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Background: Exposure to air pollution is associated with an increased risk of all-cause mortality in older adults. Promoting physical activity (PA) and avoiding sedentary behavior (SB) serve as key strategies to maintain and improve human health. However, ambient air pollution can adversely affect PA and SB, increasing the risks of health problems. This study aimed to visualize national spatial patterns of average AQI concentration, PA, and SB distributions and to examine the associations between air pollution and PA and SB in a national sample of Chinese older adults aged 60 years or older. Methods: We analyzed the data of the China Longitudinal Aging Social Survey 2020 (CLASS 2020), which sampled 11,399 older men and women from 30 cities in China. Moderate, vigorous, and light PA and SB were measured using the Chinese version of the International Physical Activity Questionnaire-Short Form (IPAQ-C). The environmental measures included the average hourly air quality index (AQI), PM2.5, PM10, and NO2 (µg/m3). The data were analyzed using multivariable linear regression. Results: Increases in the standard deviations (±SD) of AQI, PM2.5, PM10, and NO2 concentrations were associated with decreases in MVPA per week of −2.34 (95%CI = −3.36, −1.32), −2.58 (95%CI = −3.61, −1.55), −1.96 (95%CI = −3.05, −0.08), and −1.19 (95%CI = −2.06, −0.31) and decreases in LPA per week of −6.06 (95%CI = −7.15, −4.97), −4.86 (95%CI = −5.88, −3.85), −4.78 (95%CI = −5.89, −3.68), and −4.59 (95%CI = −5.57, −3.61) h/week, respectively. Increases in one SD of AQI, PM2.5, PM10, and NO2 were associated with increases in SB per week of 1.32 (95%CI = 0.77, 1.88), 0.62 (95%CI = 0.09, 1.14), 1.03 (95%CI = 0.48, 1.59), and 0.98 (95%CI = 0.46, 1.49) h/week, respectively. Conclusions: The spatial distributions of the average AQI concentration, MVPA, LPA, and SB are useful and allow environmental and health policymakers to identify the areas with the highest priority air pollution environmental equality concerns. AQI was positively associated with MVPA and LPA, and it was negatively associated with SB among older adults. AQI, PM2.5, PM10, and NO2 were hardly associated with women’s average time spent engaged in MVPA. Region-specific and multi-level health policy options are needed to reduce ambient air pollution by taking different types of pollutants into account in order to avoid changes in PA and SB in this population, especially in locations with high air pollution concentrations.

Content caching in wireless edge is considered to be a feasible approach to improve the user’s quality of experience by caching popular multimedia content from data center. In this letter, we focus on movie on-demand streaming from Internet-based servers and propose a novel proactive caching strategy over time in small cell network. First, it constructs a weighted feature matrix (WFM) and estimates content popularity in terms of spatiotemporal variation using content-aware WFM (CWFM). According to estimated content popularity, the CWFM-based proactive caching algorithm makes a caching decision by cooperatively caching the contents with a approach of linear programming and variable recovery to minimize the average delivery latency (ADL) in each time slot. The simulation results show that our algorithm improves the performance in terms of ADL based on MovieLens data set.

In 5G mobile networks, the convergence of cloud computing and communication leads to mobile edge computing, benefiting vehicular networks. However, the advent of a wide variety of new services and devices has changed the vehicular network landscape, challenging vehicle-to-network services’ migrations. In this paper, we focus on optimizing long-term average latency of multiple services with a different quality of services (QoS). We first introduce an offline algorithm, which can be used to find the optimal migration strategy of services. Then, we analyze the negative effect of trajectory prediction and suggest an optimizing method to reduce this effect by partial updating. Finally, based on this method, we propose a partial dynamic optimization algorithm to approximate the optimal solution, by integrating the priority queue, which utilizes QoS information. We simulate the average service latency, confirming that the proposed partial dynamic optimization algorithm keeps a stable service latency and performs better than other existing algorithms, considering the negative effect of trajectory prediction. We also verify that the proposed algorithm can meet the low latency requirement of the vehicles and the different demands of different services. Besides, the partial dynamic optimization algorithm has a lower time complexity.

