Search

Interannual variability of the South Equatorial Current (SEC) in the southeast Indian Ocean is investigated using Archiving, Validation, and Interpretation of Satellite Oceanographic Data (AVISO) and Global Ocean Reanalysis and Simulations (GLORYS) data from January 1993 to December 2022 and a 1.5-layer reduced-gravity model. Interannual variability of the SEC averaged over the upper 200 m in the southeast Indian Ocean is influenced by El Niño–Southern Oscillation (ENSO). The SEC has a significant positive correlation with the Niño-3.4 index and lags the Niño-3.4 index by 12–15 months, with the SEC weakening significantly during the decaying years of El Niño events and vice versa for La Niña events. Mechanistic studies suggest that during the developing years of El Niño events, the northward sea level anomaly (SLA) pressure gradient between the negative SLA off Sumatra–Java coast and the positive SLA of SEC region (90°–115°E, 9°–13°S) strengthens the SEC under geostrophic equilibrium. During the decaying years of El Niño events, the negative SLA in the tropical western Pacific Ocean propagates through the Maritime Continent to the SEC region. The SLA pressure gradient between the Sumatra–Java coast and the SEC region reverses to southward. This induces an eastward geostrophic current anomaly under geostrophic equilibrium, significantly weakening the SEC. The converse holds for La Niña events. Local wind in the southeast Indian Ocean has a suppressive effect on the SLA propagated to this area. The results of the 1.5-layer reduced-gravity model verify these phenomena, and the westward-propagating SLA from the Maritime Continent induced by the Pacific wind plays a dominant role in the SLA variation in the SEC region from model experiment. This study can improve the understanding of the effects of ENSO processes on ocean circulation in the southeast Indian Ocean. [ABSTRACT FROM AUTHOR]

Momordin Ic (MI) is a natural pentacyclic triterpenoid enriched in various Chinese natural medicines such as the fruit of Kochia scoparia (L.) Schrad. Studies have shown that MI presents antitumor properties in liver and prostate cancers. However, the activity and potential mechanisms of MI against colorectal cancer remain elusive. Here, we showed that MI inhibited cell proliferation with G0/1 phase cell cycle arrest in colon cancer cells. Moreover, it was observed that MI increased apoptosis compared to untreated cells. Further investigation showed that the SUMOylation of c-Myc was enhanced by MI and led to the down-regulated protein level of c-Myc, which is involved in regulating cell proliferation and apoptosis. SENP1 has been demonstrated to be critical for the SUMOylation of c-Myc. Meanwhile, knockdown of SENP1 by siRNA abolished the effects of MI on c-Myc level and cell viability in colon cancer cells. Together, these results revealed that MI exerted an anti-tumor activity in colon cancer cells via SENP1/c-Myc signaling pathway. These finding provide an insight into the potential of MI for colon cancer therapy.

Background: About half of the patients with esophageal cancer are presenting with metastasis at initial diagnosis. However, few studies have concerned on the prognostic factors of metastatic esophageal adenocarcinoma (mEAC). This research aimed to investigate the effects of single bone metastasis (BM) and single liver metastasis (LM) on prognosis of mEAC patients. Methods: Data were obtained from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program database. We compared the effects of LM and BM on overall survival (OS), EAC-specific survival (CSS), and EAC-specific death (EASD) by multivariate Cox regression, Kaplan-Meier analysis, and competing risk regression models. Results: A total of 1,278 EAC patients were recruited in this study. Of which 78.95% (1009/1278) were EASD, and 12.68% (162/1278) were non-EAC-specific death (non-EASD). In multivariate Cox regression analysis, surgery, chemotherapy, and AJCC.T2 (vs. T1) were identified as protective factors for OS&CSS, while divorced/separated, single/unmarried (vs. married), grade III-IV (vs. grade I-II) and BM (vs. LM) were identified as risk factors. Competing risk regression analysis further confirmed that surgery and chemotherapy were beneficial to the patients with mEAC, and BM (vs. LM) was a risk factor for mEAC patients when considering the existence of the competitive risk events. Conclusion: Our study indicated that mEAC patients with BM face a worse prognosis compared to those with LM. Additionally, surgery and chemotherapy emerge as protective factors for mEAC patients. These findings offer evidence-based insights for clinical management and contribute to the field. [ABSTRACT FROM AUTHOR]

The East African Coastal Current (EACC) is an important western boundary current of the tropical south Indian Ocean and plays an important role in the ocean circulation and biogeochemical cycles in the Indian Ocean. This study investigates the interannual variability of the EACC and its dynamical mechanisms. The result shows that the EACC has interannual variability associated with El Niño–Southern Oscillation (ENSO) during 1993–2017. The EACC shows a significantly positive correlation with the Niño-3.4 index with a correlation coefficient of 0.65, lagging the Niño-3.4 index by 18 months. During the decaying phases of El Niño (La Niña) events, the negative (positive) sea level anomaly (SLA) propagates westward as upwelling (downwelling) Rossby waves from the southeast Indian Ocean to the southwest Indian Ocean and then strengthens (weakens) the EACC due to zonal SLA gradient off the East African coast under geostrophic equilibrium. The SLA gradually weakens in the southeast Indian Ocean during its westward propagation but strengthens in the southwest Indian Ocean promoted by local wind stress curl anomaly. This study can improve our understanding of the relationship between the western boundary current of the tropical south Indian Ocean and large-scale ENSO air–sea processes and is important for managing marine fisheries and ecosystems on the East African coast. [ABSTRACT FROM AUTHOR]

We herein report a visible light induced dehydrogenative phosphonylation reaction of glycine derivatives and di‐aryl phosphine oxides. A diverse range of phosphine‐glycine derivatives were constructed under ambient condition in the absence of catalyst and additives. A plausible mechanism was also proposed. [ABSTRACT FROM AUTHOR]

Using multiple observational and reanalysis data, this paper investigates the impact of the interdecadal shift in summer Arctic Oscillation (AO) on precipitation in East Asia, by removing ENSO influences. The results indicate that the lower-layer activity center of summer AO in Atlantic shifted eastward after the mid-1980s. This regime shift of summer AO has a significant impact on precipitation in East Asia. Before the mid-1980s, the key regions in which precipitation was affected by AO in East Asia were northern East Asia and Northeastern China and adjacent regions. After the mid-1980s, the key regions in which precipitation was affected by AO in East Asia were central Inner Mongolia and Southern China. The mechanism of precipitation changes can be attributed to changes in atmospheric circulation and water vapor transport related to AO changes. After the mid-1980s, the influence of AO on geopotential height over northern East Asia weakened; meanwhile, the impact of AO on geopotential height over China increased. Consistent with the changes in atmospheric circulation, water vapor transport in East Asia also underwent interdecadal changes before and after the mid-1980s. The differences in atmospheric circulation and water vapor transport in East Asia can be traced back to the North Atlantic. Before the mid-1980s, wave activity flux related to summer AO tended to propagate in high latitudes and subtropics; after the mid-1980s, the wave activity flux changed in its subtropical path and propagated eastward from the North Atlantic through the Middle East to China, significantly affecting the summer precipitation in China. [ABSTRACT FROM AUTHOR]