 and C3) made a considerable contribution to the irreversible and total fouling of the UF membrane.However, for the two lakes, only the C3 exhibited a strong correlation with membrane fouling, indicating that the protein-like substances were the major membrane foulants in the lake waters. Significant attachment of C1, C2 and C3 to the UF membrane was also confirmed by mass balance analyses for the WWTP secondary effluent; while the attachment of C1 and C2 was shown to be negligible for the two lakes. The results may provide basic formation for developing suitable fouling control strategies for sustainable UF processes.展开更多
Static permittivity(ε),refractive index(n)and density(ρ)of binary mixtures of ethylene glycol mono phenyl ether(EGMPE)with 1-butanol(1-BuOH)over the entire range of mole fraction and at temperatures(T=303:15,313.15 ...Static permittivity(ε),refractive index(n)and density(ρ)of binary mixtures of ethylene glycol mono phenyl ether(EGMPE)with 1-butanol(1-BuOH)over the entire range of mole fraction and at temperatures(T=303:15,313.15 and 323.15 K)have been measured.From the experimental data,parameters such as excess static permittivity(ε^(E)),excess permittivity at optical frequency(ε^(E)_(∞)),effective Kirkwood correlation factor(g^(eff)),corrective Kirkwood correlation factor(g^(f))and Bruggeman factor(f^(b))have been calculated to obtain qualitative and quantitative information about the complex formation through H-bond in binary system.In order to predict the static permittivity of polar–polar binary mixtures six mixing rules were applied and for refractive index five mixing rule were applied.Experimental results of permittivity(ε)and refractive index(n)are compared with those obtained from theoretical calculations.Excess parameters were fitted to the Redlich–Kister type polynomial equation.展开更多
The Complex permittivity spectra of glycol ether(GE)compounds such as ethylene glycol mono-methyl ether(EGME)with water mixture over entire concentration range and in temperature range of 10-25℃ have been determined ...The Complex permittivity spectra of glycol ether(GE)compounds such as ethylene glycol mono-methyl ether(EGME)with water mixture over entire concentration range and in temperature range of 10-25℃ have been determined using Time Domain Reflectometry(TDR)technique in the frequency range 10MHz to 50 GHz.The complex permittivity spectra for EGME-water were fitted in the Cole-Davidson model.The Static dielectric constant(ε_(0)^(E)),Relaxation time(τ),effective Kirkwood correlation factor(g_(eff)),excess permittivity(ε_(0)),thermodynamic parameters(activation enthalpy and activation entropy)and Bruggeman factor(f_(B))have been calculated by the nonlinear least square fit method.The intermolecular interactions between EGME-water binary mixtures suggest the nonlinear behavior of dielectric parameters.The contribution of hydrogen bonding interactions among the solute-solvent mixtures is confirmed by Excess properties and Bruggeman factor.展开更多
The dielectric properties of binary mixtures of benzylamine-1,2,6-hexantriol mixtures at different volume fractions of 1,2,6-hexanetriol have been measured using Time Domain Reflectometry(TDR)technique in the frequenc...The dielectric properties of binary mixtures of benzylamine-1,2,6-hexantriol mixtures at different volume fractions of 1,2,6-hexanetriol have been measured using Time Domain Reflectometry(TDR)technique in the frequency range of 10 MHz to 30 GHz.Complex permittivity spectra were fitted using Havriliak-Negami equation.By using least square fit method the dielectric parameters such as static dielectric constant(ε_(0)),dielectric constant at high frequency(ε_(∞)),relaxation timeτ(ps)and relaxation distribution parameter(β)were extracted from complex permittivity spectra at 25℃.The intramolecular interaction of different molecules has been discussed using the Kirkwood correlation factor,Bruggeman factor.The Kirkwood correlation factor(gf)and effective Kirkwood correlation factor(g^(eff))indicate the dipole ordering of the binary mixtures.展开更多
基金Supported by the Pre-phase Project of the 973 Program(2014CB460611)
