Aim: To analyse the possible effect of seasonal variation on semen parameters. Methods: The participants consisted of 1688 men attending the andrology laboratory between 1991 and 1997 for reduced fertility in the coup...Aim: To analyse the possible effect of seasonal variation on semen parameters. Methods: The participants consisted of 1688 men attending the andrology laboratory between 1991 and 1997 for reduced fertility in the couple. Semen analysis was performed according to the WHO manual. The 84 individual months of the study period were each assigned to one of the three groups according to the average monthly outside temperature; Group A (temperature <4.4℃), Group B (4.4℃-13.3℃) and Group C (>13.3℃). Results: When comparing the different sperm parameters, the morphology was significantly better in Group C. However, when the smokers were analysed separately, this difference disappeared and significant seasonal variations were found in sperm density, total sperm count, motility and total motile sperm; they were deteriorated in the warmer season. In non-smokers, no such negative effect of increased temperature was observed. Conclusion: Sperm quality is influenced by seasonal factors. Increased environmental temperature, (maybe also light exposure) has an additional negative effect on the spermato-genesis in smokers, leading to reduced sperm quality in men with borderline fertility.展开更多
With the rapid industrialization and urbanization,the demand for air quality management is more and more urgent.High temperature dust filtration is one important environmental management technology.Porous ceramics are...With the rapid industrialization and urbanization,the demand for air quality management is more and more urgent.High temperature dust filtration is one important environmental management technology.Porous ceramics are used as filter materials in the field of high-temperature dust filtration because of their unique advantages such as high filtration efficiency,as well as high temperature stability,particle loss resistance,corrosion resistance and durability.This paper mainly introduced several common preparation techniques of porous ceramics,including the traditional organic foam impregnation method,foaming method,in-situ combustion method,pore-forming method and other new methods such as the template method,gel injection molding method,freeze-drying method,multi-component co-precipitation method and hydrogel method.The principle,advantages and disadvantages of these preparation technologies and their research status were described.The application of these technologies in the field of high temperature dust filtration was briefly reviewed.Finally,the application prospect of the porous ceramics in the field of high temperature dust filtration was prospected.展开更多
[ Objective] To explore the effect of expansion temperature on the release of seven kinds of Hoffmann components （CO, NNK, NH3, HCN,, BaP, crotonaldehyde and phenol） from the mainstream smoke of cigarette. [ Method]...[ Objective] To explore the effect of expansion temperature on the release of seven kinds of Hoffmann components （CO, NNK, NH3, HCN,, BaP, crotonaldehyde and phenol） from the mainstream smoke of cigarette. [ Method] The release amount of seven kinds of Hoffmann com-ponents from the mainstream smoke of cigarettes which were prepared from the cut tobacco treated under different expansion temperatures was de-termined. [ Result] Under the same expansion model, the temperature change produced certain impact on the release amount of NH~, phenol and BAP, while had no significant influence on that of CO, NNK, HCN and crotonaldehyde; under CO2 expansion model, the release amount of seven Hoffmann components was small; the reduction of expansion temperature was good for lowering the harmful index of cigarette to a certain extent. [ Conclusion] The study provides basis for optimizing the technical parameters of producinq less harmful cigarette.展开更多
文摘Aim: To analyse the possible effect of seasonal variation on semen parameters. Methods: The participants consisted of 1688 men attending the andrology laboratory between 1991 and 1997 for reduced fertility in the couple. Semen analysis was performed according to the WHO manual. The 84 individual months of the study period were each assigned to one of the three groups according to the average monthly outside temperature; Group A (temperature <4.4℃), Group B (4.4℃-13.3℃) and Group C (>13.3℃). Results: When comparing the different sperm parameters, the morphology was significantly better in Group C. However, when the smokers were analysed separately, this difference disappeared and significant seasonal variations were found in sperm density, total sperm count, motility and total motile sperm; they were deteriorated in the warmer season. In non-smokers, no such negative effect of increased temperature was observed. Conclusion: Sperm quality is influenced by seasonal factors. Increased environmental temperature, (maybe also light exposure) has an additional negative effect on the spermato-genesis in smokers, leading to reduced sperm quality in men with borderline fertility.
文摘With the rapid industrialization and urbanization,the demand for air quality management is more and more urgent.High temperature dust filtration is one important environmental management technology.Porous ceramics are used as filter materials in the field of high-temperature dust filtration because of their unique advantages such as high filtration efficiency,as well as high temperature stability,particle loss resistance,corrosion resistance and durability.This paper mainly introduced several common preparation techniques of porous ceramics,including the traditional organic foam impregnation method,foaming method,in-situ combustion method,pore-forming method and other new methods such as the template method,gel injection molding method,freeze-drying method,multi-component co-precipitation method and hydrogel method.The principle,advantages and disadvantages of these preparation technologies and their research status were described.The application of these technologies in the field of high temperature dust filtration was briefly reviewed.Finally,the application prospect of the porous ceramics in the field of high temperature dust filtration was prospected.
文摘[ Objective] To explore the effect of expansion temperature on the release of seven kinds of Hoffmann components （CO, NNK, NH3, HCN,, BaP, crotonaldehyde and phenol） from the mainstream smoke of cigarette. [ Method] The release amount of seven kinds of Hoffmann com-ponents from the mainstream smoke of cigarettes which were prepared from the cut tobacco treated under different expansion temperatures was de-termined. [ Result] Under the same expansion model, the temperature change produced certain impact on the release amount of NH~, phenol and BAP, while had no significant influence on that of CO, NNK, HCN and crotonaldehyde; under CO2 expansion model, the release amount of seven Hoffmann components was small; the reduction of expansion temperature was good for lowering the harmful index of cigarette to a certain extent. [ Conclusion] The study provides basis for optimizing the technical parameters of producinq less harmful cigarette.
基金financial support by the National Natural Science Foundation of China(No.52206180)the Fundamental Research Funds for the Central Universities,China(No.WK2320000050)。
