The 4.2 ka event in East Asian monsoon region, precisely reconstructed by multi-proxies of stalagmite

The 4.2 ka event is one of the most salient features of global climate change in the mid-late Holocene and influenced on the evolution of ancient civilizations. Although a lot of paleoclimate reconstructions have focused on it, the detailed structure and driving mechanism of the 4.2 ka event is still unclear. In this study, the variation of Asian summer monsoon (ASM) during 5000–3000 yr BP was reconstructed by using high-precision U-Th dating (average resolution of 7 yr) and multi-proxies (δ13C, δ18O, Ba / Ca, Sr / Ca, Mg / Ca) of stalagmite YK1306 from Yangkou Cave in southwestern China. The results showed that that the ASM weakened and precipitation decreased during 4600–4330 yr BP and 4070–3700 yr BP. During 4330–4070 yr BP, the ASM became strong, and precipitation increased. The multi-proxies variation of YK1306 showed a weak-strong-weak structure of the ASM during the 4.2 ka event, which reappeared in different geologic records. However, westerlies and Australian-Indian summer monsoon (AISM) both showed the opposite change pattern (strong-weak-strong) with the ASM. This was resulted by the different phases of North Atlantic Oscillation (NAO) on a centennial scale, which regulated by the Atlantic Meridional Overturning Circulation (AMOC). In positive NAO-like, the strength of Azores high and westerly wind restrained the intensity of ASM. Thus, the ASM and the Middle East regions experienced bimodal drought and increased dust flux from the north in both regions during the 4.2 ka event. The strengthened meridional winds in the westerlies-dominated climatic regime (WDCR) lead more water vapor from the Indian Ocean and Arabian Sea transporting to in the WDCR, and subsequently increases precipitation in the WDCR. Meanwhile, the weakening of the AMOC results in the southward migration of the Intertropical Convergence Zone (ITCZ) and strengthens the AISM in the southern Hemisphere, finally results in the opposite change of the AISM contrast to the ASM. In addition, the strong ASM in the era of the Chinese Xia Dynasty maybe produce frequent ancient floods, which led to the decline of Longshan and Liangzhu cultures. The weakening of the ASM after 4070 yr BP contributed to the successful regulation of the ancient floodwaters by Dayu in Chinese history. Therefore, it is maybe credible that the official age for the establishment of the Xia Dynasty in 4070 yr BP. Benefit from the comprehensive comparison and analysis based on the unprecedented high-precise chronology, high-resolution and multi-proxy's stalagmite records, this study not only detailed described the evolution of the ASM during the 4.2 ka event, but also is conducive to verify the age of the first dynasty of China (the Xia Dynasty), and the legend of Dayu.

Modulation Effect of Hardness on the Friction Coefficient and Its Mechanism Analysis of ZrB2/Mo Multilayers Synthesized by Magnetron Sputtering

ZrB2/Mo multilayers were prepared by the magnetron sputtering technique on Si (100) and Al2O3 (001) substrates. The friction behavior and wear mechanism of the multilayers were tested at variable modulation ratios (tZrB2:tMo) of 1:1 to 8:1 at different temperatures. Under the influence of an effective modulation ratio and temperature, the friction coefficient and hardness of ZrB2/Mo multilayers showed an almost opposite change rule, that is, the higher the hardness, the lower the friction coefficient. The hardness and elastic modulus reached the maximum value (26.1 GPa and 241.99 GPa) at tZrB2:tMo = 5:1 and the corresponding friction coefficient was 0.86. Meanwhile, the hardness and average friction coefficient at 500 °C were, respectively, 8.9 GPa and 1.23. First-principles calculations of the interface model of ZrB2 (001)/Mo (110) showed that the ionic bonds and covalent bonds at the interface can effectively improve the viscosity of the multilayer and the stability of the interface, and thus increase the hardness. This also indicated that the variation of the friction coefficient was mainly determined by the stability of the interface in the ZrB2/Mo multilayers.

