Decadal changes of macrofauna community in a semi-enclosed Bay of Yueqing in East China Sea.

To reveal the long-term variation of macrofauna community in Yueqing Bay, an aquacultural bay famous for its shellfish culturing in the East China Sea, macrofauna samples were collected in three period from 2002 to 2003 and 2006-2007 to 2020-2021. The results show that macrofaunal community structure in this area has changed significantly (ANOSIM, p < 0.01) in nearly two decades with significant decreases in species number, biodiversity index and average biomass. Meanwhile, the taxa composition also changed significantly as the dominance of annelid increased while that of mollusks, echinoderms and vertebrates decreased. As a consequence of the variation of taxa composition and total biomass, macrofauna community showed a tendency of miniaturization as individuals with smaller body size and lower biomass dominated the community. According to the results of CCA analysis, temperature, salinity and dissolved oxygen content were the main environmental factors that restricted the species composition of macrofauna community. Further studies still needed to reveal the main reasons that cause the variation of macrofauna community. Overall, the results of this study suggest that the present status of Yueqing Bay benthic ecosystem is concerning from a macrobenthos perspective, as the biodiversity index and biomass of macrofauna decreased significantly. Effective measures should be taken in urgently to restrain the safety and function of coastal ecosystems.

Elemental geochemical evidence for the river-derived sources of trace metals in surface sediments from Hangzhou Bay, East China Sea.

Coastal estuaries are often heavily subject to riverine influences by the inputs of sediment from terrestrial sources. Hangzhou Bay (HZB) is threatened by the riverine derived trace metals from two large rivers of Qiantang River (QTR) and Yangtze River (YZR). However, previous studies mainly focused on the incidental transport from the largest river in China (YZR) and failed to simultaneously evaluate the contributions of these two rivers, especially the directly flowing river of QTR, by their trace elemental geochemical composition and distribution. Herein, a comprehensive study identified the river-derived sources of multiple trace metals in surface sediments which transported from both of the rivers. The sampling stations were separated into three regions of YZR, HZB, and QTR based on their spatial distributions of sediment grain size and components. The significant variations for most of the trace metals concentrations, except for Cd, Th, and U, were found among three regions (χ2 ≥ 8.22, p ≤ 0.016). The highest concentrations in HZB were mainly resulted from the grain size effect (68.82% of the total variance), while the highest concentrations of Sr, Cd, and Ba in YZR and Zr and Hf in QTR were attributed to the anthropogenic source (11.90%) and mineral composition (6.21%) of river basins. After normalized the diversity of multiple trace metals concentrations and the influence of grain size by ratios of Igeo and EFLi, three regions were effectively distinguished. It was indicated that As, Cd, and Sb were enriched in the sediments of rivers by anthropogenic source (EFLi > 1.5 and/or Igeo > 1). The results evidenced that, after removing the influence of grain size, elemental geochemical composition of the surface sediments confidently identified the river-derived anthropogenic sources of the enriched trace metals from two major rivers, and largely from YZR.

Characteristic chromanone acids from Calophyllum membranaceum: Determination of C-3 configuration and anti-inflammatory activity.

One undescribed homologous furanochromanone (1) featuring a 6/6/5/3 tetracyclic skeleton and four highly oxidized pyranochromanones (2-5), along with a set of four pyranochromanone stereoisomers [(±)-6a and (±)-6b], were isolated from the leaves of Calophyllum membranaceum Gardn. Et Champ. Their structures were elucidated by using spectroscopic data, Snatzke's method, quantum-chemical calculations, and X-ray crystallographic analysis. The correlation of characteristic Cotton effects and specific chemical shifts with C-3 configuration provided a convenient approach to assign the C-3 configuration of 2,3-dimethylchromanones. The stereochemical assignments of 3-OH substituted pyranochromanones by quantum-based NMR methods following single/double MTPA derivatization were consistent with the ECD/NMR prediction, which verified the feasibility and reliability of the proposed empirical rule. The underlying mechanism was further clarified by conformational and molecular orbital analyses. Moreover, biological evaluation and binding assays demonstrated that compound 3 (KD = 0.45 µM) tightly binds to the TLR4-MD2 target, thereby inhibiting the TLR4/MyD88-dependent and -independent signal pathways. This study provides the first evidence that Calophyllum chromanones are a novel structural type of TLR4 inhibitors, exerting their anti-inflammatory effects by disrupting the binding between TLR4 and MD2.

