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Synthesis of the C19-truncated maltepolide E has been accomplished via a diene–ene RCM strategy without damage to the C11–C14 alkenyl epoxy unit. Upon release of the C17-OH group, it attacked at the C14 position with double bond migration and epoxide ring-opening to furnish the C19-truncated maltepolide A and B as proposed for the biosynthesis of maltepolides. Preliminary cytotoxicity data of the synthesized C19-truncated maltepolides against L929 mouse fibroblast cell line suggest irrelevance of the vinyl epoxide and importance of the conjugated dienyl keto unit for the observed anticancer activity.

Pseudourine (Ψ) is the most abundant cellular RNA modification, present in tRNA, rRNA, snRNA, mRNA, long noncoding RNA (lncRNA), and others. Ψ sites and fractions are dynamically regulated in stress response and across development stages. Although high throughput Ψ sequencing methods based on N-Cyclohexyl-N'-(2-morpholinoethyl)carbodiimide (CMC) reaction are available for Ψ detection transcriptome-wide, a simple method for the analysis of specific, targeted Ψ sites and their fraction quantitation is needed to better investigate Ψ function. Here, we describe an RT-PCR and gel electrophoresis based method that can sensitively and quantitatively assess Ψ at single-nucleotide resolution in mRNA/lncRNA, termed CMC-RT and ligation assisted PCR analysis of Ψ modification (CLAP). The principle of the CMC-method is the reverse transcription stop induced by the CMC-Ψ adduct. In CLAP, CMC reaction is first carried out with the RNA sample. Reverse transcription using a non-processive RT produces two cDNA products for each RNA transcript, one with the 3' end at the Ψ site, the other read-through product from the unmodified RNA. Using splint oligonucleotide assisted site-specific ligation, these two cDNA products are then visualized on a gel as two distinct PCR products in the same lane corresponding to the Ψ-modified and unmodified target site. CLAP validates Ψ sites identified by high throughput sequencing, quantifies Ψ levels in mRNA and lncRNA, and enables convenient and rapid investigation on the function and mechanism of the Ψ modification.

Summary Oxidative C-H/C-H cross-coupling reactions between two (hetero)arenes through 2-fold C-H activation offer rapid assembly of diverse bi(hetero)aryls. Herein, a Pd-catalyzed asymmetric oxidative C-H/C-H cross-coupling reaction of ferrocenes with indolizines was disclosed. A palladium(II)/monoprotected amino acid (MPAA) catalytic system exhibited excellent reactivity, regioselectivity, and enantioselectivity for the coupling reaction. This approach marks the first example of direct arylation of indolizines in an enantioselective oxidative C-H/C-H cross-coupling process and offers a powerful strategy for the synthesis of highly enantioenriched planar chiral ferrocenes.

In this work, a simple but effective method based on Gamma-ray initiated polymerization was reported for the first time through direct irradiation of CNCs and ionic liquid monomer to obtain poly (ionic liquids) functionalized CNCs (IL@CNCs). The adsorptive removal of Congo red (CR) from aqueous solution by IL@CNCs was also examined and the influence of contact time, pH values, initial concentrations and temperature on adsorption behavior was investigated in detail. Under the same adsorption conditions, the adsorption capacity was increased from 59.72 mg/g (CNCs) to 195.83 mg/g (IL@CNCs). The results of the adsorption isotherm and adsorption kinetics showed that the experimental data were more suitable to be described by the Freundlich isotherm adsorption model and the pseudo-second-order model. The adsorption process of CR on the surface of the adsorbent was endothermic and spontaneous. When the aqueous solution was acidic, it was more conducive to the adsorption of CR. At 100% breakthrough, the value of adsorption capacity is 199.95 mg/g and the value of partition coefficient is 9.64. Moreover, the adsorption capacity is expected to be further improved through adjustment of polymerization parameters and this method can also be used for preparation other poly (ionic liquids) modified composites.

d-2-Hydroxyglutarate (d-2-HG) is a metabolite involved in many physiological metabolic processes. When d-2-HG is aberrantly accumulated due to mutations in isocitrate dehydrogenase or d-2-HG dehydrogenase, it functions in a pro-oncogenic manner and is thus considered a therapeutic target and biomarker in many cancers. In this study, DhdR from Achromobacter denitrificans NBRC 15125 is identified as an allosteric transcriptional factor that negatively regulates d-2-HG dehydrogenase expression and responds to the presence of d-2-HG. Based on the allosteric effect of DhdR, a d-2-HG biosensor is developed by combining DhdR with amplified luminescent proximity homogeneous assay (AlphaScreen) technology. The biosensor is able to detect d-2-HG in serum, urine, and cell culture medium with high specificity and sensitivity. Additionally, this biosensor is used to identify the role of d-2-HG metabolism in lipopolysaccharide biosynthesis of Pseudomonas aeruginosa, demonstrating its broad usages., d-2-hydroxyglutarate (d-2-HG) is a metabolite that can be aberrantly accumulated and acts as a biomarker in many cancers. Here the authors report a d-2-HG biosensor based on the allosteric transcription factor DhdR which they use for detection in serum and urine.

