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11.
Ortiz RE Ortiz AC Gajardo G Zepeda AJ Parraguez VH Ortiz ME Croxatto HB 《American journal of primatology》2005,66(3):233-244
Few reports on the reproductive physiology of Cebus apella have been published. In this study we characterized menstrual cycle events by means of vaginal cytology, ultrasonography (US), and hormonal measurements in serum during three consecutive cycles in 10 females, and assessed the probability that ovulation would occur in the same ovary in consecutive cycles in 18 females. The lengths and phases of the cycles were determined according to vaginal cytology. Taking the first day of endometrial bleeding as the first day of the cycle, the mean cycle length +/- SEM was 19.5+/-0.4 days, with follicular and luteal phases lasting 8.2+/-0.2 and 11.3+/-0.4 days, respectively. The follicular phase included menstruation and the periovulatory period, which was characterized by the presence of a large number of superficial eosinophilic cells in the vaginal smear. The myometrium, endometrium, and ovaries were clearly distinguished on US examination. During each menstrual cycle a single follicle was recruited at random from either ovary. The follicle grew from 3 mm to a maximum diameter of 8-9 mm over the course of 8 days, in association with increasing estradiol (E(2)) serum levels (from 489+/-41 to 1600+/-92 pmol/L). At ovulation, the mean diameter of the dominant follicle usually decreased by >20%, 1 day after the maximum E(2) level was reached. Ovulation was associated with an abrupt fall in E(2), a decreased number of eosinophilic cells, the presence of leukocytes and intermediate cells in the vaginal smear, and a progressive increase in progesterone (P) levels that reached a maximum of 892+/-65 nmol/L on days 3-6 of the luteal phase. The menstrual cycle of Cebus apella differs in several temporal and quantitative aspects from that in humans and Old World primates, but it exhibits the same correlations between ovarian endocrine and morphologic parameters. 相似文献
12.
Andrea P. Castillo‐Monroy Matthew A. Bowker Fernando T. Maestre Susana Rodríguez‐Echeverría Isabel Martinez Claudia E. Barraza‐Zepeda Cristina Escolar 《植被学杂志》2011,22(1):165-174
Questions: To what degree do biological soil crusts (BSCs), which are regulators of the soil surface boundary, influence associated microbial communities? Are these associations important to ecosystem functioning in a Mediterranean semi‐arid environment? Location: Gypsum outcrops near Belmonte del Tajo, Central Spain. Methods: We sampled a total of 45 (50 cm × 50 cm) plots, where we estimated the cover of every lichen and BSC‐forming lichen species. We also collected soil samples to estimate bacterial species richness and abundance, and to assess different surrogates of ecosystem functioning. We used path analysis to evaluate the relationships between the richness/abundance of above‐ and below‐ground species and ecosystem functioning. Results: We found that the greatest direct effect upon the ecosystem function matrix was that of the biological soil crust (BSC) richness matrix. A few bacterial species were sensitive to the lichen community, with a disproportionate effect of Collema crispum and Toninia sedifolia compared to their low abundance and frequency. The lichens Fulgensia subbracteata and Toninia spp. also had negative effects on bacteria, while Diploschistes diacapsis consistently affected sensitive bacteria, sometimes positively. Despite these results, very few of the BSC effects on ecosystem function could be ascribed to changes within the bacterial community. Conclusion: Our results suggest the primary importance of the richness of BSC‐forming lichens as drivers of small‐scale changes in ecosystem functioning. This study provides valuable insights on semi‐arid ecosystems where plant cover is spatially discontinuous and ecosystem function in plant interspaces is regulated largely by BSCs. 相似文献
13.
Facile Metal Coordination of Active Site Imprinted Nitrogen Doped Carbons for the Conservative Preparation of Non‐Noble Metal Oxygen Reduction Electrocatalysts 下载免费PDF全文
Asad Mehmood Jonas Pampel Ghulam Ali Heung Yong Ha Francisco Ruiz‐Zepeda Tim‐Patrick Fellinger 《Liver Transplantation》2018,8(9)
Iron‐ or cobalt‐coordinated heteroatom doped carbons are promising alternatives for Pt‐based cathode catalysts in polymer‐electrolyte fuel cells. Currently, these catalysts are obtained at high temperatures. The reaction conditions complicate the selective and concentrated formation of metal–nitrogen active sites. Herein a mild procedure is introduced, which is conservative toward the carbon support and leads to active‐site formation at low temperatures in a wet‐chemical metal‐coordination step. Active‐site imprinted nitrogen doped carbons are synthesized via ionothermal carbonization employing Lewis‐acidic Mg2+ salt. The obtained carbons with large tubular porosity and imprinted N4 sites lead to very active catalysts with a half‐wave potential (E1/2) of up to 0.76 V versus RHE in acidic electrolyte after coordination with iron. The catalyst shows 4e? selectivity and exceptional stability with a half‐wave potential shift of only 5 mV after 1000 cycles. The X‐ray absorption fine structure as well as the X‐ray absorption near edge structure profiles of the most active catalyst closely match that of iron(II)phthalocyanine, proving the formation of active and stable FeN4 sites at 80 °C. Metal‐coordination with other transition metals reveals that Zn–Nx sites are inactive, while cobalt gives rise to a strong performance increase even at very low concentrations. 相似文献
14.
