共查询到20条相似文献,搜索用时 15 毫秒
2.
A new genus, Bobgunnia, is established in tribe Swartzieae for the African species of Swartzia. Two new combinations are made: B. fistuloides and B. madagascariensis. The new genus has seeds, unlike the remainder of tribe Swartzieae but like the other tribes of Faboideae. The systematic
position of Swartzieae is reevaluated. 相似文献
3.
AbstractBackground: Promoter methylation of tumour suppressor genes (TSGs) CDKN2A, CDKN2B and CDH13 has been reported in ovarian cancer. However, the clinicopathological characteristics and prognostic role of CDKN2A, CDKN2B and CDH13 promoter methylation in ovarian carcinoma remained unclear. Methods: The pooled odds ratio (OR) or hazard ratios (HRs) with their 95% confidence intervals (95% CIs) were calculated in this meta-analysis. The Cancer Genome Atlas data were obtained to confirm the role of CDKN2A, CDKN2B and CDH13 methylation in ovarian cancer. Results: CDKN2A, CDKN2B and CDH13 promoter methylation was higher in ovarian cancer than in normal ovarian tissues. CDH13 promoter methylation was correlated with tumour histology (serous vs. non-serous type: OR?=?0.33, p?=?0.031). CDKN2A promoter methylation was not linked to overall survival (OS), but it was correlated with a poor prognosis in progression-free survival (HR?=?1.55, p?=?0.004). TCGA data showed no correlation between CDKN2A, CDKN2B and CDH13 methylation and OS as well as disease-free survival (DFS). Conclusions: CDKN2A, CDKN2B and CDH13 promoter methylation may correlate with the increased risk of ovarian cancer. CDKN2A promoter methylation may be an independent prognostic biomarker for predicting progression-free survival. 相似文献
4.
In a series of papers, L. Danziger and G. Elmergreen ( Bull. Math. Biophysics, 16, 15–21, 1954; 18, 1–13, 1956; 19, 9–18, 1957) showed that a non-linear biochemical interaction between the anterior pituary gland and the thyroid gland may
result under certain conditions in sustained periodical oscillations of the rates of production and of the blood level of
the thyrotropic and of the thyroid hormone. They treated the systems, however, as a homogeneous one. N. Rashevsky ( Some Medical Aspects of Mathematical Biology, Springfield, Illinois: Charles C. Thomas, Publisher, 1965; Bull. Math. Biophysics, 29, 395–401, 1967) generalized the above results by taking into account the histological structures of the two glands as well
as the diffusion coefficients and permeabilities of cells involved. The present paper is the first step toward the theory
of interaction of any number n of glands or, more generally, n components. The differential equations which govern the behavior of such a system represent a system of 2n
2+ n
non-linear first order ordinary equations and involve a total of 7 n
2+3 n parameters of partly histological, partly biochemical nature. The requirements of the existence of sustained oscillations
demand 4 n
2+2 n+2 inequalities between those 7 n
2+3 n parameters. 相似文献
5.
ObjectiveTo study the impact of socio-economic status and ethno-racial strata on excess mortality hazard and net survival of women with breast cancer in two Brazilian state capitals. MethodWe conducted a survival analysis with individual data from population-based cancer registries including women with breast cancer diagnosed between 1996 and 2012 in Aracaju and Curitiba. The main outcomes were the excess mortality hazard (EMH) and net survival. The associations of age, year of diagnosis, disease stage, race/skin colour and socioeconomic status (SES) with the excess mortality hazard and net survival were analysed using multi-level spline regression models, modelled as cubic splines with knots at 1 and 5 years of follow-up. ResultsA total of 2045 women in Aracaju and 7872 in Curitiba were included in the analyses. The EMH was higher for women with lower SES and for black and brown women in both municipalities. The greatest difference in excess mortality was seen between the most deprived women and the most affluent women in Curitiba, hazard ratio (HR) 1.93 (95%CI 1.63–2.28). For race/skin colour, the greatest ratio was found in Curitiba (HR 1.35, 95%CI 1.09–1.66) for black women compared with white women. The most important socio-economic difference in net survival was seen in Aracaju. Age-standardised net survival at five years was 55.7% for the most deprived women and 67.2% for the most affluent. Net survival at eight years was 48.3% and 61.0%, respectively. Net survival in Curitiba was higher than in Aracaju in all SES groups.” ConclusionOur findings suggest the presence of contrasting breast cancer survival expectancy in Aracaju and Curitiba, highlighting regional inequalities in access to health care. Lower survival among brown and black women, and those in lower SES groups indicates that early detection, early diagnosis and timely access to treatment must be prioritized to reduce inequalities in outcome among Brazilian women. 相似文献
6.