4'-O-Methylpyridoxine (MPN) and MPN-5'-glucoside (MPNG) are collectively known as ginkgotoxin, which are the main toxic ingredients of excessive consumption of Ginkgo biloba seeds. Water extraction is the generally adopted sample preparation method for high-performance liquid chromatography determination of ginkgotoxin. However, endogenous enzymes such as glycosidases in Ginkgo biloba seeds can hydrolyze MPNG to MPN in the process of water extraction, which will result in the measured contents of MPN and MPNG but not their natural contents in Ginkgo biloba seeds. In this work, inhibitors for the endogenous enzymes were first screened, and it was found that silver fluoride could effectively inhibit endogenous enzymes such as glucosidase and phosphatase. The optimized concentration of silver fluoride was 25 mmol/L, which could effectively inhibit the endogenous enzymes for more than 60 h. A new sample preparation method based on water extraction with 25 mmol/L silver fluoride addition was thus developed. This method was employed to determine the native contents of MPN and MPNG in the exotesta and kernel of five Ginkgo biloba seed cultivars. The result showed that the contents of MPNG in the exotesta and kernel of five cultivars were significantly higher than those of MPN. MPNG was present at high content in raw seeds, which was the main form of ginkgotoxin in seeds. The method established in this work is simple and effective and can be used to accurately quantify the native contents of MPN and MPNG.

Stimuli-responsive materials that can be reversibly switched by light are of immense interest. Among them, photo-responsive spin crossover (SCO) complexes have great promises to combine the photoactive inputs with multifaceted outputs into switchable materials and devices. However, the reversible control the spin-state change by photochromic guests is still challenging. Herein, we report an unprecedented guest-driven light-induced spin change (GD-LISC) in a Hofmann-type metal-organic framework (MOF), [Fe(bpn){Ag(CN) 2 } 2 ]·azobenzene. ( 1 , bpn = 1,4-bis(4-pyridyl)naphthalene). The reversible trans-cis photoisomerization of azobenzene guest upon UV/vis irradiation in the solid state results in the remarkable magnetic changes in a wide temperature range of 10-180 K. This finding not only establishes a new switching mechanism for SCO complexes, but also paves the way toward the development of new generation of photo-responsive magnetic materials.

Improving the insufficient carrier separation dynamics is still of significance in carbon nitride (C3 N4 ) research. Extensive research has been devoted to improving the carrier separation efficiency through a single strategy, while ignoring the synergistic enhancement effect produced by coupling two or more conventional strategies. Herein, we reported the fabrication of cyano group-containing Fe-doped C3 N4 porous materials via direct co-calcination of iron acetylacetonate and melamine for synergistically improving the photocatalytic performance. Iron acetylacetonate can promote the generation of cyano groups and form Fe-doping in C3 N4 , thereby increasing the visible-light absorption and reactive sites. Further, the internal donor-acceptor system formed by cyano groups and Fe-doped sites promoted charge carrier separation and inhibited the radiation recombination of e- -h+ pairs. The optimized photocatalytic activity of Fe-CN-2 sample was 4.5 times of bulk C3 N4 (BCN).

Circadian rhythm disorder (CRD) in space flight can lead to memory impairment, performance decrements and adverse health outcomes, the main manifestations of which are circadian desynchronization, sleep loss and insomnia. Sleep deprivation (SD) provide the means to evaluate these effects and the risks associated with CRD on ground. Gastrodia elata Blume (GEB) has beneficial effects on the treatment of sleep disturbances and memory loss. Fresh GEB (FG), an unprocessed raw tuber of GEB, has been used as functional health food in Asian countries for a long time. However, the research report of FG to ameliorate memory impairment caused by insomnia or lack of sleep is meager. In this study, ICR male mice were sleep-deprived continuously and water extract of FG (WFG) was orally administrated (3 and 9 g/kg/d, i.g) during the SD process lasted for 25 days, except control and model groups gavage administration with water, positive control group with modafinil (MOD, 0.1 g/kg/d, i.g). We studied the effect of WFG on CRD-induced learning and memory impairment using a set of behavioral analyses including the object location recognition test (OLRT), novel object recognition test (NORT), and the passive avoidance test (PAT). In addition, oxidative stress parameters were assessed by measuring the malondialdehyde (MDA) and superoxide dismutase (SOD) reactivity in serum and hippocampus. Our results revealed that SD decreased discrimination index (DI) in OLRT and NORT, with shorter latency into the dark chamber in PAT. Both WFG and MOD treatment can reverse these changes (P0.05). We concluded that WFG treatment improve CRD-induced learning and memory impairment and oxidative stress damage which makes FG a promising candidate as herbal health product of memory decline in CRD.

In this paper, the influence of NiO support on the synthesis of methanol from CO2 hydrogenation on In2O3(110) defect surface was studied with density functional theory (DFT). Two methanol synthesis pathways, namely HCOO pathway and reverse water gas (RWGS) pathway, were analyzed. The reaction energy and activation energy barrier of each elementary reaction involved in the HCOO and RWGS pathways were calculated. The results show that the NiO support can enhance the adsorption performance of In2O3 catalyst for CO2 and promote the generation of methanol through the HCOO reaction path. In the HCOO path, the hydrogenation of HCOO to H2COO is the rate-determining step for the HCOO reaction path, and the activation energy barrier is 1.66 eV. The NiO-supported In2O3(110) defect surface has a promoting effect on the hydrogenation of CO2, which is conducive to the synthesis of methanol from CO2 along the HCOO pathway, thus improving the efficiency of methanol synthesis from CO2 hydrogenation.

A lactic acid bacteria (LAB) isolated from pickled Chinese cucumber was screened for bacteriocin production. The strain was identified to be Enterococcus faecium HDX-2. Based on the Plackett-Burman (PB) experiment, glucose, Ca2+, and initial pH were found to be the most significant parameters of bacteriocin production. Afterward, effects of the three main parameters on bacteriocin activity were further investigated by central composite design (CCD) and the optimum composition was glucose 22 g/L, Ca2+ 0.6 mM, and initial pH 7.2. Optimum results showed that bacteriocin activity was increased to 1337.60 ± 36.71 AU/mL, 2.23-fold higher than in MRS medium without parameters optimization. The bacteriocin also showed significant antimicrobial activity against Listeria monocytogenes in meat and cheese model system.