Taking Olefin Metathesis to the Limit: Stereocontrolled Synthesis of Trisubstituted Alkenes.

ConspectusIn this Account, we share the story of the development of catalytic olefin metathesis processes that efficiently deliver a wide range of acyclic and macrocyclic E- or Z-trisubstituted alkenes. The tale starts with us unveiling, in collaboration with Richard Schrock and his team, the blueprint in 2009 for the design of kinetically controlled Z-selective olefin metathesis reactions. This paved the way for the development of Mo-, W-, and Ru-based catalysts and strategies for synthesizing countless linear and macrocyclic Z-olefins. Six years later, in 2015, we found that abundant Z-alkene feedstocks, such as oleic acid, can be directly transformed to high-value and more difficult-to-access alkenes through a cross-metathesis reaction promoted by a Ru-catechothiolate complex that we had developed; the approach, later coined stereoretentive olefin metathesis, was extended to the synthesis of E-alkenes.It was all about disubstituted alkenes until when in 2017 we addressed the challenge of accessing stereodefined Z- and E-trisubstituted alkenes, key to medicine and materials research. These transformations can be most effectively catalyzed by Mo monoaryloxides pyrrolide (MAP) and chloride (MAC) complexes. A central aspect of the advance is the merging of olefin metathesis, which delivered trisubstituted alkenyl fluorides, chlorides, and bromides with cross-coupling. These catalytic and stereoretentive transformations can be used in various combinations, thereby enabling access to assorted Z- or E-trisubstituted alkene. Ensuing work led to the emergence of other transformations involving substrates that can be purchased with high stereoisomeric purity, notably E- and Z-trihalo alkenes. Trisubstituted olefins, Z or E, bearing a chemoselectively and stereoretentively alterable F,Cl-terminus or B(pin),Cl-terminus may, thus, be easily and reliably synthesized. Methods for stereoretentive preparation of other alkenyl bromide regioisomers and α,ß-unsaturated carboxylic and thiol esters, nitriles, and acid fluorides followed, along with stereoretentive ring-closing metathesis reactions that afford macrocyclic trisubstituted olefins. Z- and E-Macrocyclic trisubstituted olefins, including those that contain little or no entropic support for cyclization (minimally functionalized) and/or are disfavored under substrate-controlled conditions, can now be synthesized. The utility of this latest chapter in the history of olefin metathesis has been highlighted by applications to the synthesis of several biologically active compounds, as well as their analogues, such as those marked by one or more site-specifically incorporated fluorine atoms or more active but higher energy and otherwise unobtainable conformers.The investigations discussed here, which represent every stereoretentive method that has been reported thus far for preparing a trisubstituted olefin, underscore the inimitable power of Mo-based catalysts. This Account also showcases a variety of mechanistic attributes─some for the first time, and each instrumental in solving a problem. Extensive knowledge of mechanistic nuances will be needed if we are to address successfully the next challenging problem, namely, the development of catalysts and strategies that may be used to synthesize a wide range of tetrasubstituted alkenes, especially those that are readily modifiable, with high stereoisomeric purity.

Multiple interface coupling in ultrathin Mn-based composites for superior catalytic oxidation: Implications of interface coupling on structural defects.

Manganese oxide has been recognized as one of the most promising gaseous heterogeneous catalysts due to its low cost, environmental friendliness, and high catalytic oxidation performance. The modulation of the interfacial coupling effect of manganese oxides by chemical means is considered a critical and effective way to improve the catalytic performance. Herein, a novel one-step synthetic strategy of highly-efficient ultrathin manganese-based catalysts is proposed through optimal regulation of metal/manganese oxide multi-interfacial coupling. Carbon monoxide (CO) and propane (C3H8) oxidation are employed as probe reactions to investigate the structure-catalytic mechanism - catalytic performance relationship. The ultrathin manganese (Mn)-based catalyst exhibits superior low-temperature catalytic activity with a 90% conversion of CO/C3H8 realized at 106℃ and 350℃. Subsequently, the effect of "interfacial effect" on the intrinsic properties of manganese oxides is revealed. The ultrathin appearance of two-dimensional (2D) manganese dioxide (MnO2) nanosheets changes the binding force in the vertical direction, thus resulting in an increase in the average manganese-oxygen (Mn-O) bond length and exposing more surface defects. Besides, the introduction of Copper (Cu) species into the catalyst further weakens the Mn-O bond and promotes the generation of oxygen vacancies, which subsequently enhances the oxygen migration rate. This study provides new insights into the optimal design of transition metal oxide interfacial assemblies for efficient catalytic reactions.

