Spatial patterns of Holocene temperature changes over mid-latitude Eurasia.

The Holocene temperature conundrum, the discrepancy between proxy-based Holocene global cooling and simulated global annual warming trends, remains controversial. Meanwhile, reconstructions and simulations show inconsistent spatial patterns of terrestrial temperature changes. Here we report Holocene alkenone records to address spatial patterns over mid-latitude Eurasia. In contrast with long-term cooling trends in warm season temperatures in northeastern China, records from southwestern Siberia are characterized by colder conditions before ~6,000 years ago, thus long-term warming trends. Together with existing records from surrounding regions, we infer that colder airmass might have prevailed in the interior of mid-latitude Eurasian continent during the early to mid-Holocene, perhaps associated with atmospheric response to remnant ice sheets. Our results challenge the proposed seasonality bias in proxies and modeled spatial patterns in study region, highlighting that spatial patterns of Holocene temperature changes should be re-considered in record integrations and model simulations, with important implications for terrestrial hydroclimate changes.

Development and Test of Geogrid with Distributed Deformation Monitoring Function.

In recent years, there is a growing demand for materials that can both improve the mechanical properties of structures and carry out health monitoring and risk warning. In this case, in order to realize distributed deformation monitoring, a new method of making geogrid by 3D printing technology is proposed. The grille rib is made by embedding the conductive polymer (ground carbon fiber as conductive filler) into the insulating shell (PLA material) in the specified path, and then the rib is vertically crossed into each other to form a grille sample. In order to study the distributed deformation monitoring function of this grid, a manual push-pull testing machine was used to conduct a load-unload experiment to analyze the change rule of resistance on the grid plane. The following conclusions were obtained: the closer the ribs are to the load bearing point, the greater the change in resistance, and conversely, the farther the ribs are from the load bearing point, the smaller the change in resistance. Depending on the geogrid network characteristics, the electrical resistance distribution on the geogrid plane can be obtained by superimposing the resistance values of the horizontal and longitudinal ribs, then the location and the magnitude of deformation can be estimated. Additionally, this study carried out numerical simulation of the grid model based on ANSYS 15.0 software and compared with the loading experiment results to verify that the force deformation position can be retrieved through the change of resistance.

Complete genome sequences of Gordonia rubripertincta phages OtterstedtS21 and Patos.

We report the genomes of two viruses with siphovirus morphology, OtterstedtS21 and Patos, from Albany, New York, using Gordonia rubripertincta. The genomes of OtterstedtS21 and Patos are ~68 kbp long with 58% GC content. Both phages group with cluster DV based on gene content similarity to phages in the Actinobacteriophage database.

Extracellular vesicles in osteoarthritis of peripheral joint and temporomandibular joint.

Osteoarthritis (OA) is a disabling disease with significant morbidity worldwide. OA attacks the large synovial joint, including the peripheral joints and temporomandibular joint (TMJ). As a representative of peripheral joint OA, knee OA shares similar symptoms with TMJ OA. However, these two joints also display differences based on their distinct development, anatomy, and physiology. Extracellular vesicles (EVs) are phospholipid bilayer nanoparticles, including exosomes, microvesicles, and apoptotic bodies. EVs contain proteins, lipids, DNA, micro-RNA, and mRNA that regulate tissue homeostasis and cell-to-cell communication, which play an essential role in the progression and treatment of OA. They are likely to partake in mechanical response, extracellular matrix degradation, and inflammatory regulation during OA. More evidence has shown that synovial fluid and synovium-derived EVs may serve as OA biomarkers. More importantly, mesenchymal stem cell-derived EV shows a therapeutic effect on OA. However, the different function of EVs in these two joints is largely unknown based on their distinct biological characteristic. Here, we reviewed the effects of EVs in OA progression and compared the difference between the knee joint and TMJ, and summarized their potential therapeutic role in the treatment of OA.

Dual Role of Interleukin-20 in Different Stages of Osteoclast Differentiation and Its Osteoimmune Regulation during Alveolar Bone Remodeling.

