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11.
The current study was conducted to provide normative data on actigraphic dichotomy index (I?<?O) (the percentage of in bed activity counts that are less than the median of out of bed counts) in healthy population and to assess whether the I?<?O could be an effective index in discriminating the circadian motor activity of cancer patients from healthy controls. In this retrospective study, we recovered 408 actigraphic records from two databases: healthy controls (n?=?182; 79 males; mean age 38.7?±?12.6) and patients with metastatic colorectal cancer (n?=?226; 149 males; mean age 58.4?±?11.4). Beside the usual actigraphic sleep parameters (time in bed, sleep onset latency, total sleep time, wake after sleep onset, sleep efficiency, number of awakenings, and mean motor activity), we also computed the dichotomy index and number of actigraphic wake parameters, namely, diurnal motor activity, diurnal total sleep time, number of sleep episodes, and the mean duration of the longest diurnal sleep episode. Using the Youden index, we calculated the cut off value that performed the best for I?<?O and actigraphic wake parameters. Finally, we created Receiver Operator Characteristic curves to test the efficacy of each actigraphic parameter to discriminate cancer patient from healthy controls. Mean I?<?O was 99.5% (SD, 0.48%) in the healthy group, as compared to 96.6% (SD, 3.6%) in the cancer group (p?<?0.0001). Important age-related effects appeared unlikely after performing both the main analysis with age as a covariate, and a subset analysis in 104 subjects matched for age and sex. In the main analysis, all actigraphic parameters, except total sleep time, significantly differentiated the two groups of participants. However, the I?<?O was the one that clearly performed best. Here, we provide the first large dataset on I?<?O in healthy subjects, we confirm the relevance of this circadian index for discriminating advanced stage colorectal cancer patients from healthy subjects, and we lay the grounds for further investigations of this circadian index in patients with other chronic diseases.  相似文献   
12.
FISHER, J. B., GOH, C. J. & RAO, A. N., 1989. Non-axillary branching in the palms Eugeissona and Oncosperma (Arecaceae). The south-east Asian palms, Eugeissona (Calamoideae) and Oncosperma (Arecoideae) are multiple-stemmed. The morphology and development of branching in two species of each genus were examined in Singapore, Borneo, and the Malay Peninsula. Cultivated seedling and adult plants of 0. tigillarium were also observed in Florida. A new shoot arises most often from a longitudinal abaxial groove at the base of an enclosing leaf sheath. In some instances, especially in E. tristis , the enclosing leaf has two equal, adjacent grooves such that any distinction between an original mother shoot and a lateral daughter shoot is impossible. No axillary buds occur in Eugeissona which is hapaxanthic. In Oncosperma , which is pleonanthic, axillary buds are absent from young pre-flowering stems, but an inflorescence bud occurs in the axil of each leaf in older aerial stems. Early ontogenetic stages of vegetative branching, as seen in sectioned apices, indicate that a new vegetative shoot is present on the abaxial base of the first (youngest) leaf primordium. There is no ontogenetic evidence for the displacement of an originally axillary meristem as previously described for the palm Salacca (Calamoideae). Shoot development in Eugeissona is interpreted as a putative dichotomy of the apical meristem in which the meristem centres commonly develop unequally. In Oncosperma the smaller sucker bud meristem may be described as an abaxial leaf base bud, but ontogenetic variations indicate this form of branching is close to dichotomous branching. These new examples of non-axillary branching are compared to similar cases previously reported for palms and other monocotyledons.  相似文献   
13.
Several authors have recently argued that invasion biologists should adopt a more objective and dispassionate stance towards invasive species. Brown and Sax (Austral Ecol 29:530–536, 2004; Austral Ecol 30:481–483, 2005) assert that invasion biologists risk their objectivity, “commit the naturalist fallacy” or “embark on a slippery slope” with engaged concern about invasive species. Elsewhere, Colautti and MacIsaac (Divers Distrib 10:135–141, 2004) propose a neutral language for invasion biology, one that insulates scientific from popular discussion about invasive species. While there is certainly hyperbole about the effects of some invasive species, the type of objectivity promoted in these papers may often be inappropriate for invasion biology. It implies a policy of non-action that is inconsistent with the conservation values of many invasion biologists. To engage these values, invasion biologists can adopt deliberative methods for environmental problem-solving that involve stakeholders in their research design and which still promote high standards of scientific rigor.  相似文献   
14.
The vomeronasal organ, the chemosensory organ of the vomeronasal system, is vital in determining sexual and gender-specific behavior in mice. Here, whole-cell voltage-activated currents of individual mouse vomeronasal sensory neurons of two strains (BALB/c and CBA) were measured and correlated to sex in each strain. The average resting membrane potentials, maximal outward current magnitudes, and kinetics of activation and inactivation, were found to be independent of sex. Maximal inward current magnitudes differed significantly across gender in CBA, whereas they did not significantly differ in male and female BALB/c mice: BALB/c males –347±45 pA (n=51), and females –430±56 pA (n=27); CBA males –308±36 pA (n=56) and females –155±18 pA (n=28). These results suggest that some voltage-activated properties may differ slightly according to gender and to strain.D.M. Dean and A. Mazzatenta contributed equally to this work  相似文献   
15.