An efficient method for regioselective synthesis of C-7 Mannich bases of 6-hydroxyaurones was accomplished by the N,N-dialkylaminomethylation using aminals prepared from dimethylamine, dipropylamine, bis(2-methoxyethyl)amine, N-methylbutylamine, N-methylbenzylamine, morpholine, piperidine, and 1-methylpiperazine. Further transformation of 7-(N,N-dialkylamino)methyl group in these aurones led to formation of C-7 acetoxymethyl and methoxymethyl derivatives of 6-hydroxyaurones, some of which showed promising inhibition of PC-3 prostate cancer cell proliferation in the high nanomolar to low micromolar range that exceeded that of cisplatin. Compound 12c (R3 = Ac, Ar = 3,4-OMePh) displays 75% inhibition of PC-3 prostate cancer cells proliferation at 300 nM concentration.

With the consumption of energy and the spread of COVID-19, the demand for ethanol production is increasing in the world. The industrial ethanol fermentation microbes cannot metabolize the alginate component of macro algae, which affects the ethanol yield. In this research, the ethanol production process from macro algae by an alginate fermentation yeast Meyerozyma guilliermondii, especially the pretreatment process of Colpomenia sinuosa, was studied. At the same time, the experimental design of Box-Behnken was carried out to achieve the optimum fermentation performance. The concentration of KH2PO4 (A: 2–6 g.L−1), pH (B: 4–7), reaction time (C: 60–120 h) and temperature (D: 24–34 °C) were variable input parameters. During the ethanol production process, the algae powder was firstly mixed with water at 90 °C for 0.5 h. Later the fermentation culture medium was prepared and then it was fermented by the yeast Meyerozyma guilliermondii to produce ethanol. And the optimal fermentation parameters were as follows: fermentation temperature of 28 °C, KH2PO4 dosage of 4.7 g.L−1, initial pH of 6, and fermentation time of 99 h. The ethanol yield reached 0.268 g.g−1 (ethanol to algae), close to the predicted value of model. The generation of alginate lyase during the fermentation of algae was also examined. The highest alginate lyase activity reached 46.42 U.mL−1.

Eutrophication in water supply systems results in harmful algal blooms and water pollution such as unpleasant taste and odor, especially in summer seasons. 2-Methylisoborneol (2-MIB) and geosmin ar...

Nb-Mo5SiB2 (T2)-based composites with Ti and Si additions were prepared by mechanical alloying followed by hot pressing. The phase analysis revealed that element additions induced the phase composition change. In the Ti-added Nb-T2 composite, Ti was distributed in the grain boundary as sub-micron Ti-rich oxide particles due to insufficient oxidation. The addition of Si turned the Nb-T2 into a complete intermetallic composite by forming Nb-silicide. The mechanical properties showed that Ti- and Si-co-added Nb-T2 composite had the highest hardness (1939 HV) and compressive strength (3445 MPa), while the Ti-added Nb-T2 composite exhibited the best toughening effect, and the fracture toughness reached 13.37 MPa m1/2, which were about 31% and 300% higher than that of Nb-T2 and pure polycrystalline T2, respectively. Although the Nb and Ti had excellent toughening effect on the T2 phase, it worsened the oxidation resistance of the composites.

Moso bamboo was firstly treated in a vacuum chamber at 150°C, 170°C, 190°C, and 210°C for 1, 2, and 3 h, respectively. Nano-TiO2 gel were then coated on the surface of thermally treated (TM) bamboo...

Most cancer therapies are suffering from side effects to varying degrees, which might compromise the body functions and long-term health of patients. Balancing treatment efficacy and side effects has become a priority. Inspired by the concept that cellular ion homeostasis can lead to apoptosis, we developed a novel therapeutic strategy by incorporating the K+ transporter valinomycin into liposomes (Lipo-VM). Valinomycin is a naturally occurring polypeptide showing good biodegradation in vivo with reduced long-term side effects. Lipo-VM facilitates the K+ efflux of cells and triggers a caspase-dependent pathway of apoptosis by causing the collapse of mitochondrial membrane potential. With the help of a liposome-based nano-delivery system, Lipo-VM shows enhanced cell uptake and accumulation at the tumor site, which results in significant inhibition of tumor growth in a liver cancer model. The proposed valinomycin-anchored liposome provides an efficient and safe approach for cancer therapy.

Clonorosins A (1) and B (2), two novel indole alkaloids featuring unprecedented 6/5/6/6/5 and 6/5/5 cores, together with seven known indole-linked 2,5-diketopiperazine alkaloids (3-9), were isolated from the soil-derived fungus Clonostachys rosea YRS-06. The new structures were proposed through HR-MS, NMR, and ECD spectroscopic data. They were established by comparing the calculated NMR, ECD, and specific rotation data with the experimental. To assist in determining the absolute configuration of the chiral carbon in the side chain of 2,5-diketopiperazine derivatives, flexible analogues 3i-3iv were synthesized and analyzed. 1 was active against Fusarium oxysporum with an MIC value of 50 μg/mL. 7 and 8 showed excellent activity against human HeLa and HepG2 cells with IC50 values of 0.12-0.60 μM.