Osteoimmunology mediators are critical to balance osteoblastogenesis and osteoclastogenesis to maintain bone homeostasis. A lot of the osteoimmunology mediators are regulated by interleukin-20 (IL-20). However, little is known about the role of IL-20 in bone remodeling. Here, we showed that IL-20 expression was correlated with osteoclast (OC) activity in remodeled alveolar bone during orthodontic tooth movement (OTM). Ovariectomize (OVX) in rats promoted OC activity and enhanced IL-20 expression, while blocking OC inhibited IL-20 expression in osteoclasts. In vitro, IL-20 treatment promoted survival, inhibited apoptosis of the preosteoclast at the early stages of osteoclast differentiation, and boosted the formation of osteoclasts and their bone resorption function at the late stages. More importantly, anti-IL-20 antibody treatment blocked IL-20-induced osteoclastogenesis and the subsequent bone resorption function. Mechanistically, we showed that IL-20 synergistically acts with RANKL to activate the NF-κB signaling pathway to promote the expression of c-Fos and NFATc1 to promote osteoclastogenesis. Moreover, we found that local injection of IL-20 or anti-IL-20 antibody enhanced osteoclast activity and accelerated OTM in rats, while blocking IL-20 reversed this phenomenon. This study revealed a previously unknown role of IL-20 in regulating alveolar bone remodeling and implies the application of IL-20 to accelerated OTM.

Exceptional terrestrial warmth around 4200-2800 years ago in Northwest China.

One of the Holocene abrupt events around 4200 years ago, lasting for âˆ¼ 200 years, is thought to have caused cultural disruptions, yet terrestrial climatic status right after the cold/dry event remains poorly defined and is often presumed that a generally cool condition prevailed during the Bronze Age (∼ 4000-2200 years ago). Here we report an alkenone-based summer temperature record over the past âˆ¼ 12,000 years, in addition to two updated alkenone records, from Northwest China, providing new insights into the climatic status right after the event. Our results indicate that exceptional terrestrial warmth, up to âˆ¼ 6 °C, occurred around 4200-2800 years ago during the Bronze Age, superimposed on the long-term Holocene cooling trend. The exceptional warmth in Northwest China, together with other climate anomalies elsewhere, suggests an unusual large-scale climatic reorganization at 4200-2800 years ago when solar activity remained high, with important implications to the climate background for cultural developments during the Bronze Age.

Inhibitory effect of infliximab on orthodontic tooth movement in male rats.

OBJECTIVE: This study aimed to investigate the effect of infliximab on orthodontic tooth movement in rats. MATERIALS AND METHODS: Sixty male Sprague-Dawley rats were randomly divided into two groups: saline group and infliximab group. The two groups of rats received weekly intraperitoneally injection of saline or infliximab (5 mg/kg), respectively. After four weeks of injection, five rats in each group were euthanized and orthodontic appliances were placed in the other twenty-five rats each. On days 1, 3, 7, 14 and 21, five rats from each group were euthanised. Maxillae of all the rats were collected and examined by micro-computed tomography, haematoxylin and eosin staining, tartrate-resistant acid phosphatase staining, and immunohistochemical staining of tumour necrosis factor (TNF)-α, receptor activator of nuclear factor κB ligand (RANKL), receptor activator of nuclear factor κB (RANK), and osteoprotegerin (OPG). All data were analysed with Mann-Whitney test. RESULTS: Infliximab inhibited orthodontic tooth movement and decreased osteoclastogenesis on the compression side during orthodontic tooth movement. The elevated TNF-α level, induced by orthodontic force, was decreased by infliximab. Furthermore, infliximab reduced the expression of RANKL and RANK, while increased the expression of OPG on the compression side. CONCLUSION: Infliximab inhibits orthodontic tooth movement by reducing levels of TNF-α, RANKL, and RANK, while increasing level of OPG, and decreasing osteoclastogenesis on the compression side of periodontium.

Insights into Chlorobenzene Catalytic Oxidation over Noble Metal Loading {001}-TiO2: The Role of NaBH4 and Subnanometer Ru Undergoing Stable Ru0↔Ru4+ Circulation.

