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排序方式： 共有625条查询结果，搜索用时 15 毫秒
71.
Demewoz Haile Kenneth H. Brown Christine M. McDonald Hanqi Luo Michael Jarvis Ismael Teta Alex Ndjebayi Guintang Assiene Jules Martial Stephen A. Vosti Reina Engle-Stone 《Nutrients》2022,14(4)
Nutrient reference values (NRVs) for zinc set by several expert groups differ widely and may affect the predicted prevalence of inadequate zinc intake. We examined this possibility using NRVs published by four different authorities and nationally representative dietary intake data collected among children aged 12–59 months and women in Cameroon. Usual zinc intake was estimated from 24 h recall data using the National Cancer Institute method. Prevalences of total zinc intake below the dietary requirement and of “absorbable zinc intake” below the physiological requirement were estimated using NRVs published by the World Health Organization (WHO), US Institute of Medicine (IOM), International Zinc Nutrition Consultative Group (IZiNCG), and European Food Safety Authority (EFSA). The prevalence of inadequate zinc intake ranged from 10% (IZiNCG—physiological requirement, 95% CI 7–13%) to 81% (EFSA—physiological requirement, 95% CI 78–84%) among children and 9% (WHO—physiological requirement, 95% CI 8–11.0%) to 94% (IOM—physiological requirement, 95% CI 92–95%) among women These differences in the prevalence of inadequate intake translated into sizeable differences in the predicted benefit and cost-effectiveness of zinc fortification programs. Depending on the NRVs applied, assessments differ regarding the need for and design of zinc fortification programs. Efforts are needed to harmonize NRVs for zinc. 相似文献
72.
73.
Fernando Clavijo-Coppens Nicolas Ginet Sophie Cesbron Martial Briand Marie-Agns Jacques Mireille Ansaldi 《Viruses》2021,13(5)
Xylella fastidiosa (Xf) is a plant pathogen causing significant losses in agriculture worldwide. Originating from America, this bacterium caused recent epidemics in southern Europe and is thus considered an emerging pathogen. As the European regulations do not authorize antibiotic treatment in plants, alternative treatments are urgently needed to control the spread of the pathogen and eventually to cure infected crops. One such alternative is the use of phage therapy, developed more than 100 years ago to cure human dysentery and nowadays adapted to agriculture. The first step towards phage therapy is the isolation of the appropriate bacteriophages. With this goal, we searched for phages able to infect Xf strains that are endemic in the Mediterranean area. However, as Xf is truly a fastidious organism, we chose the phylogenetically closest and relatively fast-growing organism X. albineans as a surrogate host for the isolation step. Our results showed the isolation from various sources and preliminary characterization of several phages active on different Xf strains, namely, from the fastidiosa (Xff), multiplex (Xfm), and pauca (Xfp) subspecies, as well as on X. albilineans. We sequenced their genomes, described their genomic features, and provided a phylogeny analysis that allowed us to propose new taxonomic elements. Among the 14 genomes sequenced, we could identify two new phage species, belonging to two new genera of the Caudoviricetes order, namely, Usmevirus (Podoviridae family) and Subavirus (Siphoviridae family). Interestingly, no specific phages could be isolated from infected plant samples, whereas one was isolated from vector insects captured in a contaminated area, and several from surface and sewage waters from the Marseille area. 相似文献
74.