A series of 15 previously reported N 4-substituted isatin-3-thiosemicarbazones 3a-o has been screened for cytotoxic, antibacterial, antifungal and urease inhibitory activities. Compounds 3b, 3e and 3n proved to be active in cytotoxicity assay; 3e exhibited a high degree of cytotoxic activity (LD 50 = 1.10 × 10 ? 5 M). Compound 3h exhibited significant antibacterial activity against B. subtilis, whereas compounds 3a, 3k and 3l displayed significant antifungal activity against one or more fungal strains i.e. T. longifusus, A. flavus and M. canis. In human urease enzyme inhibition assay, compounds 3g, 3k and 3m proved to be the most potent inhibitors, exhibiting relatively pronounced inhibition of the enzyme. These compounds, being non-toxic, could be potential candidates for orally effective therapeutic agents to treat certain clinical conditions induced by bacterial ureases like H. pylori urease. This study presents the first example of inhibition of urease by isatin-thiosemicarbazones and as such provides a solid basis for further research on such compounds to develop more potent inhibitors. 相似文献
7.
AbstractCulture is a fuzzy concept without fixed boundaries, meaning different things according to situations. To address this issue, I introduce a p-model to understand culture as a system of people, places, and practices, for a purpose such as enacting, justifying, or resisting power. People refers to population dynamics, social relations, and culture in groups. Places refers to ecological dynamics, institutional influences, and culture in contexts. Practices refers to participatory dynamics, community engagement, and culture in action. Power refers to forcing others into compliance (power-over people), controlling access to spaces (power in places), and behaving as desired (power-to practice). I use racism to illustrate the p-model and suggest applications in theory, research, and practice in developmental sciences. 相似文献
8.
The theory of relations between sets, proposed and outlined in previous publications ( Bull. Math. Biophysics, 23, 233–235, 1961; 28, 117–124, 1966; 28, 309–313, 1966), is tentatively expanded and generalized with a view to biological applications. 相似文献
9.
After giving a brief review of the theory of organismic sets ( Bull. Math. Biophysics, 29, 139–152, 1967; 31, 159–198, 1969), in which the concept of relational forces, introduced earlier ( Bull. Math. Biophysics, 28, 283–308, 1966a) plays a fundamental role, the author discusses examples of possible different structures produced by relational
forces. For biological organisms the different structures found theoretically are in general agreement with observation. For
societies, which are also organismic sets as discussed in the above references, the structures can be described only in an
abstract space, the nature of which is discussed. Different isomorphisms between anatomical structures, as described in ordinary
Euclidean space, and the sociological structures described in an abstract space are noted, as should be expected from the
theory of organismic sets. 相似文献
10.
Key messageWe applied the phylogenomics to clarify the concept of rice species, aid in the identification and use of rice germplasms, and support rice biodiversity. AbstractRice (genus Oryza) is one of the most important crops in the world, supporting half of the world’s population. Breeding of high-yielding and quality cultivars relies on genetic resources from both cultivated and wild species, which are collected and maintained in seed banks. Unfortunately, numerous seeds are mislabeled due to taxonomic issues or misidentifications. Here, we applied the phylogenomics of 58 complete chloroplast genomes and two hypervariable nuclear genes to determine species identity in rice seeds. Twenty-one Oryza species were identified. Conspecific relationships were determined between O. glaberrima and O. barthii, O. glumipatula and O. longistaminata, O. grandiglumis and O. alta, O. meyeriana and O. granulata, O. minuta and O. malampuzhaensis, O. nivara and O. sativa subsp. indica, and O. sativa subsp. japonica and O. rufipogon. D and L genome types were not found and the H genome type was extinct. Importantly, we evaluated the performance of four conventional plant DNA barcodes (matK, rbcL, psbA-trnH, and ITS), six rice-specific chloroplast DNA barcodes (psaJ-rpl33, trnC-rpoB, rps16-trnQ, rpl22-rps19, trnK-matK, and ndhC-trnV), two rice-specific nuclear DNA barcodes (NP78 and R22), and a chloroplast genome super DNA barcode. The latter was the most reliable marker. The six rice-specific chloroplast barcodes revealed that 17% of the 53 seed accessions from rice seed banks or field collections were mislabeled. These results are expected to clarify the concept of rice species, aid in the identification and use of rice germplasms, and support rice biodiversity. 相似文献
11.