Catalytic combustion of ubiquitous chlorinated volatile organic compounds (CVOCs) encounters bottlenecks regarding catalyst deactivation by chlorine poisoning and generation of toxic polychlorinated byproducts. Herein, Ru, Pd, and Rh were loaded on {001}-TiO2 for thermal catalytic oxidation of chlorobenzene (CB), with Ru/{001}-TiO2 representing superior reactivity, CO2 selectivity, and stability in the 1000 min on-stream test. Interestingly, both acid sites and reactive active oxygen species (ROS) were remarkably promoted via adding NaBH4. But merely enhancing these active sites of the catalyst in CVOC treatment is insufficient. Continuous deep oxidation of CB with effective Cl desorption is also a core issue successfully tackled through the steady Ru0↔Ru4+ circulation. This circulation was facilitated by the observed higher subnanometer Ru dispersion on {001}-TiO2 than the other two noble metals that was supported by single atom stability DFT calculation. Nearly 88 degradation products in off-gas were detected, with Ru/{001}-TiO2 producing the lowest polychlorinated benzene byproducts. An effective and sustainable CB degradation mechanism boosted by the cooperation of NaBH4 enhanced active sites and Ru circulation was proposed accordingly. Insights gained from this study open a new avenue to the rational design of promising catalysts for the treatment of CVOCs.

MiR-18 inhibitor promotes the differentiation of bovine skeletal muscle-derived satellite cells by increasing MEF2D expression.

Skeletal muscle is composed of muscle fibers formed from myoblast differentiation. Recently, numerous researchers have demonstrated that microRNAs (miRNAs) play an essential role in modulating the proliferation and differentiation of myoblasts. Our previous study has shown that among the miR-17-92 cluster members, miR-17 and miR-20a together with miR-19b can efficiently promote the differentiation of murine C2C12 and bovine primary myoblasts. However, the role of miR-18 in this process remains elusive. In this study, we revealed that miR-18 inhibited the differentiation of bovine skeletal muscle-derived satellite cells (bMDSCs), whereas an miR-18 inhibitor significantly promoted cell differentiation (p < 0.001). Then, a target gene of miR-18 was found to be myocyte enhancer factor 2D (MEF2D), which is critical for myoblast differentiation. Furthermore, we found that the combination of the miR-18 inhibitor and miR-19 significantly improved the formation of bMDSCs-derived muscle fibers (p < 0.001). This study revealed the role of miR-18 in bovine skeletal muscle differentiation and contributed to the understanding of the regulatory mechanism of mammalian myogenic differentiation.

Beef is a beneficial food source, and improving muscle yield and quality has become a hot topic in the beef industry. Therefore, our study aimed to explore effective methods to improve bovine muscle cell differentiation to increase beef production. The study revealed that microRNA-18 (miR-18) inhibitor could promote the differentiation of bovine skeletal muscle-derived satellite cells (bMDSCs) by increasing the expression of myocyte enhancer factor 2D (MEF2D), a critical gene for myoblast differentiation. Furthermore, we found that combined inhibitors of miR-18 and miR-19 could significantly improve bMDSCs differentiation. Our study demonstrated the role of a new regulatory factor that may enhance beef production level and contributed to elucidating the mechanism of muscle differentiation.

Apoptotic vesicles inherit SOX2 from pluripotent stem cells to accelerate wound healing by energizing mesenchymal stem cells.

Billions of cells undergo apoptosis every day in the human body, resulting in the generation of a large number of apoptotic vesicles (apoVs) to maintain organ and tissue homeostasis. However, the characteristics and function of pluripotent stem cell (PSC)-derived apoVs (PSC-apoVs) are largely unknown. In this study, we showed that human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) produced larger numbers of apoVs than human umbilical cord mesenchymal stem cells (UMSCs) do when induced by staurosporine. In addition to expressing the general apoV markers cleaved caspase 3, Annexin V, calreticulin, ALIX, CD63 and TSG101, ESC-apoVs inherited pluripotent-specific molecules SOX2 from ESCs in a caspase 3-dependent manner. Moreover, ESC-apoVs could promote mouse skin wound healing via transferring SOX2 into skin MSCs via activating Hippo signaling pathway. Collectively, these findings reveal that apoVs are capable of inheriting pluripotent molecules from ESCs to energize adult stem cells, suggesting the potential to use PSC-apoVs for clinical applications. STATEMENT OF SIGNIFICANCE: Apoptotic vesicles (apoVs) are essential to maintain organ and tissue homeostasis. However, the characteristics and function of pluripotent stem cell (PSC)-derived apoVs (PSC-apoVs) are largely unknown. This study showed that PSC-apoVs produced 100 times more apoVs than human umbilical cord mesenchymal stem cells (UMSCs). Despite expressing the general apoV makers, PSC-apoVs inherited pluripotent-specific molecule SOX2 from PSCs in a caspase 3-dependent manner. Moreover, PSC-apoVs promote mouse skin wound healing via transferring SOX2 into skin MSCs, thus activating Hippo signaling pathway. These findings reveal that apoVs are capable of inheriting pluripotent molecules from PSCs to energize adult stem cells, thus providing a cell-free strategy for clinical applications of PSCs.