Catalytic Cross-Metathesis Reactions That Afford E- and Z-Trisubstituted Alkenyl Bromides: Scope, Applications, and Mechanistic Insights.

Stereochemically defined trisubstituted alkenes with a bromide and a methyl group at a terminus can be readily and stereoretentively derivatized through catalytic cross-coupling, affording unsaturated fragments found in many bioactive natural products. A direct method for generating such entities would be by stereocontrolled catalytic cross-metathesis (CM). Such methods are scarce however. Here, we present a stereoretentive strategy for CM between tri-, Z- or E-di, or monosubstituted olefins and Z- or E-2-bromo-2-butene, affording an assortment of E- or Z-trisubstituted alkenyl bromides. The majority of the transformations were catalyzed by two Mo monoaryloxide pyrrolide (MAP) complexes, one purchasable and the other accessible by well-established protocols. Substrates, such as feedstock trisubstituted olefins, can be purchased; the alkenyl bromide reagents are commercially available or can be prepared in two steps in a multigram scale. The catalytic process can be used to generate products that contain polar moieties, such as an amine or an alcohol, or sterically hindered alkenes that are α- or ß-branched. The utility of the approach is highlighted by a brief and stereocontrolled synthesis of an unsaturated fragment of phomactin A and a concise total synthesis of ambrein. An unexpected outcome of these investigations was the discovery of a new role for the presence of a small-molecule alkene in an olefin metathesis reaction. DFT studies indicate that this additive swiftly reacts with a short-lived Mo alkylidene and probably helps circumvent the formation of catalytically inactive square pyramidal metallacyclobutanes, enhancing the efficiency of a transformation.

Ecological risk assessment of trace metals in sediments and their effect on benthic organisms from the south coast of Zhejiang province, China.

To explore the ecological risks of trace metals in sediments and their relationship with benthic organisms, 12 trace metals were analyzed and the macrobenthos were identified in the sediments collected from the south coast of Zhejiang province which belongs to the East China Sea. Spatially, the concentrations of most trace metals were high in the estuary, except for Ba and Sr. There was no obvious enrichment for trace metals, except that the concentration of Cd slightly exceeded the coastal background. The ecological risks calculated by the concentrations of Cr, Cd, Cu, Zn, Pb, and Ni in sediments showed that the methods based on sediment quality guidelines could judge the ecological risk more intuitively than the methods based on background value (PN, PLI, RI). The significant correlations between ecological risks and benthos density and biomass revealed the negative impact of trace metals at high concentrations on macrobenthic survival in sediments.

Reagent-Controlled Highly Stereoselective Difluoromethylation: Efficient Access to Chiral α-Difluoromethylamines from Ketimines.

A reagent-controlled highly stereoselective reaction between (S)-difluoromethyl phenyl sulfoximine 1 and imines is reported, and this synthetic method provides a variety of enantiomerically enriched α-difluoromethyl amines. The main pros of this approach include high efficiency, high stereoselectivity, and a broad substrate scope, which is probably achieved through a non-chelating transition state.

Biomimetic Tremelliform Ultrathin MnO2/CuO Nanosheets on Kaolinite Driving Superior Catalytic Oxidation: An Example of CO.

Highly efficient three-dimensional (3D) kaolinite/MnO2-CuO (KM@CuO-NO3) catalysts were synthesized by a mild biomimetic strategy. Kaolinite flakes were uniformly wrapped by ultrathin tremelliform MnO2 nanosheets with thicknesses of around 1.0-1.5 nm. Si-O and Al-O groups in kaolinite hosted MnO2 nanosheets to generate a robust composite structure. The ultrathin MnO2 lamellar structure exhibited excellent stability even after calcination above 350 °C. Kaolinite/MnO2 exhibited abundant edges, sharp corners, and interconnected diffusion channels, which are superior to the common stacked structure. Open channels guaranteed fast transportation and migration of CO and O2 during CO oxidation. The synthesized KM@CuO-NO3 achieved a 90% CO conversion efficiency at a relatively low temperature (110 °C). Furthermore, the abundant oxygen vacancies on KM@CuO-NO3 assisted the adsorption and activation of oxygen species and thus enhanced the oxygen mobility and reactivity in the catalytic process. The mechanism results suggest that CuO introduced to the catalyst not only acted as CO active sites but also weakened the Mn-O bond, subsequently improved the mobilities of the oxygen species, which was found to contribute to its high activity for CO oxidation. This study provides new conceptual insights into rationally regulating structural assembly between transition metal oxides and natural minerals for high-performance catalysis reactions.

