A facile and efficient one-pot procedure for the synthesis of 5-imino-3,5-dihydro-2H-chromeno [3,4-c]pyridin-2-one derivatives via a four-component reaction of salicylaldehyde, malononitrile, ethyl cyanoacetate and hydrazine hydrate under mild conditions in excellent yield is described.The structures of fused molecules have been unambiguously confirmed by their spectroscopic techniques as well as by single crystal X-ray analysis.
Introduction Milankovitch theory has extensive application in sequence stratigraphy and the establishment of time scales. However, it is rarely applied to shallow strata rich in hydrates. Cyclostratigraphic analysis of the Quaternary unconsolidated sediments can help identify climate and sea level changes that correspond to orbital cycles and improve our understanding of the dynamic evolution of hydrates. Methods Using the natural gamma-ray log data from the deepwater area well W01 in the Qiongdongnan Basin, Milankovitch cycle analysis was conducted to identify the primary astronomical period in W01. Anchored to existing AMS-14 C age from bivalve shell as reference point, an astronomical age scale of W01 was established. Simultaneously, through the analyses of major trace elements and total organic carbon content (TOC) in sediment samples, how astronomical orbital cycles influenced past environmental conditions. Furthermore, employing sedimentary noise models, the relative sea level change of well W01 was reconstructed. Results Sedimentary cycles of 27.34 m and 6.73 m were identified in the GR data from well W01, corresponding to orbital periods of 405 kyr and 100 kyr eccentricity, with a duration of approximately 2.5 Myr. The spectral analysis of paleoenvironmental proxies reveals a sedimentary cycle of approximately 27 m, while the sedimentary noise model reconstructs the fluctuating rise in sea level change. An obliquity modulation period of approximately 170 kyr was identified in the TOC data, which may reflect the combined effects of obliquity and other orbital parameters. Discussion Spectral analysis of paleoenvironmental indicators showed that long eccentricity cycle had varying degrees of influence on changes in paleoclimate, paleosalinity, and paleoredox conditions. Additionally, a 1.2 Myr cycle was identified as a significant factor influencing sea level changes during the early Pleistocene in the South China Sea (SCS). In addition, it is confirmed that the dominant period of the glacial-interglacial cycle in the SCS from 0.6 Ma to the present is 100 kyr period. Synthesize the above analysis, during phases of low amplitude in the 405 kyr cycle or minimum value of the 100 kyr cycle, which are associated with lower temperature, conditions become more conducive to hydrate accumulation.
Abstract T and B lymphocytes are crucial players in cellular and humoral immune responses. The development, activation and differentiation of T and B lymphocytes are regulated by the best characterized PI3K‐PI (3,4,5) P3‐AKT phosphoinositide signalling pathway. As a branch of the phosphoinositide signalling pathway, the lipid phosphatase INPP4B inhibits AKT activation through degrading the phosphoinositide signalling messenger PI (3,4) P2. However, the role of Inpp4b in T and B lymphocytes remains elusive. Here, we reported that Inpp4b was highly expressed in human and murine T‐ and B‐1 lymphocytes. Despite its higher expression in T lymphocytes, neither T cell development and homeostasis nor in vitro T cell activation and CD4 + T cell differentiation were altered upon loss of Inpp4b . Interestingly, combined direct phenotype analysis of Inpp4b conventional knockout mice and adoptive transfer studies revealed that ablation of Inpp4b intrinsically reduced peritoneal B‐1 cells rather B‐2 cells. Moreover, Inpp4b deficiency led to impaired thymus independent (TI) and thymus dependent (TD) antigens‐induced antibody production. Further in vitro analysis revealed that CD40‐mediated B cell proliferation was impaired upon ablation of Inpp4b . Our findings reveal that Inpp4b is required in regulating B‐1 cell numbers and B cell‐mediated antibody production.
There is a growing body of literature on the relationships between land use and travel behavior.However,whether and how land use influences travel behavior are still unclear,due to the complexity of their relationships and differences in methodologies.This paper provides an analysis of theoretical models find in existing researches and propose future directions of research.
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