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41.
42.
3Beta-hydroxyolean-12-en-27-oic acid (1), a biologically active, pentacyclic triterpenoid isolated from the rhizomes of Astilbe chinensis, was found to be considerably more cytotoxic toward human colorectal carcinoma (COLO-205) and human cervical squamous carcinoma (HeLa) cells than its congener oleanolic acid (4). This suggests that the position of the COOH group significantly affects the cytotoxicity of oleanane-type pentacyclic triterpene carboxylic acids. To elucidate the underlying biological mechanism responsible for the cytotoxicity of 1, we investigated its growth-inhibitory effect on COLO-205 cells. Compound 1 induced a marked concentration- and time-dependent inhibition of cell proliferation, with the typical morphological characteristics of apoptosis, and under formation of DNA ladders in agarose-gel electrophoresis. Flow-cytometric analysis showed that the cell cycle of COLO-205 cells exposed to 1 was arrested in the G0/G1 phase. Also, 1 increased and decreased the expression of Bax and Bcl-2 proteins, respectively, and lowered the mitochondrial transmembrane potential (delta psi(m)). The peptidic caspase-3 inhibitor NH2-Asp-Glu-Val-Asp-CHO (at 1 microM) could increase the viability of COLO-205 cells previously treated with 1. These results indicate that 1 induces efficient cell apoptosis through down-regulating Bcl-2 expression, up-regulating Bax expression, lowering delta psi(m), and by activating the caspase-3 pathway.  相似文献   
43.
Chlorophyll (Chl) deficiency in leaves of a plastome sunflower (Helianthus annuus L.) en:chlorina-5 mutant is due to the formation of smaller chloroplasts with a markedly reduced membrane system, as compared to the parent 3629 line. Abnormalities in the structure of the photosynthetic apparatus in the mutant can be mainly attributed to changes in the formation of photosystem I and its light-harvesting complexes. Chl deficiency in en:chlorina-5 correlated with its lower capability of synthesizing the first specific Chl precursor, 5-aminolevulinic acid (ALA) in the light. Light-independent stages of Chl biosynthesis in the mutant had the same efficiency as in leaves of the parent line. ALA formation in darkness and its conversion into protochlorophyllide did not depend on the extent of photosynthetic membrane development and photosynthetic activity.  相似文献   
44.

Objective

To assess the most appropriate criteria considered by geriatricians to select patients who might benefit the most from geriatric hospital care.

Material and methods

We carried out a survey that consisted of various socio-demographic, clinical, functional and mental criteria included in the definition of the geriatric and frail elderly patient. The survey was sent to all specialists in geriatrics in the different hospitals of the Madrid Health Service. They were asked to answer to each criterion indicating whether they considered it as high priority, priority, low priority or no priority. The responses were clustered by type of hospital: acute hospitals with or without a post-graduate geriatric program for medical residents, and medium and long stay hospitals.

Results

A total of 83 questionnaires were completed (70% of the study population): 42 teaching hospitals a post-graduate geriatric program (74% of possible), 20 of those with an emergency department but without a post-graduate geriatric program (56% of possible), and 21 medium and long stay hospitals (84% of potential). All proposed criteria were considered individually as priority or high-priority by more than 50% of respondents. An age 85 years and over, admission for hip fracture, the presence of severe cognitive or functional impairment, frailty, and unexplained deterioration of health status, were considered individually as criteria for selecting high-priority target population by more than 85% of respondents.