Mesenchymal stem cells empower T cells in the lymph nodes via MCP-1/PD-L1 axis.

Mesenchymal stem cells (MSCs) are a type of immunosuppressive stromal cell found in multiple tissues and organs. However, whether MSCs possess immunosupportive characteristics remains unclear. In this study, we showed that the lymph nodes contain immunosupportive MSCs. They produce and secrete a high level of MCP-1 to promote T-cell proliferation and differentiation, in contrast to bone marrow MSCs (BMMSCs), which repress T-cell activation. Unlike BMMSCs, lymph node MSCs (LNMSCs) fail to respond to activated T-cell-induced production of PD-L1 to induce T-cell apoptosis. Mechanistically, MCP-1 activates phospho-Erk to sustain T-cell proliferation and activation while it represses NF-κB/PD-L1 pathway to avoid induction of T-cell apoptosis. Interestingly, inflammatory lymph node-derived LNMSCs abolish their immunosupportive function due to reduction of MCP-1 expression. Finally, we show that systemic infusion of LNMSCs rescues immunosuppression in cytoxan (CTX)-treated mice. This study reveals a previously unrecognized mechanism underlying MSC-based immunoregulation using the MCP-1/PD-L1 axis to energize T cells and suggests a potential to use MSCs to treat immunosuppressive disorders.

Methylation Motifs in Promoter Sequences May Contribute to the Maintenance of a Conserved m5C Methyltransferase in Helicobacter pylori.

DNA methylomes of Helicobacter pylori strains are complex due to the large number of DNA methyltransferases (MTases) they possess. H. pylori J99 M.Hpy99III is a 5-methylcytosine (m5C) MTase that converts GCGC motifs to Gm5CGC. Homologs of M.Hpy99III are found in essentially all H. pylori strains. Most of these homologs are orphan MTases that lack a cognate restriction endonuclease, and their retention in H. pylori strains suggest they have roles in gene regulation. To address this hypothesis, green fluorescent protein (GFP) reporter genes were constructed with six putative promoters that had a GCGC motif in the extended -10 region, and the expression of the reporter genes was compared in wild-type H. pylori G27 and a mutant lacking the M.Hpy99III homolog (M.HpyGIII). The expression of three of the GFP reporter genes was decreased significantly in the mutant lacking M.HpyGIII. In addition, the growth rate of the H. pylori G27 mutant lacking M.HpyGIII was reduced markedly compared to that of the wild type. These findings suggest that the methylation of the GCGC motif in many H. pylori GCGC-containing promoters is required for the robust expression of genes controlled by these promoters, which may account for the universal retention of M.Hpy99III homologs in H. pylori strains.

Interleukin-20 Acts as a Promotor of Osteoclastogenesis and Orthodontic Tooth Movement.

