首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 281 毫秒
1.
The responses of intestinal tissues to ionizing radiation can be described by comparing irradiated cell populations qualitatively or quantitatively with corresponding controls. This paper describes quantitative data obtained from resin-embedded sections of neutron-irradiated mouse small intestine at different times after treatment. Information is collected by counting cells or structures present per complete circumference. The data are assessed by using standard statistical tests, which show that early mitotic arrest precedes changes in goblet, absorptive, endocrine and stromal cells and a decrease in crypt numbers. The data can also produce ratios of irradiated: control figures for cells or structural elements. These ratios, along with tissue area measurements, can be used to summarize the structural damage as a composite graph and table, including a total figure, known as the Morphological Index. This is used to quantify the temporal response of the wall as a whole and to compare the effects of different qualities of radiation, here X-ray and cyclotron-produced neutron radiations. It is possible that such analysis can be used predictively along with other reference data to identify the treatment, dose and time required to produce observed tissue damage.  相似文献   

2.
Two incorrect values were used to calculate the density controlled figures in the article. Specifically, the value of 0.17kWh was used for the amount of electricity used for the conventional drip filter. This value should have been 0.13kWh. Also, the value used for the quantity of water used in the French press was 0.9L when it should have been 0.95L. These errors did not change the resulting relative advantages of the coffee making methods.  相似文献   

3.
Summary Laser UV microirradiation of Chinese hamster interphase cells combined with caffeine post-treatment produced different patterns of chromosome damage in mitosis following irradiation of a small area of the nucleus that may be classified in three categories: I) intact metaphase figures, II) chromosome damage confined to a small area of the metaphase spread, III) mitotic figures with damage on all chromosomes. Category III might be the consequence of a non-localized distortion of nuclear metabolism. By contrast, category II may reflect localized DNA damage induced by microirradiation, which could not be efficiently repaired due to the effect of caffeine. If this interpretation is right, in metaphase figures of category II chromosome damage should occur only at the irradiation site. The effect might then be used to investigate neighbourhood relationships of individual chromosomes in the interphase nucleus.  相似文献   

4.
In the paper, A wide-ranging cellular response to UV damage of DNA by Matthew P. Stokes and Michael J. Comb (Cell Cycle 2008; 7:2097-9), Table 1 was presented incorrectly. Protein classes not previously known to be phosphorylated in response to UV damage of DNA should have been shown in red. The correct table is found below.  相似文献   

5.
Fluctuating asymmetry (FA) of ordinarily bilaterally symmetrical traits in humans has been proposed to indicate developmental anomaly. Recent research has shown that individuals with minimal FA are judged to be attractive, and preferred as sexual partners (Thornhill and Gangestad 1993). Waist-to-hip ratios (WHR) have been also shown to reflect health and reproductive capability of woman and those with low WHRs are judged more attractive and healthy (Singh 1993a,b). The present study examines the relative roles of WHR and FA in female breasts in judgments of female attractiveness, health, and desirability for short-term and long-term relationships. Male college students were asked to judge attractiveness of female figures that differed in WHR (high and low) and breast symmetry (none, low, or high). In the first test, paired comparison method was used in which each figure was paired one at a time with all other figures. In the second test, subjects examined all figures simultaneously, estimated their age, and rated each figure for attractiveness, feminine looks, health, overall degree of body symmetry, and willingness to engage in short- and long-term relationship. Results from both tests show that figures with low WHRs were judged to be more attractive than figures with high WHRs, regardless of their degree of breast asymmetry. The figure with low WHR and symmetrical breasts was judged to be most attractive and youngest of all other figures. It appears that men use both WHR and breast asymmetry in judging attractiveness and being willing to develop romantic relationships. It is proposed that WHR and breast asymmetry may signal different aspects of overall female mate quality.  相似文献   

6.

Background

Most clinical trial publications include figures, but there is little guidance on what results should be displayed as figures and how.

Purpose

To evaluate the current use of figures in Trial reports, and to make constructive suggestions for future practice.

Methods

We surveyed all 77 reports of randomised controlled trials in five general medical journals during November 2006 to January 2007. The numbers and types of figures were determined, and then each Figure was assessed for its style, content, clarity and suitability. As a consequence, guidelines are developed for presenting figures, both in general and for each specific common type of Figure.

Results

Most trial reports contained one to three figures, mean 2.3 per article. The four main types were flow diagram, Kaplan Meier plot, Forest plot (for subgroup analyses) and repeated measures over time: these accounted for 92% of all figures published. For each type of figure there is a considerable diversity of practice in both style and content which we illustrate with selected examples of both good and bad practice. Some pointers on what to do, and what to avoid, are derived from our critical evaluation of these articles' use of figures.

