The Influence of Financial Agglomeration on the Export Trade in the Guangdong-Hong Kong-Macao Greater Bay Area: An Analysis Based on Mediation Effect of Technological Innovation

So far, the relation between financial agglomeration and export trade is complex and there are few related studies. However, research on this topic will be of great value to the development of the Guangdong-Hong Kong-Macau Greater Bay Area (the Greater Bay Area). This paper aims to use the mediation model to analyze the role of technological innovation as an mediator variable between financial agglomeration and export trade. Based on the relevant data of the Greater Bay Area from 2009 to 2018, regression analysis was performed using the three equations of the mediation model. The mediator variable was then replaced to conduct a robustness test, and it was found that there is indeed an mediation effect; technological innovation acts as an mediator variable between financial agglomeration and export trade. Therefore, it can be concluded that the financial agglomeration in the Greater Bay Area can effectively promote technological innovation, while technological innovation will inhibit exports to a certain extent

Microbial-feeding interactions reveal the effects of feeding blood on the gut microbiota of the aquaculture leech (Hirudo nipponica)

Leeches (Hirudo nipponica), as a kind of aquatic animal, mainly feed on fresh blood. After feeding, they needed to digest for a long time because the intestinal digestive enzyme content is low, so their digestive needed the help of gut microbiota. Here, we examined intestinal microbiota in captive Hirudo nipponica of different periods after feeding blood with high-throughput sequencing. The results showed that gut microbial diversity was lower before feeding than after. At the level of the core phylum of the gut microbiota of Hirudo nipponica, the focus was on Proteobacteria, Bacteroidetes, and Firmicutes. After feeding blood, the relative abundance of Proteobacteria decreased, while the opposite was true for Bacteroidetes and Firmicutes. The core bacteria at the genus level are Aeromonas and Mucinivorans. The results show that the structure of the gut microbiota and function are closely associated with the blood feeding. The study aimed to lay a theoretical foundation for the blood-digestive mechanism of Hirudo nipponica

CCL4 participates in the reprogramming of glucose metabolism induced by ALV-J infection in chicken macrophages

Interferon and chemokine-mediated immune responses are two general antiviral programs of the innate immune system in response to viral infections and have recently emerged as important players in systemic metabolism. This study found that the chemokine CCL4 is negatively regulated by glucose metabolism and avian leukosis virus subgroup J (ALV-J) infection in chicken macrophages. Low expression levels of CCL4 define this immune response to high glucose treatment or ALV-J infection. Moreover, the ALV-J envelope protein is responsible for CCL4 inhibition. We confirmed that CCL4 could inhibit glucose metabolism and ALV-J replication in chicken macrophages. The present study provides novel insights into the antiviral defense mechanism and metabolic regulation of the chemokine CCL4 in chicken macrophages

Climate changes reconstructed from a glacial lake in High Central Asiaover the past two millennia

Climatic changes in Arid Central Asia (ACA) over the past two millennia have been widely concerned. However, less attention has been paid to those in the High Central Asia (HCA), where the Asian water tower nurtures the numerous oases by glacier and/or snow melt. Here, we present a new reconstruction of the temperature and precipitation change over the past two millennia based on grain size of a well-dated glacial lake sediment core in the central of southern Tianshan Mountains. The results show that the glacial lake catchment has experienced cold-wet climate conditions during the Dark Age Cold Period (&sim;300&ndash;600 AD; DACP) and the Little Ice Age (&sim;1300&ndash;1870 AD; LIA), whereas warm-dry conditions during the Medieval Warm Period (&sim;700&ndash;1270 AD; MWP). Integration of our results with those of previously published lake sediment records, stalagmite &delta;18O records, ice core net accumulation rates, tree-ring based temperature reconstructions, and mountain glacier activities suggest that there has a broadly similar hydroclimatic pattern over the HCA areas on centennial time scale during the past two millennia. Comparison between hydroclimatic pattern of the HCA and that of the ACA areas suggests a prevailing &#39;warm-dry and cold-wet&#39; hydroclimatic pattern over the whole westerlies-dominated central Asia areas during the past two millennia. We argue that the position and intensity of the westerlies, which are closely related to the phase of the North Atlantic Oscillation (NAO), and the strength of the Siberian High pressure (SH), could have jointly modulated the late Holocene central Asia hydroclimatic changes.<br /

Neural Induction Potential and MRI of ADSCs Labeled Cationic Superparamagnetic Iron Oxide Nanoparticle In Vitro

Magnetic resonance imaging (MRI) combined with contrast agents is believed to be useful for stem cell tracking in vivo, and the aim of this research was to investigate the biosafety and neural induction of SD rat-originated adipose derived stem cells (ADSCs) using cationic superparamagnetic iron oxide (SPIO) nanoparticle which was synthesized by the improved polyol method, in order to allow visualization using in vitro MRI. The scan protocols were performed with T2-mapping sequence; meanwhile, the ultrastructure of labeled cells was observed by transmission electron microscopy (TEM) while the iron content was measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). After neural induction, nestin and NSE (neural markers) were obviously expressed. In vitro MRI showed that the cationic PEG/PEI-modified SPIO nanoparticles could achieve great relaxation performance and favourable longevity. And the ICP-AES quantified the lowest iron content that could be detected by MRI as 1.56~1.8 pg/cell. This study showed that the cationic SPIO could be directly used to label ADSCs, which could then inductively differentiate into nerve and be imaged by in vitro MRI, which would exhibit important guiding significance for the further in vivo MRI towards animal models with neurodegenerative disorders

