Biogeochemical controls on climatically active gases and atmospheric sulfate aerosols in the western Pacific.

The Pacific Ocean plays an important role in regulating the budget of climatically active gases and the burden of sulfate aerosols. Here, a field investigation was conducted to clarify the key processes and factors controlling climatically active gases, including dimethyl sulfide (DMS), carbonyl sulfide (OCS), carbon disulfide (CS2), and carbon dioxide (CO2), in both surface seawater and the lower atmosphere of the western Pacific. In addition, the relative contributions of different sources to atmospheric sulfate aerosols were quantitatively estimated, and their causes were explored. The maximum concentrations of DMS, OCS and CS2 and the minimum partial pressure of CO2 (pCO2) were observed in the Kuroshio-Oyashio Extension. Kuroshio-induced mesoscale eddies brought abundant nutrients and organic matter from the subsurface layer of Oyashio into the euphotic layer, thus enhancing primary productivity and accelerating the photoreaction of organic matter. These processes led to higher concentrations of DMS, OCS and CS2 and lower pCO2. However, the oligotrophic subsurface layer in the subtropical gyre and the strong barrier layer in the equatorial waters suppressed the upward fluxes of nutrients and organic matter, resulting in lower surface concentrations of DMS, OCS, and CS2 in these areas. Being far from the continents, atmospheric concentrations of DMS, OCS and CS2 and pCO2 in the western Pacific generally were observed to depend on the local sea-to-air exchange and may be regulated by atmospheric oxidation and mixing of air masses. In general, oceanic DMS emissions played an important role in the formation of sulfate aerosols in the western Pacific (accounting for ∼19.5% of total sulfate aerosols), especially in the Kuroshio-Oyashio Extension (∼32.3%). These processes in seawater may also determine the variations and emissions of other climatically active gases from biogenic and photochemical sources.

Fabrication, Evaluation, and Antioxidant Properties of Carrier-Free Curcumin Nanoparticles.

Curcumin (Cur), a natural hydrophobic polyphenolic compound, exhibits multiple beneficial biological activities. However, low water solubility and relative instability hinder its application in food fields. In this study, carrier-free curcumin nanoparticles (CFC NPs) were prepared by adding the DMSO solution of Cur into DI water under continuous rapid stirring. The morphology of CFC NPs was a spherical shape with a diameter of 65.25 ± 2.09 nm (PDI = 0.229 ± 0.107), and the loading capacity (LC) of CFC NPs was as high as 96.68 ± 0.03%. The thermal property and crystallinity of CFC NPs were investigated by XRD. Furthermore, the CFC NPs significantly accelerated the release of Cur in vitro owing to its improved water dispersibility. Importantly, CFC NPs displayed significantly improved DPPH radical scavenging activity. Overall, all these results suggested that CFC NPs would be a promising vehicle to widen the applications of Cur in food fields.

Testing the sensory trade-off hypothesis in New World bats.

Detection of evolutionary shifts in sensory systems is challenging. By adopting a molecular approach, our earlier study proposed a sensory trade-off hypothesis between a loss of colour vision and an origin of high-duty-cycle (HDC) echolocation in Old World bats. Here, we test the hypothesis in New World bats, which include HDC echolocators that are distantly related to Old World HDC echolocators, as well as vampire bats, which have an infrared sensory system apparently unique among bats. Through sequencing the short-wavelength opsin gene (SWS1) in 16 species (29 individuals) of New World bats, we identified a novel SWS1 polymorphism in an HDC echolocator: one allele is pseudogenized but the other is intact, while both alleles are either intact or pseudogenized in other individuals. Strikingly, both alleles were found to be pseudogenized in all three vampire bats. Since pseudogenization, transcriptional or translational changes could separately result in functional loss of a gene, a pseudogenized SWS1 indicates a loss of dichromatic colour vision in bats. Thus, the same sensory trade-off appears to have repeatedly occurred in the two divergent lineages of HDC echolocators, and colour vision may have also been traded off against the infrared sense in vampire bats.

Transcriptome profiling of the floating-leaved aquatic plant Nymphoides peltata in response to flooding stress.

