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51.
Analysis of variance, analysis of covariance, correlation coefficient, multiple correlation, and partial correlation coefficient
statistical tests were applied to Cs, Cr, Co, Fe, Rb, Sc, Se, and Zn content in human ovaries in order to evaluate statistically
the possible relationships between these trace elements at: the ovary as an organ, each ovarian phase separately, each morphological
part independent of the ovarian phase, and between cortex and medulla within the ovarian phases. The element Cs seems to have
a homogenous distribution between cortex and medulla within reproductive and menopausal phase. Zinc shows a trend to have
an antagonistic relation with Cs, Cr, Co, and Fe during fetal and reproductive phases and not during menopausal phase. The
relationship between Zn and Cs when Fe is kept constant could be used as a tool for the decontamination of the ovary from
an abnormal Cs content or for the inhibition of the accumulation of the same element to the ovarian tissue. 相似文献
52.
James K. Friel Claude Mercer Wayne L. Andrews Brian R. Simmons Simon E. Jackson 《Biological trace element research》1996,54(2):135-142
Contamination in a trace element laboratory can come from a variety of sources, including laboratory gloves. Therefore, vinyl
and latex gloves were obtained from as many manufacturers as would supply gloves. These gloves were either prepared for acid-washing
and subsequent soaking in an acid solution, or immersed in an acid solution for a duration of either 1 min or 1 h. Incubation
washes were analyzed for a variety of trace elements by flame atomic abosrption spectroscopy (AAS) or inductively coupled
mass spectrometry (ICP-MS). Results indicated that only three brands of vinyl gloves were acceptable for use in a trace element
laboratory, whereas others had contamination of different elements. Latex gloves contained such high levels of biologically
important elements that they were not considered suitable for routine trace element work. Vinyl gloves of choice should be
routinely acid-washed before use in a trace element laboratory. 相似文献
53.
Trace elements and lipid peroxidation in 26 patients with chronic renal failure treated with hemodialysis and 25 healthy subjects
were observed. Both plasma and erythrocyte trace elements and plasma malon dialdehyde (MDA) were examined immediately before
and after hemodialysis. Increased levels of plasma Cu, MDA, and erythrocyte Pb, Mn, Zn, and a significantly decreased plasma
Se, Zn and erythrocyte Se were found in patients before hemodialysis. After a single hemodialysis, erythrocyte Mn, Cu, Zn,
and plasma Cu, Al, and MDA were significantly increased whereas both plasma and erythrocyte Se were lower in patients than
in healthy subjects. The level of MDA was not significantly changed during the single hemodialysis. Both plasma and erythrocyte
Zn levels and plasma Cu and Al were significantly higher after hemodialysis than before hemodialysis. In conclusion, levels
of trace elements are altered by hemodialysis, which may increase patient susceptibility to lipid peroxidation in uremia. 相似文献
54.
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56.
Analyses of dental function are an essential component of the study of human evolution. However, with few exceptions, they have utilized the traditional analogizing method of comparative anatomy, and have assumed rather than demonstrated that proposed adaptive characters confer a performance benefit. Since food reduction is a mechanical process, it is appropriate to measure performance using mechanical parameters, specifically the ability of a given morphology to induce failure in food particle by either of the two major regimes: crush and shear, corresponding to simple stresses (tensile and compressive) and shear stress, respectively. We apply finite elements stress analysis to model the relationship between the angulation of the intercuspal occlusal surfaces in a “puncture crushing” mode of mastication. On the basis of morphological data acquired from sectioned great ape molars, we have predicted the nature, magnitude and distribution of stress in a standard food particle by models representing each morphotype. Results indicate that the blunt-cusped molars ofHomo, the gradually-sloping supporting (buccal) cusps but high-angled guiding (lingual) cusps of the lower molars ofPan, and the high angled occlusal surfaces ofGorillaare all more likely to fracture small food particles by shear, while the gradually sloping occlusal surfaces ofPongomolars are more likely to break them down by “crush”. Mechanisms of food failure induced by molars ofPanandHomowill vary according to the orientation of the tooth–food contacting surfaces, which in turn will vary according to the size of the food particle. These genera may be able to break food down either by shear or by “crush”. 相似文献
57.
三棱栎群落的区系成分初步研究 总被引:7,自引:3,他引:4
根据三棱区栎群落的野外调查结果,分析了该落的区系成分。热带及亚热带区系成分占很大的比重(占总种数90.25%),其中印度-马来西亚成分占有绝对优势(占41.46%),滇、顷、老、泰、越周边地区的区系成分次之(共占29.27%),与热带非洲有微弱联系,但与热带大洋洲与美洲并无联系。这就在该群落区系成分分析的基础上有力地支持Kevin C.Nixon和William L.Crepet的论点:三棱栎的独 相似文献
58.
Paul A. Stevenson Hans-Joachim Pflüger Manfred Eckert Jürgen Rapus 《Cell and tissue research》1994,275(2):299-308
Using a well characterized anti-serum, the distribution of octopamine-like immunoreactive neurones is described in the locust seventh abdominal (A7) and terminal ganglia (TG), which are associated with genital organs. Apart from 4 paired ventral somata occasionally observed in the TG, all labelled cells could be identified as efferent dorsal- and ventral unpaired median (DUM/VUM) neurones by virtue of the characteristic large size and position of their somata, projections of their primary neurites in DUM-cell tracts, and bifurcating axons which arise from dorsal T-junctions and enter peripheral nerves. For the examined ganglia our data indicate that the whole population of efferent DUM and VUM-cells, defined here as progeny of the segment specific unpaired median neuroblast with peripheral axons, are octopaminergic, and that equal numbers of these cells occur in both sexes: 8 in A7 and 11 in TG. Sex-specific differences are probably restricted to the axonal projections of 5 octopamine-like immunoreactive DUM-somata in A7, and 5 in TG, which in females project into their segment specific sternal nerves, but in males into the genital nerve of the TG. Numerous intersegmentally projecting octopamine-like immunoreactive fibres traverse both ganglia. The majority probably stem from previously described octopamine-like immunoreactive neurones in the thoracic and suboesophageal ganglia. 相似文献
59.
60.
Durosinmi M. A. Ojo J. O. Oluwole A. F. Ononye A. F. Akanle O. A. Spyrou N. M. 《Biological trace element research》1994,(1):357-361
The concentrations of a number of elements are determined in the plasma and erythrocytes of 21 Nigerians (11 females, 10 males)
with symptomatic affective disorders (11 depressives, 10 manics) and in 40 normal controls using proton-induced X-ray emission
(PIXE) analysis. The study shows that there is significant elevation of plasma K and Zn, as well as the erythrocyte S in the
patients relative to the controls. The plasma and erythrocyte Cu, and the erythrocyte P, Ca, Fe, and Zn are significantly
lower in the patients compared to the controls. However, the plasma levels of Ca, S, Fe, and Br are similar in both the patients
and the controls. Similarly, the concentrations of K, Br, and Rb show no significant difference in the erythrocytes of patients
and controls. 相似文献