Alzheimer's disease (AD), as the most common cause of dementia, brings huge economic burden for patients and social health care systems, which motivates researchers to study multiple protective ...factors, among which physical activity and exercise have been proven to be both effective and economically feasible.
A systematic literature search was performed for eligible studies published up to November 1st 2018 on three international databases (PubMed, Cochrane Library, and Embase) and two Chinese databases (Wanfang Data, China National Knowledge Infrastructure). All analyses were conducted using Stata 14.0. Due to heterogeneity between studies, a random-effects model was used for this meta-analysis. Meta-analysis was used to explore if physical activity and exercise can exert positive effects on cognition of elderly with AD and subgroup analyses were conducted to find out if there are dose-response effects.
A total of 13 randomized controlled trials were included with a sample size of 673 subjects diagnosed with AD. Intervention groups showed a statistically significant improvement in cognition of included subjects measured by the MMSE score (SMD = 1.12 CI:0.66~1.59) compared to the control groups. Subgroup analyses showed different amounts of physical activity and exercise can generate different effects.
As one of few meta-analyses comparing different quantities of physical activity and exercise interventions for AD in details, our study suggests that physical activity and exercise can improve cognition of older adults with AD. While the concomitant effects on cognition functions of high frequency interventions was not greater than that of low frequency interventions, the threshold remains to be settled. However, more RCTs with rigorous study design are needed to support our findings.
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•Spirulina platensis polysaccharides (SPLP) had significant hypolipidemic and hypoglycemic effects in HFD-fed rats.•SPLP intervention modulate the hepatic steatosis and mRNA ...expressions involved in lipid and carbohydrate metabolism.•SPLP altered the relative abundance of cecal short-chain fatty acids.•SPLP significantly modulated the intestinal microbiota dysbiosis.
This study aimed to evaluate the possibility that Spirulina platensis crude polysaccharides may ameliorate the lipid and carbohydrate metabolism disorder, including obesity, hyperlipidemia, hyperglycemia, hepatic steatosis, and gut dysbiosis. The results showed Spirulina platensis crude polysaccharides could improve body weight, serum/liver lipid and carbohydrate indexes, and liver antioxidant parameters in high-sucrose and high-fat diet (HFD)-fed rats, which were accompanied by regulated liver mRNA expressions involved in lipid and carbohydrate metabolism disorder. In addition, SPLP intervention significantly decreased cecal level of propionic acid in HFD-fed rats. Notably, the SPLP could alter the relative abundance of Firmicutes, Bacteroides, Proteobacteria, and Actinobacteria at phylum levels. Based on Spearman's rank correlation coefficient, serum/liver lipid and carbohydrate profiles were found significantly positively correlated with genera Romboutsia, Allobaculum, Blautia, Phascolarctobacterium, Bifidobacterium, Coprococcus, Turicibacter, Erysipelotrichaceae_unclassified, Olsenella, Escherichia/Shigella, Coprobacillus, Lachnospiracea incertae, and Lactobacillus, but strongly negatively correlated with genera Atopostipes, Flavonifractor, Porphyromonadaceae_unclassified, Barnesiella, Oscillibacter, Paraprevotella, Jeotgalicoccus, Corynebacterium, Alloprevotella and Bacteroides. It was concluded that oral administration of SPLP could remarkably ameliorate the lipid and carbohydrate metabolism disorder and significantly modulate the intestinal microbiota in HFD-fed rats.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
To investigate the mechanical properties of fused deposition modeling (FDM) parts, a compatibilizer and nanoparticles were used as additions in Polycarbonate and Acrylonitrile‐Butadiene‐Styrene ...(PC/ABS) blends, and four PC/ABS composites were used to fabricate the FDM samples in this study. Two simplified deposition modes of the FDM process were proposed and used to investigate the bonding effect and deposition effect. The bonding effects of the four materials were first investigated using model I of the FDM process. Then, a linear relationship between the bonding strength and the porosity was found, and the optimal processing conditions that produced the best bonding strength were determined. These optimal processing conditions were then used in mode II of the FDM process to fabricate four samples. The mechanical properties and structural characterizations of these samples were studied using tensile tests, dynamic mechanical analysis (DMA), and scanning electron microscopy (SEM). One interesting phenomenon observed from the tensile tests was that the necking of the PC/ABS FDM sample can spread throughout the total gauge length and measure more than 100% of the strain when the compatibilizer and the nanoparticles were added, which can be attributed to a balance between bonding properties and ductility. The results verify the applicability of PC/ABC composites to FDM technology and suggest that compatibilizers and nanoparticles are suitable candidates to improve the bonding strength and the deposition effect of PC/ABS FDM parts. In conclusion, the balance between bonding properties and ductility is key to improving the tensile behaviors of PC/ABS FDM parts by adjusting the compatibility and porosity of blended PC/ABS samples.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