BACKGROUND: Waterlogging or flooding is one of the most challenging abiotic stresses experienced by plants. Unlike many flooding-tolerant plants, floating-leaved aquatic plants respond actively to flooding stress by fast growth and elongation of its petioles to make leaves re-floating. However, the molecular mechanisms of this plant group responding to flood have not been investigated before. Here, we investigated the genetic basis of this adaptive response by characterizing the petiole transcriptomes of a floating-leaved species Nymphoides peltata under normal and flooding conditions. RESULTS: Clean reads under normal and flooding conditions with pooled sampling strategy were assembled into 124,302 unigenes. A total of 8883 unigenes were revealed to be differentially expressed between normal and flooding conditions. Among them, top ranked differentially expressed genes were mainly involved in antioxidant process, photosynthesis process and carbohydrate metabolism, including the glycolysis and a modified tricarboxylic acid cycle - alanine metabolism. Eight selected unigenes with significantly differentiated expression changes between normal and flooding conditions were validated by qRT-PCR. CONCLUSIONS: Among these processes, antioxidant process and glycolysis are commonly induced by waterlogging or flooding environment in plants, whereas photosynthesis and alanine metabolism are rarely occurred in other flooding-tolerant plants, suggesting the significant contributions of the two processes in the active response of N. peltata to flooding stress. Our results provide a valuable genomic resource for future studies on N. peltata and deepen our understanding of the genetic basis underlying the response to flooding stress in aquatic plants.

Comparative phylogeography of the wild-rice genus Zizania (Poaceae) in eastern Asia and North America.

PREMISE OF THE STUDY: Comparative phylogeography of intercontinental disjunct taxa allowed us not only to elucidate their diversification and evolution following geographic isolation, but also to understand the effect of climatic and geological histories on the evolutionary processes of closely related species. A phylogeographic analysis was conducted on the eastern Asian-North American disjunct genus Zizania to compare intracontinental phylogeographic patterns between different continents. METHODS: Surveys were conducted of 514 individuals using three chloroplast DNA fragments and three nuclear microsatellite loci. These individuals included 246 from 45 populations of Zizania latifolia in eastern Asia, and the following from North America: 154 individuals from 26 populations of Z. aquatica, 84 individuals from 14 populations of Z. palustris, and 30 individuals from one population of Z. texana. KEY RESULTS: The genetic diversity of North American Zizania was significantly higher than that of eastern Asian Zizania. High levels of genetic differentiation among populations and no signal of population expansion were detected in three widespread species. No phylogeographic structure was observed in Z. latifolia, and discordant patterns of cpDNA and microsatellite markers were observed in North American Zizania. CONCLUSIONS: Reduced variation in Zizania latifolia likely reflects its perennial life history, the North American origin of Zizania, and the relative homogeneity of aquatic environments. High levels of genetic differentiation suggest limited dispersal among populations in all Zizania species. The more complex patterns of diversification and evolution in North American Zizania may be driven by the greater impact of glaciation in North America relative to eastern Asia.

Synthesis and antibacterial activity of amino acid and dipeptide prodrugs of IMB-070593, a fluoroquinolone candidate.

A series of amino acid and dipeptide prodrugs of IMB-070593, a fluoroquinolone candidate discovered in our lab, were synthesized and evaluated for their water solubility and then antibacterial activity. Our results reveal that four amino acid prodrugs 4a,b,e,f and two dipeptide prodrugs 4k,l have much greater solubility (>85 mg/mL) than IMB-070593 mesylate (22.5 mg/mL). Compounds 4a and 4k show good in vivo efficacy against MSSA 12-1 (p.o./i.v., 5.32-7.68 mg/kg) and S. pneumoniae12-10 (p.o., 18.39-23.13 mg/kg) which is 1.19-1.50 fold more active than the parent drug.

Study on the relationship between net primary productivity and site quality in Japanese larch plantations in mountainous areas of eastern Liaoning.

