Polychlorinated biphenyls (PCBs) are widespread environmental contaminants that are possible health hazards for human beings through a variety of pathways.In the present study,50 time mated pregnant rats were divided ...Polychlorinated biphenyls (PCBs) are widespread environmental contaminants that are possible health hazards for human beings through a variety of pathways.In the present study,50 time mated pregnant rats were divided into five groups and injected daily from gestational days 7 to 18 with either 2,2′,4,4′- tetrachlorobiphenyl (PCB 47) or 3,3′,4,4′- tetrachlorobiphenyl (PCB 77) or seseme oil (control) to evaluate the effects of these PCBs on prenatal and postnatal development.Offspring were examined for malformations of genitalia at birth and in adulthood.Body weight gains of these animals were checked every 7 days through postnatal day (PND) 119.There were no clinical signs of toxicity in the PCB-treated dams or their offspring throughout the experiment.Litter size and sex ratio of the litters were not affected.Both PCBs produced a significant increase in the females' anogenital distance,suggesting a modification of androgen responsiveness in females resulting from PCB exposure during development.Similar effects were not seen with the males.The proportion of individuals with eyes open by PND 15 was significantly reduced by both PCBs.Exposure to 1 mg/kg body weight of PCB 77 significantly reduced body weight gains in male pups from PND 35 to 119.However,no significant differences were found in body weight gains of the pups exposed to PCB 47.展开更多
Cement-based composite grouting materials were used to construct grouting cutoff wall for heavy metal contaminated soil in non-ferrous metal mining areas. Cement, fly ash, and slag as principal ingredients were mixed ...Cement-based composite grouting materials were used to construct grouting cutoff wall for heavy metal contaminated soil in non-ferrous metal mining areas. Cement, fly ash, and slag as principal ingredients were mixed with water glass in different ways to produce three composite grouting materials. In order to investigate the effect of water glass mixing ratio, Baume degree, fly ash and slag contents on the mechanical properties of the composite grouting materials, particularly their gel time and compressive strength, the beaker-to-beaker method of gel time test and unconfined compressive strength test were conducted. In addition, the phase composition and microstructure of the composite grouting materials were analyzed by the X-ray diffraction（XRD） and scanning electron microscope（SEM） techniques. The test results show that their gel time increases when water glass mixing ratio and Baume degree increase. The gel time increases dramatically when fly ash is added, but decreases slightly if fly ash is partly replaced by slag. When the mixing ratio of water glass is below 20%, their compressive strength increases with the increases of the ratio; when the ratio is above 20%, it significantly decreases. The compressive strength also tends to increase as Baume degree increases, and improves if fly ash and slag are added.展开更多
We study radiative decays of T to light quark jets in nonrelativistic QCD by taking both the color singlet and color octet b^-b operators into consideration. The cut for quark jet energy and cut for the angle between ...We study radiative decays of T to light quark jets in nonrelativistic QCD by taking both the color singlet and color octet b^-b operators into consideration. The cut for quark jet energy and cut for the angle between two quark jets are introduced. The sensitivity to the soft and collinear singularities in the loop integrals are greatly reduced by these cuts. With the jet energy cut of about 1 GeV, and the jet angle cut of about 36°, the branching ratio for γ→ rq^- is found to be 8.2 × 10^-4 from color singlet contributions. The color octet contributions could be much larger than that of color singlet, depending on the estimate of the color octet matrix elements. This process may provide a new test for the color octet mechanism in nonrelativistic QCD.展开更多
Based on the charge injection and recombination processes and the triplet-triplet annihilation process, a model to calculate the electroluminescent(EL) efficiency is presented. The influences of the applied electric f...Based on the charge injection and recombination processes and the triplet-triplet annihilation process, a model to calculate the electroluminescent(EL) efficiency is presented. The influences of the applied electric field on the injection efficiency, recombination efficiency and electroluminescent efficiency are discussed. It is found that: (1) The injection efficiency is increasing while the recombination efficiency is decreasing with the applied electric field increasing. (2) The EL efficiency is enhanced at low electric field slowly but is decreasing at high electric field with the increase of applied voltage. (3) The EL efficiency is decreasing with the increase of the host-guest molecular distance (R). So, it is concluded that the EL efficiency in single-layer organic electrophosphorescent devices is dominated by injection efficiency at lower electric field and recombination efficiency at higher electric field.展开更多
