首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   11篇
  免费   7篇
  2021年   1篇
  2018年   1篇
  2017年   2篇
  2016年   1篇
  2015年   1篇
  2012年   1篇
  2010年   1篇
  2006年   1篇
  2004年   1篇
  2002年   4篇
  2000年   1篇
  1999年   1篇
  1980年   1篇
  1970年   1篇
排序方式: 共有18条查询结果,搜索用时 15 毫秒
1.
During the past several decades there has been a substantial increase in the incidence of malignant melanoma worldwide. The highest incidences were reported in New Zealand and Australia. In Europe the northern countries generally have a higher incidence. The aim of this retrospective study was to provide the incidence and mortality for all patients with malignant melanoma diagnosed in Osijek-Baranya County, Eastern Croatia, during 2000-2008. In the past 30 years in the Republic of Croatia the incidence of melanoma increased by 337%. During the period of 2000-2006 in Osijek-Baranja County, the incidence of melanoma increased by 13%. The incidence of melanoma increases with age, but in past decades melanoma is more often diagnosed in people aged 25-40. The mortality between 2000 and 2008 increased by 18%. The incidence of melanoma generally increases equally in men and women. The most common localization of skin melanoma in males was trunk and in females the lower extremities. Presently, in Osijek-Baranya County melanoma is 15th on the list of malignant tumors and represent 2% of all malignant tumors. In New Zealand, Australia and European northern countries mortality is reduced, as result of earlier diagnosis and education of risk groups. Unfortunately, in Osijek-Baranya County, in a comparison with these countries, the mortality is higher although incidence is the same or lower.  相似文献   
2.
Jamie Males 《Biotropica》2017,49(6):891-902
Terrestrial species of the megadiverse bromeliad family display a wide variety of leaf shapes, many of which have evolved convergently in different lineages. Here, I examine the links between leaf shape, venation architecture, hydraulic function, and bioclimatic relations in two bromeliad groups displaying diverse leaf shapes, the genus Pitcairnia (Pitcairnioideae) and the terrestrial grade of the Bromelioideae subfamily. Leaf shapes with broader leaf blades, notably petiolate and lanceolate morphologies, tend to show wider vein spacing, which is associated with reduced hydraulic capacity and higher hydraulic vulnerability. In turn, these leaf shapes tend to occur in species restricted to moist, aseasonal environments, suggesting that hydraulic function is an important mediator of the relationship between leaf shape and bromeliad environmental niches. This network of trait–trait and trait–environment relationships may have been of profound important in the ecological and evolutionary diversification of the bromeliads. Similar structure–function principles are likely to apply in other tropical herbaceous monocots, which are of great ecological importance but generally neglected in plant hydraulic research.  相似文献   
3.
Mass and energy fluxes were measured over a field of Agave tequilana in Mexico using eddy covariance (EC) methodology. Data were gathered over 252 d, including the transition from wet to dry periods. Net ecosystem exchanges (FN,EC) displayed a crassulacean acid metabolism (CAM) rhythm that alternated from CO2 sink at night to CO2 source during the day, and partitioned canopy fluxes (FA,EC) showed a characteristic four‐phase CO2 exchange pattern. Results were cross‐validated against diel changes in titratable acidity, leaf‐unfurling rates, energy exchange fluxes and reported biomass yields. Projected carbon balance (g C m?2 year?1, mean ± 95% confidence interval) indicated the site was a net sink of ?333 ± 24, of which contributions from soil respiration were +692 ± 7, and FA,EC was ?1025 ± 25. EC estimated biomass yield was 20.1 Mg (dry) ha?1 year?1. Average integrated daily FA,EC was ?234 ± 5 mmol CO2 m?2 d?1 and persisted almost unchanged after 70 d of drought conditions. Regression analyses were performed on the EC data to identify the best environmental predictors of FA. Results suggest that the carbon acquisition strategy of Agave offers productivity and drought resilience advantages over conventional semi‐arid C3 and C4 bioenergy candidates.  相似文献   
4.