文摘Accumulated sand-belts refer to those formed along the oasis fringe,especially at the upwind location,due to the accumulation of sand blocked by farmland windbreak. In the 60 years since the foundation of new China,a lot of trees have been planted for desertification combating in northwest and north China,thus,accumulated sand-belts were formed at the upwind location. The formation and the ecological effects of the accumulated sand-belts along the oasis fringe is a new scientific concern. To study the formation causes of these belts in Hexi corridor,21 samples were selected,and the height / width of the belts,as well as the vegetation,soil,soil moisture and climatic factors were investigated. This paper analyzed the correlation between the height / width of the belts and the vegetation,soil,soil moisture and climatic factors using the methods of variance analysis,correlation analysis and canonical correlation analysis. The results indicate that: the accumulated sand-belts take a trend of being high and wide in the east whereas low and narrow in the west,and most of the parts tend to be stable; the species on the belts are dominated by Tamarix austromongolica,the vegetation cover and the pure vegetation cover of different dominant species on the leeward slope of the accumulated sand-belts vary significantly. The canonical correlation analysis shows that: the height and width of accumulated sand-belt is the interaction of precipitation,distance to the sand source,leeward vegetation cover and annual average wind speed. Moreover,the height of accumulated sand-belts are negatively correlated to the soil moisture at the depth of 30- 50 cm,air humidity and leeward vegetation cover,and the width of the belts is also negatively correlated with the distance to the sand source. The ecological effects of the accumulated sand-belts are both positive( stopping sands from moving into farmland,protective role as an obstacle)and negative( when the belts decay and activate one day,they will become the new sand sources). At present,there are no signs showing the negative effects of the belts. The ecological effects of the accumulated sand-belts are: firstly the protective role as an obstacle,and secondly to intercept and reduce the sands moving into farmlands.
基金National Natural Science Foundation of China(No.60904056)Shanghai Municipal Natural Science Foundation,China(No.14ZR1401000)+2 种基金Science and Technology Project of Administration of Quality and Technology Supervision of Guangzhou Municipality,China(No.2014KJ29)Science and Technology Guidance Project of China National Textile and Apparel Council,China(No.2015066)the Fundamental Research Funds for the Central Universities,China
文摘Fabric-skin adhesion was objectively described by the indices of the maximum adhesion force F_(max) , the maximum separation distance L_(max) ,and adhesion work W as well as the adhesion force-separation distance curve. Firstly,gray correlation analysis method was adopted to investigate the correlation levels between adhesion indices,and secondly the relative importance of fabric structural parameters to fabric-skin adhesion,as well as the correlation levels between skin adhesion, water absorption, and wicking properties of the fabric. The results prove that W exhibits clear correlations with both F_(max) and L_(max) , yet the relevance between F_(max) and L_(max) is weak. Fabric adhesion indices are most associated with fabric mass and least with fabric thickness,whereas fabric wicking and water absorption present closest correlation with fabric thickness. Therefore, it is concluded that the relevance between fabric wicking, water absorption, and skin-adhesion properties are rather comprehensive than straight.
基金Supported by Modern Agricultural Industry Technology System Construction Project(CARS-28)Project of Hebei Provincial Department of Science and Technology(11220104D-1)
文摘In order to clarify the correlation between short-shoot Fuji apple tree structure and different factors under different trimming and pruning modes,we investigate the trunk taperingness of free-spindle short-shoot Fuji and slender-spindle short-shoot Fuji,respectively,as well as the total thickness,average thickness,total length and average length of small main branches in the standard demonstration apple garden in Xingtang County of Hebei Province. By SPSS analysis,we study the correlation between trunk taperingness of trees with different shapes and the growth indices of their small main branches. The results show that the trunk taperingness of free-spindle short-shoot Fuji apple is negatively correlated with the total thickness,average thickness,total length and average length of small main branches,but the correlation is not significant; the trunk taperingness of slender-spindle short-shoot Fuji apple is negatively correlated with the total thickness but positively correlated with other factors,and the correlation with average length reaches a significant level. The results of this study can provide a scientific basis for guiding the high-density dwarf rootstock short-shoot Fuji apple tree trimming technology.