Jessica AB van Nies Rute B Marques Stella Trompet Zuzana de Jong Fina AS Kurreeman Rene EM Toes J Wouter Jukema Tom WJ Huizinga Annette HM van der Helm-van Mil 《Arthritis research & therapy》2010,12(2):R38
Introduction
Recently an association between a genetic variation in TRAF1/C5 and mortality from sepsis or cancer was found in rheumatoid arthritis (RA). The most prevalent cause of death, cardiovascular disease, may have been missed in that study, since patients were enrolled at an advanced disease stage. Therefore, we used an inception cohort of RA patients to investigate the association between TRAF1/C5 and cardiovascular mortality, and replicate the findings on all-cause mortality. As TRAF1/C5 associated mortality may not be restricted to RA, we also studied a large cohort of non-RA patients. 相似文献15.
16.
Background
Burkholderia pseudomallei is a saprophyte in tropical environments and an opportunistic human pathogen. This versatility requires a sensing mechanism that allows the bacterium to respond rapidly to altered environmental conditions. We characterized a two-component signal transduction locus from B. pseudomallei 204, mrgR and mrgS, encoding products with extensive homology with response regulators and histidine protein kinases of Escherichia coli, Bordetella pertussis, and Vibrio cholerae. 相似文献17.
AB Johan Groeneveld 《BMC anesthesiology》2007,7(1):1-8
We have developed a two-step procedure for preparing the skin before peripheral venous catheter (PVC) insertions. This procedure involves two successive swabbings with wipes soaked in alcoholic antiseptic. We investigated whether this two-step procedure was as effective and safe as the standard four-step procedure – washing with detergent, rinsing, drying, applying antiseptic – by carrying out a multicentre randomised equivalence study comparing the frequency of precursor signs of infection at the site of insertion for the two skin preparation procedures. The study was carried out over an eight-month period, and 248 PVC insertion sites were evaluated. The two-step procedure was used for 130 subjects and the standard procedure for 118. Taking into account all the confounding factors predisposing patients to the complications studied, the characteristics of the two groups of patients were found to be similar, with no significant differences noted. The incidence of precursor signs of infection was 11 % 24 hours after PVC insertion (27/248), 25 % at 48 hours (50/203) and at 29 % at 72 hours (34/119). Eleven patients had complications necessitating the withdrawal of the PVC: sensitivity of the insertion site, with redness and/or slight swelling and/or a palpable venous cord. No major complications were observed in this study. The frequency of local complications associated with PVCs reported in this study, whether simple or severe, was not affected by the skin preparation procedure used for PVC insertion (two-step or four-step procedure). 相似文献
18.
Carlos Felipe Bosa Leopoldo Cruz‐López Cristina Silvia Zepeda‐Cisneros Javier Valle‐Mora Karina Guillén‐Navarro Pablo Liedo 《Insect Science》2016,23(1):105-116
We compared the calling and mating behavior and volatile release of wild males Anastrepha ludens (Loew) with males from 4 mass‐reared strains: (i) a standard mass‐reared colony (control), (ii) a genetic sexing strain (Tap‐7), (iii) a colony started from males selected on their survival and mating competitiveness abilities (selected), and (iv) a hybrid colony started by crossing wild males with control females. Selected and wild males were more competitive, achieving more matings under field cage conditions. Mass‐reared strains showed higher percentages of pheromone calling males under field conditions except for Tap‐7 males, which showed the highest percentages of pheromone calling males under laboratory cage conditions. For mature males of all strains, field‐cage calling behavior increased during the last hour before sunset, with almost a 2 fold increase exhibited by wild males during the last half hour. The highest peak mating activity of the 4 mass‐reared strains occurred 30 min earlier than for wild males. By means of solid phase microextraction (SPME) plus gas chromatography‐mass spectrometry (GC‐MS), the composition of volatiles released by males was analyzed and quantified. Wild males emitted significantly less amounts of (E,E)‐α‐farnesene but emitted significantly more amounts of (E,E)‐suspensolide as they aged than mass‐reared males. Within the 4 mass‐reared strains, Tap‐7 released significantly more amounts of (E,E)‐α‐farnesene and hybrid more of (E,E)‐suspensolide. Differences in chemical composition could be explained by the intrinsic characteristics of the strains and the colony management regimes. Characterization of calling behavior and age changes of volatile composition between wild and mass‐reared strains could explain the differences in mating competitiveness and may be useful for optimizing the sterile insect technique in A. ludens. 相似文献
19.
Targeted unlabeled multiple reaction monitoring analysis of cell markers for the study of sample heterogeneity in isolated rat brain cortical microvessels 下载免费PDF全文
David Gomez‐Zepeda Catarina Chaves Méryam Taghi Philippe Sergent Wang‐Qing Liu Cérina Chhuon Michel Vidal Martin Picard Elizabeth Thioulouse Isabelle Broutin Ida‐Chiara Guerrera Jean‐Michel Scherrmann Yannick Parmentier Xavier Decleves Marie‐Claude Menet 《Journal of neurochemistry》2017,142(4):597-609
20.