Most tin deposits in the world are genetically related to tin granite and form during complex magmatic-hydrothermal processes. Zircon is a common accessory mineral in granite and related ore systems ...and can host a number of ore metals, such as Sn, W, Nb, Ta, U and Th, in its crystal lattice. However, whether metal enrichment/depletion can trace ore-forming processes is still unclear. Here, we report that the metal concentrations in various types of zircons from the Mopanshan tin granites in the southern Great Xing'an Range (Northern China) can be used as good indicators of fluid metasomatism and Sn mineralization. Two lithological zones are developed in the Mopanshan pluton, including porphyritic syenogranite (PG) in the center and fine-grained syenogranite (FG) at the margin. Zircons in the PG (PGZ-1, PGZ-2, and PGZ-3) are all magmatic in origin, while zircons in the FG can be categorized into magmatic zircons (FGZ-1 and FGZ-2) and metasomatic zircons (FGZ-3). The PGZ-1 and FGZ-1 grains are transparent prismatic crystals with bright oscillatory zonation, whereas the PGZ-2 grains are murky crystals with dark oscillatory zonation. PGZ-3 and FGZ-2 grains occur as overgrowths of previously formed zircon (PGZ-1, PGZ-2, and FGZ-1) or as brown individual crystals, showing dark and homogeneous cathodoluminescence (CL) textures. The metasomatic FGZ-3 grains are translucent-opaque porous crystals with vermicular CL zonation and commonly replace FGZ-2. The trace element compositions of magmatic zircons are completely melt controlled, providing a record of magmatic evolution as a constant decrease in Zr/Hf ratios and a gradual increase in Th, U, Nb, and Ta contents. Moreover, the structure of magmatic zircons transforms from a crystalline state to an amorphous state as a consequence of radioactive decay of U and Th. A coupled dissolution-reprecipitation process is proposed for the formation of metasomatic FGZ-3. The reactive fluid is the magmatic fluid that exsolved from the melt in the late magmatic stage. The magmatic fluid replaced biotite and rare earth phosphates (mainly monazite and apatite) enclosed within biotite, resulting in significant amounts of Nb, Ta, Sn, P, Al, Ca, Fe, and REEs, which subsequently reacted with the FGZ-2 zircons to leach Th, U, Y, and HREEs. Eventually, REEs, Y, Th, and U in the fluid combined with P to form monazite and xenotime, while the other elements partially precipitated with the crystallization of the FGZ-3 zircons. Although the alteration of biotite only released approximately 190 ppm of Sn into the fluid, this is still a significant Sn source for the Sn deposits surrounding the Mopanshan pluton, taking the granite size (∼50 km2) and the volume proportion of biotite (∼5%) into account. Furthermore, based on previous studies on tourmaline from the Mopanshan granite and regional geochemistry, it may be inferred that the addition of wall rock components may also play an important role in Sn mineralization.
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•Magmatic and metasomatic zircons have been identified in the Mopanshan granite.•Formation of metasomatic zircon is due to a dissolution-reprecipitation process.•Zircon records the enrichment of Sn during magmatic-hydrothermal process.•The release of Sn by biotite alteration is a significant Sn source for Sn deposits.
We present the case of 24‐year‐old woman who presented with chronic headaches with features of raised intracranial pressure and bilateral papilledema. Brain magnetic resonance imaging revealed the ...characteristic features of idiopathic intracranial hypertension. A diagnosis supported by clinical features and other ancillary tests. These features are important for physicians to recognize early, so that timely treatment may prevent permanent complications from this rare but potentially sight‐threatening headache.
An efficient synthetic methodology to access biologically important and synthetically useful α-quaternary cysteine derivatives
via
asymmetric catalytic α-allylation of readily available ...2-thiazoline-4-carboxylates was successfully developed through a synergistic Cu/Pd catalytic system. A wide array of α-quaternary cysteine derivatives were obtained in moderate to high yields with good to excellent enantioselectivities (45-98% yields and 69->99% ee). Gram-scale asymmetric allylation was performed to obtain high yields maintaining the enantioselectivity. Moreover, some synthetic transformations to access chiral spirocyclic compounds proceeded smoothly, which exhibited the important utility of this methodology.