Conclusion

There is considerable scope for authors to improve their use of figures in clinical trial reports, as regards which figures to choose, their style of presentation and labelling, and their specific content. Particular improvements are needed for the four main types of figures commonly used.  相似文献   

7.
A new caryophyllene, named pulicaryenne A ( 1 ), along with four other known caryophyllene derivatives ( 2 , 3 , 4 and 5 ) were isolated from the ethyl acetate extract of aerial parts of Pulicaria vulgaris Gaertn . (Asteraceae). All compounds were isolated for the first time from this species. Compound 2 was identified as a new epimer of a known caryophyllene derivative isolated previously from P. dysenterica. Their structures were established by spectroscopic means including NMR analysis (1D‐ and 2D‐NMR) and ESI‐TOF‐MS. All compounds were evaluated for their anticholinesterase, antityrosinase and cytotoxic activities against two human cell lines (A549 and HeLa). Results showed that compound 5 exhibited the highest cytotoxic effect against A549 and anticholinesterase activity with IC50 values of 8.50±0.75 and 6.45±0.09 μg/mL, respectively. Furthermore, compound 5 showed also an interesting antityrosinase activity with percent inhibition value of 79.0±2.5 % at 50 μg/mL. The bioactivity and drug likeness scores of the isolated compounds 1–5 were calculated using Molinspiration software and discussed. These results may suggest that the five caryophyllene derivatives endowed with good biological properties, which could be used as bioactive alternatives in pharmaceutical preparations.  相似文献   

8.
The human diploid fibroblast culture, WI-38 was analyzed for chromosomal damage after 24 h exposures to benzo(a)pyrene (BP), 3-methylcholanthrene (MCA), n-methyl-n'-nitrosoguanidine (MNNG), 4-nitroquinoline-1-oxide (4NQO), pyrene and caffeine. A low concentration of 4NQO (0.15 micron) and MNNG (1.9 micron) produced breakage and exchange figures. A relatively high concentration of caffeine (1300 micron) caused breakage. The other compounds (BP, MCA and pyrene) caused little or no increase in damage above the control levels. A 1-h pulse exposure of WI-38 cells to BP (40 micron) in the presence of a rat liver homogenate supernate (S-9) resulted in damage significantly greater than the untreated cells or cells treated with BP alone. 4NQO (0.25 micron) produced exchange figures after a similar 1-h exposure, but this effect was eliminated by the S-9. A much higher concentration of caffeine (10,300 micron) was required to cause breakage greater than control levels after a one hour exposure. The results indicate a possible short term in vitro human cell system for distinguishing carcinogens, procarcinogens, and noncarcinogens.  相似文献   

9.
The present work completed the research that we have developed during the last years in the cave. The analysis of the painting matter has been made to recognize the anthropic origin of certain figures, to compare the natural iron oxide deposits with one of the paintings with the purpose of establishing the supply area, and to compare the pictorial matter of the different figures to characterize the technical process of the cave. Nineteen samples were taken, from the painted figures and from natural depots. The analysis made in the C2RMF have confirmed the anthropic origin of two figures and have shown the preparation of different pigments for a same painting.  相似文献   

10.
11.
Shape recognition of natural objects was studied under conditions of tachistoscopic (12 ms) presentation and different degree of noise-like ("rain drops") masking in 15 healthy subjects. Three set of figures were used: halftone, contour and silhouette. For all sets of figures, mean group data reveal a drop of the correct response probability with increase in masking. Recognition of contours was shown to be significantly better than that of halftone and silhouette figures, whereas halftone figures were recognized better than silhouettes. Possible neurophysiological mechanisms of the revealed phenomena and their functional implication are discussed.  相似文献   

12.
The semiological study of a set of rock engravings such as the one in the Haut Atlas would consist in studying the graphic elements within their context to determine their mutual relations, because such relations are meaningful. Some details could be signs to which we could attach a conventional meaning. But, being unable to identify these conventional signs by their meaning, we must look for similarities between the figures themselves. Indeed, the repetition of some relations will provide constitutive elements of the global meaning. Unfortunately, ignoring the relative positions of the figures, I can only give some indications about what such a study should entail. So, I focus on one hand on the attributes of the figures, which are, in any case, identity marks, and on the other hand, on the context of the figures, that is the graphics around the figure, in order to outline the likely semantic field and the actions, actual or symbolic, in which they are involved.  相似文献   

