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1.
In vitro liberation of charged gold atoms: autometallographic tracing of gold ions released by macrophages grown on metallic gold surfaces 总被引:2,自引:2,他引:0
The present study demonstrates that cultured macrophages are able to liberate gold ions from metallic gold surfaces, a process
suggested to be called “dissolucytosis”, in a way analogous to the release taking place when metallic implants are placed
in a body. Using the ultra-sensitive autometallographic (AMG) technique, we demonstrate that murine macrophages grown on a
surface of metallic gold liberate gold ions. Ultra-structural AMG reveals that the gold ions are located in an ultra-thin
membrane-like structure, “the dissolution membrane”, intervened between the macrophages and the metal surface. The presence
of AMG silver enhanced gold nanoparticles in the dissolution membrane proves that the release of charged gold atoms takes
place extracellularly. The dissolution membrane is most likely secreted and chemically controlled by the “dissolucytes”, here
macrophages, and the membrane is essential for the dissolution of metal implants and particles, which cannot be phagocytosed.
Our findings support the notion that whenever a metallic gold surface is attacked by dissolucytes, gold ions are liberated
and taken up by surrounding cells. As gold ions can suppress the inflammatory process, it is reasonable to expect that when
dissolucytosis takes place in the living organism the liberated gold ions will cause local immunosuppression. 相似文献
2.
Walter Mertz 《Biological trace element research》1979,1(3):259-270
The application of the concept of a “controlled environment” led to the identification of eight trace elements with a proven
or postulated biological function during this decade. Rigorous reduction of metallic contamination from air, drinking water,
and diet is necessary to reduce exposure to the element under investigation below requirement levels. An essential function
for a trace element is suggested when deficiency is produced, and indepently confirmed, in two or more animal species, and
also when the signs of deficiency are prevented or cured by supplements. As yet, a direct role for the “new trace elements”
in the human organism has not been demonstrated. 相似文献
3.
I. Opatowski 《Bulletin of mathematical biology》1945,7(4):161-180
A mathematical theory applicable to the biological effects of radiations as chain processes is developed. The theory may be
interpreted substantially as a “hit theory” involving the concepts of “sensitive volume” or “target area”. The variability
of the sensitivity of the organism to the radiation and its capacity of recovery between single hits is taken into account.
It is shown that in a continuous irradiation of a biological aggregate in which the effect of each single hit cannot be observed,
recovery and variation of sensitivity are formally equivalent to each other so that a discrimination between these two phenomena
is possible only by discontinuous irradiation or by using different radiation intensities. Methods for the calculation of
the “number of hits” and for the determination of the kinetics of the processes from “survival curves” or similar experimental
data are given. The relation between the recovery and the Bunsen-Roscoe law is discussed. The case in which the injury of
the organism is dependent on the destruction of more than one “sensitive volume” is also considered. 相似文献
4.
Maialen Garmendia Marta Revilla Juan Bald Javier Franco Aitor Laza-Martínez Emma Orive Sergio Seoane Victoriano Valencia Ángel Borja 《Biogeochemistry》2011,106(2):243-263
Eutrophication is a major threat to coastal ecosystems. Within Europe, the Water Framework Directive (WFD) has established
the need of developing methods of assessment. Bulk chlorophyll “a” is used world-wide as an indicator of eutrophication. However,
the size structure of the phytoplankton communities has not been investigated, in detail, in relation to eutrophication pressures.
This study investigates the suitability of fractionated chlorophyll “a” (<10 and >10 μm), as an indicator of eutrophication.