Affixation in Morphology

Affixation is the morphological process that consists of adding an affix (i.e., a bound morpheme) to a morphological base. It is cross-linguistically the most common process that human languages use to derive new lexemes (derivational affixation) or to adapt a word’s form to its morphosyntactic context (inflectional affixation). Suffixes (i.e., bound morphemes following the base) and prefixes (i.e., bound morphemes preceding the base) are the most common affixes, with suffixation being more frequently recorded in the world’s languages than prefixation. Minor types of affixation include circumfixation and infixation. Conversion and back-formation are related derivational processes that do not make use of affixation. Many studies have concentrated on the need to differentiate derivation from inflection, but these morphological processes are probably best described as two end points of a cline. Prototypically, derivation is used to change a word’s category (part of speech) and involves a semantic change. A word’s inflectional distinctions make up its paradigm, which amounts to the different morphological forms that correlate with different morphosyntactic functions. Form-function mapping in (derivational and inflectional) affixation is a key issue in current research on affixation. Many deviations from the canonical One Form-One Meaning principle can be observed in the field of affixation. From a diachronic point of view, it has been demonstrated that affixes often derive from free lexemes by grammaticalization, with affixoids being recognized as an intermediate step on this cline. More controversial, but still attested, is the opposite change whereby affixes and affixoids develop into free morphemes through a process of degrammaticalization.

D-dimer and C-reactive Protein Blood Levels Over Time Used to Predict Pulmonary Embolism in Two COVID-19 Patients

The diagnosis of pulmonary embolism is challenging in symptomatic COVID-19 patients since shortness of breath, chest pain, tachycardia, tachypnoea, fever, oxygen desaturation and high D-dimer blood levels might be features of both diseases. We present two COVID-19 patients in whom pulmonary embolism was suspected (and diagnosed) due to a discrepancy between an increase in D-dimer blood levels and a decrease in C-reactive protein blood levels over time. We believe that an opposite change in the blood levels of both biomarkers over time may be used as a novel method to predict pulmonary embolism in COVID-19 patients.

A meta-analytic approach to mapping co-occurrent grey matter volume increases and decreases in psychiatric disorders

Numerous studies have investigated gray matter (GM) volume changes in diverse patient groups. Reports of disorder-related GM reductions are common in such work, but many studies also report evidence for GM volume increases in patients. It is unclear whether these GM increases and decreases independent or related in some way. Here, we address this question using a novel meta-analytic network mapping approach. We used a coordinate-based meta-analysis of 64 voxel-based morphometry studies of psychiatric disorders to calculate the probability of finding a GM increase or decrease in one region given an observed change in the opposite direction in another region. Estimating this co-occurrence probability for every pair of brain regions allowed us to build a network of concurrent GM changes of opposing polarity. Our analysis revealed that disorder-related GM increases and decreases are not independent; instead, a GM change in one area is often statistically related to a change of opposite polarity in other areas, highlighting distributed yet coordinated changes in GM volume as a function of brain pathology. Most regions showing GM changes linked to an opposite change in a distal area were located in salience, executive-control and default mode networks, as well as the thalamus and basal ganglia. Moreover, pairs of regions showing coupled changes of opposite polarity were more likely to belong to different canonical networks than to the same one. Our results suggest that regional GM alterations in psychiatric disorders are often accompanied by opposing changes in distal regions that belong to distinct functional networks.