13.
Models for predicting the future course of the AIDS epidemic can be divided into five types: trend extrapolation models, compartment models, models based on the incubation period, comparison models, and models produced by expert committees. To predict the numbers of cases of AIDS in the United Kingdom and in East Anglia and Cambridge a two stage approach was chosen using trend extrapolation for the national case reports followed by reduction in scale to the two localities. The method predicted that about 2700 cases would be reported nationally during 1990 and about 6000 during 1992. The number of people with AIDS expected to present for treatment in East Anglia during 1990 was 48, and during 1992 was 105; for Cambridge the corresponding figures were 20 and 43. These figures with their estimated 95% confidence intervals will be used for planning local services for people with AIDS, and they emphasise the need for preventive action.  相似文献   

14.
Humans are exposed to many carcinogens, but the most significant may be the reactive species derived from metabolism of oxygen and nitrogen. Nitric oxide seems unlikely to damage DNA directly, but nitrous acid produces deamination and peroxynitrite leads to both deamination and nitration. Scavenging of reactive nitrogen species generated in the stomach may be an important role of flavonoids, flavonoids and other plant-derived phenolic compounds. Different reactive oxygen species produce different patterns of damage to DNA bases, e.g., such patterns have been used to implicate hydroxyl radical as the ultimate agent in H(2)O(2)-induced DNA damage. Levels of steady-state DNA damage in vivo are consistent with the concept that such damage is a major contributor to the age-related development of cancer and so such damage can be used as a biomarker to study the effects of diet or dietary supplements on risk of cancer development, provided that reliable assays are available. Methodological questions addressed in this article include the validity of measuring 8-hydroxydeoxyguanosine (8OHdG) in cellular DNA or in urine as a biomarker of DNA damage, the extent of artifact formation during analysis of oxidative DNA damage by gas chromatography-mass spectrometry and the levels of oxidative damage in mitochondrial DNA.  相似文献   

15.
The report of the Resource Allocation Working Party recommended that revenue allocations to health authorities should be based, in part, on national patterns of bed usage and local standardised mortality ratios for conditions aggregated according to the chapters of the International Classification of Diseases (ICD). Similar criteria are now being considered for planning purposes by regions. The extent to which diseases which commonly result in the use of hospital care are also common causes of deaths within their ICD chapter was studied. National utilisation figures show that most beds in ophthalmology, ear, nose, and throat surgery, gynaecology, and consultant dentistry, and an estimated one-third or more of the beds used in general surgery, neurosurgery, and plastic surgery, are used for the treatment of conditions which are uncommon causes of death, both in absolute terms and relative to their ICD chapters. It seems unlikely that the requirements for care of patients with these diseases can be measured simply, either by all-causes mortality statistics, or by the use of mortality statistics ascribed to the ICD chapter which such diseases share with other, more common, causes of death. Consideration needs to be given to the diseases treated by each specialty in deciding whether and how to apply mortality statistics in planning for and funding the specialty.  相似文献   

16.
S Iu Demin 《Tsitologiia》1999,41(1):66-86
Preparations of surface stretched amembranous nuclei and mitotic figures were used for revealing the high order nuclear and chromosomal structures. The preparations were obtained by dropping amembraneous nuclei and mitotic figures suspension in methanol-glacial acetic acid mixture (3:1) on wetted superclean slides. Amembraneous nuclei and mitotic figures were isolated from intact murine and human cells (lines L1210, SK-UT-1B, PHA-stimulated lymphocytes) by means of their 1-5 min prefixational capillary pipetting with freshly prepared 0.018-0.06% Triton X-100 solution in the conditional cultural medium. Stretched amembraneous nuclei and mitotic figures had no features of induced chromatin dispersion and compaction. Stretched interphase amembraneous nuclei showed spatially separated individual structures (thin chromatin fibres, nucleoli, intranuclear bodies), polymorphous pattern of perinucleolar chromatin aggregation and episodically expressed beaded thick chromatin fibres and a chromocenter. The chromomeric pattern of the spread chromosomes of mitotic figures was quite similar but hardly identical with that of G-banding. The stretched prometaphase mitotic figures in all tested cell types always contained loose "residual" nucleoli looking like typical prophase nucleoli as concerns their shape and number per cell (mitotic figure). The majority of chromosomes of stretched mitotic figures and of prophase amembraneous nuclei were attached to the nucleolar material. All tested cell lines showed almost the same variation in number of nucleolus-attached chromosomes, per both prophase amembraneous nucleus and prometaphase mitotic figure. Some chromosomes of stretched mitotic figures were colocated with "residual" nucleoli and looked shortened and strongly condensed. Other chromosomes, locally associated with "residual" nucleoli, were straight and oriented radially to these. Mutual chromosomal arrangements in mitotic cells on smears and in stretched mitotic figures were analogous. Equatorial plates from PBS-washed SK-UT-1B cells displayed a better stretching capacity than those from untreated cells. In the former case metaphase chromosomes were seen more uniformly stretched and well identified after GTG-banding procedure. The number of interchromosomal (mainly telomere-telomeric and telomere-centromeric) connections per stretched mitotic figure (or per stretched prophase amembraneous nucleus) was minimum in late prometaphase, maximum in prophase and early prometaphase, and intermediate in metaphase. The obtained data are discussed in terms of topology and longitudinal heterogeneity of mitotic chromosomes.  相似文献   