Beatriz Bano-Otalora Franck Martial Court Harding David A. Bechtold Annette E. Allen Timothy M. Brown Mino D. C. Belle Robert J. Lucas 《Proceedings of the National Academy of Sciences of the United States of America》2021,118(22)
Mammalian circadian rhythms are orchestrated by a master pacemaker in the hypothalamic suprachiasmatic nuclei (SCN), which receives information about the 24 h light–dark cycle from the retina. The accepted function of this light signal is to reset circadian phase in order to ensure appropriate synchronization with the celestial day. Here, we ask whether light also impacts another key property of the circadian oscillation, its amplitude. To this end, we measured circadian rhythms in behavioral activity, body temperature, and SCN electrophysiological activity in the diurnal murid rodent Rhabdomys pumilio following stable entrainment to 12:12 light–dark cycles at four different daytime intensities (ranging from 18 to 1,900 lx melanopic equivalent daylight illuminance). R. pumilio showed strongly diurnal activity and body temperature rhythms in all conditions, but measures of rhythm robustness were positively correlated with daytime irradiance under both entrainment and subsequent free run. Whole-cell and extracellular recordings of electrophysiological activity in ex vivo SCN revealed substantial differences in electrophysiological activity between dim and bright light conditions. At lower daytime irradiance, daytime peaks in SCN spontaneous firing rate and membrane depolarization were substantially depressed, leading to an overall marked reduction in the amplitude of circadian rhythms in spontaneous activity. Our data reveal a previously unappreciated impact of daytime light intensity on SCN physiology and the amplitude of circadian rhythms and highlight the potential importance of daytime light exposure for circadian health.In mammals, near-24-h (circadian) rhythms in physiology and behavior are orchestrated by a master clock located in the hypothalamic suprachiasmatic nuclei (SCN) (1, 2). The SCN clock generates a circadian rhythm in electrical activity, with neurons significantly more excited during the day (up state) than at night (down state) (3, 4). This endogenous rhythm is synchronized (entrained) to the external 24-h light–dark (LD) cycle via input from the retina (5). Thus, light exposure in the circadian night induces adjustments in circadian phase to ensure that internal time faithfully reflects external (celestial) time. Conceptual and mathematical models of light’s impact on the clock address this ability to reset circadian phase (the basis of entrainment) (6–9). However, there is evidence that another fundamental property of circadian rhythms, their amplitude, may also be influenced by light.It is well established that the amplitude and reliability of 24-h rhythms in some aspects of physiology and behavior can be enhanced by increasing daytime light exposure (10–20). Such effects may be explained by the ability of light to directly engage some of the systems under circadian control (e.g., increasing alertness and body temperature, Tb) (21–23) and thus enhance rhythm amplitude de facto, without impacting the circadian clock itself. However, reports that enhanced daytime light can also lead to higher production of melatonin on the subsequent night, many hours after light exposure has ceased (12, 24–26), pose a challenge to that explanation. The long-lasting nature of that effect raises the possibility that daytime light may have a more fundamental impact on circadian amplitude. We set out here to address this possibility by using laboratory rodents to ask whether increasing daytime irradiance produces persistent improvements in circadian amplitude and whether this can be traced back to changes in the physiological activity of the SCN circadian oscillator itself.A challenge to studying the impact of daytime light exposure in common laboratory models (mice, hamsters, and rats) is that they are nocturnal and employ strategies to avoid light in the day (such as curling up asleep). We therefore used a diurnal rodent, Rhabdomys pumilio (the four-striped mouse) (27–29) which is active through the day in both the laboratory and wild, ensuring good exposure to modulations in daytime light intensity. We find that increasing irradiance across a range equivalent to that from dim indoor lighting to natural daylight enhances the reproducibility and robustness of behavioral and physiological rhythms at the whole-animal level that persist into subsequent free run in constant darkness. This effect is associated with profound differences in the electrophysiological activity of the SCN, with bright daytime light producing persistent increases in SCN excitability and enhancing the amplitude of the circadian variation in spontaneous neuronal activity. 相似文献
75.
Yong Woo Kim Jin Ju Choi Michael J. A. Girard Jean Martial Mari Dong Gyu Choi Ki Ho Park 《Investigative ophthalmology & visual science》2021,62(4)
PurposeTo investigate the change of border tissue configuration during axial elongation in childhood.MethodsFifty-four subjects (108 eyes; age range, 29.3–132.5 months) who had undergone a series of swept-source optical coherence tomography scans at intervals of 6 months or longer were classified into stable axial length (AXL) eyes (n = 55; AXL change of ≤0.36 mm) and elongating AXL eyes (n = 53; AXL change of >0.36 mm). The angle between the Bruch''s membrane opening (BMO) reference plane and the border tissue of Elschnig was defined as the border tissue angle (BTA). The border tissue angle, BMO distance (BMOD) and minimum rim width (MRW) were measured in the temporal and nasal regions.ResultsDuring 15.6 ± 7.2 months of follow-up, the AXL significantly increased from 22.8 ± 1.3 mm to 23.3 ± 1.4 mm (P < 0.001). Changes of border tissue angle and AXL showed a significant correlation only in the temporal region of elongating AXL eyes (r = –0.409; P = 0.002), but not in stable AXL eyes. Both BMOD and nasal MRW significantly increased from 1482.5 ± 153.0 to 1506.1 ± 154.6 µm and from 310.6 ± 83.2 to 324.6 ± 95.6 µm, respectively (all Ps < 0.001). The changes of BMOD and nasal MRW showed a significant positive correlation with changes of AXL in elongating AXL eyes but not in stable AXL eyes.ConclusionsDuring the axial elongation in childhood, temporal border tissue configuration change, BMO enlargement, and nasal peripapillary tissue elevation showed a significant correlation with changes in the AXL. 相似文献
76.