In recent years, tunable metamaterials have attracted intensive research interest due to their outstanding characteristics, which are dependent on the geometrical dimensions rather than the material ...composition of the nanostructure. Among tuning approaches, micro-electro-mechanical systems (MEMS) is a well-known technology that mechanically reconfigures the metamaterial unit cells. In this study, the development of MEMS-based metamaterial is reviewed and analyzed based on several types of actuators, including electrothermal, electrostatic, electromagnetic, and stretching actuation mechanisms. The moveable displacement and driving power are the key factors in evaluating the performance of actuators. Therefore, a comparison of actuating methods is offered as a basic guideline for selecting micro-actuators integrated with metamaterial. Additionally, by exploiting electro-mechanical inputs, MEMS-based metamaterials make possible the manipulation of incident electromagnetic waves, including amplitude, frequency, phase, and the polarization state, which enables many implementations of potential applications in optics. In particular, two typical applications of MEMS-based tunable metamaterials are reviewed, i.e., logic operation and sensing. These integrations of MEMS with metamaterial provide a novel route for the enhancement of conventional optical devices and exhibit great potentials in innovative applications, such as intelligent optical networks, invisibility cloaks, photonic signal processing, and so on.
The basic helix-loop-helix (bHLH) proteins, a large transcription factors family, are involved in plant growth and development, and defensive response to various environmental stresses. The ...resurrection plant Myrothamnus flabellifolia is known for its extremely strong drought tolerance, but few bHLHs taking part in abiotic stress response have been unveiled in M. flabellifolia.
In the present research, we cloned and characterized a dehydration-inducible gene, MfbHLH38, from M. flabellifolia. The MfbHLH38 protein is localized in the nucleus, where it may act as a transcription factor. Heterologous expression of MfbHLH38 in Arabidopsis improved the tolerance to drought and salinity stresses, as determined by the studies on physiological indexes, such as contents of chlorophyll, malondialdehyde (MDA), proline (Pro), soluble protein, and soluble sugar, water loss rate of detached leaves, reactive oxygen species (ROS) accumulation, as well as antioxidant enzyme activities. Besides, MfbHLH38 overexpression increased the sensitivity of stomatal closure to mannitol and abscisic acid (ABA), improved ABA level under drought stress, and elevated the expression of genes associated with ABA biosynthesis and ABA responding, sucha as NCED3, P5CS, and RD29A.
Our results presented evidence that MfbHLH38 enhanced tolerance to drought and salinity stresses in Arabidopsis through increasing water retention ability, regulating osmotic balance, decreasing stress-induced oxidation damage, and possibly participated in ABA-dependent stress-responding pathway.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
It is economical to transform abandoned oil/geothermal wells into closed deep geothermal heat exchangers with coaxial tubes. A numerical model of a coaxial geothermal heat exchanger (CGHE) with ...varying borehole diameters is established according to an abandoned well in Northern China. The finite difference method is adopted to solve the temperature distribution, and the accuracy of the model is validated with experimental data. Based on the existing structure of the abandoned well with different depths, the feasibility of its conversion into a deep CGHE is discussed, and this study uses the orthogonal experimental method to analyze the influence of four main factors and their significance level on the average heat extraction rate, with the heat extraction rate up to 422.18 kW in the optimal combination. This study also integrates with actual project considerations and conducts an economic analysis to determine the most appropriate circulation fluid flow rate. The results highlight the key factors on the heat transfer performance of the CGHE, with the inlet water temperature to the CGHE being the most significant, followed by the configuration of the CGHE retrofitted from abandoned. From the economic perspective, given that the CGHE in this study is retrofitted from the abandoned oil Wells, the drilling cost can be reduced by up to CNY 1800 thousand, and the flow rate design of 35 m3/h is the optimal choice, ensuring a cost-effective system operation while meeting the operational requirements of the deep CGHE.
