Another Year of Record Heat for the Oceans Cheng, Lijing; Abraham, John; Trenberth, Kevin E. ...
Advances in atmospheric sciences,
2023/6, Letnik:
40, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Changes in ocean heat content (OHC), salinity, and stratification provide critical indicators for changes in Earth’s energy and water cycles. These cycles have been profoundly altered due to the ...emission of greenhouse gasses and other anthropogenic substances by human activities, driving pervasive changes in Earth’s climate system. In 2022, the world’s oceans, as given by OHC, were again the hottest in the historical record and exceeded the previous 2021 record maximum. According to IAP/CAS data, the 0–2000 m OHC in 2022 exceeded that of 2021 by 10.9 ± 8.3 ZJ (1 Zetta Joules = 10
21
Joules); and according to NCEI/NOAA data, by 9.1 ± 8.7 ZJ. Among seven regions, four basins (the North Pacific, North Atlantic, the Mediterranean Sea, and southern oceans) recorded their highest OHC since the 1950s. The salinity-contrast index, a quantification of the “salty gets saltier—fresh gets fresher” pattern, also reached its highest level on record in 2022, implying continued amplification of the global hydrological cycle. Regional OHC and salinity changes in 2022 were dominated by a strong La Niña event. Global upper-ocean stratification continued its increasing trend and was among the top seven in 2022.
Grazing is widely used in more than one-forth of global terrestrial ecosystems, with three quarters are distributed on complex topography. Grazing and topography have both resulted in degradation of ...approximately 49 % of natural grasslands. However, research on the interaction between topography and livestock exclusion on grassland characteristics is scarce. This study was carried out on a typical steppe to explore the effect of topography and enclosure year on vegetation characteristics. Aboveground biomass, and species richness were examined for three different enclosure years (0, 3, and 6 years), on four slopes (0°, 15°, 30°, and 45° slope), and three aspects (flat, shady and sunny). The results indicated that: The aboveground biomass on the 0° slope had a greater value after 6 years of the enclosure. Aboveground biomass increased with the increasing enclosure year, while it decreased with increasing slope except enclosure for 0 year on shady slope. Aboveground biomass on the shady slopes was greater than on the sunny slopes. Species richness of community and perennial plants increased with increasing slope and enclosure year. The annual plants richness inversely correlated with slope and enclosure year. All plant diversity indexes increased with increasing enclosure year. Margalef and Shannon-wiener indexes decreased with increasing slope, while Simpson and Pielou indexes increased. This paper demonstrates that aspect, slope and enclosure affect aboveground biomass by affecting other vegetation characteristics. In conclusion, grassland production can be improved with moderate livestock exclusion under different topography.
(1) Enclosure is beneficial to the stability of grassland productivity, and a too-long enclosure is not conducive to the update of plants. (2) The shady slope is beneficial to the growth of certain functional groups, and may cause an increase of community richness. The aboveground biomass and species richness decrease with the increasing slope. (3) The effects of enclosure and topography on vegetation characteristics may be offset. Display omitted
•Aboveground biomass, plant richness and plant diversity indexes depend on enclosure year and slope.•Slope, enclosure year and their interaction showed a higher ratio to explain the total variation of community AGB.•Moderate livestock exclusion under different topography indicates the improvement of grassland production.
The long-range transport of Asian dust (AD) can carry large quantities of trace elements to the marginal seas of the Northwest Pacific, and the deposition of soluble fractions of aerosol elements may ...significantly impact the primary productivity and ecosystem structure. Samples of total suspended particulates (TSP) and size-segregated aerosols were collected synchronously at Huaniao Island in the East China Sea (ECS) between April 2010 and March 2011 and then analyzed for the total and soluble fractions of 14 trace elements. Twelve AD events were identified in the spring and autumn of the sampling year based on official records of AD storms from the China Meteorological Administration and verified by the high Al concentration in the aerosol samples. The dry deposition flux of the total or soluble fraction of each analyzed aerosol element was estimated using its concentration in the TSP samples and dry deposition velocity derived from the size-segregated samples. The dry deposition velocity varied from 0.7cms-1 for total Pb to 1.5cms-1 for total Al based on the mass median diameters (MMD) of 1.6 and 4.9 mu m, respectively, of associated particles. During AD events, the mean concentrations of the total and soluble fractions of Al, Fe, Mn, P and Ba increased significantly and led to enhanced dry deposition fluxes of these elements to the ECS (over a factor of 3 for the total and over 30% for the soluble fraction). The concentrations of the soluble fractions of anthropogenically derived elements (As, Cd, Cu, Pb, V and Zn) during AD events were lower than at other times and resulted in lower dry deposition fluxes. Asian dust events were associated with higher than average dry deposition fluxes of soluble Fe and P and lower fluxes of soluble Cu and Zn.