In this paper, we propose a W-band 8-quadrature-amplitude-modulation (8QAM) frequency tripling photonic vector millimeter-wave (mm-wave) signal generation method by using a phase modulator (PM) with only amplitude pre-coding. The PM is driven by 2-Gbaud 8QAM-modulated amplitude precoded signal at 25 GHz. Instead of phase pre-coding, we only need to reverse the real part of the signal at the receiver after photo detector (PD). The structure of the transmitter and the structure of the receiver are simple. The frequency tripling scheme is completed by numerical simulation, the output optical spectrum is consistent with the theoretical analysis, and bit-error-ratio (BER) curves indicate that the put forward 75 GHz 8QAM vector signal generation technique has good performance. The BER of 6 Gbit/s 75 GHz 8QAM vector mm-wave signal is below 3.8 × 10-3 after 12 km optical fiber transmission. For all we know, it is the first time to report on the generation of high-order QAM photonic mm-wave signal with odd times of RF frequency by using a single external modulator.

Water pollution is a worldwide problem that needs to be solved urgently and has a significant impact on the efficiency of sustainable cities. The evaluation of water pollution is a Multiple Criteria Decision-Making (MCDM) problem and using a MCDM model can help control water pollution and protect human health. However, different evaluation methods may obtain different results. How to effectively coordinate them to obtain a consensus result is the main aim of this work. The purpose of this article is to develop an ensemble learning evaluation method based on the concept of water quality to help policy-makers better evaluate surface water quality. A valid application is conducted to illustrate the use of the model for the surface water quality evaluation problem, thus demonstrating the effectiveness and feasibility of the proposed model.

In this paper, we propose a Packet Cache-Forward (PCF) method based on improved Bayesian outlier detection to eliminate out-of-order packets caused by transmission path drastically degradation during handover events in the moving satellite networks, for improving the performance of TCP. The proposed method uses an access node satellite to cache all received packets in a short time when handover occurs and forward them out in order. To calculate the cache time accurately, this paper establishes the Bayesian based mixture model for detecting delay outliers of the entire handover scheme. In view of the outliers' misjudgment, an updated classification threshold and the sliding window has been suggested to correct category collections and model parameters for the purpose of quickly identifying exact compensation delay in the varied network load statuses. Simulation shows that, comparing to average processing delay detection method, the average accuracy rate was scaled up by about 4.0%, and there is about 5.5% cut in error rate in the meantime. It also behaves well even though testing with big dataset. Benefiting from the advantage of the proposed scheme in terms of performance, comparing to conventional independent handover and network controlled synchronized handover in simulated LEO satellite networks, the proposed independent handover with PCF eliminates packet out-of-order issue to get better improvement on congestion window. Eventually the average delay decreases more than 70% and TCP performance has improved more than 300%.

Magnetofluorescent nanocomposites (MFNCs) providing a single nanoscale platform with multimodal properties are gaining momentum in biological manipulation, biomedical imaging and therapy. In this work, we report the preparation of MFNCs integrating MnFe2O4 magnetic nanoparticles (MNPs), CuInS2/ZnS quantum dots (QDs) and poly(ethylene glycol)-b-poly(lactide-co-glycolide) (PEG-PLGA) in a tetrahydrofuran (THF)/water solvent system. Through sonication and quick solvent displacement, multiple nanoparticles of each type are co-encapsulated within the hydrophobic core of PEG-PLGA micelles. The developed fabrication process is simple and fast. Moreover, due to the low toxicity of CuInS2/ZnS QDs, the fabrication process is environmentally benign. The fabricated MFNCs were further characterized regarding their fundamental physical, chemical and biological properties. Results reveal that the MFNCs possess high (Mn + Fe) recovery rates, and the optical properties and magnetic relaxivity of the MFNCs are sensitive to the MNP:QD mass ratios in the fabrication. Furthermore, the MFNCs present excellent stability in aqueous solutions, minimal cytotoxicity, and capability for bioconjugation. This study opens an avenue for the MFNCs to be employed in broad biological or biomedical applications.

Ionotropic activation of NMDA receptors (NMDARs) requires agonist glutamate and co-agonist glycine. Here we show that glycine enhances the activation of cell survival-promoting kinase Akt in cultured cortical neurons in which both the channel activity of NMDARs and the glycine receptors are pre-inhibited. The effect of glycine is reduced by shRNA-mediated knockdown of GluN2A subunit-containing NMDARs (GluN2ARs), suggesting that a non-ionotropic activity of GluN2ARs mediates glycine-induced Akt activation. In support of this finding, glycine enhances Akt activation in HEK293 cells over-expressing GluN2ARs. The effect of glycine on Akt activation is sensitive to the antagonist of glycine-GluN1 binding site. As a functional consequence, glycine protects against excitotoxicity-induced neuronal death through the non-ionotropic activity of GluN2ARs and the neuroprotective effect is attenuated by Akt inhibition. Thus, this study reveals an unexpected role of glycine in eliciting a non-ionotropic activity of GluN2ARs to confer neuroprotection via Akt activation.