Along the Basque coast (northern Spain) several water bodies, ranging from offshore waters to the heads of the estuaries,
were surveyed during 2008. Physico-chemical conditions and chlorophyll “a” showed a distinct spatial gradient. Trophic richness
increased towards the middle and inner parts of the estuaries, where nutrient inputs, from natural or anthropogenic sources,
together with the residence time of the water are usually higher. In summer, phytoplankton biomass and abundance decreased,
generally, in offshore and coastal waters; in estuaries, they tended to increase. The chlorophyll distribution within the
two size fractions was coherent with the phytoplankton taxonomic composition. In summer, the relative abundance of small-sized
cells (diatoms and non-siliceous taxa) increased. The relationships between size-fractionated chlorophyll and physico-chemical
variables differed, when comparing the offshore and coastal waters, with the estuaries. In the offshore and coastal waters,
a strong seasonality was observed; in estuaries, an important spatial component was found. Fractionated chlorophyll provided
complementary useful information on anthropogenic pressures. However, more research is necessary to utilise this variable
as a tool for ecological status assessment, within the WFD. 相似文献
5.
Forestry is obliged to record as well as maintain and/or enhance biological diversity in forests due to national and international
agreements. Accordingly, it is necessary to work out methodological approaches for the assessment of biodiversity in forests.
In the study presented here, we focus on the total plant species pool (563 vascular plant and bryophyte species) of pine (Pinus sylvestris L.) forests in NE Germany to identify indicators for plant species richness. We distinguished several groups like “herb”,
“grass-like”, “woody”, “endangered”, and “exotic species”, for which we detected indicators for low (class #1), intermediate
(class #2), and high (class #3) species numbers. From a total of 84 species, which were identified by a three-step procedure,
most indicators were found for class #3. Only few indicators have been revealed for intermediate species numbers, i.e. class
#2. With help of Ellenberg’s ecological indicator values and information on the main occurrence in Central European vegetation
types and plant communities, respectively, we characterized the indicator species ecologically. The ecological site preferences
of the indicator species in general reflect the fact that species richness is highest in base-rich, light, and anthropogenically
disturbed pine forests. On the contrary, species-poor forests were revealed by indicators, which mainly occur on acidic sites.
It is concluded that a considerable set of indicators for species richness can help facilitate biodiversity assessments in
forestry and ecosystem restoration practice.
Electronic Supplementary Material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. 相似文献
6.
Inventory, differentiation, and proportional diversity: a consistent terminology for quantifying species diversity 总被引:1,自引:0,他引:1
Almost half a century after Whittaker (Ecol Monogr 30:279–338, 1960) proposed his influential diversity concept, it is time
for a critical reappraisal. Although the terms alpha, beta and gamma diversity introduced by Whittaker have become general textbook knowledge, the concept suffers from several drawbacks. First, alpha
and gamma diversity share the same characteristics and are differentiated only by the scale at which they are applied. However,
as scale is relative––depending on the organism(s) or ecosystems investigated––this is not a meaningful ecological criterion.
Alpha and gamma diversity can instead be grouped together under the term “inventory diversity.” Out of the three levels proposed
by Whittaker, beta diversity is the one which receives the most contradictory comments regarding its usefulness (“key concept”
vs. “abstruse concept”). Obviously beta diversity means different things to different people. Apart from the large variety
of methods used to investigate it, the main reason for this may be different underlying data characteristics. A literature
review reveals that the multitude of measures used to assess beta diversity can be sorted into two conceptually different
groups. The first group directly takes species distinction into account and compares the similarity of sites (similarity indices,
slope of the distance decay relationship, length of the ordination axis, and sum of squares of a species matrix). The second
group relates species richness (or other summary diversity measures) of two (or more) different scales to each other (additive
and multiplicative partitioning). Due to that important distinction, we suggest that beta diversity should be split into two
levels, “differentiation diversity” (first group) and “proportional diversity” (second group). Thus, we propose to use the
terms “inventory diversity” for within-sample diversity, “differentiation diversity” for compositional similarity between
samples, and “proportional diversity” for the comparison of inventory diversity across spatial and temporal scales.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
7.