Lead (Pb) is a toxic heavy metal and environmental pollutant that adversely affects the nervous system. However, effective therapeutic drugs for Pb-induced neurotoxicity have yet to be developed. In the present study, we investigated the ameliorative effect of sodium para-aminosalicylic acid (PAS-Na) on Pb-induced neurotoxicity. Male Sprague–Dawley rats were treated with (CH3COO)2 Pb•4H2O (6 mg/kg) for 4 weeks, followed by 3 weeks of PAS-Na (100, 200, and 300 mg/kg). The results showed that subacute Pb exposure significantly decreased rats body-weight gains and increased liver coefficient, and impaired spatial learning and memory. HE staining showed that Pb damaged the structure of the hippocampus. Moreover, Pb activated the ERK1/2-p90RSK/ NF-κB pathway concomitant with increased inflammatory cytokine IL-1β levels in rat hippocampus. PAS-Na reversed the Pb-induced increase in the liver coefficient as well as the learning and memory deficits. In addition, PAS-Na reduced the phosphorylation of ERK1/2, p90RSK and NF-κB p65, decreasing IL-1β levels in hippocampus. Our findings indicated that PAS-Na showed efficacy in reversing Pb-induced rats cognitive deficits and triggered an anti-inflammatory response. Thus, PAS-Na may be a promising therapy for treating Pb-induced neurotoxicity.

Developing effective treatments for colorectal cancers through combinations of small-molecule approaches and immunotherapies present intriguing possibilities for managing these otherwise intractable cancers. During a broad-based, screening effort against multiple colorectal cancer cell lines, we identified indole-substituted quinolines (ISQ), such as N7,N7-dimethyl-3-(1-methyl-1H-indol-3-yl)quinoline-2,7-diamine (ISQ-1), as potent in vitro inhibitors of several cancer cell lines. We found that ISQ-1 inhibited Wnt signaling, a main driver in the pathway governing colorectal cancer development, and ISQ-1 also activated adenosine monophosphate kinase (AMPK), a cellular energy–homeostasis master regulator. We explored the effect of ISQs on cell metabolism. Seahorse assays measuring oxygen consumption rate (OCR) indicated that ISQ-1 inhibited complex I (i.e., NADH ubiquinone oxidoreductase) in the mitochondrial, electron transport chain (ETC). In addition, ISQ-1 treatment showed remarkable synergistic depletion of oncogenic c-Myc protein level in vitro and induced strong tumor remission in vivo when administered together with BI2536, a polo-like kinase-1 (Plk1) inhibitor. These studies point toward the potential value of dual drug therapies targeting the ETC and Plk-1 for the treatment of c-Myc–driven cancers.

A solvothermal reaction of Zn(NO3)2 and 4-(1H-pyrazol-4-yl)benzoic acid (H2pba) with toluene (Tol) as the template yielded a porous coordination polymer, [Zn(pba)]·0.5Tol, possessing a three-dimensional (3D) fence-like coordination framework based on inclined two-dimensional (2D) fence-like coordination layers. By virtue of the classic deformation mode of the 2D/3D fence structures, the guest-free structure exhibits very large positive thermal expansion of 347 MK-1 and moderate negative thermal expansion of -63/-83 MK-1, which are remarkably enhanced to new records of 689 and -171/-249 MK-1, respectively, by inclusion of Tol.

Staphylococcus aureus is a common pathogen of bovine mastitis which can induce autophagy and inhibit autophagy flux, resulting in intracellular survival and persistent infection. The aim of the current study was to investigate the role of p38α in the autophagy induced by intracellular S. aureus in bovine mammary epithelial cells. An intracellular infection model of MAC-T cells was constructed, and activation of p38α was examined after S. aureus invasion. Through activating/inhibiting p38α by anisomycin/SB203580, the autophagosomes, LC3 and p62 level were analyzed by immunofluorescence and western blot. To further study the detailed mechanism of p38α, phosphorylation of ULK1ser757 was also detected. The results showed that intracellular S. aureus activated p38α, and the activation developed in a time-dependent manner. Inhibition of p38α promoted intracellular S. aureus-induced autophagy flow, up-regulated the ratio of LC3 II/I, reduced the level of p62 and inhibited the phosphorylation of ULK1ser757, whereas the above results were reversed after activation of p38α. The current study indicated that intracellular S. aureus can inhibit autophagy flow by activating p38α in bovine mammary epithelial cells.

Lithium-sulfur (Li-S) batteries have drawn a lot of attention owing to the high theoretical capacity of 1675 mAh g-1, environmental friendliness and relative abundance of sulfur. Nevertheless, the severe dissolution and migration of lithium polysulfides (LiPSs) and poor conductivity of sulfur greatly hinder the practical application of Li-S batteries. In this work, Fe-Ni-P@nitrogen-doped carbon (named as Fe-Ni-P@NC) derived from Fe-Ni Prussian blue analog (Fe-Ni PBA) was used as highly efficient sulfur host for Li-S batteries. The Fe-Ni-P particles not only enhance the adsorption of LiPSs but also effectively promote the conversion of LiPSs. In addition, the CN- of PBAs can readily generate nitrogen-doped carbon during pyrolysis, which can improve the conductivity of composites. Due to these advantages, Li-S batteries using S@Fe-Ni-P@NC composites cathodes exhibited good electrochemical performance with outstanding rate capability and stable cycling over 500 cycles with a lower capacity fading rate of 0.08% per cycle at 1 C.