Relationships between fish and otolith measurements were analyzed in nine demersal fishes from the north‐eastern Tasmanian waters: Foetorepus calauropomus, Trachurus declivis, Parequula melbournensis, Neosebastes scorpaenoides, Platycephalus aurimaculatus, Platycephalus bassensis, Platycephalus conatus, Lepidotrigla mulhalli and Lepidotrigla vanessa. The values of exponent b from the relationships between fish weight and fish total length, total length and otolith length, total length and otolith width, and fish weight and otolith length were estimated. All above relationships were statistically significant. The analysis of covariance (ANCOVA) was used to test the effect of the categorical factor of species in the fish length and otolith length relationship. Significant differences in fish length and otolith length relationship between species were highlighted in both gurnards and flatheads. Results from this study will provide novel information on quantitative biometric relationships between body and otolith measurements of fish species in Australian waters. 相似文献
12.
AbstractA novel protease-resistant and thermostable phytase from Bacillus subtilis subsp. subtilis JJBS250 was purified 36-fold to homogeneity with a combination of ammonium sulfate precipitation followed by Q-Sepharose and Sephadex G-50 chromatographic techniques. The estimated molecular mass of the purified phytase was 46?kDa by electrophoresis with optimal activity at pH 7.0 and 70?°C. About 19% of original activity was maintained at 80?°C for 10?min. Phytase activity was stimulated in presence of surfactants like Tween-20, Tween-80, and Triton X-100 and metal ions like Ca +2, K +, and Co +2 and it was inhibited by SDS and Mg +2, Al +2, and Fe +2. Purified enzyme showed specificity to different salts of phytic acid and values of Km and Vmax were 0.293?mM and 11.49 nmoles s ?1, respectively for sodium phytate. The purified enzyme was resistant to proteases (trypsin and pepsin) that resulted in amelioration of food nutrition with simultaneous release of inorganic phosphate, reducing sugars, and soluble protein. 相似文献
14.
The principle of biotopological mapping (Rashevsky, 1954, Bull. Math. Biophysics, 16, 317–48) is given a generalized formulation, as the principle of relational epimorphism in biology. The connection between
this principle and Robert Rosen’s representation of organisms by means of categories (1958, Bull. Math. Biophysics, 20, 317–41) is studied. Rosen’s theory of ( M, R)-systems, (1958, Bull. Math. Biophysics, 20, 245–60) is generalized by dropping the assumption that only terminal M
i
components are sending inputs into the R
i
components. It is shown that, if the primordial organism is an ( M, R)-system, then the higher organisms, obtained by a construction well discussed previously (1958, Bull. Math. Biophysics, 20, 71–93), are also ( M, R)-systems. Several theorems about such derived ( M, R)-systems are demonstrated.
It is shown that Rosen’s concept of an organism as a set of mappings throws light on phenomena of synesthesia and also leads
to the conclusion that Gestalt phenomena must occur not only in the fields of visual and auditory perception but in perceptions
of any modality. 相似文献
15.
The regulation of salt absorption in the sea water cell intestine was studied by evaluating the effects of theophylline, 8 Br cyclic adenosine monophosphate, 8 Br cyclic guanosine monophosphate, atriopeptin III, porcine vasoactive intestinal peptide and prostaglandin E
1 on the short-circuit current, the transepithelial voltage difference and conductance and on the dilution potentials. It was shown that theophylline increased the transepithelial conductance and reduced the magnitude of the dilution potentials, indicating that the drug increase the anion conductance of the tight junctions. In addition its inhibitory effect on short-circuit current and transepithelial voltage difference suggests that theophylline also affects the transcellular transport mechanisms. It was shown that 8 Br cyclic guanosine monophosphate and 8 Br cyclic adenosine monophosphate affect transcellular mechanisms underlying Cl – transport since both compounds reduced short-circuit current and transepithelial voltage difference; however, cyclic adenosine monophosphate is less effective since unlike cyclic guanosine monophosphate, even at maximal concentration, it was