Temporal dynamics of GABA and Glx in the visual cortex

ABSTRACTMagnetic resonance spectroscopy (MRS) can be used in vivo to quantify neurometabolite concentration and provide evidence for the involvement of different neurotransmitter systems, e.g., inhibitory and excitatory, in sensory and cognitive processes. The relatively low signal-to-noise of MRS measurements has shaped the types of questions that it has been used to address. In particular, temporal resolution is often sacrificed in MRS studies to achieve sufficient signal to produce a reliable estimate of neurometabolite concentration. Here we apply novel analyses with large datasets from human participants (both sexes) to reveal the dynamics of GABA+ and Glx in visual cortex while participants are at rest (with eyes closed) and compare this with changes in posterior cingulate cortex. We find that the dynamic concentration of GABA+ and Glx in visual cortex drifts in opposite directions, that is, GABA+ decreases while Glx increases over time. Further, we find that in visual, but not posterior cingulate cortex, the concentration of GABA+ predicts that of Glx 120 s later, such that a change in GABA+ is correlated with a subsequent opposite change in Glx. Together, these results expose novel temporal trends and interdependencies of primary neurotransmitters in visual cortex. More broadly, we demonstrate the feasibility of using MRS to investigate in vivo dynamic changes of neurometabolites.SIGNIFICANCE STATEMENTUsing large datasets of magnetic resonance spectroscopy acquisitions from human participants, we develop novel analyses to investigate the temporal dynamics of neurometabolite concentration in visual cortex. We find that while participants are at rest, the concentration of GABA+ and Glx drifts in opposite directions, that is, GABA+ decreases while Glx increases over time. Further, we find that the concentration of GABA+ predicts that of Glx 120 s later, such that a change in GABA+ is correlated with a subsequent opposite change in Glx. We show these phenomena are regionally localized to visual cortex.

Investigation on the Effects of SiO2 Content on the NTC Thermistor Properties of Ce1.2(1-x)Mn1-xSix System

Ce1.2(1-x)Mn1-xSix(x=0.1,0.2.0.3,0.4) NTC thermistor materials were prepared by the traditional solid-state reaction method. The effects of SiO2 content on the microstructure and electric properties of prepared materials are investigated through XRD, SEM, XPS and several instruments for electrical properties characterization. The results indicate that the average grain size increases with the increasing SiO2 content. The resistivity and materials constant B value exhibit opposite change laws. The minimum room resistivity of 7.18×105 Ω·cm and the maximum characteristic parameter B value of 5507K are obtained when x=0.2. And when x=0.1 the aging factor η is 0.34% and it decreases as the CeO2 content increases.

miR-217 Is a Useful Diagnostic Biomarker and Regulates Human Podocyte Cells Apoptosis via Targeting TNFSF11 in Membranous Nephropathy

Background. MicroRNAs have recently been verified as useful diagnostic biomarkers in various diseases. In this study, we investigated whether miR-217 is a useful diagnostic biomarker and the possible pathological mechanism of miR-217 in this disease. Methods. Patients with focal segmental glomerulosclerosis (FSGS), membranous nephropathy (MN), and diabetic nephropathy (DN) and control patients were enrolled in this study. The miR-217 inhibitor and mimics were transfected into human podocyte cells to investigate the pathological mechanism of miR-217 in this disease. Relevant indicators were detected and tested. Results. Compared with control patients, miR-217 was significantly downregulated and TNFSF11 was significantly upregulated in MN. Then, miR-217 had obvious separation between patients with MN and control patients, with an AUC of 0.941, a cutoff value of <750.0 copies/ul, and sensitivity and specificity of 88.9% and 75.9%. In addition, the TNFSF11 was confirmed to be the target gene of miR-217. Finally, in in vitro experiments, the upregulation of miR-217 could decrease the expression of TNFSF11 and not induce human podocyte cells apoptosis; however, the downregulation of miR-217 could bring about an opposite change. Conclusions. miR-217 is a useful diagnostic biomarker and is involved in human podocyte cells apoptosis via targeting TNFSF11 in membranous nephropathy.

Research on the influence of alkyl ammonium bromides on the properties of Ag/AgBr/GO composites

The photocatalytic activities of as-synthesized Ag/AgBr/GO nanocomposites became weaker when alkyl chain became shorter, whereas an opposite change for their SERS enhancements.