Aim： To assess that metabolic status of spermatozoa could provide a useful tool for evaluation of semen quality. Methods： The accuracy of the spectrophotometric application of the resazurin reduction assay was asses...Aim： To assess that metabolic status of spermatozoa could provide a useful tool for evaluation of semen quality. Methods： The accuracy of the spectrophotometric application of the resazurin reduction assay was assessed using receiver operating characteristic （ROC） analysis. Results： Areas under ROC curves （AUC） for motile sperm concentration and sperm index （SI） （sperm concentration multiplied by the square root of percentage sperm motility multiplied by the percentage normal sperm morphology） were 0.922. The best discrimination between poor and good semen samples according to the SI was achieved at a cut-off point of A610 = 0.209, where high sensitivity （94.1%） and specificity （91.7%） were calculated. The assay was less accurate when motile sperm concentration was used as the criterion value, yielding sensitivity of 88.2% and specificity of 87.5%, respectively. Likelihood ratios （LR） indicate that absorbances lower than 0.209 were at least 11.3 times as likely to be found in good semen samples than those in poor according to the SI, whereas in the case of motile sperm concentration, the LR was calculated to be 7.06. Conclusion： These results show that the resazurin reduction assay combined with spectrophotometry is an accurate method of assessing the quality of boar semen.展开更多
Aim: To delineate the factors associated with operative reduction of intussusception, in contrast to enema reduction only without surgical intervention, in children aged less than 14 years. Methods: We retrospectively...Aim: To delineate the factors associated with operative reduction of intussusception, in contrast to enema reduction only without surgical intervention, in children aged less than 14 years. Methods: We retrospectively reviewed the records of all children aged <14 years who experienced intussusception between 2002 and 2012 and were treated at a single hospital in Qatar. Clinical outcomes were correlated with age, sex, clinical symptoms, diagnosticand treatmentrelated characteristics, and length of hospital stay. Results: A total of 141 children were diagnosed and treated for intussusception over 11 years. The male to female ratio of intussusception was 1.4:1. The length of hospital stay was longer in patients who underwent operative reduction than those that did not. Conclusion: Delay in presentation did not decrease the success of radiologic reduction and did not increase the risk of operative intervention and bowel resection.展开更多
The metallurgical properties of cold bound pellet were tested and analysed, and the behaviour and characters of reduction in the shaft were further investigated on the basis of analysis. The experimental results indic...The metallurgical properties of cold bound pellet were tested and analysed, and the behaviour and characters of reduction in the shaft were further investigated on the basis of analysis. The experimental results indicated that the metallurgical properties of cold bound pellet could satisfy the demands of the shaft direct reduction. The reduction of ferrous oxide with gas was taken as the domination. The reduction ratio of ferrous oxide with fixed carbon increased with the raising of temperature, and most part of the carbon remained in metallized pellet. The shaft could be smoothly operated to obtain rather higher constant utilization.展开更多
This paper proposes a novel pair of induced IF covering approximation operators in an IF covering approximation space,and discusses some basic properties about definable IFSs.A measure is defined to describe the uncer...This paper proposes a novel pair of induced IF covering approximation operators in an IF covering approximation space,and discusses some basic properties about definable IFSs.A measure is defined to describe the uncertainty of IFSs in IF covering approximation spaces.Finally,we study the properties of reductions of an IF covering respectively based on induced IF covering approximation operators and IF covering approximation operators.展开更多
Ti3+ self-doping modified V2O5/TiO2 catalyst was prepared by sol-gel and impregnation methods and used for selective catalytic reduction (SCR) of NOx with NH3. Results showed that Ti3+ self-doped V2O5/TiO2 catalyst pe...Ti3+ self-doping modified V2O5/TiO2 catalyst was prepared by sol-gel and impregnation methods and used for selective catalytic reduction (SCR) of NOx with NH3. Results showed that Ti3+ self-doped V2O5/TiO2 catalyst performed the better catalytic activity. And X-ray diffraction and scanning electron microscopy were used to evaluate the phase composition and morphology of the prepared catalyst. The effects of calcinations temperature of the support, oxygen concentration, [NH3]/[NO] molar ratio and the GHSV on the denitration performance were investigated. It was found that more than 80% NOx conversion was obtained at 210°C when the O2 volume fraction was 5%, the NO concentration was 500 ppm, the [NH3]/[NO] molar ratio = 1 and the GHSV was 23,885 h−1. The results showed that the catalytic activity increased first with the increasing of O2 concentration and [NH3]/[NO] molar ratio, then remained stable. At the same time, the stability of the catalyst was also studied at the temperature of 210°C. The reaction continued for 750 minutes, and the catalytic activity remained above 80%, indicating that the catalyst has a good stability. Moreover, the Ti3+ self-doped V2O5/TiO2 catalyst also showed good SO2 and H2O resistance. Therefore, these findings provide important information to better understand the application of the prepared catalyst.展开更多