Highly efficient synergistic Cu/Pd catalyzed asymmetric α-allylation of 2-thiazoline-4-carboxylate was successfully achieved to access various α-allylated cysteine derivatives in moderate to high yields with excellent enantioselectivities (45-98% yields and 69->99% ee).
Neuropeptides, as pervasive intercellular signaling molecules in the CNS, modulate a variety of behavioral systems in both protostomes and deuterostomes. Allatostatins are neuropeptides in arthropods ...that inhibit the biosynthesis of juvenile hormones. Based on amino acid sequences, they are divided into three different types in arthropods: allatostatin A, allatostatin B, allatostatin C. Allatostatin C (AstC) was first isolated from Manduca sexta, and it has an important conserved feature of a disulfide bridge formed by two cysteine residues. Moreover, AstC appears to be the ortholog of mammalian somatostatin, and it has functions in common with somatostatin, such as modulating feeding behaviors. The AstC signaling system has been widely studied in arthropods, but minimally studied in molluscs. In this study, we seek to identify the AstC signaling system in the marine mollusc Aplysia californica. We cloned the AstC precursor from the cDNA of Aplysia. We predicted a 15-amino acid peptide with a disulfide bridge, i.e., AstC, using NeuroPred. We then cloned two putative allatostatin C-like receptors and through NCBI Conserved Domain Search we found that they belonged to the G protein-coupled receptor (GPCR) family. In addition, using an inositol monophosphate 1 (IP1) accumulation assay, we showed that Aplysia AstC could activate one of the putative receptors, i.e., the AstC-R, at the lowest EC
, and AstC without the disulfide bridge (AstC') activated AstC-R with the highest EC
. Moreover, four molluscan AstCs with variations of sequences from Aplysia AstC but with the disulfide bridge activated AstC-R at intermediate EC
. In summary, our successful identification of the Aplysia AstC precursor and its receptor (AstC-R) represents the first example in molluscs, and provides an important basis for further studies of the AstC signaling system in Aplysia and other molluscs.
Although many methods and new therapeutic drugs have been developed, the overall survival rate and long‐term survival rate of patients with gastric cancer (GC) are still not satisfactory. In this ...study, we investigated the effects of microRNA miR‐133a‐3p and transcription factor FOXP3 on proliferation and autophagy of GC cells and their interactions. Our results showed that knockdown of FOXP3 increased the proliferation and autophagy of GC cells. The relationship between FOXP3 and autophagy has not been reported previously. In addition, FOXP3 could directly bind the promoter region of TP53 and inhibit its expression. miR‐133a‐3p increased the proliferation and autophagy via decreasing the protein level of FOXP3 by targeting its 3′‐UTR. Our research provides new insights into the development of GC and provides new ideas and theoretical basis for the clinical treatment of GC and the development of new drug targets.
miR‐133a‐3p increased the proliferation and autophagy via decreasing the protein level of FOXP3 by targeting its 3′‐untranslated region. Our research provides new insights into the development of gastric cancer and provides new ideas and theoretical basis for the clinical treatment of gastric cancer and the development of new drug targets.
Hyperuricemia is a common metabolic disease that is caused by high serum uric acid levels. It is considered to be closely associated with the development of many chronic diseases, such as obesity, ...hypertension, hyperlipemia, diabetes, and cardiovascular disorders. While pharmaceutical drugs have been shown to exhibit serious side effects, and bioactive compounds from plant-based functional foods have been demonstrated to be active in the treatment of hyperuricemia with only minimal side effects. Indeed, previous reports have revealed the significant impact of bioactive compounds from plant-based functional foods on hyperuricemia. This review focuses on plant-based functional foods that exhibit a hypouricemic function and discusses the different bioactive compounds and their pharmacological effects. More specifically, the bioactive compounds of plant-based functional foods are divided into six categories, namely flavonoids, phenolic acids, alkaloids, saponins, polysaccharides, and others. In addition, the mechanism by which these bioactive compounds exhibit a hypouricemic effect is summarized into three classes, namely the inhibition of uric acid production, improved renal uric acid elimination, and improved intestinal uric acid secretion. Overall, this current and comprehensive review examines the use of bioactive compounds from plant-based functional foods as natural remedies for the management of hyperuricemia.