Revealing the relationship between reactive oxygen species (ROS) and levels of protein phosphorylation is of great significance for understanding the pathogenesis of diseases. Although mass spectrometry is used as a classical method for protein phosphorylation analysis, there are still some challenges to realize in vivo protein phosphorylation recognition. Herein, we designed and prepared an metal-organic framework (MOF)-based fluorescent nanoprobe with Zr(IV) and boronate ester as an active center, which achieved simultaneous recognition of ROS and phosphorylation sites. The ROS unit was constructed by 1,8-naphthalimide and boronate ester as a fluorophore and a recognition group, respectively. The specific interaction between Zr(IV) and a phosphate group was used to realize fluorescence imaging of phosphorylation sites. Using the advantages of two-photon property of the ROS recognition unit, the nanoprobe can effectively reduce the background fluorescence and thus improve the imaging sensitivity. Finally, the MOF-based nanoprobe was successfully applied to reveal the relationship between ROS and levels of phosphorylation in pneumonia mice, which illustrated that the ROS and phosphorylation levels in the process of pulmonary inflammation were obviously higher than those of the normal mice. This work provides feasible fluorescence tools that have important significance for revealing pathogenesis of diseases.

The purpose of the present study was to examine the protective action and mechanisms of quercetin on the blood-brain barrier (BBB) in rats subjected to transient middle cerebral artery occlusion (tMCAO) and reperfusion. Quercetin (10, 30, 50 mg/kg) was intraperitoneally administered at the onset of reperfusion. The results showed that quercetin significantly reduced cerebral infarct volume, neurological deficit, BBB permeability and ROS generation via Sirt1/Nrf2/HO-1 signaling pathway. Moreover, EX527, a selective inhibitor of Sirt1, reversed these neuroprotective effects. Our findings indicate that quercetin has neuroprotective effects against cerebral ischemia-reperfusion injury by protecting BBB through Sirt1 signaling pathway in MCAO rats.

The gold deposits in the Jiaodong Peninsula constitute the largest gold mineralized province in China. The mineralization shows common characteristics in their tectonic setting, ore-forming fluid and metallogenic system. Sulfidation and fluid immiscibility are two important mechanisms controlling gold precipitation, both of which consume sulfur in the ore-forming fluids. The escape of H2S from the main ore-forming fluids and the decrease of total sulfur concentration not only lead to the efficient precipitation of gold, but also result in the crystallization of reducing minerals such as pyrrhotite and oxidizing minerals such as magnetite. Quartz solubility shows strong dependence on temperature, pressure, and CO2 content. The dependence of quartz solubility on pressure is weak at low temperatures, and progressively stronger at higher temperatures. Similarly, the temperature dependence of quartz solubility is relatively low at low pressures, but becomes gradually stronger at high pressures. The results of solubility modeling can constrain the dissolution and reprecipitation behavior of quartz in the ore-forming veins and the formation mechanism of different types of quartz veins. The multi-stage mineralization fluid activity resulted in the complex dissolution structure of quartz in the Jiaodong gold veins. Pyrite in the main metallogenic period in the Jiaodong gold deposits shows complex microstructure characteristics at single crystal scale. The trace elements (mainly the coupling of As- and Au-rich belt) and sulfur isotope composition also display a certain regularity. The As-rich fluids might have formed by the initial pulse of ore-forming fluids through As-rich metasedimentary strata, while the As-Au oscillation zone at the margin of pyrite grains is related to the pressure fluctuation caused by fault activity and the local phase separation of fluids. There is a temporal and spatial evolution of gold fineness in the Jiaodong gold deposits. Water/rock reaction (sulfidation) was the main ore-forming mechanism of early gold mineralization, forming relatively high fineness gold, while significant pressure drop in the shallow part accompanied by fluid phase separation promoted the late gold mineralization, forming low fineness gold. Under cratonic destruction setting, dehydration of the amphibolite and granulite facies metamorphic lower-crust resulted in the formation of Au-CO2-rich ore-forming fluids, which rose along the deep fault and secondary structure, and formed the largescale fault-controlled gold deposits in Jiaodong.

Carbon nitride (C3N4) is promising for photocatalytic hydrogen production, but photogenerated electrons and holes in C3N4 usually tend to exist as excitons due to intrinsic Coulomb interactions making its photocatalytic activity unsatisfactory. Herein, a well-designed intramolecular C3N4-based donor-acceptor (D-A) photocatalytic system was constructed to promote exciton dissociation. Due to its good chemical compatibility with melamine and appropriate sublimation property, 2-amino-4,6-dichloropyrimidine unit was chosen as the monomer to react with melamine to construct intramolecular D-A system (CNClx). The hydrogen evolution rate of CNCl0.15 is 15.3 times higher than that of bulk C3N4 under visible light irradiation, with apparent quantum efficiency of 13.6% at 420 nm. The enhanced activity is attributed to introduced electron-withdrawing −Cl group as terminal group in the resulted CNClx samples, which can build internal electric field to promote the exciton dissociation into free electron and hole. In addition, lower work function value of CNClx samples indicates that internal electric field can help free electrons and holes transfer to the surface of CNClx samples for photocatalytic reaction.

A facile synthesis strategy by combination self-activation of biomass materials with heteroatom dopant in one-step is developed to fabricate porous carbons (NO-PCMs) doping with N, O, and S elements from direct carbonization of sodium lignosulfonate and melamine mixture. Two different types of active defects are constructed simultaneously through the decomposition of sodium lignosulfonate in NO-PCMs, exhibiting hierarchical porosity and abundant heteroatoms contents. The typical NO-PCMs displayed high specific capacitance (300 F g−1 at 0.1 A g−1) and outstanding cycling stability (99% capacitance retention after 10,000 charge/discharge cycles at 10 A g−1) in 6 M KOH electrolyte. Furthermore, the assembled symmetric supercapacitors exhibited high specific capacitance of 162 F g−1 at 20 A g−1, 71% capacitance retention at current density up to 20 A g−1, and possessed high specific energy density of 21.6 Wh kg−1 with an excellent power density of 92 W kg−1 operated in the wide voltage range of 1.8 V in 1 M Na2SO4 aqueous electrolyte, demonstrating the broad prospects of biomass/biowaste being used to prepare electrode materials.