Outflows and Bubbles in Taurus: Star-formation Feedback Sufficient to Maintain Turbulence

We have identified outflows and bubbles in the Taurus molecular cloud based on the ~100 deg^2 Five College Radio Astronomy Observatory ^(12)CO(1-0) and ^(13)CO(1-0) maps and the Spitzer young stellar object catalogs. In the main 44 deg^2 area of Taurus, we found 55 outflows, of which 31 were previously unknown. We also found 37 bubbles in the entire 100 deg^2 area of Taurus, none of which had been found previously. The total kinetic energy of the identified outflows is estimated to be ~3.9 x 10^(45) erg, which is 1% of the cloud turbulent energy. The total kinetic energy of the detected bubbles is estimated to be ~9.2 x 10^(46) erg, which is 29% of the turbulent energy of Taurus. The energy injection rate from the outflows is ~1.3 x 10^(33) erg s^(-1), which is 0.4–2 times the dissipation rate of the cloud turbulence. The energy injection rate from bubbles is ~6.4 x 10^(33) erg s^(−1), which is 2–10 times the turbulent dissipation rate of the cloud. The gravitational binding energy of the cloud is ~1.5 x 10^(48) erg, that is, 385 and 16 times the energy of outflows and bubbles, respectively. We conclude that neither outflows nor bubbles can provide sufficient energy to balance the overall gravitational binding energy and the turbulent energy of Taurus. However, in the current epoch, stellar feedback is sufficient to maintain the observed turbulence in Taurus

Chemotype-selective Modes of Action of κ-Opioid Receptor Agonists

The crystal structures of opioid receptors provide a novel platform for inquiry into opioid receptor function. The molecular determinants for activation of the κ-opioid receptor (KOR) were studied using a combination of agonist docking, functional assays, and site-directed mutagenesis. Eighteen positions in the putative agonist binding site of KOR were selected and evaluated for their effects on receptor binding and activation by ligands representing four distinct chemotypes: the peptide dynorphin A(1–17), the arylacetamide U-69593, and the non-charged ligands salvinorin A and the octahydroisoquinolinone carboxamide 1xx. Minimally biased docking of the tested ligands into the antagonist-bound KOR structure generated distinct binding modes, which were then evaluated biochemically and pharmacologically. Our analysis identified two types of mutations: those that affect receptor function primarily via ligand binding and those that primarily affect function. The shared and differential mechanisms of agonist binding and activation in KOR are further discussed. Usually, mutations affecting function more than binding were located at the periphery of the binding site and did not interact strongly with the various ligands. Analysis of the crystal structure along with the present results provide fundamental insights into the activation mechanism of the KOR and suggest that “functional” residues, along with water molecules detected in the crystal structure, may be directly involved in transduction of the agonist binding event into structural changes at the conserved rotamer switches, thus leading to receptor activation

Structure of the human smoothened receptor bound to an antitumour agent

The smoothened (SMO) receptor, a key signal transducer in the Hedgehog (Hh) signaling pathway is both responsible for the maintenance of normal embryonic development and implicated in carcinogenesis. The SMO receptor is classified as a class Frizzled (class F) G protein-coupled receptor (GPCR), although the canonical Hh signaling pathway involves the transcription factor Gli and the sequence similarity with class A GPCRs is less than 10%. Here we report the crystal structure at 2.5 Å resolution of the transmembrane domain of the human SMO receptor bound to the small molecule antagonist LY2940680. Although the SMO receptor shares the seven transmembrane helical (7TM) fold, most conserved motifs for class A GPCRs are absent, and the structure reveals an unusually complex arrangement of long extracellular loops stabilized by four disulfide bonds. The ligand binds at the extracellular end of the 7TM bundle and forms extensive contacts with the loops

Structure of the nociceptin/orphanin FQ receptor in complex with a peptide mimetic

Members of the Opioid Receptor (OR) family of G protein-coupled receptors (GPCRs) are found throughout the peripheral and central nervous system where they play key roles in nociception and analgesia. Unlike the classical ORs, δ–OR, κ–OR,1 and μ-OR,2 which were delineated by pharmacological criteria in the 1970’s and 1980’s, the nociceptin/orphanin FQ (N/OFQ) peptide receptor (NOP, aka ORL-1) was discovered relatively recently via molecular cloning and characterization of an orphan GPCR3. Despite its high sequence similarity (~60%) with ORs, NOP has a strikingly distinct pharmacology4,5. Despite high sequence similarity with classical opioid G protein-coupled receptor subtypes, the nociceptin/orphanin FQ (N/OFQ) peptide receptor (NOP) has a distinct biological and pharmacological role, featuring activation by the endogenous peptide N/OFQ, and unique selectivity for exogenous ligands. This study reports the crystal structure of human NOP solved in complex with the peptide mimetic antagonist Banyu Compound-24 (C-24), revealing atomic details of ligand-receptor recognition and selectivity. C-24 mimics the first four N-terminal residues of the NOP-selective peptide antagonist UFP-101, a close derivative of N/OFQ, and provides important clues to binding of these peptides. The X-ray structure also reveals substantial conformational differences in the pocket regions between NOP and the “classical” opioid receptors κ (Ref. 1) and μ (Ref. 2), which are likely due to a small number of residues that vary between the two receptors. The NOP/C-24 structure explains the divergent selectivity profile of NOP and provides a new structural template for the design of NOP ligands