Plantation forests enhance carbon storage in terrestrial ecosystems in China. Larix kaempferi (Lamb.) Carrière (Lamb.) (Larix olgensis Henry) is the main species for afforestation in the eastern Liaoning Province. Therefore, it is important to understand the correlation between the site class and carbon sink potential of Larix kaempferi plantations in Liaoning Province for afforestation and carbon sink in this area. The model was fitted using three classical theoretical growth equations: the Richards model, the Korf model, and the Hossfeld model. This study used the forest resource inventory data for management in Liaoning Province in 2011 to build six dynamic height-age models for a Larix kaempferi plantation in Dandong City regardless of base-age. The optimal model derived by the generalized algebraic difference approach (GADA) method was compared with the model derived by the algebraic difference approach (ADA) method. The superiority of GADA was demonstrated by comparison. The Levenberg-Marquardt algorithm was used to fit the model. The statistical and biological characteristics were considered synthetically when comparing the models. The best model was screened out by statistical analysis and graphic analysis. The results show that the differential height-age model derived from Richards equation can well explain the growth process of Larix kaempferi in Dandong City, Liaoning Province under different conditions. The site index model based on Richards equation and derived by GADA was used to calculate the site class of a Larix kaempferi plantation in Dandong City. The net primary productivity (NPP) value from the past ten years was extracted from the MOD17A3HGF data set. Spearman correlation analysis and Kendall correlation analysis were used to show that there is a significant positive correlation between NPP value and site class of Larix kaempferi plantation in Dandong City. Among them, the highest growth occurred in 2016; NPP increased by about 3.914 gC/m2/year for every two increases in height-age grade; the lowest increase in NPP was in 2014; NPP increased by about 2.113 gC/m2/year for every two increases in height-age grade; and for every two increases in height-age grade in the recent ten years, the average NPP value increased by about 2.731 gC/m2/year.

Rapid cycling and emission of volatile sulfur compounds in the eastern Indian Ocean: Impact of runoff inputs and implications for balancing atmospheric carbonyl sulfide budget.

Volatile sulfur compounds, such as dimethyl sulfide (DMS), carbonyl sulfide (OCS), and carbon disulfide (CS2), significantly influence atmospheric chemistry and climate change. Despite the oceans being an important source of these sulfides, the limited understanding of their biogeochemical cycles in seawater introduces considerable uncertainties in quantifying their oceanic emissions and assessing atmospheric OCS budgets. To address this issue, we conducted a comprehensive field survey in the tropical eastern Indian Ocean (EIO) to examine the spatial distributions, source-sink dynamics, and sea-air exchange fluxes of marine DMS, OCS, and CS2. Our study indicates that nutrients, organic matter, and freshwater input from terrestrial runoff significantly affect most of the source-sink processes of these sulfides in the Bay of Bengal and even the tropical EIO. The resulting sulfide accumulation in seawater combined with high wind speeds establishes the tropical EIO as a considerable direct and indirect atmospheric OCS source. These insights underscore the potentially critical role of marine environments influenced by runoff in contributing to the atmospheric OCS budget. However, by integrating these results with previous field surveys, we believe that actual OCS emissions from tropical oceans exceed some bottom-up box-model simulations, yet fall significantly below those predicted by top-down models, still insufficient to bridge the atmospheric OCS source gap. Our detailed examination of source-sink dynamics offers deeper insights into the marine sulfur cycle and has potential implications for refining future box-models, thus mitigating uncertainties in estimating marine sulfur emissions.

Synthesis and in vitro antibacterial activity of quinolone/naphthyridone derivatives containing 3-alkoxyimino-4-(methyl)aminopiperidine scaffolds.

We report herein the synthesis of a series of 7-[3-alkoxyimino-4-(methyl)aminopiperidin-1-yl]quinolone/naphthyridone derivatives. In vitro antibacterial activity of these derivatives was evaluated against representative strains, and compared with ciprofloxacin (CPFX), levofloxacin (LVFX) and gemifloxacin (GMFX). The results reveal that all of the target compounds 19a-c and 20 have considerable Gram-positive activity, although they are generally less active than the reference drugs against the Gram-negative strains with some exceptions. Especially, novel compounds 19a2, 19a4 and 19a5 were found to show strong antibacterial activity (MICs: <0.008-0.5µg/mL) against all of the tested 15 Gram-positive strains including MRSA, LVFX- and GMFX-resistant MRSE, and CPFX-, LVFX- and GMFX-resistant MSSA.

Target-triggered double fluorescent biosensors for rapid and sensitive detection of long-chain perfluorinated compounds using DNA probe and lysozyme fiber.