The stereoselective construction of all-carbon quaternary stereocenters, especially acyclic ones, represents an important challenge in organic synthesis. In particular, homopropargyl amides with a quaternary stereocenter β to a nitrogen atom are valuable synthetic intermediates, which could be transformed to diverse chiral structures through alkyne transformations. However, highly enantioselective synthetic methods for homopropargyl amides with a β quaternary stereocenter are extremely rare. We report here unprecedented substrate-directed, iridium-catalyzed enantioselective hydroalkynylations of trisubstituted alkenes to form an acyclic all-carbon quaternary stereocenter β to a nitrogen atom. The hydroalkynylation of enamide occurred with unconventional selectivity, favoring the more hindered reaction site. Homopropargyl amides with β-stereocenters were prepared in high regio- and enantioselectivities. Combined experimental and computational studies revealed the origin of the regio- and enantioselectivities.

Iodide-adduct chemical ionization mass spectrometry (I-CIMS) is a widely used technique in the atmospheric chemistry community to detect oxygenated volatile organic compounds (OVOCs) in real time. In this work, we report the occurrence of secondary ion chemistry from interactions between a strong oxygen donor (such as O3 and peracids) and acidic OVOCs (such as carboxylic acids and organic hydroperoxides) in the ion-molecule reaction (IMR) region of I-CIMS. Such interactions can lead to acidic organic molecules (HA or HB) clustering with [IO]- (e.g., [HA + IO]-) and dimer adducts ([A + B + I]-), in addition to the well-known iodide clusters ([HA + I]-). This ion chemistry was probed using common chemical standards as well as the gas-phase oxidation products of α-pinene and isoprene in a flowtube reactor. The results show that secondary ion chemistry can lead to misinterpretations of molecular compositions and distributions of the gas-phase products and an overestimation of the elemental O/C ratio overall. Nevertheless, the varying degrees of signal change in response to the secondary ion chemistry might be a clue to inform OVOCs' functionalities. Specifically, in the α-pinene ozonolysis system, the extents of ion signal reduction in the presence of additional acids in the IMR suggest that C9H14O4 produced in the gas phase is a peracid, rather than the often-assumed pinic acid. Thus, we suggest that the potential application of the secondary ion chemistry to inform organic functionalities is promising, which could help better understand the molecular compositions of gas-phase OVOCs and the reaction mechanisms therein.

Cardiovascular disease (CVD) results in more than half of the mortality and the majority of morbidity in patients with type 2 diabetes. We aim to evaluate the associations of urinary concentrations of phthalate metabolites with CVD in diabetic patients and explore whether CVD risk factors mediate or interact with these associations. A total of 675 type 2 diabetic participants were enrolled from Shanghai, China, in 2018. CVD was defined as a self-reported diagnosis by a physician including coronary heart disease, myocardial infarction, or stroke; it was further reconfirmed in the records from the registration platform. Ten phthalate metabolites were measured in urine. We found positive associations were found among the level of monoethyl phthalate and monoisobutyl phthalate and CVD (OR 1.138, 95% CI 1.032, 1.254; OR 1.369, 95% CI 1.049, 1.786, respectively). Monoisobutyl phthalate and monobenzyl phthalate were marginally and positively associated with carotid intima-media thickness and common carotid artery diameter, respectively. None of the CVD risk factors, including HOMA-IR, body mass index, lipid profile, or blood pressure, significantly mediated the association between the metabolites and CVD. The conditional indirect effect on CVD was significantly stronger for current smoking and dyslipidemia for monoethyl phthalate and for no statin usage and men for monoisobutyl phthalate. In conclusion, phthalate exposure was positively associated with CVD in Chinese with type 2 diabetes. Type 2 diabetic men who are currently smoking, have an uncontrolled lipid profile, and are not using statins might be more susceptible to CVD when exposed to phthalates.

Five new cassane-type diterpenoids, including 16-O-ethyl caesalpin A (1), 16-O-ethyl caesalpin B (2), norcaesalpinin ME (3), 6α-hydroxynorcaesalpinin A (4), and 17-acetylcaesalmin Z (5), were isolated from the seeds of Caesalpinia minax Hance, along with twelve known compounds. The structures of the new compounds were established by means of spectroscopic technique (NMR, HRESIMS and IR). The absolute configurations of the new compounds were determined by their ECD spectra. In palmitic acid/oleic acid-treated AML12 mouse hepatocytes, compound 5 greatly reduced intracellular lipid accumulation, as well as total triglyceride and cholesterol contents, which could be further developed to treat fatty liver disease.

In our previous studies, a kind of novel benzenesulfonamides was found to be a candidate insecticidal compounds. It was shown that propargyloxy and sulfonamide groups are pharmacodynamic groups. One hundred and twenty-six (126) naphthalenesulfonamides derivatives with propargyloxy functionality were designed and synthesized, and their insecticidal activities were determined. Some of them showed outstanding activity, with LC50 values as low as 0.202 mg ml-1, much lower than that of the positive control celangulin V (23.9 mg ml-1). In addition, the structure-activity relationships were discussed, and molecular docking was used to verify the binding mode of the compound and the target receptor.