Background/Aims: Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and is a leading cause of cancer-related death worldwide. Luteolin, a flavonoid from traditional Chinese ...medicine, shows anti-cancer activity in many cancer cells, including HCC. However, the mechanism underlying the action of luteolin in HCC, especially its role in regulating cell autophagy, remains unclear. In the present study, we investigated the role of luteolin in regulating cell autophagy and the role of autophagy in luteolin-induced apoptosis. Methods: The 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay (MTT) was used to investigate cell viability. Flow cytometry analysis was used to detect the cell cycle and cell apoptosis. Hoechst 33342 staining was used to detect cell apoptosis. Transmission electron microscopy was used to investigate autophagy. qRT-PCR and western blotting were used to detect apoptosis- and autophagy-related mRNAs and proteins. Results: Luteolin reduced the viability of SMMC-7721 cells in a time and dose-dependent manner, and induced significant G0/G1-phase arrest. In addition, the results of flow cytometry analysis and Hoechst 33342 staining showed that luteolin treatment increased the number of apoptotic cells obviously, and the results of qRT-PCR and western blotting showed that luteolin treatment increased caspase 8 and decreased bcl-2 at the mRNA and protein levels. Furthermore, luteolin increased the number of intracellular autophagosomes, promoted LC3B-I conversion to LC3B-II, and increased Beclin 1 expression. Finally, co-treatment with the autophagy inhibitor chloroquine weakened the effects of luteolin on cell apoptosis. Conclusion: Luteolin induced apoptosis in human liver cancer SMMC-7721 cells, partially via autophagy. Thus, luteolin could be used as a regulator of autophagy in HCC treatment.
The traditional Chinese medicine
has been reported to be valid for cardiovascular and cerebrovascular diseases. However, its active components for the protection of ischemic stroke are not clear. We ...aimed to explore the active components of
against ischemic stroke as well as its potential mechanisms.
We investigated the brain protective effects of extracts from
, total glycosides (TGs), polysaccharides (PSs), and oligosaccharides (OSs) in a rat model of middle cerebral artery occlusion-reperfusion (MCAO/R). 2, 3, 5-Triphenyltetrazolium chloride (TTC) staining was used to assess the cerebral infarction volume, and Evans blue assay was adopted to assess the blood-brain barrier (BBB) permeability. Then, the expressions CD31, α-SMA, PDGFRβ, SYN, PSD95, MAP-2, ZO-1, claudin-5, occludin, Keap-1, and Nrf-2 were analyzed using western blotting or immunofluorescence, and the activities MDA, SOD, CAT, and GSH-Px were analyzed using kits.
TGs treatment remarkably decreased neurological deficit scores and infarction volumes, promoted angiogenesis and neural remodeling, and effectively maintained blood-brain-barrier integrity compared with the model group. Furthermore, TGs significantly decreased MDA levels and increased antioxidant activities (SOD, CAT, and GSH-Px) in brains. Meanwhile, TGs remarkably downregulated Keap-1 expression and facilitated Nrf-2 nuclear translocation. On the contrary, no protective effects were observed for PSs and OSs groups.
TGs are the main active components of
against MCAO/R-induced cerebral injury, and protection is mainly
the Nrf-2/Keap-1 pathway.
Chemotherapy and targeted therapy are the major treatments for gastric cancer (GC), but drug resistance limits its effectiveness. Here, we profile the proteome of 206 tumor tissues from patients with ...GC undergoing either chemotherapy or anti-HER2-based therapy. Proteome-based classification reveals four subtypes (G-I–G-IV) related to different clinical and molecular features. MSI-sig high GC patients benefit from docetaxel combination treatment, accompanied by anticancer immune response. Further study reveals patients with high T cell receptor signaling respond to anti-HER2-based therapy; while activation of extracellular matrix/PI3K-AKT pathway impair anti-tumor effect of trastuzumab. We observe CTSE functions as a cell intrinsic enhancer of chemosensitivity of docetaxel, whereas TKTL1 functions as an attenuator. Finally, we develop prognostic models with high accuracy to predict therapeutic response, further validated in an independent validation cohort. This study provides a rich resource for investigating the mechanisms and indicators of chemotherapy and targeted therapy in GC.
The mechanisms of resistance to therapy in gastric cancer remain to be explored. Here, proteomic profiling of 206 tumour tissues from patients treated with chemotherapy and anti-HER2-based therapy results in the identification of four molecular subtypes and the development of prognostic models.
Pterocephalus hookeri (C.B. Clarke) Höeck, one of the most popular Tibetan herbs, has been widely applied in Tibetan medicine prescriptions. Chemical investigations have led to the isolation of many ...bis-iridoids. However, the pharmacological activities of bis-iridoid constituents of this plant have never been reported before.
This study evaluated the anti-inflammatory and analgesic activities of afraction of bis-iridoid constituents of P. hookeri (BCPH) in order to provide experimental evidence for its traditional use, such as for cold, flu, and rheumatoid arthritis.