Perfluorinated compounds (PFCs) are useful man-made chemicals and serve as new emerging organic pollutants due to their environmental and health concerns. Chromatography-mass detection methods often need complex procedure and are also too expensive, so there is a critical demand to develop rapid, inexpensive, easy-to-operate and sensitive methods for PFCs detection. In this work, double fluorescent biosensors ('DT sensor' and 'FT sensor') have been designed to quantitatively detect long-chain perfluorinated compounds (PFCs), due to their strong hydrophobic interaction with DNA probe or lysozyme fiber. The ratio and rapid fluorescence responses offered more obvious signal changes, and high sensitivity with a limit of detection (LOD) of 0.16 µM (98.2 ppb) for perfluorododecanoic acid (PFDoA). For three PFCs with longer perfluoroalkyl chain (CF2), increased detection sensitivity was achieved due to a stronger hydrophobicity. The fluorescent biosensors showed a good selectivity for long-chain PFCs and served as cross-reactive sensors to differentiate three different long-chain PFCs. The biosensors also had robust signal response in tap water or serum samples, and the LOD can be further lowered to pM (ppt) level after sample preconcentration.

Yeast ß-D-glucan functionalized graphene oxide for macrophage-targeted delivery of CpG oligodeoxynucleotides and synergistically enhanced antitumor immunity.

Immunostimulatory CpG oligodeoxynucleotides (CpG ODNs) show strong potential in cancer immunotherapy. However, therapeutic efficacy of CpG ODNs is hindered due to rapid nuclease degradation and insufficient cellular uptake. Transfecting CpG ODNs into antigen presenting cells (APCs) is vital to enhance their therapeutic efficacy while reduce the potential side effects. Herein, a multifunctional CpG ODNs vector was fabricated through functionalization of graphene oxide (GO) with yeast ß-D-glucan, and its potential in cancer immunotherapy was further investigated. GO-ß-D-glucan protected CpG ODNs from nuclease digestion. ß-D-glucan endowed the delivery system with targeting ability for macrophage due to its recognition with dectin-1. Thus, GO-ß-D-glucan enhanced the delivery of CpG ODNs into RAW264.7 cells due to dectin-1-mediated endocytosis. More importantly, ß-D-glucan functioned synergistically with CpG ODNs in inducing antitumor immunity. GO-ß-D-glucan/CpG ODNs inhibited the tumor cells growth more effectively. This work provides a macrophage-targeted CpG ODNs delivery system for cancer immunotherapy. Graphic abstract.

Comparative transcriptome analysis reveals molecular adaptations underlying distinct immunity and inverted resting posture in bats.

Understanding how natural selection shapes unique traits in mammals is a central topic in evolutionary biology. The mammalian order Chiroptera (bats) is attractive for biologists as well as the general public due to their specific traits of extraordinary immunity and inverted resting posture. However, genomic resources for bats that occupy key phylogenetic positions are not sufficient, which hinders comprehensive investigation of the molecular mechanisms underpinning the origin of specific traits in bats. Here, we sequenced the transcriptomes of 5 bats that are phylogenetically divergent and occupy key positions in the phylogenetic tree of bats. In combination with the available genomes of 19 bats and 21 other mammals, we built a database consisting of 10 918 one-to-one ortholog genes and reconstructed phylogenetic relationships of these mammals. We found that genes related to immunity, bone remodeling, and cardiovascular system are targets of natural selection along the ancestral branch of bats. Further analyses revealed that the T cell receptor signaling pathway involved in immune adaptation is specifically enriched in bats. Moreover, molecular adaptations of bone remodeling, cardiovascular system, and balance sensing may help to explain the reverted resting posture in bats. Our study provides valuable transcriptome resources, enabling us to tentatively identify genetic changes associated with bat-specific traits. This work is among the first to advance our understanding of the molecular underpinnings of inverted resting posture in bats, which could provide insight into healthcare applications such as hypertension in humans.

Adaptations to a cold climate promoted social evolution in Asian colobine primates.

The biological mechanisms that underpin primate social evolution remain poorly understood. Asian colobines display a range of social organizations, which makes them good models for investigating social evolution. By integrating ecological, geological, fossil, behavioral, and genomic analyses, we found that colobine primates that inhabit colder environments tend to live in larger, more complex groups. Specifically, glacial periods during the past 6 million years promoted the selection of genes involved in cold-related energy metabolism and neurohormonal regulation. More-efficient dopamine and oxytocin pathways developed in odd-nosed monkeys, which may have favored the prolongation of maternal care and lactation, increasing infant survival in cold environments. These adaptive changes appear to have strengthened interindividual affiliation, increased male-male tolerance, and facilitated the stepwise aggregation from independent one-male groups to large multilevel societies.