The athlete biological passport (ABP) was implemented by the International Cycling Union (UCI) in 2008. However, this improvement in the fight against doping was preceded with different milestones since 1996. In this paper, a detailed evolution of the ABP from traditional direct (urine) testing for antidoping purposes is presented. A chronological overview of the ABP including earlier non‐disclosed information and contemporary documentation are shown and documented. The strategic development from on‐site competition blood testing, called “health tests”, to the structure of the ABP is explained in this historical overview which provides information to the antidoping community and general public regarding the beginning of blood doping tests. 相似文献
77.
78.
B. Grimaldi Alexandre Bonnin Marie-Paule Fillion Martial Ruat Elisabeth Traiffort Gilles Fillion 《Naunyn-Schmiedeberg's archives of pharmacology》1998,357(4):393-400
We have determined the pharmacological characteristics of the rat 5-ht6 receptor stably expressed in CHO cells. Moreover, using RT-PCR experiments the in vivo expression of the gene encoding this receptor was studied in rat at various embryonic days (ED) starting from ED10 to birth (PN0) and at post-natal days (PN) up to PN36. The pharmacological analysis of the [3H]5-HT binding in stably transfected CHO cells expressing rat 5-ht6 receptors revealed the presence of a single class of high affinity saturable binding sites for 5-HT corresponding to an affinity constant: Kd = 27.2±3.4 nM. This receptor also exhibited a high affinity for a number of typical and atypical antipsychotics, tricyclic antidepressant drugs and ergot alkaloïds. In stably transfected CHO cells, serotonin elicited a potent stimulation of adenylyl cyclase activity which was blocked by antipsychotic and antidepressant drugs. These results confirm the hypothesis that 5-ht6 receptors may correspond to an important target for atypical antipsychotics and reveal an original pharmacological profile for this receptor. The study of the ontogeny of the 5-ht6 mRNA in rat developing brain showed that 5-ht6 mRNA were first detectable with a high level on ED12, slighly decreased up to ED17 and then remained stable at high level until the adult age. The ontogenetic pattern of 5-ht6 mRNA expression appeared to correlate with the occurence of the first cell bodies of serotonergic neurons; the early expression of 5-ht6 mRNA and the fact that this receptor is positively coupled to the production of cAMP may suggest a role for 5-ht6 receptor in the early growth process involving the serotonergic system. 相似文献
79.
J M Heard S Fichelson B Sola M A Martial R Berger B Varet J P Levy 《International journal of cancer. Journal international du cancer》1983,32(2):237-245
A Friend helper virus I-5(F-MuLV) which induces myeloblastic leukemias in mice after a latency of several months, was used to infect long-term bone marrow cultures. From 48 to 71 weeks after in vitro infection, 4/14 cultures gave rise to transplantable malignant myeloblastic cells. These cells were shown to genuinely result from as in vitro transformation of virus-infected normal bone marrow cells. The in vitro transformation reproduced the course of the in vivo disease. It provided unique material for in vitro investigation of the preleukemic stages of long-term leukemogenesis. Successive cellular events were: (1) freezing of the normal myelomonocytic differentiation process; (2) change from factor-dependent to an autonomous growth; (3) acquisition of in vivo tumorigenicity. 相似文献
80.
Kenneth M. Kent Lamberto G. Bentivoglio Peter C. Block Michael J. Cowley Gerald Dorros Arthur J. Gosselin Andreas Gruentzig Richard K. Myler John Simpson Simon H. Stertzer David O. Williams Martial G. Bourassa Sheryl F. Kelsey Katherine M. Detre Suzanne Mullin Eugene Passamani 《The American journal of cardiology》1982,49(4):904