The aim of the study was to determine motor and morphological factors, and to assess their impact on specific motor skill performance in rhythmic gymnastics (RG). Experimental training process aimed at learning and improving basic movement structures of rhythmic gymnastics was performed for nine months in a sample of 50 female rhythmic gymnastics novices (mean age 7.1 +/- 0.3 years). Seven dimensions in total were isolated by factorial analysis of 13 motor, 11 morphological, and 20 specific rhythmic gymnastics tests. The factors of flexibility (Beta = 0.26; p < 0.05), explosive strength (Beta = 0.25; p < 0.05) and adipose voluminosity (Beta = -0.42; p < 0.001) explains 41% of the success in performing RG basic body elements--jumps, rotations, balance and flexibility (R = 0.64), while the frequency of movement (Beta = 0.44; p < 0.001) and non-adipose voluminosity (Beta = 0.26; p < 0.05) explains 26% of RG-specific manipulations with the apparatus--club, ribbon and ball wrist manipulation (R = 0.52; p < 0.01). According to study results, the RG-training process intended for rhythmic gymnastics novices should be programmed, with preset objectives for the development of flexibility and explosive strength, speed and peripheral joint strength and adipose tissue reduction.  相似文献   
5.
6.
7.
The essential oils of Stachys alpina L., Stachys officinalis (L.) Trevis., Stachys palustris L., Stachys recta L. subsp. recta, S. recta L. subsp. subcrenata (Vis.) Briq., Stachys salviifolia Ten., and Stachys sylvatica L. were obtained by hydrodistillation and analysed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS). Sesquiterpene hydrocarbons were the main group of constituents of all taxa, except S. alpina, which was rich in oxygenated sesquiterpenes. S. alpina and S. palustris had a significant aldehyde fraction and a high amount of alcohols. Some differences in the essential oil composition of two subspecies of S. recta (S. recta subsp. recta and S. recta subsp. subcrenata), growing under almost identical conditions, have been found.  相似文献   
8.
The Neotropical Bromeliaceae display an extraordinary level of ecological variety, with species differing widely in habit, photosynthetic pathway and growth form. Divergences in stomatal structure and function, hitherto understudied in treatments of bromeliad evolutionary physiology, could have been critical to the generation of variety in ecophysiological strategies among the bromeliads. Because humidity is a key factor in bromeliad niches, we focussed on stomatal responses to vapour pressure deficit (VPD). We measured the sensitivity of stomatal conductance and assimilation rate to VPD in eight C3 bromeliad species of contrasting growth forms and ecophysiological strategies and parameterised the kinetics of stomatal responses to a step change in VPD. Notably, three tank‐epiphyte species displayed low conductance, high sensitivity and fast kinetics relative to the lithophytes, while three xeromorphic terrestrial species showed high conductance and sensitivity but slow stomatal kinetics. An apparent feedforward response of transpiration to VPD occurred in the tank epiphytes, while water‐use efficiency was differentially impacted by stomatal closure depending on photosynthetic responses. Differences in stomatal responses to VPD between species of different ecophysiological strategies are closely linked to modifications of stomatal morphology, which we argue has been a pivotal component of the evolution of high diversity in this important plant family.  相似文献   
9.
A major goal of our research is to produce, by genetic manipulation, Brassica napus L. cultivars with higher levels of 22:1 in their seed oil than in present Canadian HEA cultivars developed through traditional breeding. Previously, we reported that transgenic expression of a mutated yeast sn-2 acyltransferase (SLC1-1) in industrial rapeseed cv. Hero resulted in increased seed oil content, increased proportions of erucic acid and increased average seed weight (Zou et al. 1997). Those results were reported only for plants grown in a controlled greenhouse setting. Here we report a summary of the results from two successive years of field trials with T4 and T5 generations of B. napus cv. Hero transformed with the SLC1-1 gene. These trials, conducted at Rosthern, Saskatchewan, in two very different growing seasons, show that the SLC1-1 transgenics clearly and consistently out-performed controls, with much increased oil and 22:1 contents, as well as yield, under varying field conditions.  相似文献   
10.
Structural, i.e. qualitative changes in some motor dimensions (strength and endurance) were assessed during a 2-month period in a sample of 307 male subjects, Croatian Navy draftees, mean age 21 years. Study subjects were divided into three groups: experimental group 1 (n = 102), experimental group 2 (n = 97) and control group (n = 108), submitted to different kinesiologic treatments. The structure of isolated dimensions for 13 motor variables showed significant changes between two time points (two transitive states) in all three groups of subjects. In experimental groups, the treatments influenced the highest correlation of repetitive strength and aerobic endurance, with this very dimension integrating these capabilities at the second time point. Second dimension integrated explosive strength and anaerobic capacity, whereas third dimension integrated repetitive strength of the trunk and aerobic endurance in experimental group 1. In the control group of subjects, repetitive strength, aerobic endurance and anaerobic capacity were isolated as specific dimensions.  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