288 research outputs found
The role of myeloid cells in neurodegenerative diseases. Studies on cellular phenotype and communication.
Neurological disorders are listed as the second leading cause of death worldwide. Stroke and Alzheimer’s disease (AD) are the major contributors to neurological disorders of deaths. Every year, around 14 million new people are affected by stoke and nearly 10 million new cases of AD are diagonosed worldwide. The number of deaths and disabilities due to these disorders have increased considerably. Neuroinflammation is a major pathological feature appearing in the central nervous system (CNS) in these disorders. The central cellular components for neuroinflammation in CNS is microglia. The multifaceted roles of microglia under pathological conditions have been investigated by several research groups. Even if the knowledge about these cells is extensive, many aspects of their role in diseases have not been well elucidated. One of them is how microglia contribute to the pathology. Thus, I investigated how microglia communicate with other cells through extracellular vesicles (EVs) and how microglia cross-talk with the periphery under AD pathology. Firstly, upon LPS activation of microglia, we found that larger sizes of EVs were released and the levels of proinflammatory cytokines, TNF and IL-6, were increased in EVs. The proteomic profile was shifted to ribosomal assembly and translation. Complete ablation of TNF expression alleviated the inflammation and lead to reduced EVs secretion in a mouse model of stroke, as well as in vitro with LPS stimulation. Microglia are highly dynamic cells and can alter their phenotypes in response to diverse conditions. Therefore, we wanted to elucidate the activation profile of microglia under pathogenic conditions. In the early phase of AD pathogenesis, there is little known about how microglia contribute to the pathology. Thus, the 5xFAD mouse model of AD was used to investigate the effects before the formation of amyloid-β (Aβ) plaques in the CNS. Using a proteomic approach, early inflammatory activation of microglia was found before the formation of plaques.Last but not least, we studied the cross-talk between CNS and periphery under Aβ pathology. There are conflicting findings from animal studies on the contribution of peripheral inflammation on AD due to the variations in the degree of inflammation, timepoint of the stimulation, and the duration. Therefore, we designed our study to have two timepoints wherein we modulate the innate immunity, one was at the pre-plaque stage and the other was at the postnatal stage. Strikingly, a reduced number of plaques was found in hippocampus accompanied by less microglial activation in 5xFAD mice 4.5 months after the peripheral LPS challenge during the pre-plaque state. Subsequently, single-cell sequencing demonstrated that the early inflammation at the postnatal phase affected microglia and bone marrow resident monocytes (BM-Mo) similar to how AD affects these cell types. Interestingly, unique subpopulations of microglia were identified that were enriched in genes associated with lysosomal function (Lyz2) and a detrimental inflammatory marker (Galectin-3). These particular subsets carried a BM-Mo-like phenotype and appeared in response to acute peripheral inflammation and chronic inflammation caused by AD. We also observed that some subsets of myeloid cells were provoked by Aβ pathology but not systemic inflammation and vice versa.To summarize, microglia have multiple ways of contributing to the pathology of AD. Systemic inflammatory challenge can have pronounced effects on innate immunity in the CNS and the underlying mechanism remains to be elucidated. The findings of this thesis also provide potential candidates for use in early diagnostics and pharmacological targets to prevent the progression of AD
Electrodeposition of p-Type Cuprous Oxide and its Application in Oxide Solar Cells
Cuprous oxide (Cu2O) is a promising material for the fabrication of oxide solar cells due to its abundance, nontoxicity, stability and ability to be deposited under mild conditions. At the moment, the reported efficiencies for Cu2O-based solar cells are well below its theoretical limit and most of the high performance devices are fabricated using energy-intensive processes. Electrodeposition of Cu2O thin films is a well-known process although a systematic study of the dependence of Cu2O film properties on the deposition conditions has not been reported, especially in the context of photovoltaic applications. The purpose of this study is to optimize the electrodeposited p-type Cu2O film properties for the application in heterojunction solar cells through the manipulation of electrodeposition conditions.