N. A. Kashulin P. M. Terentyev P. -A. Amundsen V. A. Dauvalter S. S. Sandimirov A. N. Kashulin 《Inland Water Biology》2011,4(3):383-392
The spatial regularities of the accumulation of heavy metals in two ecological morphs of whitefish of the Pasvik River (northern
Fennoscandia) under long-term pollution have been investigated. It was revealed that the accumulation of priority pollutants
(Ni and Cu) in fish declines the further you go from the source of pollution. The concentration of Hg in the tissues of fish
from the Pasvik River was determined for the first time. It was found that metal accumulation depends on the ecological morphs
of the fish, the natural conditions of the waterbodies, and the intensity of pollution. The specific features of heavy-metal
distribution in the “bottom sediment-fish organism” system were determined. These may indicate the heterogeneity of the pollution
processes of the Pasvik system of waterbodies. 相似文献
8.
Yukio Takahata 《Primates; journal of primatology》1982,23(1):1-23
Some dyads of Japanese monkey adult males and females show remarkable spatial proximity and frequent exchanges of social behaviors.
It is suggested that some kind of “affinity” exists between them. Females obtain much unilateral benefit from “proximity effects”;
even lowranking females can dominate high-ranking females as long as they stay nearby their “affinitive” males. Males acquire
female followers in return. Mating relations and female mother-daughter relations play important roles in forming new “affinitive
relations.” Once monkeys have formed “affinitive relations,” however, they seldom mate with each other, as if they were kin-related.
Therefore, the acquisition of female followers appears inconsistent with a male's strategy for reproducing many genes in the
next generation.
This study was financed partly by the Cooperative Research Fund of the Primate Research Institute, Kyoto University. The outline
of this paper has already been published inTakahata (1980b). 相似文献
9.
Personality means suites of correlated behavioural traits, also referred to as “behavioural syndromes” or “personality dimensions”.
Across animal taxa similar combinations of traits seem to prevail, which may have proximate foundation in common neuroendocrine
mechanisms. Hitherto, these have been rarely studied in intact social settings. We investigated personalities of greylag goose
males from a free-roaming flock that shows complex social relationships. In connection with our longitudinal study on the
consistency of behavioural and physiological responses to multiple challenges, we asked whether and how single, personality-related
behavioural traits correlate with each other to form personality dimension(s). We tested whether these dimensions were related
to physiological characteristics that previously showed limited plasticity (heart rate (HR), baseline and stress-induced excreted
immuno-reactive corticosterone (BM), and testosterone metabolites levels) and, furthermore, to age, body measures, and dominance
rank. Principal-components analysis based on behavioural variables revealed two factors: 51.1% of variability was explained
by “aggressiveness” and a further 19.1% by “sociability”. “Aggressiveness” comprised correlated measures of aggression, subordinance,
boldness, vigilance, and proximity to the mate. This “aggressiveness” positively correlated with stress-induced BM levels,
the HR increase during aggressive interactions, and with dominance rank, which may suggest proximate and functional contingencies
of this personality dimension. 相似文献
10.
W. Ernst 《Helgoland Marine Research》1980,33(1-4):301-312
The majority of organic chemicals identified so far in the sea are pesticides and products of technical use; most contain
chlorine. Only a limited amount of the actual pollutant load is detectable because few data for “unconventional ” pollutants
are available. In view of the considerable structural variety of the large number of chemicals produced, there is a need for
prediction measurements of bioconcentration and toxic effects. Physico-chemical data may be used for predicting bioconcentration
and life-cycle toxicity tests for the estimation of safe levels. The degree of biomagnification via food chains increases
with half lives of the pollutants. When comparing pollutant concentrations with toxicological data it becomes apparent that
estuaries and coastal areas deserve special concern, whereas pollutant levels of open ocean waters are unlikely to endanger
marine life at present. 相似文献
11.