A. Salvo  G. Valladares 《BioControl》1995,40(2):273-280
Wing and body lengths of polyphagous parasitoids of leafminers are analyzed in order to understand the relationship between host and parasitoid sizes. A distinct positive relationship was observed: within each parasitoid species, smaller individuals were reared from smaller hosts. There was no difference between idio-and koinobionts in sexual dimorphism, with females being significantly larger than males in both groups.  相似文献   
16.
Recent studies show that YTH domain family 2 (YTHDF2) preferentially binds to m6A-containing mRNA regulates localization and stability of the bound mRNA. However, the role of YTHDF2 in pancreatic cancers remains to be elucidated. Here, we find that YTHDF2 expression is up-regulated in pancreatic cancer tissues compared with normal tissues at both mRNA and protein levels, and is higher in clinical patients with later stages of pancreatic cancer, indicating that YTHDF2 possesses potential clinical significance for diagnosis and prognosis of pancreatic cancers. Furthermore, we find that YTHDF2 orchestrates two cellular processes: promotes proliferation and inhibits migration and invasion in pancreatic cancer cells, a phenomenon called “migration-proliferation dichotomy”, as well as epithelial-mesenchymal transition (EMT) in pancreatic cancer cells. Furthermore, YTHDF2 knockdown significantly increases the total YAP expression, but inhibits TGF-β/Smad signaling, indicating that YTHDF2 regulates EMT probably via YAP signaling. In summary, all these findings suggest that YTHDF2 may be a new predictive biomarker of development of pancreatic cancer, but a serious consideration is needed to treat YTHDF2 as a target for pancreatic cancer.  相似文献   
17.
Shifting cultivation is identified as a major cause of tropical deforestation. Sources that recount such impacts routinely employ an Eden-lost narrative structure that represents shifting cultivators as having their relatively harmonious human-environment relationships disrupted by various forces. While such disruptions lead to land degradation, official development institutions via research into alternatives to such agriculture offer redemption, or the return to relative ecological harmony. This Edenic narrative vehicle allows shifting cultivators to be represented as primitives in need of modernization, yet it also more commonly allows a sympathetic representation as holders of valuable, albeit threatened, indigenous knowledge that can be applied to the development of solutions. However, embedded within both hostile and sympathetic accounts from both scientific and policy sources are cultural images that persist as a legacy of colonialist assumptions of social evolution and cultural hierarchy.  相似文献   
18.
利用指数二分性、Banach不动点定理与微分不等式分析技巧,在不要求激活函数有界的条件下,给出了变系数变时滞的BAM神经网络概周期解的存在唯一性和全局吸引性的充分条件.所得结果推广和改进了相应文献的结果。对设计BAM神经网络概周期振荡有重要意义.  相似文献   
19.
  • 1 The validity of the slow—fast lifestyle dichotomy proposed by Sih (1987) was tested in a suite of six odonate species from a restricted geographical area. Data on activity and microhabitat use were obtained in a laboratory study. Further necessary information on life history, macrohabitat (ephemeral‐permanent) use and vulnerability to fish predation was provided by a literature survey.
  • 2 Activity was estimated as number of moves and distance moved for the six odonate larvae. Aeschna juncea, Lestes sponsa and Sympetrum danae were categorised as high‐active species, whereas Coenagrion hastulatum, Cordulia aenea and Leucorhinia dubia were categorised as low‐active species.
  • 3 C. hastulatum and L. sponsa exploited microhabitats close to the water surface, C. aenea and L. dubia close to the bottom, and A. juncea and S. danae were intermediate in their water depth utilisation.
  • 4 A principal component analysis of the data from the laboratory experiment and the literature survey supported the slow—fast life style dichotomy since the variables activity, macrohabitat use, life cycle length and sensitivity to fish predators were highly correlated.
  相似文献   
20.
王炜晔  翟大业  刘金龙 《生态学报》2024,44(13):5459-5475
保护科学前沿研究重视克服单一学科的局限而向超越自然科学和社会科学跨学科交叉融合转型。基于世界自然保护联盟-世界保护区委员会(IUCN-WCPA)自然保护地管理有效性框架,从规划制定、执行和评估三个方面系统梳理了我国保护科学的研究进展,分析了保护自然科学和社会科学在研究内容、方法和视角等方面的差异,识别出潜在的跨学科综合研究领域。结果表明,我国保护自然科学与社会科学研究大多相互独立、缺乏融合协作,少有的跨学科研究在整体性、系统性、兼容性、深入性和规范性上有待提高。自然科学家在介入社会科学研究时缺乏对现实制度的科学理解,所提出的保护政策和行动建议偏向理想主义,阻碍保护科学跨学科知识生产;社会科学家则缺乏自然科学方法和数据的知识积累,所提出的政策和行动建议脱离事实和证据,偏向主观主义,不利于保护科学知识进步。为此,构建了基于自然保护地适应性管理逻辑下的保护科学跨学科整合框架,以推动保护科学共同话语的形成,实现社会与生态的耦合协调发展。  相似文献   
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