A range of Cu2O morphologies are formed by varying the parameters during the constant potential deposition of Cu2O thin films from a copper-lactate electrolyte including applied potential, temperature, pH, copper concentration and lactate concentration. The variation in morphology is mostly attributed to the relative growth rates of and orientations. It is found that the variation in growth orientation is mostly due to the relative rates or reaction and transport. When reaction kinetics is the limiting factor, growth is preferred when the conditions are close to thermodynamic equilibrium. On the other hand, when transport limitation in the system is significant, -oriented growth and cubic grains are favored as the surface concentration of CuLac2 is reduced. In other conditions, mixed orientations tend to be formed. Evidence of adsorption of lactate ions onto the (111) faces is also observed, promoting directed growth at high lactate concentration. In addition, significant evidence of film dissolution during deposition is observed at high electrolyte pH of 13 and above.
The performance of Cu2O thin films in photovoltaic devices is evaluated using an FTO/Cu2O/AZO cell structure. It is found that the electrolyte pH has the most prominent effect on the device performance among different electrodeposition parameters. Performance variables including JSC, VOC and FF all improve significantly as the Cu2O deposition pH increases. An optimal cell efficiency of ~1.55% is obtained using Cu2O thin films deposited at a high pH of 13.4, which exceeds the majority of previously reported efficiencies using the same deposition technique. The reason for the improved efficiency is attributed to the dissolution and reformation of Cu2O grains during deposition at high pH through the improvement of charge carrier mobility and band gap in the Cu2O layer. Film orientation of Cu2O also plays a minor role in cell efficiency.
Alternative electrodeposition procedures are investigated. Galvanostatic deposition is found to be less suitable than potentiostatic deposition for solar cell fabrication due to the difficulty in controlling Cu metal content in the film. Evidence of dissolution by oxidation is observed under both pulsed and stirred conditions. Different morphologies to the typical polyhedral shapes with higher carrier concentration and low carrier mobility are obtained in both cases. These effects are attributed to the lowering of diffusion limitations during the deposition process either by allowing more time for transport or by increasing transport rate. These processes result in lower device performance compared to potentiostatic deposition under similar conditions.
Finally, FTO/Cu2O/ZnO devices are fabricated by depositing ZnO onto electrodeposited Cu2O layer through a seed-layer assisted chemical growth method in zinc nitrate-HMTA solution. Ordered ZnO nanorods are obtained using this technique and their dimensions can be controlled by adjusting bath compositions. Smooth ZnO thin films with no pin-hole defects are obtained although the performance of Cu2O/ZnO devices is not as high as devices with AZO layers
Effects of nanoparticle zinc oxide on spatial cognition and synaptic plasticity in mice with depressive-like behaviors
Background: Nanomaterials, as a new kind of materials, have been greatly applied in different fields due to their special properties. With the industrialization of nanostructured materials and increasing public exposure, the biosafety and potential influences on central nervous system (CNS) have received more attention. Nanosized zinc oxide (nanoZnO) was suggested to up-regulate neuronal excitability and to induce glutamate release in vitro. Therefore, we hypothesized nanoparticles of nanoZnO may lead to changes in balance of neurotransmitter or neuronal excitability of CNS. This study was to investigate if there were effects of nanoZnO on animal model of depression. Methods: Male Swiss mice were given lipopolysaccharides (LPS, 100 mu g/kg, 100 mu g/ml, every other day, 8 times, i.p.) from weaning to induce depressive-like behaviors. NanoZnO (5.6 mg/kg, 5.6 mg/ml, every other day, 8 times, i.p.) was given as the interaction. The mouse model was characterized using the methods of open field test, tail suspension test and forced swim test. Furthermore, the spatial memory was evaluated using Morris water maze (MWM) and the synaptic plasticity was assessed by measuring the long-term potentiation (LTP) in the perforant pathway (PP) to dentate gyrus (DG) in vivo. Results: Results indicated that model mice showed disrupted spatial memory and LTP after LPS injections and the behavioral and electrophysiological improvements after nanoZnO treatment. Conclusion: Data suggested that nanoZnO may play some roles in CNS of mental disorders, which could provide some useful direction on the new drug exploring and clinical researches.Peer reviewe
The Insulation Properties of Oil-Impregnated Insulation Paper Reinforced with Nano-TiO 2