To increase the conductivity of proton exchange membranes in the membrane thickness direction, a novel mixed matrix membrane of Nafion ionomer and sulfonated graphene nanoplates (sGNP) with aligned proton channels is prepared with the assistance of an electric field. A high voltage alternative electric field is applied to a casting solution consisting of Nafion ionomer, sGNP, N, N-dimethylformamide (DMF), and p-xylene (PX) while evaporating the solvents. The sGNP, naturally attracting the ionic groups of Nafion ionomer to their vicinity, is polarized and rotated under the electric field, leaving aligned proton channels in the solidified membrane. The trans-plane proton conductivity of the mixed matrix membrane can reach 0.155 S cm−1 at 80 °C and 100% RH, an increase of 48% as compared with the conventional cast Nafion membrane. Accordingly, the peak power output of H2/O2 fuel cell with the mixed matrix membrane increases by 15%, reaching 440 mW cm−2 at 80 °C.

To study the pollution features and underlying mechanism of PM2.5 in Luoyang, a typical developing urban site in the central plain of China, 303 PM2.5 samples were collected from April 16 to December 29, 2015 to analyze the elements, water soluble inorganic ions, organic carbon and elemental carbon. The annual mean concentration of PM2.5 was 142.3 μg/m3, and 75% of the daily PM2.5 concentrations exceeded the 75 μg/m3. The secondary inorganic ions, organic matter and mineral dust were the most abundant species, accounting for 39.6%, 19.2% and 9.3% of the total mass concentration, respectively. But the major chemical components showed clear seasonal dependence. SO42− was most abundant specie in spring and summer, which related to intensive photochemical reaction under high O3 concentration. In contrast, the secondary organic carbon and ammonium while primary organic carbon and ammonium significantly contributed to haze formation in autumn and winter, respectively. This indicated that the collaboration effect of secondary inorganic aerosols and carbonaceous matters result in heavy haze in autumn and winter. Six main sources were identified by positive matrix factorization model: industrial emission, combustion sources, traffic emission, mineral dust, oil combustion and secondary sulfate, with the annual contribution of 24%, 20%, 24%, 4%, 5% and 23%, respectively. The potential source contribution function analysis pointed that the contribution of the local and short-range regional transportation had significant impact. This result highlighted that local primary carbonaceous and precursor of secondary carbonaceous mitigation would be key to reduce PM2.5 and O3 during heavy haze episodes in winter and autumn.

Functional small-diameter tissue-engineered blood vessels (TEBVs) have been developed in silico using biodegradable polymeric scaffolds under pulsatile perfusion. Accurate simulation of physiological mechanical stimulations in vitro is a crucial factor in vascular engineering. However, little is known about the patterns of mechanical stimulation on silicone tubes. This study aimed to determine the optimal mechanical conditions required for inducing circumferential deformations in silicone tubes during in vitro vascular development under pulsatile perfusion. For this purpose, we established a data acquisition (DAQ) system with a laser micrometer and pressure transducers to evaluate changes in the diameter of silicone tubes in response to pulsatile flow and validated the results on cultured TEBVs. The established DAQ system showed satisfactory reproducibility for measuring diameter variation in the in silico model. Furthermore, the hardness and thickness of the silicone tubes affected the mechanical conditioning in the three-dimensional culture system under different working pressures, frequencies, and circumferential deformations. We demonstrated a simple and reliable approach to quantify the circumferential strain and deformations to ensure optimal mechanical stimulation of the cultured TEBVs under pulsatile perfusion. Based on the results, we were able to dynamically culture dense cellularized small-diameter TEBVs. This study highlights the importance of mechanical stimulation in vascular tissue engineering. Impact statement This study demonstrated a direct and noncontact data acquisition system for quantifying the strain on the supporting silicone medium during three-dimensional tissue-engineered blood vessel culture, which can help optimize the mechanical parameters for vascular tissue engineering.

Poly (N-ethylaniline) (PNEA) composites with varying silicate content were fabricated on copper through a novel electropolymerized strategy in acidic solution. Thickness, compactness, conductivity and adhesive strength of the composite (PNEA-10Si) were optimized as silicate content reached 10 mM. Electrochemical, morphological and solution analyses were employed to evaluate the protective performance of PNEA and PNEA-10Si coatings for copper in 3.5 % NaCl solution. Results of electrochemical analyses indicated that as-prepared coatings retarded the oxygen reduction process efficiently for copper in 3.5 % NaCl solution, drained corrosion current density and elevated interfacial charge transfer resistance. Due to favorable barrier effect, compact structure and low porosity index, PNEA-10Si composite exhibited superior anti-corrosive performance, which was more tolerant than PNEA during long-time immersion. PNEA-10Si coated sample exhibited a stable topography after 144 h immersion with the minimum concentration of released ions revealing the improved protection capacity. Electronic/atomic-multiscale calculations were conducted to clarify the deposition and protection mechanism of as-prepared coatings. Outcomes of density functional theory corroborated that silicate is stabilized in the PNEA layer via electrostatic force; and immobile silicate positively contributed to the charge transfer barrier of the composite. Molecular dynamics simulations evidenced that the favorable compatibility between PNEA and silicate facilitated polymer deposition and confined in-situ ions diffusion.