not able to completely abolish transepithelial voltage difference and short-circuit current. The effects of cyclic guanosine monophosphate and cyclic adenosine monophosphate were not additive even if cyclic guanosine monophosphate may produce further inhibition of ion transport in 8 Br cyclic adenosine monophosphate-treated tissues. In addition, cyclic guanosine monophosphate but not cyclic adenosine monophosphate reduced the magnitude of the dilution potentials, suggesting that cyclic guanosine monophosphate acts also on the paracellular pathway. Rat atriopeptin III, a peptide known to increase cyclic guanosine monophosphate cellular levels, behaved like 8 Br cyclic guanosine monophosphate since it lowered the dilution potentials and reduced short-circuit current and transepithelial voltage difference to near zero values, suggesting that the hormone modulates both paracellular and transcellular transport mechanisms, probably acting on the Na-K-2Cl cotransport. Agents acting via cyclic adenosine monophosphate, like porcine vasoactive intenstinal peptide and prostaglandin, behaved like 8 Br cyclic adenosine monophosphate. They were less effective in inhibiting ion transport and did not interfere with the paracellular pathway.Abbreviations
AP III
rat artriopeptin III
-
8 Br cAMP 8
Br cyclic adenosine monophosphate
-
8 Br cGMP 8
Br cyclic guanosine monophosphate
-
g
t
transepithelial conductance
-
I
sc
short circuit current
-
IC
50
half-maximal inhibitory concentration
-
NaK ATPase
Na-K-adenosine monophosphate
-
NPPB
5-nitro-2-(3-phenylpropylamino)-benzoic acid
-
PGE
prostaglandin E
1
-
R
t
tissue resistance
-
SITS
4-acetamide-4-isothiocyano-stilbene-2,2-disulfonic acid
-
V
t
transepithelial voltage difference
-
VIP
porcine vasoactive intestinal peptide 相似文献
17.
The enantiomers of cis-verbenol ( 4a and 4a′) were first synthesized in optically pure state. (1 S, 4 S, 5 S)-2-Pinen-4-ol ( 4a′) was dextrorotatory in acetone or in methanol but it was levorotatory in chloroform; cis-verbenols are indistinguishable by a prefix (+) or (?). The designation of the Ips pheromone as (+)- cis-verbenol is therefore ambiguous and it should be called as (1 S, 4 S, 5 S)-2-pinen-4-ol ( 4a′) or ( S)- cis-verbenol. 相似文献
18.
The tribal name Bocageeae Endlicher is reestablished and the tribe is circumscribed on the basis of solitary internodal ebracteate
pedicels that are articulated at the base, and pollen shed in polyads of eight or more grains. Septate anther locules, large
pollen size, and seed appendages are prevalent in the tribe. Intectate pollen with free-standing columellae, rare in Annonaceae,
occurs not only in the genus Trigynaea but also in some species of Bocagea and Hornschuchia. As defined here, the Bocageeae include seven neotropical genera: Cymbopetalum, Porcelia, Bocagea, Cardiopetalum, Froesiodendron, Hornschuchia, and Trigynaea. The latter five genera are revised and the treatments include ten new species: Cardiopetalum plicatum, Froesiodendron urceocalyx, Hornschuchia lianarum, H. santosii, H. leptandra, Trigynaea cinnamomea,
T. lanceipetala, T. triplinervis, T. lagaropoda, and T. axilliflora, all from tropical South America. A new combination, Froesiodendron longicuspe, changes the rank of that taxon from subspecies to species. Cardiopetalum surinamense is removed from Froesiodendron and reassigned to Cardiopetalum on the basis of its connate petals, dehiscent monocarps, and seeds with bilobed arils. A cladogram provides an explicit hypothesis
of intergeneric relationships in the tribe. The new combination Onychopetalum periquino, based on Trigynaea periquino, is made. 相似文献
19.
In combining the author's theories of organismic sets (Rashevsky, Bull. Math. Biophysics, 31, 159–198, 1969a) and Robert Rosen's theory of ( M, R)-systems ( Bull. Math. Biophysics, 20, 245–265, 1958), a conclusion is reached that the number of either normal or pathological phenomena in organismic sets may
occur. Those phenomena are characterized by occurring spontaneously once in a while but are not exactly periodic. Some epilepsies
are an example of such pathological phenomena in the brain. 相似文献
20.
????? 目的 了解不同地区患者对三级公立医院公益性的评价,探究公益性评价的影响因素。 方法 通过问卷的形式,在东、中、西3个地区选择在三级医院就诊的患者进行调查, 使用Pearson Chi-square、非参数检验和Logistic回归方法对数据进行分析。 结果 患者对于公立医院的公益性评价存在一定的地区差异,但公益性总体评价的影响因素类似,医疗服务的适宜性和公平性是主要影响因素。 结论 加强三级公立医院的公益性应该着重提高医疗服务的适宜性,提高医疗服务的公平性。 相似文献
|