Summary Dysfunction of PTEN-induced kinase 1 (PINK1) or DJ-1 promotes neuronal death and is implicated in the pathogenesis of Parkinson’s disease, but the underlying mechanisms remain unclear. Given the roles of N-methyl-d-aspartate receptor (NMDAr)-mediated neurotoxicity in various brain disorders including cerebral ischemia and neurodegenerative diseases, we investigated the effects of PINK1 and DJ-1 on NMDAr function. Using protein overexpression and knockdown approaches, we showed that PINK1 increased NMDAr-mediated whole-cell currents by enhancing the function of NR2A-containing NMDAr subtype (NR2ACNR). However, DJ-1 decreased NMDAr-mediated currents, which was mediated through the inhibition of both NR2ACNR and NR2B-containing NMDAr subtype (NR2BCNR). We revealed that the knockdown of DJ-1 enhanced PTEN expression, which not only potentiated NR2BCNR function but also increased PINK1 expression that led to NR2ACNR potentiation. These results indicate that NMDAr function is differentially regulated by DJ-1-dependent signal pathways DJ-1/PTEN/NR2BCNR and DJ-1/PTEN/PINK1/NR2ACNR. Our results further showed that the suppression of DJ-1, while promoted NMDA-induced neuronal death through the overactivation of PTEN/NR2BCNR-dependent cell death pathway, induced a neuroprotective effect to counteract DJ-1 dysfunction-mediated neuronal death signaling through activating PTEN/PINK1/NR2ACNR cell survival–promoting pathway. Thus, PINK1 acts with DJ-1 in a common pathway to regulate NMDAr-mediated neuronal death. This study suggests that the DJ-1/PTEN/NR2BCNR and DJ-1/PTEN/PINK1/NR2ACNR pathways may represent potential therapeutic targets for the development of neuroprotection strategy in the treatment of brain injuries and neurodegenerative diseases such as Parkinson’s disease.

The widespread distribution of the tumor suppressor PTEN (phosphatase and tensin homolog deleted on chromosome 10) in the adult brain suggests its role in a broad range of brain functions. Here we show evidence supporting a physical interaction of PTEN with a region in the third intracellular loop (3L4F) of the serotonin 5-HT2C receptor (5-HT2cR, formerly 5-HT1c receptor) in cell cultures. PTEN limits agonist-induced phosphorylation of 5-HT2cR through its protein phosphatase activity. We showed the probable existence of PTEN:5-HT2cR complexes in putative dopaminergic neurons in the rat ventral tegmental area (VTA), a brain region in which virtually all abused drugs exert rewarding effects by activating its dopamine neurons. We synthesized the interfering peptide Tat-3L4F, which is able to disrupt PTEN coupling with 5-HT2cR. Systemic application of Tat-3L4F or the 5-HT2cR agonist Ro600175 suppressed the increased firing rate of VTA dopaminergic neurons induced by delta9-tetrahydrocannabinol (THC), the psychoactive ingredient of marijuana. Using behavioral tests, we found that Tat-3L4F or Ro600175 blocks conditioned place preference of THC or nicotine, and that Ro600175, but not Tat-3L4F, produces anxiogenic effects, penile erection, hypophagia and motor functional suppression. These results suggest a potential strategy for treating drug addiction with the Tat-3L4F peptide.

Magnetofluorescent nanocomposites (MFNCs) providing a single nanoscale platform with multimodal properties are gaining momentum in biological manipulation, biomedical imaging and therapy. In this work, we report the preparation of MFNCs integrating MnFe2O4 magnetic nanoparticles (MNPs), CuInS2/ZnS quantum dots (QDs) and poly(ethylene glycol)-b-poly(lactide-co-glycolide) (PEG-PLGA) in a tetrahydrofuran (THF)/water solvent system. Through sonication and quick solvent displacement, multiple nanoparticles of each type are co-encapsulated within the hydrophobic core of PEG-PLGA micelles. The developed fabrication process is simple and fast. Moreover, due to the low toxicity of CuInS2/ZnS QDs, the fabrication process is environmentally benign. The fabricated MFNCs were further characterized regarding their fundamental physical, chemical and biological properties. Results reveal that the MFNCs possess high (Mn + Fe) recovery rates, and the optical properties and magnetic relaxivity of the MFNCs are sensitive to the MNP:QD mass ratios in the fabrication. Furthermore, the MFNCs present excellent stability in aqueous solutions, minimal cytotoxicity, and capability for bioconjugation. This study opens an avenue for the MFNCs to be employed in broad biological or biomedical applications.

