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121.
D. H. LEWIS 《The Journal of eukaryotic microbiology》1975,22(3):344-352
SYNOPSIS. The ultrastructure of promastigotes of 4 reptilian isolates of Leishmania grown in culture, is described. One mammalian isolate of Leishmania is also examined for comparison. No differences in the basic ultrastructure of these strains are apparent; neither is there any significant digression from the organization described for other trypanosomatids. It appears, however, that the numbers of subpellicular microtubules are of potential use in taxonomy, and that differences in the spacing of these organelles exist between reptilian and mammalian forms. In addition, an attempt is made to clarify aspects of attachment of the flagellum to the subpellicular tubule network, and to the anterior face of the kinetoplast. Finally, the formation of multivesiculate bodies from the Golgi apparatus is described, together with some features of dividing forms. 相似文献
122.
Takachika Hiroi Kazuo Fukushima Ikuo Kantake Yuji Namiki Tadashi Ikeda 《FEMS microbiology letters》1992,96(2-3):193-198
Adherence of 3H-labelled cells of Streptococcus gordonii and Streptococcus milleri to artificial pellicles prepared from saliva supplemented with glucosyltransferases from mutants streptococci was examined using a new assay for sucrose-dependent cell-to-pellicle attachment. Results indicate that S. gordonii, but not S. milleri, could attach tightly to hydroxylapatite surfaces through de novo glucan synthesis by mutants streptococcal glucosyltransferases present in the experimental salivary pellicles. 相似文献
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Attachment theory is a useful lens through which to examine both perceptions and selection of companion animals. Study 1 compared perceptions of dogs and cats, and found that dogs were perceived as having more positive relationship qualities and secure attachment-related characteristics, whereas cats were perceived as having more negative relationship qualities and avoidant attachment-related characteristics. In addition, people perceived relationships with dogs to involve less avoidance and less anxiety relative to relationships with people. In study 2, which built on the findings of study 1, attachment avoidance was negatively associated with wanting to own a pet, whereas attachment anxiety was positive associated with wanting to own a pet. These attachment dimensions were not associated with wanting to own a dog, but lower avoidance and higher anxiety were associated with wanting to own a cat. Study 3 was a longitudinal study of SPCA-type shelter visitors (510 participants, with 169 reporting a recent pet adoption). Lower attachment anxiety predicted recently adopting a dog rather than a cat, though neither anxiety nor avoidance predicted adopting a cat. Individuals who wanted a pet in order to facilitate human relationships were more likely to adopt a dog than a cat. Those high in attachment avoidance reported turning to their pet as a replacement for human companionship, and those high in attachment anxiety reported feeling more concern about their pets requiring more attention. Attachment anxiety and avoidance may influence the decision whether or not to adopt a pet, as well as the motivation underlying the adoption choice. Attachment also may influence the type of pet chosen (i.e., dog versus cat). In addition, attachment may influence the nature of the human–animal relationship, such as the time spent together, and the security felt regarding the relationship. 相似文献
126.
Pet ownership is associated with both positive and negative emotions. Given that not everyone responds to pet care in a stressful way, perceptions of companion animals may play a role in how owners respond to them. In this study, we explored the relationship between pet ownership and perceived stress among Chinese pet owners. We also examined the effect of care practices and perceptions of pets on perceived stress. A total of 288 Hong Kong Chinese, adult pet owners, aged 18 to 70 years, were recruited. Participants were surveyed using a self-administered questionnaire covering demographics, pet ownership background, pet attachment, and perceived stress. Regression analyses were performed to examine pet attachment in different demographic groups and its relationship with perceived stress. Moderation and mediation analyses were performed to elucidate their underlying mechanisms. After adjusting for demographics and pet ownership background, greater attachment to a pet was associated with lower stress in owners. The perception of pets as family members minimized the stressful burden of pet care. More time spent caring for a pet increased attachment to that animal which in turn reduced stress in owners. The findings suggest attachment to companion animals and the perception of them as family members can help manage and reduce stress in owners. 相似文献
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Enhanced development of mouse single blastomeres into blastocysts via the simultaneous inhibition of TGF‐β and ERK pathways in microdroplet culture
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Farshid Yekani Mahnaz Azarnia Fereshteh Esfandiari Seyedeh‐Nafiseh Hassani Hossein Baharvand 《Journal of cellular biochemistry》2018,119(9):7621-7630
Optimization of an in vitro culture that supports blastocyst (BL) development from single blastomeres (SBs) is essential to generate additional embryos for farm animals and humans and unravel the mechanisms that underlie totipotency. In this study, we have examined BL development from SBs that were derived from 2‐cell and 4‐cell mouse embryos in different media. Moreover, BLs were assessed for inner cell mass (ICM) by staining with Oct4. We found that BL development was improved in a lower volume of medium (1 µL) compared with a higher volume (5 µL). Furthermore, the supplementation of medium with the inhibitors of ERK1/2 and TGFβ (R2i) signaling pathways in 1 µL droplets of T6 medium improved BL development. The co‐culture of SBs with intact embryos in the presence of R2i showed more BL development and ICM to trophectoderm cell number ratio in comparison with SB culture and SB group culture. We also observed reduced total cell number, ICM, and trophectoderm cell numbers in all of the SB culture conditions versus intact embryo development. These findings might facilitate the successful generation of additional embryos for biomedical applications and elucidate the mechanisms that underlie totipotency. 相似文献
129.
Analysis of Vibrio seventh pandemic island II and novel genomic islands in relation to attachment sequences among a wide variety of Vibrio cholerae strains
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Tuan Hai Nguyen Tho Duc Pham Naomi Higa Hanako Iwashita Taichiro Takemura Makoto Ohnishi Kouichi Morita Tetsu Yamashiro 《Microbiology and immunology》2018,62(3):150-157
130.
The effect of three carbohydrate-digesting enzymes, β-glucuronidase, lyticase and α-mannosidase and three proteolytic enzymes,
α-chymotrypsin, papain and pronase E, on the strength of conidial attachment ofLemonniera aquatica andMycoentrospora filiformis was determined using the LH_Fowler cell Adhesion Measurement Module. Carbohydrate-digesting enzyme treatments showed significant
differences in number of attached and detached, conidia versus control samples; little or no effect was observed for the proteolytic
enzymes. Scanning and transmission electron microscopy showed different degrees of mucilage digestion by the carbohydrate-digesting
enzymes on the germ hyphae, hyphae subtending appressoria, and appressoria of the two species. The loss of mucilage integrity
and decrease in mucilage thickness were more pronounced on the hyphal sheaths than on the appressorial sheaths. Lyticase caused
the most severe damage to the mucilage and cytoplasm of both fungi, particularlyL. aquatica. β-Glucuronidase and α-mannosidase exhibited more effective mucilage digestion onM. filiformis than onL. aquatica. Results indicate that the mucilage of the two species is mainly polysaccharide, containing more β-1,3-glucans than β-glucuronide
and α-mannosyl residues. Variability of mucilage composition exists between these species and also between different structures
of the same fungus. 相似文献