OBJECTIVES: Bones constitute organs that are engaged in constant self-remodelling. Osteoblast and osteoclast homeostasis during remodelling contribute to overall skeletal status. Orthodontics is a clinical discipline that involves the investigation and implementation of moving teeth through the bone. The application of mechanical force to the teeth causes an imbalance between osteogenesis and osteogenesis in alveolar bone, leading to tooth movement. Osteoimmunology comprises the crosstalk between the immune and skeletal systems that regulate osteoclast-osteoblast homeostasis. Interleukin- (IL-) 20, an IL-10 family member, is regarded as a proinflammatory factor for autoimmune diseases and has been implicated in bone loss disease. However, the mechanism by which IL-20 regulates osteoclast differentiation and osteoclastogenesis activation remains unclear. This study investigated the effects of IL-20 on osteoclast differentiation in a rat model; it explored the underlying molecular mechanism in vitro and the specific effects on orthodontic tooth movement in vivo. METHODS: For in vitro analyses, primary rat bone marrow-derived macrophages (BMMs) were prepared from Sprague-Dawley rats for osteoclast induction. After BMMs had been treated with combinations of recombinant IL-20 protein, siRNA, and plasmids, the expression levels of osteoclast-specific factors and signalling pathway proteins were detected through real-time polymerase chain reaction, western blotting, and immunofluorescence staining. For in vivo analyses, IL-20 was injected into the rat intraperitoneal cavity after the establishment of a rat orthodontic tooth movement (OTM) model. OTM distance was detected by Micro-CT and HE staining; the expression levels of protein were detected through immunofluorescence staining. RESULTS: In vitro analyses showed that a low concentration of IL-20 promoted preosteoclast proliferation and osteoclastogenesis. However, a high concentration of IL-20 inhibited BMM proliferation and osteoclastogenesis. IL-20 knockdown decreased the expression of osteoclast specific-markers, while IL-20 overexpression increased the expression of osteoclast specific-markers. Furthermore, IL-20 regulated osteoclast differentiation through the OPG/RANKL/RANK pathway. Overexpression of IL-20 could significantly upregulate RANKL-mediated osteoclast differentiation and osteoclast specific-marker expression; moreover, RANKL/NF-κB/NFATc1 acted as downstream signalling molecule for IL-20. In vivo analysis showed that OTM speed was significantly increased after intraperitoneal injection of IL-20; additionally, mechanical stress sensing proteins were markedly activated. CONCLUSIONS: IL-20 augments osteoclastogenesis and osteoclast-mediated bone erosion through the RANKL/NF-κB/NFATc1 signalling pathway. IL-20 inhibition can effectively reduce osteoclast differentiation and diminish bone resorption. Furthermore, IL-20 can accelerate orthodontic tooth movement and activate mechanical stress sensing proteins.

Interleukin-20 inhibits the osteogenic differentiation of MC3T3-E1 cells via the GSK3ß/ß-catenin signalling pathway.

OBJECTIVE: To investigate the effects of interleukin-20 (IL-20) on the osteogenic differentiation of MC3T3-E1 cells. METHODS: The pre-osteoblast line MC3T3-E1 was treated with different concentrations of IL-20 (0, 2, 20 and 100 ng/mL), and the cell viability was detected by the CCK8 assay. To assess the influence of IL-20 on osteogenic differentiation, alkaline phosphatase (ALP) activity and Alizarin red staining were performed at predetermined times. The expression levels of Runt-related transcription factor 2 (RUNX2), Osterix (Osx), glycogen synthase kinase-3ß (GSK-3ß) and ß-catenin were detected by qRT-PCR and Western blotting analyses. 5 nmol/L lithium chloride (LiCl) was used as GSK-3ß inhibitor. RESULTS: IL-20 promoted cell proliferation but decreased ALP activity and mineralization. Moreover, IL-20 downregulated the expression of RUNX2, Osx and ß-catenin but upregulated the level of GSK-3ß. CONCLUSIONS: The results suggest that IL-20 could inhibit the osteogenic differentiation of MC3T3-E1 cells via the GSK3ß/ß-catenin signalling pathway.

[Industrial Emission Characteristics and Control Countermeasures of VOCs in Chinese Rapid Economic Development Areas].