In situ growth of nanostructures on substrates is a strategy for designing highly efficient catalytic materials. Herein, multimetallic CuCoNi oxide nanowires are synthesized in situ on a ...three-dimensional nickel foam (NF) substrate (CuCoNi–NF) by a hydrothermal method and applied to peroxydisulfate (PDS) activation as immobilized catalysts. The catalytic performance of CuCoNi–NF is evaluated through the degradation of organic pollutants such as bisphenol A (BPA) and practical wastewater. The results indicate that the NF not only plays an important role as the substrate support but also serves as an internal Ni source for material fabrication. CuCoNi–NF exhibits high activity and stability during PDS activation as it mediates electron transfer from BPA to PDS. CuCoNi–NF first donates electrons to PDS to arrive at an oxidized state and subsequently deprives electrons from BPA to return to the initial state. CuCoNi–NF maintains high catalytic activity in the pH range of 5.2–9.2, adapts to a high ionic strength up to 100 mM, and resists background HCO3 – and humic acid. Meanwhile, 76.6% of the total organic carbon can be removed from packaging wastewater by CuCoNi–NF-catalyzed PDS activation. This immobilized catalyst shows promising potential in wastewater treatment, well addressing the separation and recovery of conventional powdered catalysts.
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IJS, KILJ, NUK, PNG, UL, UM
Abstract
We report the observations of FRB 20220912A using the Five-hundred-meter Aperture Spherical radio Telescope. We conducted 17 observations totaling 8.67 hr and detected a total of 1076 bursts ...with an event rate up to 390 hr
−1
. The cumulative energy distribution can be well described using a broken power-law function with the lower- and higher-energy slopes of −0.38 ± 0.02 and −2.07 ± 0.07, respectively. We also report the
L
-band (1–1.5 GHz) spectral index of the synthetic spectrum of FRB 20220912A bursts, which is −2.6 ± 0.21. The average rotation measure value of the bursts from FRB 20220912A is −0.08 ± 5.39 rad m
−2
, close to 0 rad m
−2
and was relatively stable over 2 months. Most bursts have nearly 100% linear polarization. About 45% of the bursts have circular polarization with Signal-to-Noise ratio > 3, and the highest circular polarization degree can reach 70%. Our observations suggest that FRB 20220912A is located in a relatively clean local environment with complex circular polarization characteristics. These various behaviors imply that the mechanism of circular polarization of FRBs likely originates from an intrinsic radiation mechanism, such as coherent curvature radiation or inverse Compton scattering inside the magnetosphere of the FRB engine source (e.g., a magnetar).
When a robot picks green fruit under natural light, the color of the fruit is similar to the background; uneven lighting and fruit and leaf occlusion often affect the performance of the detection ...method. We take green mangoes as an experimental object. A lightweight green mangoes detection method based on YOLOv3 is proposed here. To improve the detection speed of the method, we first combine the color, texture, and shape features of green mango to design a lightweight network unit to replace the residual units in YOLOv3. Second, the improved Multiscale context aggregation (MSCA) module is used to concatenate multilayer features and make predictions, solving the problem of insufficient position information and semantic information on the prediction feature map in YOLOv3; this approach effectively improves the detection effect for the green mangoes. To address the overlap of green mangoes, soft non-maximum suppression (Soft-NMS) is used to replace non-maximum suppression (NMS), thereby reducing the missing of predicted boxes due to green mango overlaps. Finally, an auxiliary inspection green mango image enhancement algorithm (CLAHE-Mango) is proposed, is suitable for low-brightness detection environments and improves the accuracy of the green mango detection method. The experimental results show that the F1% of Light-YOLOv3 in the test set is 97.7%. To verify the performance of Light-YOLOv3 under the embedded platform, we embed one-stage methods into the Adreno 640 and Mali-G76 platforms. Compared with YOLOv3, the F1% of Light-YOLOv3 is increased by 4.5%, and the running speed is increased by 5 times, which can meet the real-time running requirements for picking robots. Through three sets of comparative experiments, we could determine that our method has the best detection results in terms of dense, backlit, direct light, night, long distance, and special angle scenes under complex lighting.
The circadian clock plays multiple functions in the regulation of plant growth, development and response to various abiotic stress. Here, we showed that the core oscillator component late elongated ...hypocotyl (LHY) was involved in rice response to salt stress. The mutations of OsLHY gene led to reduced salt tolerance in rice. Transcriptomic analyses revealed that the OsLHY gene regulates the expression of genes related to ion homeostasis and the abscisic acid (ABA) signalling pathway, including genes encoded High-affinity K
transporters (OsHKTs) and the stress-activated protein kinases (OsSAPKs). We demonstrated that OsLHY directly binds the promoters of OsHKT1;1, OsHKT1;4 and OsSAPK9 to regulate their expression. Moreover, the ossapk9 mutants exhibited salt tolerance under salt stress. Taken together, our findings revealed that OsLHY integrates ion homeostasis and the ABA pathway to regulate salt tolerance in rice, providing insights into our understanding of how the circadian clock controls rice response to salt stress.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK