| 1. |
- Peng, Shushi, et al.
(author)
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Benchmarking the seasonal cycle of CO2 fluxes simulated by terrestrial ecosystem models
- 2015
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In: Global Biogeochemical Cycles. - 0886-6236. ; 29:1, s. 46-64
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Journal article (peer-reviewed)abstract
- We evaluated the seasonality of CO2 fluxes simulated by nine terrestrial ecosystem models of the TRENDY project against (1) the seasonal cycle of gross primary production (GPP) and net ecosystem exchange (NEE) measured at flux tower sites over different biomes, (2) gridded monthly Model Tree Ensembles-estimated GPP (MTE-GPP) and MTE-NEE obtained by interpolating many flux tower measurements with a machine-learning algorithm, (3) atmospheric CO2 mole fraction measurements at surface sites, and (4) CO2 total columns (X-CO2) measurements from the Total Carbon Column Observing Network (TCCON). For comparison with atmospheric CO2 measurements, the LMDZ4 transport model was run with time-varying CO2 fluxes of each model as surface boundary conditions. Seven out of the nine models overestimate the seasonal amplitude of GPP and produce a too early start in spring at most flux sites. Despite their positive bias for GPP, the nine models underestimate NEE at most flux sites and in the Northern Hemisphere compared with MTE-NEE. Comparison with surface atmospheric CO2 measurements confirms that most models underestimate the seasonal amplitude of NEE in the Northern Hemisphere (except CLM4C and SDGVM). Comparison with TCCON data also shows that the seasonal amplitude of X-CO2 is underestimated by more than 10% for seven out of the nine models (except for CLM4C and SDGVM) and that the MTE-NEE product is closer to the TCCON data using LMDZ4. From CO2 columns measured routinely at 10 TCCON sites, the constrained amplitude of NEE over the Northern Hemisphere is of 1.60.4 gC m(-2)d(-1), which translates into a net CO2 uptake during the carbon uptake period in the Northern Hemisphere of 7.92.0 PgC yr(-1).
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| 2. |
- Jin, Hongfang, et al.
(author)
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The Role of Sulfur Dioxide in the Regulation of Mitochondrion-Related Cardiomyocyte Apoptosis in Rats with Isopropylarterenol-Induced Myocardial Injury
- 2013
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In: International Journal of Molecular Sciences. - : MDPI. - 1661-6596 .- 1422-0067. ; 14:5, s. 10465-10482
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Journal article (peer-reviewed)abstract
- The authors investigated the regulatory effects of sulfur dioxide (SO2) on myocardial injury induced by isopropylarterenol (ISO) hydrochloride and its mechanisms. Wistar rats were divided into four groups: control group, ISO group, ISO plus SO2 group, and SO2 only group. Cardiac function was measured and cardiomyocyte apoptosis was detected. Bcl-2, bax and cytochrome c (cytc) expressions, and caspase-9 and caspase-3 activities in the left ventricular tissues were examined in the rats. The opening status of myocardial mitochondrial permeability transition pore (MPTP) and membrane potential were analyzed. The results showed that ISO-treated rats developed heart dysfunction and cardiac injury. Furthermore, cardiomyocyte apoptosis in the left ventricular tissues was augmented, left ventricular tissue bcl-2 expression was down-regulated, bax expression was up-regulated, mitochondrial membrane potential was significantly reduced, MPTP opened, cytc release from mitochondrion into cytoplasm was significantly increased, and both caspase-9 and caspase-3 activities were increased. Administration of an SO2 donor, however, markedly improved heart function and relieved myocardial injury of the ISO-treated rats; it lessened cardiomyocyte apoptosis, up-regulated myocardial bcl-2, down-regulated bax expression, stimulated mitochondrial membrane potential, closed MPTP, and reduced cytc release as well as caspase-9 and caspase-3 activities in the left ventricular tissue. Hence, SO2 attenuated myocardial injury in association with the inhibition of apoptosis in myocardial tissues, and the bcl-2/cytc/caspase-9/caspase-3 pathway was possibly involved in this process.
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| 3. |
- Zhao, Juan, et al.
(author)
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A cross-sectional study on upright heart rate and BP changing characteristics: basic data for establishing diagnosis of postural orthostatic tachycardia syndrome and orthostatic hypertension
- 2015
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In: BMJ Open. - : BMJ Publishing Group: Open Access / BMJ Journals. - 2044-6055. ; 5:6
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Journal article (peer-reviewed)abstract
- Objective: We aimed to determine upright heart rate and blood pressure (BP) changes to suggest diagnostic criteria for postural orthostatic tachycardia syndrome (POTS) and orthostatic hypertension (OHT) in Chinese children. Methods: In this cross-sectional study, 1449 children and adolescents aged 6-18 years were randomly recruited from two cities in China, Kaifeng in Henan province and Anguo in Hebei province. They were divided into two groups: 844 children aged 6-12 years (group I) and 605 adolescents aged 13-18 years (group II). Heart rate and BP were recorded during an active standing test. Results: 95th percentile (P-95) of delta heart rate from supine to upright was 38 bpm, with a maximum upright heart rate of 130 and 124 bpm in group I and group II, respectively. P-95 of delta systolic blood pressure (SBP) increase was 18 mm Hg and P-95 of upright SBP was 132 mm Hg in group I and 138 mm Hg in group II. P-95 of delta diastolic blood pressure (DBP) increase was 24 mm Hg in group I and 21 mm Hg in group II, and P-95 of upright DBP was 89 mm Hg in group I and 91 mm Hg in group II. Conclusions: POTS is suggested when delta heart rate is greater than= 38 bpm (for easy memory, greater than= 40 bpm) from supine to upright, or maximum heart rate greater than= 130 bpm (children aged 6-12 years) and greater than= 125 bpm (adolescents aged 13-18 years), associated with orthostatic symptoms. OHT is suggested when delta SBP (increase) is greater than= 20 mm Hg, and/or delta DBP (increase) greater than= 25 mm Hg (in children aged 6-12 years) or greater than= 20 mm Hg (in adolescents aged 13-18 years) from supine to upright; or upright BP greater than= 130/90 mm Hg (in children aged 6-12 years) or greater than= 140/90 mm Hg (in adolescents aged 13-18 years).
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