A. Chandra Sekar 《International Journal of Anthropology》1995,10(2-3):125-132
The highest values of consanguinity was found among “Kamma” (45.0%), “Ediga” (47.5%) and “Mala” (55.7%) who occupy different
strata of Indian caste hierarchy. In the way of searchout the factors influencing consanguineous marriages, the present paper
finda the negative relationship between educational levels of the spouses and consanguinity. The educational levels of men
has significant effect on the frequency of consanguinious marriages among “Kamma” and “Mala”. However, further analysis deplore
significant differences in the mean levels consanguinity between educational groups. It divulge low level of higher education
among the populations. Only 12% of men and 1.6% of women have degree level and above education in the total sample. 相似文献
12.
On the occasion of the first international workshop on systems radiation biology we review the role of cell renewal systems
in maintaining the integrity of the mammalian organism after irradiation. First, 11 radiation emergencies characterized by
chronic or protracted exposure of the human beings to ionizing irradiation were “revisited”. The data provide evidence to
suggest that at a daily exposure of about 10–100 mSv, humans are capable of coping with the excess cell loss for weeks or
even many months without hematopoietic organ failure. Below 10 mSv/day, the organisms show some cellular or subcellular indicators
of response. At dose rates above 100 mSv/day, a progressive shortening of the life span of the irradiated organism is observed.
To elucidate the mechanisms relevant to tolerance or failure, the Megakaryocyte–thrombocyte cell renewal system was investigated.
A biomathematical model of this system was developed to simulate the development of thrombocyte concentration as a function
of time after onset of chronic radiation exposure. The hematological data were taken from experimental chronic irradiation
studies with dogs at the Argonne National Laboratory, USA. The results of thrombocyte response patterns are compatible with
the notion of an “excess cell loss” (compared to the steady-state) in all proliferative cell compartments, including the stem
cell pool. The “excess cell loss” is a function of the daily irradiation dose rate. Once the stem cell pool is approaching
an exhaustion level, a “turbulence region” is reached. Then it takes a very little additional stress for the system to fail.
We conclude that in mammalian radiation biology (including radiation medicine), it is important to understand the physiology
and pathophysiology of cell renewal systems in order to allow predicting the development of radiation induced lesions. 相似文献
13.
A. M. Vaiserman V. P. Voitenko L. V. Mekhova 《Russian Journal of Developmental Biology》2011,42(1):25-42
Many studies have shown that organism is mostly sensitive to different influences in pre- and postnatal periods of ontogenesis.
During the critical periods of development, these influences induce changes in the organism that relate to ontogenetic plasticity
and lead to permanent changes in structure and function of different organs and systems of the organism. It is suggested that
the main molecular mechanisms of so-called “ontogenetic programming” are based on changes that occur on the epigenetic level,
including changes in the genetic expression not connected with modifications of DNA structure. The present review deals with
experimental and epidemiologic evidences of the role of epigenetic processes in aging and determination of susceptibility
to some age-related diseases, such as cancer, cardiovascular and neurodegenerative diseases, and insulin-independent diabetes. 相似文献
14.
A. V. Arkadieva A. A. Mamonov I. G. Popovich V. N. Anisimov V. M. Mikhelson I. M. Spivak 《Cell and Tissue Biology》2011,5(2):151-159
It has been shown recently that metformin, the indirect mTOR-kinase inhibitor, significantly increases medium (by 37.8 %)
and maximum (by 10.3 %) life span of SHR mice (Anisimov et al., 2008). We obtained fibroblasts from skin of 11-, 16-, 19-
and 23-months-old SHR mice treated with metformin since the third and ninth day of life. We studied markers of cellular senescence
in these fibroblasts. Significant differences were observed between the average number of senescence-associated heterchromatic
foci (SAHF), the average of area nuclei and fluorescence intensity of nucleus after staining for y-H2AX in control and experimental
animals. Also, we showed that metformin prevented the accumulation of fibroblasts with large area of nuclei; high activity
of senescence-associated P-galactosidase (SA-(3-gal), and high fluorescence intensity after staining for y-H2AX. It appears
that accumulation of large quantity of senescence markers within a cell triggers it to enter the aging process. It appears
that the increase of “old” cell population above the threshold disrupts the normal function of certain tissues, organs, and
finally, the whole organism. It appears that metformin delays the “old” cells accumulation and prolongs the organism youth. 相似文献
15.