基金supported by the Major Research Plan of Tianjin (No.16YFXTSF00460)the National Natural Science Foundation of China (No.21878220)
文摘Diversity in bacterial communities was investigated along a petroleum hydrocarbon content gradient(0-0.4043 g/g)in surface(5-10 cm)and subsurface(35-40 cm)petroleum-contaminated soil samples from the Dagang Oilfield,China.Using 16S rRNA Illumina high-throughput sequencing technology and several statistical methods,the bacterial diversity of the soil was studied.Subsequently,the environmental parameters were measured to analyze its relationship with the community variation.Nonmetric multidimensional scaling and analysis of similarities indicated a significant difference in the structure of the bacterial community between the nonpetroleum-contaminated surface and subsurface soils,but no differences were observed in different depths of petroleum-contaminated soil.Meanwhile,many significant correlations were obtained between diversity in soil bacterial community and physicochemical properties.Total petroleum hydrocarbon,total organic carbon,and total nitrogen were the three important factors that had the greatest impacts on the bacterial community distribution in the long-term petroleum-contaminated soils.Our research has provided references for the bacterial community distribution along a petroleum gradient in both surface and subsurface petroleum-contaminated soils of oilfield areas.
文摘The effects of three factors (i.e., drop height h, hopper outlet diameter do, and material temperature T] on the dust generation rate derived from a free falling particle stream were investigated via filll factorial experiments. The correlation between the three factors and dust generation rate was also analysed. Results show that Tand h affect the first fugitive dust rate largely, whereas the second fugitive dust rate is mainly dominated by h and do. Through analysing the first fugitive dust percentage data, it is found that h and T should be considered first for higher temperatures and lower flow rates, whereas h and do can be considered under contrasting conditions, and h should be controlled in the remaining two sets of conditions. Relationships between the influencing factors and total and first fugitive dust rates were developed via multiple regression to quantify the dust emission rates for different contact surfaces (rigid or water).
基金Project (No. 19832030) supported by the National Natural Science Foundation of China
文摘Experimental investigations were conducted on the process of combustion and explosion vent in a 200 mm (diame- ter)×400 mm (length) vertical cylindrical vessel. When CH4-air mixture gases were used and the vent diameter was 55 mm, conditions of Φ (equivalent ratio)=0.8, Φ=1.0 and Φ=1.3 and two ignition positions (at the cylinder center and bottom) were selected. The venting processes and the correlated factors are discussed in this paper.
文摘With correlation analysis and factor analysis methods, the effects of preceding Pacific SSTs on subtropical high indexes of main raining seasons are discussed. The results of correlation analysis show that the effects of SSTs on five subtropical high indexes differ in seasons and regions. The variation of SSTs mostly affects the area and intensity indexes of the subtropical high, followed by the western ridge index, and the effect on the ridge line index is more remarkable than on the north boundary index. The results of factor analysis reveals that the first common factor of SST of each season reflected mainly the inverse relation of SSTs variation between the central and eastern part of equatorial Pacific and the western Pacific, which correlates better with the subtropical high indexes in the main raining seasons than other common factors of SST. The analysis of interdecadal variation indicated that the variation of SSTs was conducive to the emergence of the La Ni?a event before the end of 1970s, such that in the summer the subtropical high is likely to be weaker and smaller and located eastward and northward. After the 1980s, the opposite characteristics prevailed.
文摘Objective To investigate whether correlation existsbetween quantitative perfusion parameters obtained from dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)and different prognostic factors or immunohistochemical subtypes of breast cancers.Methods A retrospective analysis of DCE-MRI was performed in
基金This work was supported by grants from the National Natural Science Foundation of China(Nos.81301374 and 82072322)Shanghai Municipal Commission of Health and Family Planning(No.20184Y0225)+1 种基金Shanghai Committee of Science and Technology(Nos.YDZX20193100002868 and 17DZ2293300)National Megaprojecton on Key Infectious Diseases(No.2017ZX10202102-001-007).
