RESUMO
Soil respiration (Rs), as a key process of carbon cycle in terrestrial ecosystems, has a direct impact on atmospheric CO2 concentration. How Rs responds to global change factors, such as rainfall changes and increased N deposition, has become a hot and difficult issue in the field of global change. Compared with the responses of Rs to the single factor of rainfall changes or increased N deposition, studying the response of Rs to the interaction of these two factors is more in line with natural environment, which can predict the future changes of soil carbon emission more accurately. At present, the related researches focused on different terrestrial ecosystems all over the world, and revealed the response mechanism from three aspects: soil, microorganism, and plant. Here, the research progress of soil respiration in response to the interaction of rainfall changes and increased N deposition in different terrestrial ecosystems was reviewed from the aspects of Rs and its components, factors related with soil properties, microorganisms and plant, and the deficiencies of current researches, and the research direction to be strengthened in the future were pointed out. Our review would provide a reference for further understanding the response law and the mechanism of soil respiration to the interaction between rainfall changes and increased N deposition.
Assuntos
Nitrogênio , Solo , Carbono , Ciclo do Carbono , Ecossistema , Respiração , Microbiologia do SoloRESUMO
Purpose: To examine the role of ocular axial length as an ocular parameter for the prevalence and severity of diabetic retinopathy (DR). Methods: The cross-sectional Kailuan Diabetic Retinopathy Study included patients with diabetes who participated in the community-based longitudinal Kailuan Study and who had undergone ocular fundus photography. The fundus photographs were graded using the Early Treatment of Diabetic Retinopathy Study criteria. Results: The study included 1096 patients with diabetes (mean age: 60.8 ± 9.4 years; axial length: 23.37 ± 0.92 mm). In binary regression analysis, a higher DR prevalence was associated with shorter axial length (P = 0.007; odds ratio [OR]: 0.81; 95% confidence interval [CI]: 0.70, 0.95) after adjusting for longer known duration of diabetes (P = 0.02; OR: 1.13; 95%CI: 1.02, 1.24) and higher fasting blood glucose concentration (P < 0.001; OR: 1.38; 95%CI: 1.26, 1.52). A more severe DR stage was associated (regression coefficient r: 0.46) with shorter ocular axial length (P = 0.047; standardized regression coefficient ß: -0.06) after adjusting for higher fasting blood glucose (P < 0.001; ß: 0.41) and longer known duration of diabetes (P = 0.045; ß: 0.07). Longer axial length was associated with a lower DR prevalence (P = 0.003; ß: -0.10) after adjusting for younger age (P < 0.001), male sex (P < 0.001), higher body mass index (P = 0.016), and lower fasting blood glucose concentration (P = 0.036). Conclusions: After adjusting for systemic risk factors, DR prevalence decreased by 19% (95%CI: 5, 30) for each millimeter increase in axial length. With longer axial length being a surrogate for axial myopia, the marked increase in myopia prevalence worldwide may lead to a relative decrease in the prevalence and incidence of DR in future.
Assuntos
Comprimento Axial do Olho/fisiopatologia , Retinopatia Diabética/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Glicemia/metabolismo , China/epidemiologia , Estudos Transversais , Diabetes Mellitus Tipo 2/fisiopatologia , Retinopatia Diabética/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de RiscoRESUMO
In the title compound, C(26)H(32)N(8)O(6) (2+)·2BF(4) (-), the cation is built up from four fused rings, viz. two nearly planar imidazole rings and two triazine rings exhibiting chair conformations. One eth-oxy group is disordered between two positions in an approximate ratio 3:2. The F atoms of the two anions are each rotationally disordered between two orientations in the same 3:2 ratio. The crystal structure is stabilized by inter-molecular N-Hâ¯O, C-Hâ¯F and N-Hâ¯F inter-actions.