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1.
Huan Jing Ke Xue ; 45(3): 1615-1628, 2024 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-38471874

RESUMO

Quantitatively determining the direct, indirect, and comprehensive effects of climatic factors on the growing season of the vegetation GPP (GPPGS) in the middle and lower reaches of the Yangtze River at the regional and vegetation type scales can provide a scientific basis for the management and restoration of regional vegetation resources under the background of global climate change. Using MODIS GPP data, meteorological data, and vegetation type data, combined with Theil-Sen Median trend analysis and the Mann-Kendall significance test, the spatiotemporal characteristics of the GPPGS in the middle and lower reaches of the Yangtze River were investigated at different temporal and spatial scales. Path analysis was used to further reveal the direct, indirect, and comprehensive effects of climate factors on GPPGS variation in different vegetation types. The results showed that:① from 2000 to 2021, the vegetation GPPGS in the middle and lower reaches of the Yangtze River showed a fluctuating upward trend, with a rising rate (in terms of C, same below) of 2.70 g·(m2·a)-1 (P<0.01). The GPPGS of different vegetation types all showed a significant upward trend (P<0.01), with shrubs having the highest upward rate of 3.31 g·(m2·a)-1 and cultivated vegetation having the lowest upward rate of 2.54 g·(m2·a)-1. ② The proportion of the area with an upward trend in GPPGS in the middle and lower reaches of the Yangtze River was 88.11%. The proportion of the area with an upward trend in GPPGS was greater than 84% for all different vegetation types, with shrubs (49.76%) and cultivated vegetation (44.36%) having significantly higher proportions of the area with an upward trend than that in other vegetation types. ③ The path analysis results showed that precipitation and the maximum temperature had a significant positive direct effect on vegetation GPPGS (P<0.05), whereas solar radiation had a non-significant positive effect (P ≥ 0.05). The indirect effects of maximum temperature, precipitation, and solar radiation on vegetation GPPGS were all non-significantly negative (P ≥ 0.05). Under the combined effects of direct and indirect influences, precipitation and maximum temperature had a non-significant positive effect on vegetation GPPGS (P ≥ 0.05), whereas solar radiation had a non-significant negative effect on vegetation GPPGS (P ≥ 0.05). Among different vegetation types, precipitation was the main climate factor affecting the changes in GPPGS of cultivated vegetation, whereas the maximum temperature was the main climate factor affecting the changes in GPPGS of coniferous forests, broad-leaved forests, shrubs, and grasslands. ④ The changes in vegetation GPPGS in the middle and lower reaches of the Yangtze River were mainly influenced by the direct effects of maximum temperature, precipitation, and solar radiation, with the direct effect of precipitation dominating 56.72% of the changes in GPPGS. The research results can provide a reference for quantifying the carbon sequestration potential of vegetation in the middle and lower reaches of the Yangtze River and formulating ecological restoration governance policies tailored to local conditions under the background of global climate change.


Assuntos
Mudança Climática , Ecossistema , Rios , Estações do Ano , Florestas , Temperatura , China
2.
Huan Jing Ke Xue ; 44(4): 1852-1864, 2023 Apr 08.
Artigo em Chinês | MEDLINE | ID: mdl-37040936

RESUMO

This study explored the temporal and spatial variation in PM2.5 concentration and its relationship with the vegetation landscape pattern in three typical economic zones in China, which is of great significance for regional PM2.5pollution control and atmospheric environmental protection. In this study, the pixel binary model, Getis-Ord Gi* analysis, Theil-Sen Median analysis, Mann-Kendall significance test, Pearson correlation analysis, and multiple correlation analysis were used to explore the spatial cluster and spatio-temporal variation in PM2.5 and its correlation with the vegetation landscape index in the three economic zones of China on the basis of PM2.5 concentration data and MODIS NDVI data set. The results showed that PM2.5 in the Bohai Economic Rim was mainly dominated by the expansion of hot spots and the reduction in cold spots from 2000 to 2020. The proportion of cold spots and hot spots in the Yangtze River Delta showed insignificant changes. Both cold and hot spots in the Pearl River Delta had expanded. PM2.5 showed a downward trend in the three major economic zones from 2000 to 2020, and the magnitudes of increasing rates were higher in the Pearl River Delta, followed by those in the Yangtze River Delta and Bohai Economic Rim. From 2000 to 2020, PM2.5 exhibited a downward trend in the context of all vegetation coverage grades, and PM2.5 had most significantly improved within extremely low vegetation coverage in the three economic zones. On the landscape scale, PM2.5 values were mostly correlated with aggregation index in the Bohai Economic Rim, with the largest patch index in the Yangtze River Delta and Shannon's diversity in the Pearl River Delta, respectively. Under the context of different vegetation coverage levels, PM2.5showed the highest correlation with aggregation index in the Bohai Economic Rim, landscape shape index in the Yangtze River Delta, and percent of landscape in the Pearl River Delta, respectively. PM2.5 showed significant differences with vegetation landscape indices in the three economic zones. The combined effect of multiple vegetation landscape pattern indices on PM2.5 was stronger than that of the single vegetation landscape pattern index. The above results indicated that the spatial cluster of PM2.5 in the three major economic zones had changed, and PM2.5 showed a decreasing trend in the three economic zones during the study period. The relationship between PM2.5 and vegetation landscape indices exhibited obvious spatial heterogeneity in the three economic zones.

3.
Med Oncol ; 26(3): 303-8, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19003546

RESUMO

To investigate the expressions of PIM-1 and hK2 mRNA in normal prostate, benign prostatic glandular hyperplasia (BPH), and prostate cancer (PCa), and to explore the association of PIM-1 and hK2 expressions with PCa progression. The samples were harvested from 37 patients with BPH, 23 patients with PCa, and three with normal prostate tissues. Total RNA was extracted from their prostate tissues and analyzed for PIM-1 and hK2 mRNA levels using SYBR green I-based quantitative real-time RT-PCR (QRT-PCR) assays and Southern blot analysis. The differences of gene expressions were calculated based on standard curve. Quantitative expressions of PIM-1 and hK2 mRNA in normal prostate, BPH, and PCa were 1.05 +/- 0.04, 2.57 +/- 0.74, 4.45 +/- 0.63, and 1.02 +/- 0.03, 2.264 +/- 0.46, 5.905 +/- 0.78, respectively. PIM-1 and hK2 were expressed higher in PCa than those in BPH and normal prostate tissues, the differences among which had statistic significance (P < 0.05). Our results support the hypothesis that PIM-1 and hK2 play a significant role in the growth of PCa and the detection of PIM-1 and hK2 mRNA expressions by QRT-PCR provided more reliable and helpful information on diagnosis, treatment, and prognosis of PCa.


Assuntos
Biomarcadores Tumorais/genética , Hiperplasia Prostática/metabolismo , Neoplasias da Próstata/metabolismo , Proteínas Proto-Oncogênicas c-pim-1/genética , RNA Mensageiro/biossíntese , Calicreínas Teciduais/genética , Idoso , Benzotiazóis , Biomarcadores Tumorais/biossíntese , Distribuição de Qui-Quadrado , Diaminas , Expressão Gênica , Humanos , Masculino , Compostos Orgânicos/química , Hiperplasia Prostática/genética , Neoplasias da Próstata/genética , Proteínas Proto-Oncogênicas c-pim-1/biossíntese , Quinolinas , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Calicreínas Teciduais/biossíntese
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