This paper describes the conductivity modifications induced by heavy ion implantation in pyrolysis products obtained by thermal treatment of polyacrylonitrile （PAN） thin films at temperatures of 435℃ （PAN435） and...This paper describes the conductivity modifications induced by heavy ion implantation in pyrolysis products obtained by thermal treatment of polyacrylonitrile （PAN） thin films at temperatures of 435℃ （PAN435） and 750℃ （PAN750） under vacuum. Ionic species having different chemical reactivities such as Kr, As, Cl. and F ions were utilized to allow interpretation of the conductivity＇ data either in terms of implantation induced molecular rearrangements or in terms of specific chemical doping effects. The temperature dependence of conductivity in the range between 25-3000C followed nearly a simple activation conduction relationship from which the temperature coefficients of resistivity （ct） were determined. In this temperature range, PAN750 provided the smallest α value compared with ion implanted PAN750 or with products obtained at the lower pyrolysis temperature. However. the corresponding lowest rate of conductivity change with temperatures （0.49%/℃） obtained in this study far exceeds the specification value required for thin film resistor applications （〈 0.1%/℃）.展开更多
Objective:To assess inter-and intraobserver reproducibility for measuring perfusion CT derived cerebral blood volume (CBV) and relative cerebral blood volume (rCBV) with different slice thickness in patients with brai...Objective:To assess inter-and intraobserver reproducibility for measuring perfusion CT derived cerebral blood volume (CBV) and relative cerebral blood volume (rCBV) with different slice thickness in patients with brain neoplasms. Meth- ods: Three independent observers who were blinded to the histopathologic diagnosis performed perfusion derived CBV and rCBV measurements with 5 mm and 10 mm slice thickness in 52 patients with various cerebral neoplasms. The results of the measurements with different slice thickness were compared. Calculation of coefficient of variation (CV), and relative paired difference of the measurements were used to determine the levels of inter- and intraobserver reproducibility. Results: The differences of CBV and rCBV measurements between different slice thickness groups were statistically significant (P < 0.05) respectively in observer 2, and were not significant in the other two observers (P > 0.05). For the same slice thickness, both the difference of CBV and rCBV measurements among the three observers were not statistically significant. Interobserver CV and relative paired difference of the measurements with 10 mm slice thickness group were slightly lower than those of 5 mm slice thickness group. Interobserver CV and relative paired difference of CBV group were slightly lower than those of rCBV group. The intraobserver differences of CBV and rCBV in 10 mm slice thickness group were statistically significant for observer 2 respectively. No other intraobserver differences of measurements were statistically significant. CV and relative paired difference of intraobserver CBV and rCBV measurements for observer 2 were significantly higher than for the other two observers. Conclusion: High reproducibility of CBV and rCBV measurements was acquired with the two different slice thickness. Suitable training may be helpful to maintain a high level of consistency for measurements.展开更多
This paper discusses the technique of casting concrete ofmicropiles with pressures and the consequence of comparisons with normal way of casting concrete （casting with gravity）. Preliminary geotechnical studies have...This paper discusses the technique of casting concrete ofmicropiles with pressures and the consequence of comparisons with normal way of casting concrete （casting with gravity）. Preliminary geotechnical studies have been made in specific area in Sudan to predict the soil parameters and then an experimental work has been done for an estimated number ofmicropiles with different diameters and different techniques of placing concrete with various amount of pressure. This study was carried out to learn the usefulness of this technique in the field of structural foundations in Sudan. Capacities of micropiles were compared in cases of non-pressure casting （normal way of casting concrete） and pressure casting. Through the results, it was found that the entry of pressure factor in the operation of casting concrete increases the capacities of micropiles. The increased value of ultimate load depends on the amount of pressure applied.展开更多