Oil-impregnated insulation paper has been widely used in transformers because of its low cost and desirable physical and electrical properties. However, research to improve the insulation properties of oil-impregnated insulation paper is rarely found. In this paper, nano-TiO2 was used to stick to the surface of cellulose which was used to make insulation paper. After oil-impregnated insulation paper reinforced by nano-TiO2 was prepared, the tensile strength, breakdown strength, and dielectric properties of the oil-impregnated insulation paper were investigated to determine whether the modified paper had a better insulation performance. The results show that there were no major changes in tensile strength, and the value of the breakdown strength was greatly improved from 51.13 kV/mm to 61.78 kV/mm. Also, the values of the relative dielectric constant, the dielectric loss, and conductivity declined. The discussion reveals that nano-TiO2 plays a major role in the phenomenon. Because of the existence of nano-TiO2, the contact interface of cellulose and oil was changed, and a large number of shallow traps were produced. These shallow traps changed the insulation properties of oil-impregnated insulation paper. The results show that the proposed solution offers a new method to improve the properties of oil-impregnated insulation paper
Chaos Firefly Algorithm With Self-Adaptation Mutation Mechanism for Solving Large-Scale Economic Dispatch With Valve-Point Effects and Multiple Fuel Options
This paper presents a new metaheuristic optimization algorithm, the firefly algorithm (FA), and an enhanced version of it, called chaos mutation FA (CMFA), for solving power economic dispatch problems while considering various power constraints, such as valve-point effects, ramp rate limits, prohibited operating zones, and multiple generator fuel options. The algorithm is enhanced by adding a new mutation strategy using self-adaptation parameter selection while replacing the parameters with fixed values. The proposed algorithm is also enhanced by a self-adaptation mechanism that avoids challenges associated with tuning the algorithm parameters directed against characteristics of the optimization problem to be solved. The effectiveness of the CMFA method to solve economic dispatch problems with high nonlinearities is demonstrated using five classic test power systems. The solutions obtained are compared with the results of the original algorithm and several methods of optimization proposed in the previous literature. The high performance of the CMFA algorithm is demonstrated by its ability to achieve search solution quality and reliability, which reflected in minimum total cost, convergence speed, and consistency
Cross-view Semantic Alignment for Livestreaming Product Recognition
Live commerce is the act of selling products online through live streaming.
The customer's diverse demands for online products introduce more challenges to
Livestreaming Product Recognition. Previous works have primarily focused on
fashion clothing data or utilize single-modal input, which does not reflect the
real-world scenario where multimodal data from various categories are present.
In this paper, we present LPR4M, a large-scale multimodal dataset that covers
34 categories, comprises 3 modalities (image, video, and text), and is 50x
larger than the largest publicly available dataset. LPR4M contains diverse
videos and noise modality pairs while exhibiting a long-tailed distribution,
resembling real-world problems. Moreover, a cRoss-vIew semantiC alignmEnt
(RICE) model is proposed to learn discriminative instance features from the
image and video views of the products. This is achieved through instance-level
contrastive learning and cross-view patch-level feature propagation. A novel
Patch Feature Reconstruction loss is proposed to penalize the semantic
misalignment between cross-view patches. Extensive experiments demonstrate the
effectiveness of RICE and provide insights into the importance of dataset
diversity and expressivity. The dataset and code are available at
https://github.com/adxcreative/RICEComment: Accepted to ICCV202
NICE: Improving Panoptic Narrative Detection and Segmentation with Cascading Collaborative Learning
Panoptic Narrative Detection (PND) and Segmentation (PNS) are two challenging
tasks that involve identifying and locating multiple targets in an image
according to a long narrative description. In this paper, we propose a unified
and effective framework called NICE that can jointly learn these two panoptic
narrative recognition tasks. Existing visual grounding tasks use a two-branch
paradigm, but applying this directly to PND and PNS can result in prediction
conflict due to their intrinsic many-to-many alignment property. To address
this, we introduce two cascading modules based on the barycenter of the mask,
which are Coordinate Guided Aggregation (CGA) and Barycenter Driven
Localization (BDL), responsible for segmentation and detection, respectively.