The tumor suppressor PTEN (phosphatase and tensin homolog deleted on chromosome 10) is a lipid and protein phosphatase. We report here that PTEN physically associates with the NR1 and NR2B subunits of NMDA receptors (NMDARs) in rat hippocampus. Downregulating the protein expression of PTEN inhibits the function of extrasynaptic NMDARs and decreases NMDAR surface expression, suggesting a crucial role for endogenous PTEN in the modulation of NMDAR-mediated neuronal function. Reducing PTEN expression also enhances Akt/Bad phosphorylation in hippocampal neurons. Importantly, suppressing lipid and protein phosphatase activity of PTEN, respectively, activates Akt and inhibits extrasynaptic NMDAR activity and thereby protects against ischemic neuronal deathin vitroandin vivo. Thus, our study reveals a dual neuroprotective mechanism by which Akt/Bad and extrasynaptic NMDARs are regulated via downregulation of two distinct PTEN phosphatase activities and present the possibility of PTEN as a potential therapeutic target for stroke treatment.

A surface modification approach adopting polymer encapsulation was developed to prepare zwitterion-like quantum dots (ZWL-QDs). The fundamental physical, chemical, and biological properties of the ZWL-QDs were characterized. It is found that the ZWL-QDs almost preserve the quantum yield (QY) of native hydrophobic QDs in organic solvents, and also are compact in size (7 ~ 10 nm hydrodynamic diameter) and stable over wide pHs or in high salinity solutions. Further cellular study shows that the ZWL-QDs with a concentration less than 100 nM have a minimal cytotoxicity and thus are biocompatible. Characterizing and understanding these essential properties of the ZWL-QDs are an important step before employing them for various applications.

The developmental variation of 2-[125I]iodomelatonin binding sites in membrane preparations of the chicken spinal cords was investigated. In 19-day-old embryos, the maximum number of binding sites (Bmax) was the highest during the development. With the increase in age posthatch, the Bmax decreased gradually and significantly from 1-day-old to 4-month-old chickens. However, there were no significant changes in equilibrium dissociation constant (Kd) among all age-groups studied. To study the circadian variation, the 2-[125I]iodomelatonin binding sites in the spinal cords of 3-week-old chickens were determined at 4-hour intervals throughout a 24-hour period under a 12-hour light/12-hour dark cycle. There was a diurnal rhythm in both Bmax and Kd of [125I]iodomelatonin binding sites in which Bmax decreased and Kd increased in the dark period. The characteristics of developmental and circadian variation of melatonin receptors in the chicken spinal cord suggest that melatonin may exert a direct action on spinal cord functions and that it plays a more important role in the young animal.

The dysfunction of TAR DNA-binding protein-43 (TDP-43) is implicated in neurodegenerative diseases. However, the function of TDP-43 is not fully elucidated. Here we show that the protein level of endogenous TDP-43 in the nucleus is increased in mouse cortical neurons in the early stages, but return to basal level in the later stages after glutamate accumulation-induced injury. The elevation of TDP-43 results from a downregulation of phosphatase and tensin homolog (PTEN). We further demonstrate that activation of NR2A-containing NMDA receptors (NR2ARs) leads to PTEN downregulation and subsequent reduction of PTEN import from the cytoplasm to the nucleus after glutamate accumulation. The decrease of PTEN in the nucleus contributes to its reduced association with TDP-43, and thereby mediates the elevation of nuclear TDP-43. We provide evidence that the elevation of nuclear TDP-43, mediated by NR2AR activation and PTEN downregulation, confers protection against cortical neuronal death in the late stages after glutamate accumulation. Thus, this study reveals a NR2AR–PTEN–TDP-43 signaling pathway by which nuclear TDP-43 promotes neuronal survival. These results suggest that upregulation of nuclear TDP-43 represents a self-protection mechanism to delay neurodegeneration in the early stages after glutamate accumulation and that prolonging the upregulation process of nuclear TDP-43 might have therapeutic significance.

In this paper, we designed a Reed-Solomon(240,K) structure for CMMB system,which was based on analyzing the coding theory of Reed-Solomon(RS) code in CMMB system,the design of encoder was taking advantage of FPGA,could complete coding for data stream from the upper layer quickly and efficiently.We also analyzed the structure of multipliers in RS encoder,that are simple and can achieve high speed operation. Finally,under the ModelSim6.2b,the coding function was simulated,The simulation results show that the designed structure has such advantages as high efficiency and low complexity with good coding performance,it is consistent with the theoretical analysis.