With the rapid development of China's economy, volatile organic compounds (VOCs) as the precursor of smog and ozone are of increasing concern, especially in rapidly developing areas. This paper is a systematic analysis of VOCs emissions and distribution trends in 12 typical industrial sectors, garbage and wastewater treatment plants, comprehensive industrial parks, and residential districts in Beijing-Tianjin-Hebei, Yangtze River Delta, and Pearl River Delta Regions. The results show that pharmacy, rubber producing, as well as paint spraying are the top three industries among the 12 typical industries with the highest average VOCs emission concentrations at 541, 499, and 450 mg·m-3, respectively. By comparison, the average emission concentration of VOCs from the pharmaceutical industry in Yangtze River Delta and Beijing-Tianjin-Hebei Region was, respectively, about 112 and 1.00×103 mg·m-3. The paint spraying industry in the Pearl River Delta region has the highest emission rate with an average concentration of 1.04×103 mg·m-3. The investigation pertaining to the distribution of different VOCs categories indicates that highly toxic aromatics and halogenated hydrocarbons account for the highest emissions in paint spraying and pharmaceutical industries, reaching ratios of 55.99% and 26.57%, respectively. Additionally, among the three major economic zones, the VOCs concentration is the lowest in residential areas and comprehensive industrial parks in the Yangtze River Delta but the highest in the Beijing-Tianjin-Hebei Region, which is consistent with the distribution of industrial emissions in each region. Moreover, the research reveals that VOCs concentration in residential districts experienced a fluctuating reduction from 2002 to 2018. The significant reduction since 2016 suggests that formulated policies, laws and standards, along with the performed techniques have made significant contributions to the control of VOCs.

Recent advances in the removal of persistent organic pollutants (POPs) using multifunctional materials:a review.

Persistent organic pollutants (POPs) have gained heightened attentions in recent years owing to their persistent property and hazard influence on wild life and human beings. Removal of POPs using varieties of multifunctional materials have shown a promising prospect compared with conventional treatments. Herein, three main categories, including thermal degradation, electrochemical remediation, as well as photocatalytic degradation with the use of diverse catalytic materials, especially the recently developed prominent ones were comprehensively reviewed. Kinetic analysis and underlying mechanism for various POPs degradation processes were addressed in detail. The review also systematically documented how catalytic performance was dramatically affected by the nature of the material itself, the structure of target pollutants, reaction conditions and treatment techniques. Moreover, the future challenges and prospects of POPs degradation by means of multiple multifunctional materials were outlined accordingly. Knowing this is of immense significance to enhance our understanding of POPs remediation procedures and promote the development of novel multifunctional materials.

Interleukin-20 differentially regulates bone mesenchymal stem cell activities in RANKL-induced osteoclastogenesis through the OPG/RANKL/RANK axis and the NF-κB, MAPK and AKT signalling pathways.

The immune and skeletal systems share common mechanisms, and the crosstalk between the two has been termed osteoimmunology. Osteoimmunology mainly focuses on diseases between the immune and bone systems including bone loss diseases, and imbalances in osteoimmune regulation affect skeletal homeostasis between osteoclasts and osteoblasts. The immune mediator interleukin-20 (IL-20), a member of the IL-10 family, enhances inflammation, chemotaxis and angiogenesis in diseases related to bone loss. However, it is unclear how IL-20 regulates the balance between osteoclastogenesis and osteoblastogenesis; therefore, we explored the mechanisms by which IL-20 affects bone mesenchymal stem cells (BMSCs) in osteoclastogenesis in primary cells during differentiation, proliferation, apoptosis and signalling. We initially found that IL-20 differentially regulated preosteoclast proliferation and apoptosis; BMSC-conditioned medium (CM) significantly enhanced osteoclast formation and bone resorption, which was dose-dependently regulated by IL-20; IL-20 inhibited OPG expression and promoted M-CSF, RANKL and RANKL/OPG expression; and IL-20 differentially regulated the expression of osteoclast-specific gene and transcription factors through the OPG/RANKL/RANK axis and the NF-kB, MAPK and AKT pathways. Therefore, IL-20 differentially regulates BMSCs in osteoclastogenesis and exerts its function by activating the OPG/RANKL/RANK axis and the NF-κB, MAPK and AKT pathways, which make targeting IL-20 a promising direction for targeted regulation in diseases related to bone loss.

Synthesis of three-dimensional Au-graphene quantum dots@Pt core-shell dendritic nanoparticles for enhanced methanol electro-oxidation.