A commercial recombinant fowl pox vectored infectious laryngotracheitis （ILT） vaccine was examined its protection efficacy in one-day-old chicks by subcutaneous route with various dose-strength. The treatment groups...A commercial recombinant fowl pox vectored infectious laryngotracheitis （ILT） vaccine was examined its protection efficacy in one-day-old chicks by subcutaneous route with various dose-strength. The treatment groups I-III birds were vaccinated with a full, 1/2 and 1/3 dose of recommendation dose, respectively. Thereafter, at 6 wk post vaccination, they were challenged with 5x labeled dose of live ILT vaccine. Protection efficacy of the vaccine was compared among groups based on antibody production and eye lesion score. The results of eye lesion score showed that there was a significant difference between control and treatment groups, whereas the difference was not found among the treatment groups. For seroconversion, there was no significant difference between birds in group I and II. However, higher number of seroconversion birds in groups I and II than group III was observed （P 〈 0.05）. It was concluded that a half dose of recommendation dose had the same protection efficacy as a full dose of recombinant YP-LT vaccine.展开更多
Aiming at the problems such as low reconstruction efficiency,fuzzy texture details,and difficult convergence of reconstruction network face image super-resolution reconstruction algorithms,a new super-resolution recon...Aiming at the problems such as low reconstruction efficiency,fuzzy texture details,and difficult convergence of reconstruction network face image super-resolution reconstruction algorithms,a new super-resolution reconstruction algorithm with residual concern was proposed.Firstly,to solve the influence of redundant and invalid information about the face image super-resolution reconstruction network,an attention mechanism was introduced into the feature extraction module of the network,which improved the feature utilization rate of the overall network.Secondly,to alleviate the problem of gradient disappearance,the adaptive residual was introduced into the network to make the network model easier to converge during training,and features were supplemented according to the needs during training.The experimental results showed that the proposed algorithm had better reconstruction performance,more facial details,and clearer texture in the reconstructed face image than the comparison algorithm.In objective evaluation,the proposed algorithm's peak signalto-noise ratio and structural similarity were also better than other algorithms.展开更多
To evaluate the effects of sperm with different parameters and sources on the outcomes of intracytoplasmic sperm injection (ICSI), 1972 ICSI cycles were analyzed retrospectively. Groups 1 to 5 were composed of cycles ...To evaluate the effects of sperm with different parameters and sources on the outcomes of intracytoplasmic sperm injection (ICSI), 1972 ICSI cycles were analyzed retrospectively. Groups 1 to 5 were composed of cycles using ejaculated sperm and were grouped according to sperm quantity, quality, and morphology into normal (288 cycles), or mild (329 cycles), moderate (522 cycles), severe (332 cycles), and extremely severe (171 cycles) oligozoospermia and/or asthenozoospermia and/or teratozoospermia (OAT) groups. Group 6 was composed of 250 cycles using testicular or epididymal sperm, and Group 7 consisted of 80 cycles using frozen-thawed sperm. We found that fertilization rates were gradually reduced from Groups 1 to 6, and reached statistical difference in Groups 5 and 6 (P<0.05). The high-quality embryo rate was higher in Group 1 than in Groups 2, 3, 5, 6, and 7 (P<0.05). No statistical differences were observed in the rates of embryo cleavage, clinical pregnancy, miscarriage, live-birth, premature birth, low birth weight, weeks of premature birth, average birth weight, or sex ratio for all seven groups (P>0.05). A total of nine cases of malformation were observed, with a malformation rate of 1.25% (9/719). In conclusion, different sperm sources and parameters can affect ICSI outcomes before embryo implantation. A full assessment of offspring mal-formation will require further study using a larger sample size.展开更多
To study the curative effect of wil sonii injecta on severe head injury (SHI).Methods: A total of 120 patients with SHI were divided randomly into 2 groups, the patients treated with conventional methods as Group A (n...To study the curative effect of wil sonii injecta on severe head injury (SHI).Methods: A total of 120 patients with SHI were divided randomly into 2 groups, the patients treated with conventional methods as Group A (n=60) and the patients treated with wilsonii injecta as Group B (n=60). The changes o f neural function indexes were evaluated with Glasgow Coma Scale (GCS) before tr eatment and with Glasgow Outcome Scale (GOS) after treatment, simultaneously, th e parameters of hemorrheological indexes (HI), brain electrical activity map (BE AM) and transcranial Doppler sonography (TCD) were observed before and after tre atment.Results: In Group B, the clinical GCS, the HI, the BEAM and the prognosis GOS were improved much more than those in Group A. And the TCD parame ters in Group B decreased, which had significant difference compared with that i n Group A (P< 0.01 ).Conclusions: Wilsonii injecta can rapidly improve the injured p ersons’ conscious states, the abnormal BEAM and the surviving quality. It sugges ts that the improvement of the HI is related to the relief of the vasospasm of the arterial blood vessels in the brain, which may be one of the important mecha nisms of wilsonii injecta in improving the prognosis.展开更多