文摘Objective: Neurosyphilis is challenging to diagnose, especially in patients with human immunodeficiency virus (HIV)/syphilis co-infection. The aim of this study was to profile the clinical features of neurosyphilis and evaluate the correlation between neurosyphilis and clinical or laboratory factors among patients with HIV/syphilis co-infection.Methods: We retrospectively analyzed the data of 479 HIV/syphilis co-infected patients examined between August 2009 and September 2018. A multivariate logistic regression model was used to identify factors correlated with neurosyphilis.Results: The overall prevalence of neurosyphilis was 21.7%. The prevalence of neurosyphilis differed among patients with primary (11.1%), secondary (20.1%), and latent syphilis (29.1%). The prevalences of neurosyphilis in patients with serological non-response and serofast patients were 26.1% and 6.3%, respectively, while 12.5% of patients with serological relapse had neurosyphilis. Patients with secondary and latent syphilis had serum rapid plasma reagin (RPR) titers (per unit) of 1.44-fold [95% confidence interval (CI): 1.08-1.93,P= 0.014] and 2.73-fold (95%CI: 1.49-5.00,P= 0.001), respectively, which increased the risk of confirmed neurosyphilis. Among patients with latent syphilis, a serum RPR titer of ≥1:32 and peripheral blood CD4 cell count of ≤350/mL were significantly associated with neurosyphilis, with adjusted odds ratios of 9.45 (95%CI: 1.86-48.03,P= 0.007) and 3.75 (95%CI: 1.11-12.66,P= 0.033), respectively.Conclusion: A serum RPR titer of ≥1:32 and a peripheral blood CD4 cell count of ≤350/mL have predictive value in screening for neurosyphilis among HIV-positive patients with latent syphilis.
文摘The correlation between the wear behavior of a heavy commercial vehicle (HCV) brake liner tested under controlled laboratory conditions and that in actual field conditions is investigated.A brake liner study for friction and wear is performed on an inertia brake dynamometer (IBD) at different temperatures (200 ℃,250 ℃,and 300 ℃) using 6000 brake actuations in a laboratory.The total wear loss of the brake liner at three different temperatures for 6000 brake actuations in IBD is found to be 1.12 mm.The actual field test is conducted on four different HCVs,namely,a city bus (CB),a high speed bus (HSB),a highway truck (HWT),and a tipper lorry (TL).These HCVs run at different terrain/traffic conditions and load conditions.When comparing the predicted life of the brake liner through the IBD test with the actual life of the brake liner in different HCVs,a vast difference is observed.Due to the large variation of liner life observed between the actual and predicted tests,an extensive field test is conducted.In the field test,the liner with identical formulation is fitted in the four types of HCVs.The predicted life of the liner using IBD is then correlated with the field test observation and a correlation factor is determined.Based on this correlation factor,the predicted life of the liner and the achieved life on the HCV are found to be fairly close.This study will be useful to design the friction material formulation and to predict the actual life of the brake liner for various HCVs.
文摘Objective To analyze the correlative factors of peptic ulcer recurrence in the elderly.Methods From January to December 2009,169 elderly patients(≥60 years old)with peptic ulcer delected by edoscopy were enrolled,whose treatment and usage of medication were analyzed.Data of treatment and recurrence in 3-year follow-up were recorded.Mann-Whitney rank sum test
基金supported by the National Natural Science Foundation of China(No.51208140)the National Water Pollution Control and Treatment Science and Technology Major Project of China(No.2012ZX07201002)
文摘Three-dimensional fluorescence excitation–emission matrix(EEM) coupled with parallel factor analysis(PARAFAC) was performed for a total of 18 water samples taken from three water sources(two lakes and one wastewater treatment plant(WWTP) secondary effluent),with the purpose of identifying the major ultrafiltration(UF) membrane foulants in different water sources. Three fluorescent components(C1, C2 and C3) were identified,which represented terrestrially derived humic-like substances(C1), microbially derived humic-like substances(C2), and protein-like substances(C3). The correlations between the different fluorescent components and UF membrane fouling were analyzed. It was shown that for the WWTP secondary effluent, all three components(C1, C2 and C3) made a considerable contribution to the irreversible and total fouling of the UF membrane.However, for the two lakes, only the C3 exhibited a strong correlation with membrane fouling, indicating that the protein-like substances were the major membrane foulants in the lake waters. Significant attachment of C1, C2 and C3 to the UF membrane was also confirmed by mass balance analyses for the WWTP secondary effluent; while the attachment of C1 and C2 was shown to be negligible for the two lakes. The results may provide basic formation for developing suitable fouling control strategies for sustainable UF processes.