The analgesic effects of BCPH were investigated using the hot-plate test and acetic acid-induced writhing test. The anti-inflammatory activities were observed using the following models: carrageenin-induced edema of the hind paw of rats and xylene-induced ear edema in mice. The effects of dexamethasone administration were also studied.
BCPH significantly increased the hot-platepain threshold and reduced acetic acid-induced writhing response in mice. Moreover, BCPH remarkably inhibited xylene-induced ear edema and reduced the carrageenin-induced rat paw edema perimeter.
The results reveal that BCPH has central, peripheral analgesic activities as well as anti-inflammatory effects, supporting the traditional application of this herb in treating various diseases associated with inflammation and pain.
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Atmospheric deposition is one of important sources for nutrients to the surface ocean. Previous estimates for dry deposition fluxes of nutrients have mainly employed a single-mode particle model, and ...here we attempt to use size-segregated samples collected at Huaniao Island of the East China Sea (ECS) and dry deposition velocities derived from particle size and meteorological conditions of each sampling day. The dry deposition fluxes of NO3−, NH4+, and SP are estimated to be 6080, 10,006, and 26 μmol m−2 yr−1 respectively over the ECS using size-segregated samples. It is found that assuming a constant deposition velocity could overestimate the dry flux of NO3− by a factor of 6 while underestimate the flux of NH4+, which would alter the dry flux ratio of NH4+/NO3− from 1.6 to 0.1 with potential effects on the primary production and phytoplanktonic structure in the ECS. For coastal oceans influenced significantly by NH3 sources, aerosol NH4+ to non-sea-salt (nss-) SO42− ratio could be high and excess NH4+ may drag 34–54% of NO3− to fine mode aerosols, which may cause a large overestimation of dry flux of NO3− over the ocean by assuming its deposition velocity similar to that of coarse particle.
► Dry depositions of nutrients are the highest in spring and the lowest in summer over the ECS. ► Assuming a constant deposition velocity may overestimate dry flux of NO3−. ► High NH4+/SO42− ratio implies the existence NO3− in fine mode aerosols. ► Atmospheric input of DIN could support over 20% of the new production.
Although the effects of grazing on soil respiration are well understood, there is still a lack of understanding about the mechanisms underlying the effects of grazing intensity on soil respiration. ...In addition, the response of soil respiration to the grazing season, such as warm- and cold-season grazing, remains unclear. To determine how grazing intensity (no, light grazing, moderate grazing, heavy grazing) and grazing season (warm-season grazing, WG; cold-season grazing, CG) affect soil respiration, we conducted soil respiration measurements in two long-term grazed grasslands under CG and WG from 2010 to 2011. Our results showed that light, moderate, and heavy grazing significantly increased soil respiration relative to no grazing in 2010, but grazing intensity had little effect on soil respiration in 2011. With the increase in grazing intensity, soil respiration decreased by 10–17% at the WG site but increased by 23–30% at the CG site. Structural equation modeling analysis indicated that grazing intensity indirectly affected soil respiration by altering aboveground and soil microbial biomass carbon. CG enhanced soil respiration by 22% relative to WG. Grazing season-induced soil moisture, soil temperature, soil microbial biomass carbon and nitrogen could be mechanisms underlying increased soil respiration under in grazed grasslands. Precipitation had a strong correlation with soil respiration. Our results highlight the importance of grazing season altering soil respiration in semiarid grassland ecosystems and indicate that interactive effects of grazing season and precipitation events on soil respiration need to be considered in the future.
Total suspended particulate (TSP) samples were collected at a pristine island (Huaniao) in northern East China Sea (ECS) between Mar. 2011 and Jan. 2013 and analyzed for the concentrations of major ...ions and trace elements. Aerosol sources and the distribution of source regions are identified using positive matrix factorization (PMF) and potential source contribution function (PSCF) methods. It is found that aerosols over Huaniao Island are contributed by six main factors including primary industrial emissions (11.3%), secondary aerosol (22%), oxalate-associated aerosol (15.7%), sea salt (36.7%), ship emission (6.3%) and mineral dust (8.1%). Anthropogenic source contribution to the resolved aerosol mass reached the highest (76.6%) and lowest (18%) values in January 2013 and August 2012 respectively, strongly influenced by the prevailing winds of East Asian monsoon. The main source regions of secondary aerosol are southeastern Hebei and Shandong, which is consistent with the most intensive distribution of coal-fired power plants and the largest emission of precursors in this area. Oxalate-associated aerosol is produced primarily along the coastal line. Primary industrial emissions mainly originate from southwestern Shandong and Yangtze River Delta.
•Six main contributors to aerosols over coastal ECS are identified.•Over 50% of resolved aerosol mass is contributed by anthropogenic sources.•Anthropogenic emissions are mainly from Shandong and Yangtze River Delta.•Ship emission is a significant source of aerosols over coastal ECS in summer.
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