文摘Polychlorinated biphenyls (PCBs) are widespread environmental contaminants that are possible health hazards for human beings through a variety of pathways.In the present study,50 time mated pregnant rats were divided into five groups and injected daily from gestational days 7 to 18 with either 2,2′,4,4′- tetrachlorobiphenyl (PCB 47) or 3,3′,4,4′- tetrachlorobiphenyl (PCB 77) or seseme oil (control) to evaluate the effects of these PCBs on prenatal and postnatal development.Offspring were examined for malformations of genitalia at birth and in adulthood.Body weight gains of these animals were checked every 7 days through postnatal day (PND) 119.There were no clinical signs of toxicity in the PCB-treated dams or their offspring throughout the experiment.Litter size and sex ratio of the litters were not affected.Both PCBs produced a significant increase in the females' anogenital distance,suggesting a modification of androgen responsiveness in females resulting from PCB exposure during development.Similar effects were not seen with the males.The proportion of individuals with eyes open by PND 15 was significantly reduced by both PCBs.Exposure to 1 mg/kg body weight of PCB 77 significantly reduced body weight gains in male pups from PND 35 to 119.However,no significant differences were found in body weight gains of the pups exposed to PCB 47.
基金Projects(41472278,41202220)supported by the National Natural Science Foundation of ChinaProject(20120022120003)supported by the Research Fund for the Doctoral Program of Higher Education,China+1 种基金Project(51900265647)supported by the Beijing Higher Education Young Elite Teacher Project,ChinaProject(2652012065)supported by the Fundamental Research Funds for the Central Universities,China
文摘Cement-based composite grouting materials were used to construct grouting cutoff wall for heavy metal contaminated soil in non-ferrous metal mining areas. Cement, fly ash, and slag as principal ingredients were mixed with water glass in different ways to produce three composite grouting materials. In order to investigate the effect of water glass mixing ratio, Baume degree, fly ash and slag contents on the mechanical properties of the composite grouting materials, particularly their gel time and compressive strength, the beaker-to-beaker method of gel time test and unconfined compressive strength test were conducted. In addition, the phase composition and microstructure of the composite grouting materials were analyzed by the X-ray diffraction（XRD） and scanning electron microscope（SEM） techniques. The test results show that their gel time increases when water glass mixing ratio and Baume degree increase. The gel time increases dramatically when fly ash is added, but decreases slightly if fly ash is partly replaced by slag. When the mixing ratio of water glass is below 20%, their compressive strength increases with the increases of the ratio; when the ratio is above 20%, it significantly decreases. The compressive strength also tends to increase as Baume degree increases, and improves if fly ash and slag are added.
基金The project supported in part by National Natural Science Foundation of China under Grant No. 10421503 and the Key Project of the Ministry of Education under Grant No. 305001, and the Research Found of Doctorial Programs of Higher Education of China. We thank E. Berger for bringing their earlier work on inelastic photoproduction of T （Ref. [12]） to our attention. We would also like to thank Ce Meng for valuable discussions.
文摘We study radiative decays of T to light quark jets in nonrelativistic QCD by taking both the color singlet and color octet b^-b operators into consideration. The cut for quark jet energy and cut for the angle between two quark jets are introduced. The sensitivity to the soft and collinear singularities in the loop integrals are greatly reduced by these cuts. With the jet energy cut of about 1 GeV, and the jet angle cut of about 36°, the branching ratio for γ→ rq^- is found to be 8.2 × 10^-4 from color singlet contributions. The color octet contributions could be much larger than that of color singlet, depending on the estimate of the color octet matrix elements. This process may provide a new test for the color octet mechanism in nonrelativistic QCD.