基金Experimental facilities developed using financial assistance provided by Department of Sciences and Technology(DST),New Delhi through the DST-FIST(Level-I)project(SR/FST/PSI-001/2006)University Grant Commission(UGC),New Delhi through major research project(37-159/2009(SR))DRS-SAP program grant[No.F.530/10/DRS/2010(SAP-I)]have been utilized to carry out this work and it is gratefully acknowledged.
文摘Static permittivity(ε),refractive index(n)and density(ρ)of binary mixtures of ethylene glycol mono phenyl ether(EGMPE)with 1-butanol(1-BuOH)over the entire range of mole fraction and at temperatures(T=303:15,313.15 and 323.15 K)have been measured.From the experimental data,parameters such as excess static permittivity(ε^(E)),excess permittivity at optical frequency(ε^(E)_(∞)),effective Kirkwood correlation factor(g^(eff)),corrective Kirkwood correlation factor(g^(f))and Bruggeman factor(f^(b))have been calculated to obtain qualitative and quantitative information about the complex formation through H-bond in binary system.In order to predict the static permittivity of polar–polar binary mixtures six mixing rules were applied and for refractive index five mixing rule were applied.Experimental results of permittivity(ε)and refractive index(n)are compared with those obtained from theoretical calculations.Excess parameters were fitted to the Redlich–Kister type polynomial equation.
基金This work was supported by the Department of Science and Technology,New Delhi(Project No.DST PROJECTSB/S2/LOP-032/2013)as well as School of Physical Sciences,SRTM University,Nanded,India for providing necessary facilities。
文摘The Complex permittivity spectra of glycol ether(GE)compounds such as ethylene glycol mono-methyl ether(EGME)with water mixture over entire concentration range and in temperature range of 10-25℃ have been determined using Time Domain Reflectometry(TDR)technique in the frequency range 10MHz to 50 GHz.The complex permittivity spectra for EGME-water were fitted in the Cole-Davidson model.The Static dielectric constant(ε_(0)^(E)),Relaxation time(τ),effective Kirkwood correlation factor(g_(eff)),excess permittivity(ε_(0)),thermodynamic parameters(activation enthalpy and activation entropy)and Bruggeman factor(f_(B))have been calculated by the nonlinear least square fit method.The intermolecular interactions between EGME-water binary mixtures suggest the nonlinear behavior of dielectric parameters.The contribution of hydrogen bonding interactions among the solute-solvent mixtures is confirmed by Excess properties and Bruggeman factor.
基金New Delhi is gratefully acknowledged(project No.SR/S2/LOP-25/2007)for laboratory facility.
文摘The dielectric properties of binary mixtures of benzylamine-1,2,6-hexantriol mixtures at different volume fractions of 1,2,6-hexanetriol have been measured using Time Domain Reflectometry(TDR)technique in the frequency range of 10 MHz to 30 GHz.Complex permittivity spectra were fitted using Havriliak-Negami equation.By using least square fit method the dielectric parameters such as static dielectric constant(ε_(0)),dielectric constant at high frequency(ε_(∞)),relaxation timeτ(ps)and relaxation distribution parameter(β)were extracted from complex permittivity spectra at 25℃.The intramolecular interaction of different molecules has been discussed using the Kirkwood correlation factor,Bruggeman factor.The Kirkwood correlation factor(gf)and effective Kirkwood correlation factor(g^(eff))indicate the dipole ordering of the binary mixtures.