For assisted reproduction technologies （ART）, numerous techniques were developed to isolate spermatozoa capable of fertilizing oocytes. While early methodologies only focused on isolating viable, motile spermatozoa,...For assisted reproduction technologies （ART）, numerous techniques were developed to isolate spermatozoa capable of fertilizing oocytes. While early methodologies only focused on isolating viable, motile spermatozoa, with progress of ART, particularly intracytoplasmic sperm injection （ICSI）, it became clear that these parameters are insufficient for the identification of the most suitable spermatozoon for fertilization. Conventional sperm preparation techniques, namely, swim-up, density gradient centrifugation and glass wool filtration, are not efficient enough to produce sperm populations free of DNA damage, because these techniques are not physiological and not modeled on the stringent sperm selection processes taking place in the female genital tract. These processes only allow one male germ cell out of tens of millions to fuse with the oocyte. Sites of sperm selection in the female genital tract are the cervix, uterus, uterotubal junction, oviduct, cumulus oophorus and the zona pellucida. Newer strategies of sperm preparation are founded oni （i） morphological assessment by means of＇motile sperm organelle morphological examination （MSOM E）＇; （ii） electrical charge; and （ili） molecular binding characteristics of the sperm cell. Whereas separation methods based on electrical charge take advantage of the sperm＇s adherence to a test tube surface or separate in an electrophoresis, molecular binding techniques use Annexin V or hyaluronic acid （HA） as substrates. Techniques in this category are magnet-activated cell sorting, Annexin V-activated glass wool filtration, flow cytometry and picked spermatozoa for ICSI （PICSI） from HA-coated dishes and HA-containing media. Future developments may include Raman microspectrometry, confocal light absorption and scattering spectroscopic microscopy and polarization microscopy.展开更多
European companies rely on advanced manu- facturing technologies （AMTs） in order to succeed in an environment of high labour costs, increasing competition and rising customer expectations. AMT implementation is ofte...European companies rely on advanced manu- facturing technologies （AMTs） in order to succeed in an environment of high labour costs, increasing competition and rising customer expectations. AMT implementation is often a high-risk investment. Many companies experience a misalignment between the installed functionality and pro- duction needs. There is a need for decision support in order to take into account all possible advantages and disad- vantages of the technology implementation, and ensure that the technology meets the requirements of the production processes. In this article, a differentiated technology justi- fication approach is introduced. The approach suggests a combination of strategic, financial and risk justification methods. The recommended number and type of methods depend on the integration level of the technical system under consideration, ranging from stand-alone machines to large and integrated production systems. The approach was developed based on a literature review and a case study. The application of the approach was presented in a case where several types of pipe bending technology were evaluated.展开更多
文摘For assisted reproduction technologies （ART）, numerous techniques were developed to isolate spermatozoa capable of fertilizing oocytes. While early methodologies only focused on isolating viable, motile spermatozoa, with progress of ART, particularly intracytoplasmic sperm injection （ICSI）, it became clear that these parameters are insufficient for the identification of the most suitable spermatozoon for fertilization. Conventional sperm preparation techniques, namely, swim-up, density gradient centrifugation and glass wool filtration, are not efficient enough to produce sperm populations free of DNA damage, because these techniques are not physiological and not modeled on the stringent sperm selection processes taking place in the female genital tract. These processes only allow one male germ cell out of tens of millions to fuse with the oocyte. Sites of sperm selection in the female genital tract are the cervix, uterus, uterotubal junction, oviduct, cumulus oophorus and the zona pellucida. Newer strategies of sperm preparation are founded oni （i） morphological assessment by means of＇motile sperm organelle morphological examination （MSOM E）＇; （ii） electrical charge; and （ili） molecular binding characteristics of the sperm cell. Whereas separation methods based on electrical charge take advantage of the sperm＇s adherence to a test tube surface or separate in an electrophoresis, molecular binding techniques use Annexin V or hyaluronic acid （HA） as substrates. Techniques in this category are magnet-activated cell sorting, Annexin V-activated glass wool filtration, flow cytometry and picked spermatozoa for ICSI （PICSI） from HA-coated dishes and HA-containing media. Future developments may include Raman microspectrometry, confocal light absorption and scattering spectroscopic microscopy and polarization microscopy.
文摘European companies rely on advanced manu- facturing technologies （AMTs） in order to succeed in an environment of high labour costs, increasing competition and rising customer expectations. AMT implementation is often a high-risk investment. Many companies experience a misalignment between the installed functionality and pro- duction needs. There is a need for decision support in order to take into account all possible advantages and disad- vantages of the technology implementation, and ensure that the technology meets the requirements of the production processes. In this article, a differentiated technology justi- fication approach is introduced. The approach suggests a combination of strategic, financial and risk justification methods. The recommended number and type of methods depend on the integration level of the technical system under consideration, ranging from stand-alone machines to large and integrated production systems. The approach was developed based on a literature review and a case study. The application of the approach was presented in a case where several types of pipe bending technology were evaluated.