Estuarine ecosystems along the Pacific coast of North America are vulnerable to invasions by non-indigenous planktonic copepods,
with documented invasions by at least nine species introduced via ship’s ballast. One of these, the calanoid copepod Pseudodiaptomus inopinus, now occurs in a relatively wide geographical area in coastal estuaries of Washington and Oregon States. Although it appears
to be well established in the region, plankton surveys conducted in 1992, 1996, 2000, and 2004 in estuaries from southern
Vancouver Island in British Columbia, Canada, to northern California, United States indicate that it has not expanded its
range. This static distribution suggests that P. inopinus has reached a distributional limit, and it may thus be a good organism for applying models for predicting planktonic invasions,
by characterizing estuaries with and without populations of the copepod. In this study, we applied both parametric, linear
(discriminant function analysis, logistic regression) and nonparametric, non-linear (classification trees) techniques to develop
models for occurrence of P. inopinus, to identify parameters that may lead to successful invasions and to identify specific estuaries or regions that might be
at risk of invasion by this species. Both model types had similar results, identifying relatively simple salinity- and stratification-based
models as good predictors of P. inopinus. While different models selected slightly different sets of variables and thresholds, all models identified relatively low
salinity and stratification of water column temperature and salinity as important predictors of P. inopinus presence. The models also identified several “false positives” that mainly occurred in more inland waters of Puget Sound—estuaries
that did not have P. inopinus, but had the conditions that support it, and which may be at risk for future invasions by this species. 相似文献
16.
As a contribution towards identification of the principal environmental factors involved in cadmium accumulation in Antarctic
marine organisms and the establishment of a baseline near the Italian Antarctic Station “Baia Terra Nova”, surface sediments,
plankton and benthic organisms were studied in coastal waters of Terra Nova Bay (Ross Sea). The cadmium content of sediments
was similar to that regarded as background in most marine coastal areas, whereas in surface water, phyto- and zooplankton
it was similar to values measured in areas of enhanced upwelling. Algal and animal taxa dominating benthic associations had
a higher cadmium content than related species from other seas. Very high concentrations of the metal were found in sponges
(10–80 μg/g dw) and in the digestive gland of molluscs (up to 345 μg/g in Neobuccinum eatoni). The rapid regeneration of cadmium and its natural occurrence and bioavailability in highly productive coastal waters seem
to be responsible for cadmium accumulation in the tissues of marine organisms near the “Baia Terra Nova” station.
Received: 6 June 1995/Accepted: 23 November 1995 相似文献
17.
Four strains ofYersinia philomiragia were studied biochemically and genetically. They showed a high degree of phenotypic similarity and formed a homogenous DNA
relatedness group. We could not demonstrate any significant DNA relatedness between this group and otherYersinia species, other Enterobacteriaceae, orPasteurella multocida. Y. philomiragia is phenotypically quite different from other yersiniae and Enterobacteriaceae. These DNA and phenotypic data indicate thatY. philomiragia is not a member of the genusYersinia or a member of the family Enterobacteriaceae. It is suggested that, pending further study, this organism be referred to as
the “Philomiragia” bacterium. 相似文献
18.
I. N. Konareva 《Neurophysiology》2006,38(3):201-208
Modifications of different EEG rhythms induced by a single neurofeedback session (by the EEG characteristics) directed toward
an increase in the ratio of the spectral powers (SPs) of the α vs θ oscillations were compared with the psychological characteristics of the tested subjects (the group included 30 persons).
A generally accepted neurofeedback technique was used; the intensity of acoustic white noise served as the feedback signal.