17.
Telocytes had been identified as a peculiar stromal cell type implicated in tissue homeostasis and the development and pathophysiology of diseases. Telocyte existed in most organs and tissues in humans and animals. However, few studies have examined telocytes in ApoE gene deficient mice. In our studies, we verified the existence, the morphology and immunohistochemical characteristics of telocytes in critical organs of the ApoE?/? mice. Male adult ApoE?/? mice were selected as an experimental model. Immunohistochemical bio‐markers, such as CD34, CD117, CD28, Vimentin and PDGFR‐α were utilized to determine the distribution and morphology of telocytes in the heart, liver and kidney. Telocyte expressed positively for CD34 and CD117, and partial telocyte and telopode expressed positively for PDGFR‐α in heart and liver, but negatively in kidney. Double immunofluorescence assays for CD28/Vimentin, CD34/CD117 and CD34/PDGFR‐α were used to demonstrate the biochemistry speciality of telocytes, respectively. The evidence of telocytes in the ApoE‐/‐ mice is the first step of our sturdy, which aims to demonstrate changes in telocytes in atherosclerosis in this animal model.  相似文献   

18.
The effects of imidacloprid, propargite, and pymetrozine on the common green lacewing, Chrysoperla carnea (Stephens) were investigated in the laboratory, using the IOBC-system and the life table response experiment. Residual glass plate bioassays were carried out using two-day-old larvae at the Iranian maximum field recommended rate of each commonly used pesticide. All three tested pesticides produced significant adverse effects on pre-imaginal survival (p < 0.01). Imidacloprid had no significant effect on fecundity, but propargite and pymetrozin caused significant reductions (p < 0.05). According to the IOBC classification, imidacloprid was found to be harmless (E = 27.44%); propargite (E = 49.78%) and pymetrozine (E = 66.9%) were slightly harmful. Life table assays revealed that imidacloprid and propargite had no significant effects on the intrinsic rate of natural increase, while pymetrozine caused a 34% reduction in r m value (p < 0.05). Propargite was non-toxic to C. carnea under the tested conditions. In the case of imidacloprid, using a glass plate as test substrate led to␣underestimation of its effects. The life table assay showed more adverse effects of pymetrozine than the IOBC method.  相似文献   

19.
A common feature of several psychiatric disorders is the attentional impairment. eEF2K ?/?, IL1RAPL1 ?/? and SHANK3Δ11 ?/? mice were used as animal models consistently linked to changes in synaptic plasticity, learning and memory. All knockout (KO) mice and their corresponding littermates were submitted to the novel object recognition (NOR) and visual object recognition (VOR) tasks. In the NOR, eEF2K?/? mice exhibited a normal performance in terms of mean discrimination index, while SHANK3Δ11?/? and IL1RAPL1 ?/? mice were impaired when a delay of 2 and 24 hours was introduced. Surprisingly, when submitted to VOR, where the two objects were replaced with two shapes delivered from two iPods, all the mutant mice performed worse than those in the NOR. In VOR, the application of motion to different shapes, to increase attention, improved performance in eEF2K ?/? and IL1RAPL1 ?/? but not in SHANK3Δ11 ?/? mice. In SHANK3Δ11 ?/? mice, attentional deficit was also present even if different motions were applied to the same shapes or when these mice were repeatedly exposed for 5 days to the context. Behavioral analysis showed that eEF2K?/? and IL1RAPL1 ?/? mice had a good flexibility tested in the T‐maze. eEF2K?/? showed normal self‐grooming. On the basis of previous literature data indicating that SHANK3Δ11 ?/? showed impaired flexibility and reduced sociability, we identified in this genotype the most exhaustive model showing all the core symptoms of autism spectrum disorder including a heavy visual attention deficit. These findings show the importance of VOR to identify mouse models of autism.  相似文献   

20.
A. C. Irwin 《CMAJ》1976,114(6):539-541
Selected figures from Canadian life tables have been analysed to illustrate one potential use of routinely collected and published data. A plea is made for the inclusion of the fundamentals of demography in undergraduate medical education.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号