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Our understanding of climate dynamics during millennial-scale events is incomplete, partially due to the lack of their precise phase analyses under various boundary conditions. Here we present nine speleothem oxygen-isotope records from mid-to-low-latitude monsoon regimes with sub-centennial age precision and multi-annual resolution, spanning the Heinrich Stadial 2 (HS2) - a millennial-scale event that occurred at the Last Glacial Maximum. Our data suggests that the Greenland and Antarctic ice-core chronologies require +320- and +400-year adjustments, respectively, supported by extant volcanic evidence and radiocarbon ages. Our chronological framework shows a synchronous HS2 onset globally. Our records precisely characterize a centennial-scale abrupt "tropical atmospheric seesaw" superimposed on the conventional "bipolar seesaw" at the beginning of HS2, implying a unique response/feedback from low-latitude hydroclimate. Together with our observation of an early South American monsoon shift at the HS2 termination, we suggest a more active role of low-latitude hydroclimate dynamics underlying millennial events than previously thought.

The Younger Dryas (YD), arguably the most widely studied millennial-scale extreme climate event, was characterized by diverse hydroclimate shifts globally and severe cooling at high northern latitudes that abruptly punctuated the warming trend from the last glacial to the present interglacial. To date, a precise understanding of its trigger, propagation, and termination remains elusive. Here, we present speleothem oxygen-isotope data that, in concert with other proxy records, allow us to quantify the timing of the YD onset and termination at an unprecedented subcentennial temporal precision across the North Atlantic, Asian Monsoon-Westerlies, and South American Monsoon regions. Our analysis suggests that the onsets of YD in the North Atlantic (12,870 ± 30 B.P.) and the Asian Monsoon-Westerlies region are essentially synchronous within a few decades and lead the onset in Antarctica, implying a north-to-south climate signal propagation via both atmospheric (decadal-time scale) and oceanic (centennial-time scale) processes, similar to the Dansgaard-Oeschger events during the last glacial period. In contrast, the YD termination may have started first in Antarctica at ∼11,900 B.P., or perhaps even earlier in the western tropical Pacific, followed by the North Atlantic between ∼11,700 ± 40 and 11,610 ± 40 B.P. These observations suggest that the initial YD termination might have originated in the Southern Hemisphere and/or the tropical Pacific, indicating a Southern Hemisphere/tropics to North Atlantic-Asian Monsoon-Westerlies directionality of climatic recovery.

The prevalence of osteoarthritis (OA) in Tibetans is higher than that in Han, while Tibetans have a habit of drinking brick tea with high fluoride. A cross-sectional study was conducted to explore the association between fluoride exposure in drinking brick tea and OA. All subjects were divided into four groups by the quartiles (Q) of tea fluoride (TF) and urine fluoride (UF). ROC was plotted and OR were obtained using logistic regression model. The prevalence of OA in the Q3 and Q4 group of TF were 2.2 and 2.7 times higher than in the Q1 group, and the prevalence of OA in the Q2, Q3 and Q4 group of UF were 3.2, 3.5, and 4.1 times higher than in the Q1 group. ROC analysis showed the cutoff values were 4.523 mg/day (TF) and 1.666 mg/L (UF). In conclusion, excessive fluoride in drinking brick tea could be a risk factor for developing OA. [ABSTRACT FROM AUTHOR]

We report an anomalous structural transformation of a Cu(I) cluster into two different types of copper‐silver (CuAg) alloy nanoclusters. Different from previous reports, we demonstrate that under specifically designed reaction conditions, the Ag‐doping could induce a substantial growth of the starting Cu15 and a Ag13Cu20 nanocluster was obtained via the unexpected insertion of an Ag13 kernel inside the Cu(I)‐S shell. Ag13Cu20 demonstrates high activity to initiate the photopolymerization of previously hard‐to‐print inorganic polymers in 3D laser microprinting. Interestingly, a slight modification of the reaction condition leads to the formation of another Ag18‐xCuxS (8≤x) nanocluster templated by a central S2− anion, which possesses a unique electronic structure compared to conventional template‐free CuAg nanoclusters. Overall, this work unveils the intriguing doping chemistry of Cu clusters, as well as their capability to create different types of alloy nanoclusters with previously unobtainable structures and multifunctionality. [ABSTRACT FROM AUTHOR]

BackgroundExcessive gestational weight gain (GWG) is a potential risk factor for hypertensive disorders of pregnancy (HDP).MethodsWe systematically reviewed three electronic databases for relevant articles published in English: PubMed, EMBASE and Web of Science. The Newcastle-Ottawa Scale was used to assess study quality. Random-effects meta-analyses were performed to supply a pooled estimation of the OR comparing the risk of HDP among healthy pregnant women with and without excessive GWG.ResultsThe pooled estimation for the association between excessive GWG and the risk of HDPs yielded an odds ratio (OR) of 1.79 (95% CI: 1.61-1.99). A subgroup analysis showed that women who had excessive GWG were more likely to have an HDP (OR 1.82; 95% CI 1.53-2.17), preeclampsia (OR 1.92; 95% CI 1.36-2.72), or gestational hypertension (OR 1.67; 95% CI 1.43-1.95). The pooled estimation for the association between excessive GWG and the risk of HDPs among pregestational normal weight women yielded an OR of 1.57 (95% CI 1.26-1.96). A subgroup analysis showed that women who had excessive GWG were more likely to have HDP (OR 1.45; 95% CI 1.09-1.92) or gestational hypertension (OR 1.51; 95% CI 1.22-1.86). The summary ORs of pre-gestational underweight women and pre-gestational overweight and obese women were 2.17 (95% CI 1.56-3.02) and 1.32 (95% CI 1.08-1.63), respectively.ConclusionsThe findings of this study suggest that excessive GWG in accordance with the IOM recommendations influences the rate of HDP.