Effects of primary PCI and facilitated PCI on myocardial viability and ventricular systolic synchrony in acute myocardial infarction patients

Objective To evaluate short time effects of primary percutaneous coronary intervention (pPCI) and rtPA thrombolysis+PCI (rtPA+PCI) on myocardial viability and ventricular systolic synchrony in AMI patients.Methods Eighty seven patients with first AMI were divided into two groups: group A ( n =42), pPCI group, the patients underwent PCI within 6h after onset of AMI; group B ( n =45), rtPA+PCI group, the patients underwent PCI after thrombolysis within 6h after onset of AMI; Myocardial viability was measured by 99m Tc MIBI SPECT. While, the parameters of cardiac function LVEF and ventricular systolic synchrony LVPS were measured by 99m Tc gated cardiac blood pool image on the first and the fourth weekend. Results (1) The peak CK MB was significantly lower in group A than that in group B( P <0.01 ). (2) Myocardial infarction area (MIA) was decreased and radioactivity counts in MIA was significantly increased in group A and B on the 4th weekend compared with that on the first weekend ( P <0.01 ), but there were no significant difference between group A and group B. (3) LVEF, LVPS were no significant difference between group A and group B.Conclusions (1)pPCI in acute myocardial infartion can limit infarct area, maintain ventricular systolic synchrony and improve ventricular function; (2) but, in those hospitals that there were no any condition for PCI, they should transfer the patients to central hospital for PCI after thrombolysis at the first time. It is beneficial to improve myocardial viability and ventricular systolic synchrony of AMI patients in short time.

Compensatory effects between Pinus massoniana and broadleaved tree species

Aims Evaluation of the interaction intensity between Masson pine(Pinus massoniana)and broadleaved trees will facilitate selecting tree combinations suitable for reforestation in abandoned sites in subtropical areas.Methods Pinus massoniana and seven broadleaved trees species were grown either in monoculture or in two-species mixture.Biomass of tree species was measured and inter-specific interactions were estimated using log response ratio.Test of homogeneity of variances was performed to compare the stability of biomass in the monoculture of the broadleaved trees with that in the mixture.Important Findings Our results showed that the direction and intensity of interactions between P.massoniana and the broadleaved trees varied from year to year and the identity of the broadleaved species.Facilitative interactions were found between Camellia oleifera,Rhus chinensis and P.massoniana.Pinus massoniana had competitive effects on Lithocarpus glaber,Cyclobalanopsis glauca and Elaeocarpus japonicus.Significantly negative relations were found between biomass of P.massoniana and the broadleaved trees in the third year of the experiment,and the compensatory effects between P.massoniana and the broadleaved trees may be involved in stability maintenance in the multi-species forests in the subtropical area.The results of homogeneity test of variances also showed that the biomass per pot in the mixture had significantly lower variances than that in the monoculture,suggesting that total biomass is more stable in the mixture than the monoculture.

Assembly of plant communities in coastal wetlands--the role of saltcedar Tamarix chinensis during early succession

Aims The mechanisms of plant community assembly are hypothesized to vary at different stages of succession.Here,we explore the local assemblage structure of a herbaceous plant community at its early stage of succession in a supratidal wetland.specifically,we assess the role of Chinese saltcedar(Tamarix chinensis),the lone dominant shrub species,in shaping the spatial structure and species composi-tion in the local plant community,after landscape alteration.Methods We used the multivariate trend-surface analysis for analyzing the spatial structure of the community composition.a null model was also used to detect potential biotic interactions between species.statistical significance was derived from a permutation test by randomizing the presence-absence matrix and functional traits independently.sensitivity analysis by randomly selecting 50 subplots and repeating the null model tests was also done.Finally,rank correlation analysis was used to study the relationship between effect sizes and distance to nearest T.chinensis individuals.Important Findings The herbaceous plant community was highly structured and shaped by the presence of T.chinensis.at local scale,two functional traits,plant height and leaf area,were found to be significantly convergent.Dispersal,environmental stress and interspecific competition played a trivial effect on the local community assembly.The facilitating effect of T.chinensis on the pioneering herbaceous plants,through acting as a wind shelter,was put forward as the dominant community assembly process.

Interactions of the indigenous evergreen shrub Sabina vulgariswith coexisting species in the Mu Us sandland

Aims Facilitation is widespread in plant communities and particularly common in highly stressful environments.In the semi-arid Mu Us sandland where soil water and nutrients are short and grazing is heavy,many species grow within the large patches formed by the dense individuals of the unpalatable clonal shrub Sabina vulgaris,the only natural evergreen shrub species in the Mu Us sandland.However,the interactions between S.vulgaris and these coexisting species remain unclear,and we hypothesize that S.vulgaris can facilitate at least some species because within the patches vegetation is not grazed and soil water and nutrients may also be higher.Methods We measured the maximum height,coverage and number of individuals of each vascular species,little cover and thickness of biological crust at the soil surface in 1 m×1 m plots in three types of microsites associated with 40 patches of S.vulgaris:(i)at the center,(ii)at the inner edge and(iii)outside the patches.We also took soil samples and measured soil water content and content of total N,P,K and organic matter.Important Findings Soil water,nitrogen,organic matter and litter cover were the highest at the patch center,lowest outside the patches and intermediate at the inner edge of the patches,whereas thickness of biological crust was greater outside than at the center or at the inner edge.Among the 32 species recorded,six species preferred to occur within the patches,suggesting that S.vulgaris can facilitate these species most likely by grazing exclusion,increasing water and/or nitrogen resources in soil.However,most(19)species did not show preference and seven preferred outside.Also,species richness,pooled cover and number of individuals of all species were greater outside than within the patches,and such effects did not vary with the size of the S.vulgaris patches.These results suggest that the dominant interactions between S.vulgaris and the coexisting species are competition.The findings add to our knowledge that facilitation can be shown even when the competitive effects from the potential nurse plants are very strong.