By linking PNS and PND in series with the barycenter of segmentation as the
anchor, our approach naturally aligns the two tasks and allows them to
complement each other for improved performance. Specifically, CGA provides the
barycenter as a reference for detection, reducing BDL's reliance on a large
number of candidate boxes. BDL leverages its excellent properties to
distinguish different instances, which improves the performance of CGA for
segmentation. Extensive experiments demonstrate that NICE surpasses all
existing methods by a large margin, achieving 4.1% for PND and 2.9% for PNS
over the state-of-the-art. These results validate the effectiveness of our
proposed collaborative learning strategy. The project of this work is made
publicly available at https://github.com/Mr-Neko/NICE.Comment: 18 pages. 9 figures, 9 table
Enhanced magnetoresistance in NiFe/GaAs/Fe hybrid magnon valve
The magnon valve (MV), which consists of a one spacer layer sandwiched between two ferromagnetic layers, is a potential spintronic device. The operation principle of the magnon valve depends on magnon current propagating between the two magnetic layers. More specifically, the magnon current is induced in one ferromagnetic layer and then injects magnons into the other ferromagnetic layer through the spacer layer. During this process, the magnetization of the injected ferromagnetic layer is changed, leading to the different relative magnetic orientations of the two magnetic layers. Here, we investigated the electromagnetic property of the NiFe/GaAs/Fe magnon valve assisted by microwaves with various frequencies. We find that the magnetoresistance (MR) of the magnon valve increases up to 40% when applying an external 3.4GHz microwave. The increase in the magnetoresistance results from the magnon current propagating between the two ferromagnetic layers. The magnons induced by the external microwave share the same phase, and thus the magnon current can penetrate into a 70 μm thick GaAs by coherent propagation
OR-032 Effects of Protein Supplement Timing during 4-Week Resistance Training on Muscle Hypertrophy in Males
Objective Nutrient timing is a new system of exercise nutrition that can help improve strength and lean body mass in a short time and does not require a change in exercise plan and energy intake. The concept of nutrient timing began to be used to solve problems such as the stagnation of muscle strength growth in high-protein diets, high quality proteins to gain weight and strength, but to obtain and utilize nutrient supplements at the right time to maximize muscle growth. Therefore, it is necessary to supplement the appropriate nutrients at different times.
At present, some studies have found that the type and protein supplementation timing have some influence on the resistance training of high-level athletes. Protein supplementation before or after exercise plays a positive role in improving sports performance, recovery after exercise, muscle hypertrophy and muscle strength improvement. Due to the different types, dosage and time of protein supplementation, there are still some differences.
It is still necessary to study the effect of nutrient timing of whey protein and the CEUS on the morphological indices of the rectus femoris. Therefore, by observing the thickness, circumference and area of the rectus femoris, we observed the effect of different nutrient timing and lower limb strength training on the shape of rectus femoris in healthy male youth. It is suggested that the different timing and dosage produce different effects and provide scientific suggestions for the later strength training and whey protein supplementation.
Methods A total of 32 healthy male students participated in a randomized, double-blind, placebo-controlled study. Subjects were randomly divided into four groups, the control group (Group A), the pre-exercise supplementary group (Group B), the after-exercise supplementary group (Group C) and both pre-exercise and after-exercise supplementary group (Group D), which were supplemented by: two bottles of placebo before and after the training in Group A. two bottles of whey protein water before training and two bottles of placebo after training in Group B. two bottles of placebo before training and two bottles of whey protein water after training in Group C. two bottles of whey protein water before and after training in Group D. the bottles of supplements before training should be supplemented half an hour before the start of training, and the bottles of supplements after training should be supplemented within half an hour after training. Each bottle of whey protein water was 350ml which contained 15g whey protein. The training method was 70% 1RM for barbell squat, 4 sets of 10 times, each set rest for 60s. Three training sessions were conducted each week, and the training lasted for four weeks. During this period, in order to deal with the training effect, at the end of the second week, we performed a maximum squat strength test to adjust the training intensity for the following two weeks. The body composition test used GE lunar IDXA, a dual-energy X-ray scanning method and the indexes were body weight, muscle mass and FFM. The CEUS used GE Vivid 7 holographic Color Doppler Ultrasound Diagnostic system. The test sites of CEUS were in the anterior superior iliac crest and the upper margin of the patella 1/4, and the indexes were the thickness of the femoral rectus femoris, the circumference of the rectus femoris, and the cross-sectional area of the femoral rectus femoris. Tests were performed before and after 4-week resistance training. After the intervention, the variance of paired sample t test and One Way ANOVA were used to test the significance of each group.