Conclusions

Certain criteria, such as advanced age, or the presence of geriatrics-specific conditions, such as hip fracture or severe functional or cognitive impairment, are identified by geriatricians as useful to select patients to receive geriatric specialist hospital care.  相似文献   
45.
《L'Anthropologie》2018,122(3):385-401
The two regions southwestern Germany and southwestern France have yielded Gravettian personal ornaments in form of tear-drop-shaped beads. We present updated numbers of these artefacts, because during the recent excavations since 2002 in Hohle Fels cave near the city of Ulm, Southwest Germany, additional beads were found. The present paper proposes for the first time a typo-technological study of the tear-drop-shaped beads.  相似文献   
46.
《Comptes Rendus Palevol》2019,18(3):287-297
The probable trace maker of B. hemispherica is the fact that one encounters different age groups of sea anemone burrows extended at variable depths in soft, unconsolidated, non-fluidized mud to get stability. It occurs as densely packed, vertical to subvertical, usually unornamented, occasionally showing faint, thin, ring-like structures, allochemic sandstone-filled cylinders with hemispherical base extending to variable depths in the shale. The diameter-to-height ratio calculated for 44 burrow specimens shows that the diameters of most of the specimen are smaller than their height. The probable trace maker of B. hemispherica is the fact that one encounters different age groups of sea anemones, which extended their column at variable depth in soft, unconsolidated, non-fluidized mud to get stability. The inclined nature of paired burrows towards each other suggests social aggression while unpaired inclined burrows suggest swaying in search of food. The monodominant occurrence of B. hemispherica as pre-storm colonization of r-selected organisms (sea anemones) suggest sstressed environment and simultaneous vacation of the burrower reflects rapid sedimentation due to high-energy storm events. Further, storm and inter-storm events deposited sandy allochemic limestone and shale series, respectively, but did not form an identical condition for the colonization of the sea anemone. The species B. hemispherica of the Bagh Group revealed physicochemical parameters (energy conditions, turbidity, sedimentation rate, bathymetry, suspended organic matter, substrate consistency, oxygen, and salinity) of the Late Cretaceous transgressive sea.  相似文献   
47.
Daget  Philippe 《Plant Ecology》1977,34(2):87-103
Plant Ecology - In this second report on the Mediterranean bioclimate, the author treats the method developed by Emberger (1930 to 1971) to analyse the Mediterranean climate as defined in the...  相似文献   
48.
SEM examination of second-stage juveniles (J2) and adults of Atalodera ucri, A. lonicerae (syn. Sherodera lonicerae), Thecavermiculatus sp. (undescribed new species), T. andinus, and T. crassicrustatus revealed new characters. A primitive en face pattern with six separate lips occurs in J2 of Thecavermiculatus spp. examined and in about half the polymorphic A. lonicerae. A derived en face pattern with fused adjacent submedial lips occurs in the other half of A. lonicerae and all A. ucri. Posteriorly, the J2 head of all species is annulated. The primitive en face pattern also occurs in males of A. lonicerae and Thecavermiculatus spp., and posteriorly the head of these species consists of plates. Fewer plates occur rarely in males of A. ucri. Males of A. ucri have a derived en face pattern where lips are fused and the head is annulated. Fusion of lips occurs rarely in males of A. lonicerae. Females of all species have similar derived en face patterns. En face patterns of J2 and males o f Atalodera and Thecavermiculatus may aid in species identification and to elucidate intergeneric relationships, but en face characters shared by the two genera are primitive and are not useful for demonstrating monophyly. Perineal region of females indicates the closeness of the vulval-anal distance, as a derived character, which is shared by Atalodera and most Thecavermiculatus spp. suggesting possible monophyly. T. andinus, while having a similar en face pattern to J2 of other Thecavermiculatus species, lacks the derived character of the perineal region. Phasmid openings were not observed in adults of any of the species examined.  相似文献   
49.
Rate parameters have been obtained for the oxidation of cuprous stellacyanin by cobalt(III) ions of the form cis(N)-[CoN2O4]?, including cis(N)-[Co(NTA)(gly)]?, cis(N)-[Co(IDA)2]?, [Co(en)(ox)2]?(μ 0.5 M(phosphate), pH 7.0), and Co(EDTA)?(μ 0.1 M(NaCl), pH 7.2, 0.001 M phosphate). An excellent isokinetic correlation between the activation parameters ΔH and ΔS exists for the reactions of aminopolycarboxylatocobalt(III) ions with reduced stellacyanin (β = 300 ± 12 K; correlation coefficient = 0.995). It is concluded that enthalpy-entropy compensation in these reactions may be understood in terms of differing orientations preferred by the various oxidants in forming precursor complexes with the reduced blue protein. While ΔH and ΔS values for electron transfer from stellacyanin to cis(N)-[CoN2O4]? ions vary over ranges of 10.7 kcal/mol and 34 cal/mol-deg, respectively, room temperature rate constants are relatively constant (3.6–34.5 M?1 sec?1), as expected from Marcus theory for outer sphere electron transfer.  相似文献   
50.
Time-series analyses in ecology usually involve the use of autoregressive modelling through direct and/or delayed difference equations, which severely restricts the ability of the modeler to structure complex causal relationships within a multivariate frame. This is especially problematic in the field of population regulation, where the proximate and ultimate causes of fluctuations in population size have been hotly debated for decades. Here it is shown that this debate can benefit from the implementation of structural modelling with latent constructs (SEM) to time-series analysis in ecology. A nonparametric bootstrap scheme illustrates how this modelling approach can circumvent some problems posed by the climate-ecology interface. Stochastic Monte Carlo simulation is further used to assess the effects of increasing time-series length and different parameter estimation methods on the performance of several model fit indexes. Throughout, the advantages and limitations of the SEM method are highlighted.  相似文献   
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