Inhibition of GPR40 protects MIN6 ß cells from palmitate-induced ER stress and apoptosis.

Chronic exposure to elevated concentration of free fatty acids (FFA) has been verified to induce endoplasmic reticulum (ER) stress, which leads to pancreatic ß-cell apoptosis. As one of the medium and long chain FFA receptors, GPR40 is highly expressed in pancreatic ß cells, mediates both acute and chronic effects of FFA on ß-cell function, but the role of GPR40 in FFA-induced ß-cell apoptosis remains unclear. In this study, we investigated the possible effects of GPR40 in palmitate-induced MIN6 ß-cell apoptosis, and found that DC260126, a novel small molecular antagonist of GPR40, could protect MIN6 ß cells from palmitate-induced ER stress and apoptosis. Similar results were observed in GPR40-deficient MIN6 cells, indicating that palmitate-induced ß-cell apoptosis is at least partially dependent on ER stress pathway via GRP40.

2-Arylbenzofuran, flavonoid, and tyrosinase inhibitory constituents of Morus yunnanensis.

Two novel 2-arylbenzofuran dimers, morusyunnansins A and B (1 and 2), two new biflavonoids, morusyunnansins C and D (3 and 4), two new flavans, morusyunnansins E and F (5 and 6), and four known flavans (7-10) were isolated from the leaves of Morus yunnanensis. Compounds 5-8 showed potent inhibitory effects on mushroom tyrosinase with IC(50) values ranging from 0.12 ± 0.02 to 1.43 ± 0.43 µM.

New isoprenylated flavonoids and adipogenesis-promoting constituents from Morus notabilis.

Five new isoprenylated flavonoids, notabilisins A-E (1-5), and two known Diels-Alder adducts (6 and 7), were isolated from the twigs of Morus notabilis. Compounds 4 and 5 possess two novel pyran rings, which may be biogenetically derived from 3. Compounds 1 and 3 significantly promoted adipogenesis, characterized by increased lipid droplet and triglyceride content in 3T3L1 cells, and induced up-regulation of the expression of adipocyte-specific genes, aP2 and GLUT4.

Isoprenylated flavonoids and adipogenesis-promoting constituents from Morus nigra.

Ten new isoprenylated flavonoids, nigrasins A-J (1-10), and three known compounds were isolated from the twigs of Morus nigra. Compounds 8 and 9 promoted adipogenesis, characterized by increased lipid droplet and triglyceride content in 3T3L1 cells, and induced up-regulation of the expression of adipocyte-specific genes, aP2 and GLUT4.

5-(1H-Indol-3-yl-methyl-idene)-2,2-di-methyl-1,3-dioxane-4,6-dione.

In the title compound, C(15)H(13)NO(4), the conjugated double-bond system between the two rings adopts a cis configuration and there is an intra-molecular indole-ketone C-H⋯O inter-action. The indole N-H group forms an inter-molecular hydrogen bond with a ketone O-atom acceptor, giving a chain structure along the ab direction. The O-heterocyclic ring adopts a boat conformation and makes a dihedral angle of 16.72 (6)° with the indole ring system.

N-Cyclo-hexyl-4-[(2-nitro-anilino)-meth-yl]thio-phene-2-sulfonamide.

In the title compound, C(17)H(21)N(3)O(4)S(2), an intra-molecular N-H⋯O hydrogen bond involving the proximate amine and nitro groups is observed. In the crystal, inter-molecular N-H⋯O hydrogen bonds involving the amine and SO(2) groups occur. One of the notro O atoms is disordered over two conformations with occupancies of 0.578 (12) and 0.422 (12).

2,2-Dimethyl-5-[(2-nitro-anilino)methyl-idene]-1,3-dioxane-4,6-dione.

The crystal of the title compound, C(13)H(12)N(2)O(6), contains a bifurcated intra-molecular hydrogen bond between the N-H group and one of the O atoms from both the nitro group and the dioxane-4,6-dione moiety. In addition, mol-ecules are linked by a series of inter-molecular C-H⋯O secondary inter-actions. The dihedral angles between the benzene ring and the nitro group and the conjugated part of the dioxane-4,6-dione moiety are 19.1 (2) and 17.89 (7)°, respectively.