Noble metal nanostructures (NMNSs) play a crucial role in many heterogeneous catalytic reactions. Hollow and porous NMNSs possess generally prominent advantages over their solid counterparts due to ...their unordinary structural features. In this work, we describe a facial one-pot synthesis of hollow and porous Pd–Cu alloy nanospheres (Pd–Cu HPANSs) through a polyethylenimine (PEI)-assisted oxidation–dissolution mechanism. The strong coordination interaction between CuII and PEI facilitates the oxidation–dissolution of the Cu2O nanospheres template under air conditions, which is responsible for the generation of the Pd–Cu alloy and the convenient removal of the Cu2O nanospheres template at room temperature. Compared to the commercial Pd black, the Pd–Cu HPANSs show remarkably improved catalytic activity for the reduction of K2Cr2O7 by HCOOH at room temperature, attributing to the enhanced catalytic activity of the Pd–Cu HPANSs for the dehydrogenation decomposition of HCOOH.
Lung cancer is one of the most common malignant cancers in the world. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) is a second- or third-line therapy for mutated non-small ...cell lung cancer (NSCLC). It usually becomes drug resistance after a period of treatment. Triptolide (TPL) is an epoxy diterpenoid lactone compound extracted from Tripterygium wilfordii HOOK. F. and many studies demonstrated that TPL has a synergistic effect when combined with chemotherapy drugs. In this research, we plan to evaluate the combined effect of TPL and EGFR-TKIs (Gefitinib, Erlotinib, and Icotinib) and investigate the possible mechanisms. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was conducted to detect the cell viabilities, combined effect was evaluated by Combination Index. Molecular docking study was used to predict the binding ability of TPL. The expression of proteins was detected by Western blot. MTT results showed TPL had synergistic effect with three EGFR-TKIs at different concentrations on H1975 cells but not on H1299 cells. Molecular docking study demonstrated that TPL with T790M/L858R EGFR can form a more stable compound than that with wild type EGFR. Western blot results showed TPL inhibited the EGFR/Akt pathway and increased the expression of Bax and the ratio of Bax and Bcl-2 in H1975 cells. In conclusion, TPL had synergistic effect with three EGFR-TKIs on H1975 cells but not on H1299 cells, which may be due to the binding ability of TPL and different-type EGFR. The synergistic effect of TPL on H1975 cells may be partly related to the inhibition of the EGFR/Akt pathway.
An integrated observation of NOx that included coastal cities and oceanic cruises covering the Qingdao coastal waters sites (QDCW) and the Yellow Sea and East China Sea sites (YECS) was conducted in ...spring. The average concentrations of the coastal cities, the QDCW, and the YECS were 5.4 ± 4.1, 4.2 ± 3.5, and 2.9 ± 6.8 ppb for NO while 18.5 ± 7.2, 9.4 ± 5.2, and 4.9 ± 6.4 ppb for NO2, depicting lowest levels in the open seas. Atmospheric NO and NO2 showed similar spatial variations over the seas, the stations where the air masses originated from land or nearshore regions showed higher levels, but the decisive influencing factors were not the same in the different study areas. The calculated NOx flux value in the YECS (−8.7 × 10−17 mol N cm−2) indicated that the sea surface was a net sink of atmospheric NOx.
The sea was an important sink of the atmospheric NOx.NOx showed a decreasing trend from the coastal cities to the open seas.Light and wind speed were decisive factors influencing atmospheric NOx distributions.
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