Catalytic and Stereoselective Transformations with Easily Accessible and Purchasable Allyl and Alkenyl Fluorides.

Stereochemically defined organofluorine compounds are vital to drug discovery and many applicable catalytic strategies have been introduced for accessing these entities stereoselectively. One approach entails incorporation of a fluorine atom (C-F bond formation) or an organofluorine moiety (e.g., CF3 or CF2 H), and another exploits commercially available compounds with one or more fluorine atoms. Here, we present the state-of-the-art regarding the use of alkenyl and allylic fluorides in preparation of stereochemically defined fluoro-organic molecules. Allylic and alkenyl fluorides may be purchased or generated from a commercially available acid, carboxylate salt, ester, aldehyde hydrate, or ketone bearing several fluorine atoms next to a carbonyl group. We underscore the untapped potential of purchasable organofluorine compounds, many allylic and alkenyl fluorides, as launching points for development of stereoselective processes that are of value to therapeutic science.

Dynamic Kinetic Resolution-Enabled Highly Stereoselective Nucleophilic Fluoroalkylation to Access Chiral ß-Fluoro Amines.

ß-Fluorinated amine is highly desirable for biological and pharmaceutical science, because replacing a C-H bond with a C-F bond can change the physical and chemical properties of the parent molecule to a large extent but not significantly alter its overall geometry. Herein, the highly stereoselective nucleophilic monofluoromethylation of imines have been developed. It is proposed that the chelated transition state enables the chiral induction by the dynamic kinetic resolution of the chiral α-fluoro carbanions.

The association between childhood trauma and the age of onset in drug-free bipolar depression.

OBJECTIVE: This study aimed to investigate the relationship between childhood trauma and clinical correlates in bipolar depression. METHODS: A total of 61 bipolar depression patients were enrolled and assessed based on the Childhood Trauma Questionnaire-Short Form (CTQ-SF), Patient Health Questionaire-15 (PHQ-15), Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7) systems. RESULTS: The age of onset in bipolar depression patients with either trauma or abuse or neglect was significantly lower than in patients without these factors. There were statistically significant negative correlations between the age of onset and the number of different trauma types in bipolar depression patients. Multiple variable regression showed a significant association between the number of trauma types and the age of onset. Furthermore, there was a significant negative correlation between the age of onset with CTQ-SF total score (CTS), emotional abuse score and emotional neglect score, and physical neglect score. However, multiple variable regression analysis revealed that there was a significant association between emotional abuse score and the age of onset of bipolar depression patients. CONCLUSION: Our results suggest that childhood trauma may be associated with physical symptoms and the age of onset in bipolar depression patients.

LncRNA PTCSC3 is upregulated in osteoporosis and negatively regulates osteoblast apoptosis.

BACKGROUND: It is known that long non-coding RNA (lncRNA) PTCSC3 is involved in thyroid cancer and glioma, but its function in osteoporosis is unknown. The aim of our study was to investigate the role of lncRNA PTCSC3 in osteoporosis. METHODS: A total of 80 patients with osteoporosis (4 clinical stages) and four corresponding groups of healthy controls were enrolled. Plasma PTCSC3 levels in the 80 osteoporosis patients and 80 healthy volunteers were measured using RT-qPCR. The diagnostic potential of plasma PTCSC3 for osteoporosis was evaluated by ROC curve analysis with healthy volunteers as the true negative cases and corresponding osteoporosis patients as the true positive cases. RESULTS: PTCSC3 was upregulated in osteoporosis patients compared with healthy controls. PTCSC3 levels increased with osteoporosis stages increasing, but not with healthy controls aging. PTCSC3 overexpression separated each stage of osteoporosis from corresponding controls. PTCSC3 overexpression promoted while PTCSC3 silencing inhibited osteoblast apoptosis. However, PTCSC3 overexpression and silencing showed no significant effect on osteoclast apoptosis. LncRNA PTCSC3 was upregulated in osteoporosis and negatively regulated osteoblast apoptosis. CONCLUSION: LncRNA PTCSC3 may serve as a potential therapeutic target for osteoporosis.