MIL-88A(Fe)@sponge(MS) was synthesized by a dip-coating method, which displayed efficient photocatalytic Cr(Ⅵ) reduction efficiency under both low power LED UV light and real solar light irradiation. It was observed ...MIL-88A(Fe)@sponge(MS) was synthesized by a dip-coating method, which displayed efficient photocatalytic Cr(Ⅵ) reduction efficiency under both low power LED UV light and real solar light irradiation. It was observed that MS(0.2 g/L) could remove 100% Cr(Ⅵ)(10 mg/L) by adding 0.4 mmol/L tartaric acid(TA) without adjusting pH(pH 5.05) within 6.0 min and 3.0 min under UV light and real solar light irradiation, respectively. Besides, the photo-induced e-and radicals(O_(2)^(·-) and CO_(2)^(·-)) were found to play the momentous roles in the MS/TA/UVL/Cr(Ⅵ) system by the scavenger experiments and electron spin resonance(ESR) tests. MS was also filled into a fixed-bed reactor to test the possibility of long-term Cr(Ⅵ)reduction operation in TA/UVL system. As expected, the results revealed that MS could still maintain 100% activity up to 60 h. These results demonstrated that MIL-88A(Fe) might be the potentially efficient catalyst for large-scale wastewater treatment in the near future.展开更多
The life-cycle assessment method,which originates from general products and services,has gradually come to be applied to investigations of the life-cycle carbon emissions(LCCE)of buildings.A literature review was cond...The life-cycle assessment method,which originates from general products and services,has gradually come to be applied to investigations of the life-cycle carbon emissions(LCCE)of buildings.A literature review was conducted to clarify LCCE implications,calculations,and reductions in the context of buildings.A total of 826 global building carbon emission calculation cases were obtained from 161 studies based on the framework of the building life-cycle stage division stipulated by ISO 21930 and the basic principles of the emission factor(EF)approach.The carbon emission calculation methods and results are discussed herein,based on the modules of production,construction,use,end-of-life,and supplementary benefits.According to the hotspot distribution of a building’s carbon emissions,carbon reduction strategies are classified into six groups for technical content and benefits analysis,including reducing the activity data pertaining to building materials and energy,reducing the carbon EFs of the building materials and energy,and exploiting the advantages of supplementary benefits.The research gaps and challenges in current building LCCE studies are summarized in terms of research goals and ideas,calculation methods,basic parameters,and carbon reduction strategies;development suggestions are also proposed.展开更多
文摘Aim： To assess that metabolic status of spermatozoa could provide a useful tool for evaluation of semen quality. Methods： The accuracy of the spectrophotometric application of the resazurin reduction assay was assessed using receiver operating characteristic （ROC） analysis. Results： Areas under ROC curves （AUC） for motile sperm concentration and sperm index （SI） （sperm concentration multiplied by the square root of percentage sperm motility multiplied by the percentage normal sperm morphology） were 0.922. The best discrimination between poor and good semen samples according to the SI was achieved at a cut-off point of A610 = 0.209, where high sensitivity （94.1%） and specificity （91.7%） were calculated. The assay was less accurate when motile sperm concentration was used as the criterion value, yielding sensitivity of 88.2% and specificity of 87.5%, respectively. Likelihood ratios （LR） indicate that absorbances lower than 0.209 were at least 11.3 times as likely to be found in good semen samples than those in poor according to the SI, whereas in the case of motile sperm concentration, the LR was calculated to be 7.06. Conclusion： These results show that the resazurin reduction assay combined with spectrophotometry is an accurate method of assessing the quality of boar semen.
文摘Aim: To delineate the factors associated with operative reduction of intussusception, in contrast to enema reduction only without surgical intervention, in children aged less than 14 years. Methods: We retrospectively reviewed the records of all children aged <14 years who experienced intussusception between 2002 and 2012 and were treated at a single hospital in Qatar. Clinical outcomes were correlated with age, sex, clinical symptoms, diagnosticand treatmentrelated characteristics, and length of hospital stay. Results: A total of 141 children were diagnosed and treated for intussusception over 11 years. The male to female ratio of intussusception was 1.4:1. The length of hospital stay was longer in patients who underwent operative reduction than those that did not. Conclusion: Delay in presentation did not decrease the success of radiologic reduction and did not increase the risk of operative intervention and bowel resection.