基金Excellent Youth Foundation of Hunan Province(03JJY1008) Science Foundation for Post-doctorate of China(2004035083) Science Foundation of Central South University(0601059)
文摘Based on the charge injection and recombination processes and the triplet-triplet annihilation process, a model to calculate the electroluminescent(EL) efficiency is presented. The influences of the applied electric field on the injection efficiency, recombination efficiency and electroluminescent efficiency are discussed. It is found that: (1) The injection efficiency is increasing while the recombination efficiency is decreasing with the applied electric field increasing. (2) The EL efficiency is enhanced at low electric field slowly but is decreasing at high electric field with the increase of applied voltage. (3) The EL efficiency is decreasing with the increase of the host-guest molecular distance (R). So, it is concluded that the EL efficiency in single-layer organic electrophosphorescent devices is dominated by injection efficiency at lower electric field and recombination efficiency at higher electric field.
文摘This paper describes the conductivity modifications induced by heavy ion implantation in pyrolysis products obtained by thermal treatment of polyacrylonitrile （PAN） thin films at temperatures of 435℃ （PAN435） and 750℃ （PAN750） under vacuum. Ionic species having different chemical reactivities such as Kr, As, Cl. and F ions were utilized to allow interpretation of the conductivity＇ data either in terms of implantation induced molecular rearrangements or in terms of specific chemical doping effects. The temperature dependence of conductivity in the range between 25-3000C followed nearly a simple activation conduction relationship from which the temperature coefficients of resistivity （ct） were determined. In this temperature range, PAN750 provided the smallest α value compared with ion implanted PAN750 or with products obtained at the lower pyrolysis temperature. However. the corresponding lowest rate of conductivity change with temperatures （0.49%/℃） obtained in this study far exceeds the specification value required for thin film resistor applications （〈 0.1%/℃）.
文摘Objective:To assess inter-and intraobserver reproducibility for measuring perfusion CT derived cerebral blood volume (CBV) and relative cerebral blood volume (rCBV) with different slice thickness in patients with brain neoplasms. Meth- ods: Three independent observers who were blinded to the histopathologic diagnosis performed perfusion derived CBV and rCBV measurements with 5 mm and 10 mm slice thickness in 52 patients with various cerebral neoplasms. The results of the measurements with different slice thickness were compared. Calculation of coefficient of variation (CV), and relative paired difference of the measurements were used to determine the levels of inter- and intraobserver reproducibility. Results: The differences of CBV and rCBV measurements between different slice thickness groups were statistically significant (P < 0.05) respectively in observer 2, and were not significant in the other two observers (P > 0.05). For the same slice thickness, both the difference of CBV and rCBV measurements among the three observers were not statistically significant. Interobserver CV and relative paired difference of the measurements with 10 mm slice thickness group were slightly lower than those of 5 mm slice thickness group. Interobserver CV and relative paired difference of CBV group were slightly lower than those of rCBV group. The intraobserver differences of CBV and rCBV in 10 mm slice thickness group were statistically significant for observer 2 respectively. No other intraobserver differences of measurements were statistically significant. CV and relative paired difference of intraobserver CBV and rCBV measurements for observer 2 were significantly higher than for the other two observers. Conclusion: High reproducibility of CBV and rCBV measurements was acquired with the two different slice thickness. Suitable training may be helpful to maintain a high level of consistency for measurements.
文摘This paper discusses the technique of casting concrete ofmicropiles with pressures and the consequence of comparisons with normal way of casting concrete （casting with gravity）. Preliminary geotechnical studies have been made in specific area in Sudan to predict the soil parameters and then an experimental work has been done for an estimated number ofmicropiles with different diameters and different techniques of placing concrete with various amount of pressure. This study was carried out to learn the usefulness of this technique in the field of structural foundations in Sudan. Capacities of micropiles were compared in cases of non-pressure casting （normal way of casting concrete） and pressure casting. Through the results, it was found that the entry of pressure factor in the operation of casting concrete increases the capacities of micropiles. The increased value of ultimate load depends on the amount of pressure applied.