CircTMOD3 promotes lipopolysaccharide-induced chondrocyte apoptosis in osteoarthritis by sponging miR-27a.

INTRODUCTION: The progression of osteoarthritis (OA) requires the involvement of lipopolysaccharide (LPS)-induced inflammation, in which circTMOD3 plays an important role. We predicted that circTMOD3 could interact with miR-27a to inhibit LPS-induced chondrocyte apoptosis and explored the interaction between circTMOD3 and miR-27a in OA. MATERIALS AND METHODS: Total RNAs were isolated from cartilage tissue samples from both OA patients (n = 62) and controls (n = 62) and subjected to RT-qPCRs to determine circTMOD3 and miR-27a (mature and premature) expression. Subcellular location of circTMOD3 and its interaction with premature miR-27a were analyzed using subcellular fractionation assay and RNA-RNA pulldown assay, respectively. CircTMOD3 was overexpressed in chondrocytes to study its role in miR-27a maturation. The roles of circTMOD3 and miR-27a in LPS-induced chondrocyte apoptosis were analyzed using cell apoptosis assay. RESULTS: CircTMOD3 and premature miR-27a levels were increased while mature miR-27a level was decreased in OA. CircTMOD3 was located in both nuclear and cytoplasm fractions of chondrocytes. CircTMOD3 directly interacted with premature miR-27a and promoted LPS-induced chondrocyte apoptosis, while miR-27a inhibited LPS-induced chondrocyte apoptosis. Moreover, circTMOD3 overexpression suppressed miR-27a maturation and reduced the inhibitory effects of miR-27a on LPS-induced chondrocyte apoptosis. CONCLUSION: CircTMOD3 suppresses miR-27a maturation in OA to promote chondrocyte apoptosis induced by LPS.

Stereodefined alkenes with a fluoro-chloro terminus as a uniquely enabling compound class.

Trisubstituted alkenyl fluorides are important compounds for drug discovery, agrochemical development and materials science. Despite notable progress, however, many stereochemically defined trisubstituted fluoroalkenes either cannot be prepared efficiently or can only be accessed in one isomeric form. Here we outline a general solution to this problem by first unveiling a practical, widely applicable and catalytic strategy for stereodivergent synthesis of olefins bearing a fluoro-chloro terminus. This has been accomplished by cross-metathesis between two trisubstituted olefins, one of which is a purchasable but scarcely utilized trihaloalkene. Subsequent cross-coupling can then be used to generate an assortment of trisubstituted alkenyl fluorides. The importance of the advance is highlighted by syntheses of, among others, a fluoronematic liquid-crystal component, peptide analogues bearing an E- or a Z-amide bond mimic, and all four stereoisomers of difluororumenic ester (an anti-cancer compound).

Deoxyfluorination of alcohols with aryl fluorosulfonates.

Aryl fluorosulfonates are developed as a deoxyfluorinating reagent in the transformation of primary and secondary alcohols into the corresponding alkyl fluorides. These reagents feature easy availability, low-cost, high stability and high efficiency. Diverse functionalities including aldehyde, ketone, ester, halogen, nitro, alkene, and alkyne are well tolerated under mild reaction conditions.

Review of the genus Haloschizopera (Harpacticoida: Miraciidae, Diosaccinae) with description of a new species.

Haloschizopera cheni sp. n., was recognized from our latest collections from the East China Sea. The new species is similar to H. abyssi Becher, 1974 but differs from it by the following combined features: baseoendopodal lobe of female P5 with five setae, P2 and P3 enp-3 both longer than enp-1-2 combined, and caudal rami longer than broad. Comparison of all the known species of Haloschizopera was performed. Species in the genus can be divided into four groups by the setal formulae of P3 and P4. The main diagnostic characters of each species are listed and a key to all known species of Haloschizopera is also provided.

Recent collections of sea spiders (Arthropoda: Pycnogonida) from China seas, with some new records and a checklist of the area.

Though research about sea spiders limited in China seas, a complete checklist has not yet exist so far. After checking recent collections obtained from Shandong, Zhejiang, Fujian and the East China Sea, all these sixty-eight specimens were identified as six species belonged to four families and five genera, including three ones new to China. We described and illustrated them in this study, and also revised all previous records about Chinese pycnogonids and provided a checklist for the presently known forty-one species.