Au-graphene quantum dots (GQDs)@Pt core-shell nanodendrites are synthesized through a two-step reduction approach, in which Au forms the core, GQDs form an intermediate layer and dendritic Pt forms the shell. Among the above synthesized catalysts, the GQDs can manipulate the binding of reaction intermediates on the Pt surface as well as assemble π-π * conjugate bonds, thus forming a dendritic Pt shell instead of a compact Pt shell. The obtained core-shell structure was characterized by transmission electron microscopy, energy-dispersive x-ray and x-ray photoelectron spectroscopy. The methanol electro-oxidation was investigated in alkaline media on the Au-GQDs@Pt modified electrode via cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy analysis. In particular, we discovered that Au-Pt assembled with GQDs could dramatically improve the activity and stability of the catalysts, owing to the synergistic effect raised by the GQDs, which exhibit prominent electron conductivity and great chemical/physical stability. It was also found that the Pt/Au mole ratios could control the Pt shell thickness, which significantly affected the catalytic methanol oxidation activity of the Au-GQDs@Pt nanodendrites. The Au-GQDs@Pt nanodendrites with optimum Pt/Au mole ratios of 1.0 exhibited a 2.5 times increase in electrocatalytic activity toward methanol oxidation compared with the commercial catalyst (Pt/C), and its CO tolerance was also greatly improved. The above results show that the Au-GQDs@Pt nanocatalysts have potential application prospects in direct methanol fuel cells.

The effect of risedronate on orthodontic tooth movement in ovariectomized rats.

OBJECTIVE: This study aimed to investigate the effect of risedronate on orthodontic tooth movement in ovariectomized rats. METHODS: Forty-five female Sprague-Dawley rats were divided into three groups. Bilateral ovariectomies were performed on the rats in the ovariectomy and ovariectomy + risedronate groups. Two weeks after ovariectomy, risedronate was administered intraperitoneally every three days in the ovariectomy + risedronate group, while rats in the ovariectomy and sham groups were administered saline until they were sacrificed. One month after ovariectomy, nickel-titanium alloy closed-coil springs were placed between the maxillary left first molar and the maxillary left incisor. On days 3, 7 and 14, five rats from each group were sacrificed. The distance of orthodontic tooth movement was measured by a digital caliper, and slides were obtained for histological analysis. RESULTS: The distance of orthodontic tooth movement and the number of tartar-resistant acid phosphatase (TRAP)-positive cells were the highest in the ovariectomy group, followed by those in the ovariectomy + risedronate group, on days 3, 7 and 14. The positive expression levels of receptor activator of nuclear factor-kappa ß (RANK) ligand and cathepsin K were the strongest while the positive expression of osteoprotegerin in the ovariectomy group was the weakest, followed by the corresponding expression levels in the ovariectomy + risedronate group, on days 3, 7 and 14. CONCLUSIONS: Risedronate can inhibit orthodontic tooth movement in ovariectomized rats and may function by regulating the RANK/RANK ligand/osteoprotegerin pathway.

Antinociceptive effects of the adenylyl cyclase inhibitor ST034307 on tooth-movement-induced nociception in rats.

OBJECTIVE: This study aimed to investigate the antinociceptive effects of the selective adenylyl cyclase type 1 (AC1) inhibitor ST034307 on tooth movement nociception through orofacial nociceptive behavior tests and molecular examination. METHODS: We placed fixed nickel-titanium alloy closed-coil springs around the incisors of male Sprague-Dawley rats to induce tooth movement. We subsequently administered ST034307 (3 mg/kg), for 2 days, intraperitoneally, and then subjected the rats to a battery of behavioral tests (n = 10/group) to assess orofacial nociception. The changes in the expression of key molecules in the anterior cingulate cortex were measured by ELISA (n = 8/group) and Western blotting (n = 8/group). RESULTS: Tooth movement increased face-grooming activities and rat grimace scale scores. Tooth movement was also associated with enhanced cyclic adenosine monophosphate (cAMP) generation as well as protein kinase A (PKA) activation. Moreover, the phosphorylation of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors and expression of N-methyl-d-aspartate (NMDA) receptors in the anterior cingulate cortex increased during tooth movement. ST034307 significantly decreased mouth wiping and rat grimace scale scores, accompanied by reductions in cAMP generation, PKA activation, AMPA receptor phosphorylation, and NMDA receptor expression in the anterior cingulate cortex. CONCLUSIONS: These results suggest that adenylyl cyclase type 1 plays an important role in the development of orthodontic tooth movement nociception. Furthermore, ST034307 can be used as an effective pharmacotherapy for orthodontic nociception.