文摘The metallurgical properties of cold bound pellet were tested and analysed, and the behaviour and characters of reduction in the shaft were further investigated on the basis of analysis. The experimental results indicated that the metallurgical properties of cold bound pellet could satisfy the demands of the shaft direct reduction. The reduction of ferrous oxide with gas was taken as the domination. The reduction ratio of ferrous oxide with fixed carbon increased with the raising of temperature, and most part of the carbon remained in metallized pellet. The shaft could be smoothly operated to obtain rather higher constant utilization.
基金supported by the National Natural Science Foundation of China(Nos.60773174 and 60963006)Hebei Province Science and Technology Research and Development Program(No.09276158).
文摘This paper proposes a novel pair of induced IF covering approximation operators in an IF covering approximation space,and discusses some basic properties about definable IFSs.A measure is defined to describe the uncertainty of IFSs in IF covering approximation spaces.Finally,we study the properties of reductions of an IF covering respectively based on induced IF covering approximation operators and IF covering approximation operators.
文摘Ti3+ self-doping modified V2O5/TiO2 catalyst was prepared by sol-gel and impregnation methods and used for selective catalytic reduction (SCR) of NOx with NH3. Results showed that Ti3+ self-doped V2O5/TiO2 catalyst performed the better catalytic activity. And X-ray diffraction and scanning electron microscopy were used to evaluate the phase composition and morphology of the prepared catalyst. The effects of calcinations temperature of the support, oxygen concentration, [NH3]/[NO] molar ratio and the GHSV on the denitration performance were investigated. It was found that more than 80% NOx conversion was obtained at 210°C when the O2 volume fraction was 5%, the NO concentration was 500 ppm, the [NH3]/[NO] molar ratio = 1 and the GHSV was 23,885 h−1. The results showed that the catalytic activity increased first with the increasing of O2 concentration and [NH3]/[NO] molar ratio, then remained stable. At the same time, the stability of the catalyst was also studied at the temperature of 210°C. The reaction continued for 750 minutes, and the catalytic activity remained above 80%, indicating that the catalyst has a good stability. Moreover, the Ti3+ self-doped V2O5/TiO2 catalyst also showed good SO2 and H2O resistance. Therefore, these findings provide important information to better understand the application of the prepared catalyst.
基金supported by National Natural Science Foundation of China (Nos. 22176012, 51878023)Beijing Natural Science Foundation (No. 8202016)+1 种基金Beijing Talent Project (No. 2020A27)BUCEA Doctor Graduate Scientific Research Ability Improvement Project (No. DG2021004)。
文摘MIL-88A(Fe)@sponge(MS) was synthesized by a dip-coating method, which displayed efficient photocatalytic Cr(Ⅵ) reduction efficiency under both low power LED UV light and real solar light irradiation. It was observed that MS(0.2 g/L) could remove 100% Cr(Ⅵ)(10 mg/L) by adding 0.4 mmol/L tartaric acid(TA) without adjusting pH(pH 5.05) within 6.0 min and 3.0 min under UV light and real solar light irradiation, respectively. Besides, the photo-induced e-and radicals(O_(2)^(·-) and CO_(2)^(·-)) were found to play the momentous roles in the MS/TA/UVL/Cr(Ⅵ) system by the scavenger experiments and electron spin resonance(ESR) tests. MS was also filled into a fixed-bed reactor to test the possibility of long-term Cr(Ⅵ)reduction operation in TA/UVL system. As expected, the results revealed that MS could still maintain 100% activity up to 60 h. These results demonstrated that MIL-88A(Fe) might be the potentially efficient catalyst for large-scale wastewater treatment in the near future.
基金supported by the National Natural Science Foundation of China(51825802,52130803,52278020,and 72374121)the China National Key Research and Development Program(2018YFE0106100)+1 种基金the China Postdoctoral Science Foundation(2022M711815)the New Cornerstone Science Foundation through the XPLORER PRIZE.
文摘The life-cycle assessment method,which originates from general products and services,has gradually come to be applied to investigations of the life-cycle carbon emissions(LCCE)of buildings.A literature review was conducted to clarify LCCE implications,calculations,and reductions in the context of buildings.A total of 826 global building carbon emission calculation cases were obtained from 161 studies based on the framework of the building life-cycle stage division stipulated by ISO 21930 and the basic principles of the emission factor(EF)approach.The carbon emission calculation methods and results are discussed herein,based on the modules of production,construction,use,end-of-life,and supplementary benefits.According to the hotspot distribution of a building’s carbon emissions,carbon reduction strategies are classified into six groups for technical content and benefits analysis,including reducing the activity data pertaining to building materials and energy,reducing the carbon EFs of the building materials and energy,and exploiting the advantages of supplementary benefits.The research gaps and challenges in current building LCCE studies are summarized in terms of research goals and ideas,calculation methods,basic parameters,and carbon reduction strategies;development suggestions are also proposed.