Liver cancer is one of the most frequent causes of cancer-related deaths worldwide. The current study sought to screen, for the first time, a Ficus carica variety from the Shandong province of China against hepatocellular (HepG2) cells. Crude extracts of F. carica with various polarities were prepared and screened against HepG2 cells. The acetone extract of the leaf (FLA) exhibited significant antiproliferative effects against HepG2 cells (IC50 = 0.179 mg/mL) while producing the least toxicity on normal human umbilical vein endothelial cells (HUVECs). Biochemical evidence of apoptosis was confirmed by staining with DAPI and AO/EB. FLA also exhibited moderate anti-colonization potential against the population of HepG2 cells. It selectively arrested the cell cycle of HepG2 cells at the S phase and exerted anticancer activity by significantly increasing the reactive oxygen species (1.59 fold) inside the cells, which subsequently resulted in loss of the mitochondrial membrane potential as revealed by JC-1 probe assay. FLA downregulated the expression of tumor-promoter Transcription Factor (TP53), anti-apoptotic proteins (Bcl-2), and cell cycle regulatory kinases (CDK1, 5, 9) with respect to untreated cells for 24 h, 48 h, and 72 h. High-performance liquid chromatography (HPLC) of FLA revealed the presence of gallic acid and quercetin as major antiproliferative compounds along with trace amounts of rutin, luteolin, apigenin, benzoic acid, and β-sitosterol. Notably, our study showed FLA operating via novel mechanisms involving reactive oxygen species (ROS) generation and CDKs involvement in HepG2 cells. Thus, it suggests that FLA may be a potential source of new drugs in the treatment of liver cancer.

A couple of enantiomers of 2, 6-diaminotriptycene ( R, R - 1 and S, S - 1 ) are split by chiral HPLC and their absolute configurations are identified by single-crystal X-ray diffraction technology. Using the enantiomers as monomers, a couple of chiral porous polyimides ( R - FTPI and S - FTPI ) are prepared by polycondensation reactions and display good heat stability, high BET surface area and good solubility in organic solvents. Moreover, both of R - FTPI and S - FTPI can be cast into robust, free-standing films suitable for enantioselective separation with symmetrical chiral selectivity.

Drug-induced liver injury (DILI) is the most common reason for the post-marketing withdrawal of drugs. Poor understanding of the mechanisms of DILI presents a large challenge in clinical diagnosis. Previous evidences indicate a potential relationship between reactive nitrogen species (RNS) and DILI. Hence, we developed two specific probes, Golgi-HNO and Mito-HNO, for the multicolored and simultaneous in situ imaging of nitroxyl (HNO) in the Golgi apparatus and mitochondria, respectively. We discovered a significant rise in HNO levels in the livers of mice with DILI, which means that for the first time, we revealed a positive correlation between HNO levels and DILI. Based on changes in the HNO level, we also successfully explored the extent of liver damage induced by an anticarcinogen, bleomycin. In addition, we uncovered catalase was involved in HNO synthesis, which is the unprecedented function of catalase. These findings demonstrate that HNO is an ideal biomarker for DILI diagnosis, and Golgi-HNO and Mito-HNO are ideal fluorescent probes to study in situ HNO changes in various physiological and biochemical processes.

Real-time non-destructive monitoring of nitrogen accumulation by hyperspectral remote sensing is important for crop nitrogen management. In this study, winter wheat field experiment incorporating several varieties and exogenous nitrogen treatments was performed at multiple sites. Using hyperspectral readings of the experimental crops, the continuum removal method was used to expand the chlorophyll absorption characteristic band. The correlation among the spectral reflectance of the wheat canopy, the continuum removal spectrum, and leaf nitrogen accumulation (LNA) were systematically analyzed. The correlations between LNA and spectral parameters (e.g., original spectral reflectance, two-band combination parameters, and common vegetation indices) and continuum-removed absorption feature parameters were all compared. Three nonlinear modeling methods were considered (partial least squares regression, SVM regression, and random forest regression) and their relative ability to predict LNA was compared. Continuum removal treatment significantly improved the correlation between the continuum-removed spectra of the chlorophyll absorption regions (550–750 nm) and LNA. Results also show that RSI (NBDI743, NBDI703) could be used to estimate LNA using univariate linear regression (R2 and root mean square error were 0.806 and 1.231 g m−2, respectively). The SVM regression was found to be the most accurate regression model when chlorophyll absorption characteristic band reflectivity values normalized by the continuum removal process were taken as an input (R2 and root mean square error values were 0.895 and 0.903 g m−2, respectively). This approach was able to predict LNA of wheat using continuum-removed absorption features through hyperspectral measurements, which provide technical support for nitrogen diagnosis and precise crop production management.

The deep dehalogenation of polyhalogenated organic pollutants is receiving widespread attention. In this work, Raney Ni (R-Ni) catalyst with a sponge porous structure was selected, and nascent hydr...

To search naturally occurring interleukin-1β (IL-1β) inhibitors, biscaesalmins A (1) and B (2), two highly oxidized dimeric cassane diterpenoids with a newly formed alicyclic skeleton, have been isolated from the traditional Chinese medicine Kushilian (Caesalpinia minax). Their full structures were determined by comprehensive spectroscopic analysis and quantum chemical TD-DFT (time-dependent density functional theory) calculation. Biosynthetically, 1 and 2 were formed via an intermolecular [4 + 2] Diels-Alder cycloaddition of two monomers, affording an additional six-membered carbon ring linkage. Compounds 1 and 2 inhibited nitric oxide production on lipopolysaccharide-stimulated THP-1 macrophages, with IC50 values being at 1.20 ± 0.23 and 2.30 ± 0.15 μmol/L, respectively. Furthermore, compound 1 inhibited NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) inflammasome-mediated IL-1β production and blocked the migration of macrophages towards adipocyte conditioned medium. Biscaesalmins A and B might be candidates for treating inflammation-related metabolic diseases.