文摘A commercial recombinant fowl pox vectored infectious laryngotracheitis （ILT） vaccine was examined its protection efficacy in one-day-old chicks by subcutaneous route with various dose-strength. The treatment groups I-III birds were vaccinated with a full, 1/2 and 1/3 dose of recommendation dose, respectively. Thereafter, at 6 wk post vaccination, they were challenged with 5x labeled dose of live ILT vaccine. Protection efficacy of the vaccine was compared among groups based on antibody production and eye lesion score. The results of eye lesion score showed that there was a significant difference between control and treatment groups, whereas the difference was not found among the treatment groups. For seroconversion, there was no significant difference between birds in group I and II. However, higher number of seroconversion birds in groups I and II than group III was observed （P 〈 0.05）. It was concluded that a half dose of recommendation dose had the same protection efficacy as a full dose of recombinant YP-LT vaccine.
基金supported by National Natural Science Foundation of China(No.62063014)。
文摘Aiming at the problems such as low reconstruction efficiency,fuzzy texture details,and difficult convergence of reconstruction network face image super-resolution reconstruction algorithms,a new super-resolution reconstruction algorithm with residual concern was proposed.Firstly,to solve the influence of redundant and invalid information about the face image super-resolution reconstruction network,an attention mechanism was introduced into the feature extraction module of the network,which improved the feature utilization rate of the overall network.Secondly,to alleviate the problem of gradient disappearance,the adaptive residual was introduced into the network to make the network model easier to converge during training,and features were supplemented according to the needs during training.The experimental results showed that the proposed algorithm had better reconstruction performance,more facial details,and clearer texture in the reconstructed face image than the comparison algorithm.In objective evaluation,the proposed algorithm's peak signalto-noise ratio and structural similarity were also better than other algorithms.
基金Project supported by the National Natural Science Foundation of China (No. 81070532)the National Basic Research Program (973) of China (Nos. 2012CB944901 and 2007CB948104)the Zhejiang Provincial Natural Science Foundation of China (No. Z207021)
文摘To evaluate the effects of sperm with different parameters and sources on the outcomes of intracytoplasmic sperm injection (ICSI), 1972 ICSI cycles were analyzed retrospectively. Groups 1 to 5 were composed of cycles using ejaculated sperm and were grouped according to sperm quantity, quality, and morphology into normal (288 cycles), or mild (329 cycles), moderate (522 cycles), severe (332 cycles), and extremely severe (171 cycles) oligozoospermia and/or asthenozoospermia and/or teratozoospermia (OAT) groups. Group 6 was composed of 250 cycles using testicular or epididymal sperm, and Group 7 consisted of 80 cycles using frozen-thawed sperm. We found that fertilization rates were gradually reduced from Groups 1 to 6, and reached statistical difference in Groups 5 and 6 (P<0.05). The high-quality embryo rate was higher in Group 1 than in Groups 2, 3, 5, 6, and 7 (P<0.05). No statistical differences were observed in the rates of embryo cleavage, clinical pregnancy, miscarriage, live-birth, premature birth, low birth weight, weeks of premature birth, average birth weight, or sex ratio for all seven groups (P>0.05). A total of nine cases of malformation were observed, with a malformation rate of 1.25% (9/719). In conclusion, different sperm sources and parameters can affect ICSI outcomes before embryo implantation. A full assessment of offspring mal-formation will require further study using a larger sample size.
文摘To study the curative effect of wil sonii injecta on severe head injury (SHI).Methods: A total of 120 patients with SHI were divided randomly into 2 groups, the patients treated with conventional methods as Group A (n=60) and the patients treated with wilsonii injecta as Group B (n=60). The changes o f neural function indexes were evaluated with Glasgow Coma Scale (GCS) before tr eatment and with Glasgow Outcome Scale (GOS) after treatment, simultaneously, th e parameters of hemorrheological indexes (HI), brain electrical activity map (BE AM) and transcranial Doppler sonography (TCD) were observed before and after tre atment.Results: In Group B, the clinical GCS, the HI, the BEAM and the prognosis GOS were improved much more than those in Group A. And the TCD parame ters in Group B decreased, which had significant difference compared with that i n Group A (P< 0.01 ).Conclusions: Wilsonii injecta can rapidly improve the injured p ersons’ conscious states, the abnormal BEAM and the surviving quality. It sugges ts that the improvement of the HI is related to the relief of the vasospasm of the arterial blood vessels in the brain, which may be one of the important mecha nisms of wilsonii injecta in improving the prognosis.