EEG potentials were recorded from the C3 and C4 leads. Psychological testing was carried out using Eysenck’s (EPQ), Rusalov’s
(OST), and (16 PF) questionnaires. The directions of changes in the SPs of EEG frequency components were found to significantly
correlate with some individuality-related peculiarities of the tested subjects. The SP of the δ rhythm correlated with the
EPQ scale “neuroticism,” OST scale “social plasticity,” and 16 PF factors H (“parmia”), I (“premsia”), and Q3 (“self-control of behavior”). The SP of the θ component demonstrated correlations with the OST scales “ergisity,” “plasticity,”
and “social temp” and with 16 PF factors M (“autia”), Q4 (“frustration”), and Q1 (“exvia”). The SP of the α rhythm correlated with 16 PF factors Q3 (“self-control of behavior”), G (“strength of superEgo”), O (“hypothymia”), L (“protension”), and N (“shrewdness”). The SP
of the β rhythm correlated with the OST scale “emotionality,” while that of the γ rhythm showed correlations with the 16 PF
indices L (“protension”) and M (“autia”). Changes in the ratio of the α vs θ SPs correlated with the EPQ scale “neuroticism.” Thus, our data confirm the statement that a high individual variability
of the results of a single (first in the series) neurofeedback session is to a great extent related to peculiarities of the
individual psychological pattern of the subject.
Neirofiziologiya/Neurophysiology, Vol. 38, No. 3, pp. 239–247, May–June, 2006. 相似文献
19.
Jing Zhang Yan Liu Dan Yu Hongze Song Jingjin Cui Tao Liu 《Journal of applied phycology》2011,23(2):165-171
Hybridization of gametophytes, continuous self-crossing and targeted selection were utilized to breed a new Laminaria variety. After five-generation selection breeding, the new variety “Rongfu” was obtained. Its male parent “Yuanza No.10”
was the high-yield cultivation variety, and its female parent was variety “Fujian” which could tolerate relatively high seawater
temperature. “Yuanza No.10” and “Fujian” were different but complement in their morphological characteristics and biological
habits. Variety “Rongfu” was bred through their hybridization which exhibited high-yield potential and high seawater temperature
tolerance. The results of traits evaluation in consecutive years showed that “Rongfu” attained higher yields by 24–27% compared
to the control (widely used commercial variety) and also contained considerable amounts of iodine, mannitol, and algin. When
seawater temperature was 18–21°C, the blade growth of “Rongfu” was maintained and tissue loss by abrasion was significantly
lower than the control. Since the adoption of variety “Rongfu” in 2001, its cultivation areas have been extended to Shandong,
Fujian and Guangdong province and have reached 14,133 ha currently, i.e., almost one-tenth of the total cultivation areas
of Laminaria in China. The results of Random Amplified Polymorphic DNA analysis showed that the relationship between “Rongfu” and other
cultivation varieties in China was very close. 相似文献
20.
Kenji Konishi Tsutomu Tamura Ryoko Zenitani Takeharu Bando Hidehiro Kato Lars Walløe 《Polar Biology》2008,31(12):1509-1520
The annual trend in energy storage in the Antarctic minke whale was examined using catch data from all 18 survey years in
the Japanese Whale Research Program (JARPA). Regression analyses clearly showed that blubber thickness, girth and fat weight
have been decreasing for nearly 2 decades. The decrease per year is estimated at approximately 0.02 cm for mid-lateral blubber
thickness and 17 kg for fat weight, corresponding to 9% for both measurements over the 18-year period. Furthermore, “date”,
“extent of diatom adhesion”, “sex”, “body length”, “fetus length”, “latitude”, “age” and “longitude” were all identified as
partially independent predictors of blubber thickness. The direct interpretation of this substantial decline in energy storage
in terms of food availability is difficult, since no long-term krill abundance series is available. However, an increase in
the abundance of krill feeders other than minke whales and a resulting decrease in the krill population must be considered
as a likely explanation. 相似文献