Dysfunction of PTEN-induced kinase 1 (PINK1) or DJ-1 promotes neuronal death and is implicated in the pathogenesis of Parkinson's disease, but the underlying mechanisms remain unclear. Given the roles of N-methyl-d-aspartate receptor (NMDAr)-mediated neurotoxicity in various brain disorders including cerebral ischemia and neurodegenerative diseases, we investigated the effects of PINK1 and DJ-1 on NMDAr function. Using protein overexpression and knockdown approaches, we showed that PINK1 increased NMDAr-mediated whole-cell currents by enhancing the function of NR2A-containing NMDAr subtype (NR2ACNR). However, DJ-1 decreased NMDAr-mediated currents, which was mediated through the inhibition of both NR2ACNR and NR2B-containing NMDAr subtype (NR2BCNR). We revealed that the knockdown of DJ-1 enhanced PTEN expression, which not only potentiated NR2BCNR function but also increased PINK1 expression that led to NR2ACNR potentiation. These results indicate that NMDAr function is differentially regulated by DJ-1-dependent signal pathways DJ-1/PTEN/NR2BCNR and DJ-1/PTEN/PINK1/NR2ACNR. Our results further showed that the suppression of DJ-1, while promoted NMDA-induced neuronal death through the overactivation of PTEN/NR2BCNR-dependent cell death pathway, induced a neuroprotective effect to counteract DJ-1 dysfunction-mediated neuronal death signaling through activating PTEN/PINK1/NR2ACNR cell survival-promoting pathway. Thus, PINK1 acts with DJ-1 in a common pathway to regulate NMDAr-mediated neuronal death. This study suggests that the DJ-1/PTEN/NR2BCNR and DJ-1/PTEN/PINK1/NR2ACNR pathways may represent potential therapeutic targets for the development of neuroprotection strategy in the treatment of brain injuries and neurodegenerative diseases such as Parkinson's disease.

Dysfunction of PTEN-induced kinase-1 (PINK1) is implicated in neurodegeneration. We report here that oxygen-glucose deprivation (OGD), an in vitro insult mimicking ischemic neuron injury, resulted in a significant reduction of PINK1 protein expression in cultured cortical neurons. The decrease of PINK1 expression was blocked by the antagonists of NMDA receptors. We revealed that the overactivation of NR2B-containing NMDA receptors (NR2BRs) was responsible for the OGD-induced PINK1 reduction. The overactivated NR2BRs also inhibited the phosphorylation, but not the protein expression, of the cell survival-promoting kinase Akt after OGD insult, indicating that OGD-induced reduction of PINK1 protein is specific in the injury paradigm. We further showed that enhancing the protein expression of PINK1 antagonized OGD-induced reduction of Akt phosphorylation, suggesting that Akt may be a downstream target of PINK1 in ischemic neuron injury. Importantly, we provided evidence that both NR2BR antagonist and PINK1 over-expression protected against OGD-induced neuronal death. These results suggest that the overactivation of NR2BRs may contribute to ischemic neuron death through suppressing PINK1-dependent survival signaling. Thus, selectively antagonizing NR2BR signal pathway-induced neurotoxicity may be a potential neuroprotection strategy.

The type A GABA receptors are thought to mediate synchronization of clock cell activity within the suprachiasmatic nuclei (SCN). Here we report that casein kinases I epsilon and delta (CKI epsilon and CKI delta), the crucial clock regulators, form a complex with GABA(A) receptors and inhibit the receptors' function within the SCN according to a circadian rhythm. These results indicate that circadian variation of the kinase-receptor association may mediate regulation of GABA(A) receptor function by CKI epsilon-CKI delta in the SCN.

Melatonin receptors in the rabbit spinal cord were studied. Using in vitro quantitative autoradiography we have localized and characterized 2-[ 125 I]iodomelatonin ([ 125 I]MEL) binding sites in the central gray substance (lamina X) of the rabbit spinal cord. Saturation study revealed a single class of high affinity binding sites in the central gray substance with an equilibrium dissociation constant ( K d ) o 38.8 ± 5.25 pM and a maximum number of binding sites of 5.69 ± 0.84 fmol/mg protein in the mid-light period. These [ 125 I]MEL binding sites were highly specific for melatonin. Coincubation with 10 μM or 50 μM guanosine 5′- O -(3-thiotriphosphate) produced a significant change in K d . These results suggest that melatonin receptors in the rabbit spinal cord are coupled to a guanine-nucleotide-bind protein (G-protein). Our studies suggest that melatonin exerts a direct action on the rabbit spinal cord.

Circadian regulation of GABA A receptor function by CKIe-CKIδ in the rat suprachiasmatic nuclei