Results According to the change of the body composition, compared with the control group (Group A), the FFM of Group B, Group C and Group D were decreased, but there were no significant differences (p>0.05). The muscle mass of Group C increased from 54.53±4.64 kg to 58.54±5.82 kg, and muscle mass of Group D increased from 55.74±4.09 kg to 58.75±4.74 kg, compared to group A, Group C and Group D had significant increase in muscle mass (p<0.05). Body composition is mainly composed of adipose tissue and lean tissue, the body composition is influenced by the acquired factors, resistance training will also decrease the FFM and the increase the lean weight. Combined with 4-week resistance training with protein supplementation, we can see that the FFM in Group B, Group C and Group D declined a lot, which may be related to protein supplementation. The muscle mass of Group C and Group D were significantly improved, it was indicated that after resistance training, protein supplementation can improve muscle mass, but there was no differences between Group C and Group D, which indicates that the increase of protein supplementation has little effect on the increase of muscle mass, which may be due to the increase of protein supplement, the amount of muscle synthesis will increase, but the amount of decomposition will increase, too. In addition, the changes in the synthesis and decomposition, resulting in little change in muscle mass.
About the morphological changes of rectus femoris in dominant leg, compared with the control group (Group A), the thickness of the rectus femoris (changed from 12.55±3.94 mm to 16.71±3.04 mm), the circumference of the rectus femoris (changed from 8.38±1.98 cm to 10.08±1.79 cm), the cross-sectional area of the rectus femoris (changed from 3.64±1.91 cm2 to 5.43±1.61 cm2) in Group C and the thickness of the rectus femoris (changed from 14.12±2.33 mm to 15.91±2.10 mm) in Group D were significantly increased (P<0.05). The thickness of the rectus femoris, the circumference of the rectus femoris, the cross-sectional area of the rectus femoris in Group B and the circumference of the rectus femoris and the cross-sectional area of the rectus femoris in Group D were also increased, but there were no significant changes (p>0.05). About the morphological changes of rectus femoris in non-dominant leg, compared with the control group (Group A), the thickness of the rectus femoris (changed from 13.54±3.82 mm to 16.77±3.37 mm), the cross-sectional area of the rectus femoris (changed from 4.07±2.11 cm2 to 5.42±1.86 cm2) in Group C and the thickness of the rectus femoris (changed from 13.46±2.91 mm to 16.39±1.24 mm) in Group D were significantly increased (P<0.05). The thickness of the rectus femoris, the circumference of the rectus femoris, the cross-sectional area of the rectus femoris in Group B, the circumference of the rectus femoris in Group C and the circumference of the rectus femoris and the cross-sectional area of the rectus femoris in Group D were also increased, but there were no significant changes (p>0.05).
It could be seen from the results that the thickness, circumference and cross-sectional area of rectus femoris in Group C and Group D had a significant increase, and the change in Group B was not significant, indicating that after resistance training, protein supplementation will have better effects, more conducive to promoting the synthesis of muscle protein, so that the morphology of muscle was more obvious. From the comparison between Group C and Group D, we can see that the morphology of the rectus femoris in Group C has a significant change, although there were significant changes in the thickness of the rectus femoris in Group D, there was no significant increase in the circumference and cross-sectional area of the rectus femoris, which showed that the increase of protein supplementation had little effect on the morphology of the rectus femoris. This may be related to the synthesis and decomposition rate of the muscle, the increase in protein intake, to some extent, accelerated the rate of muscle synthesis, but the rate of decomposition of the muscle will also be accelerated, the synthesis rate and the rate of decomposition to achieve a positive balance. The rectus femoris of Group D will have a significant increase, but compared to group C, the effects were not obvious.
Conclusions For the nutrient timing of the whey protein, taking whey protein after exercise is the better timing to improve the thickness, circumference, cross-sectional area of rectus femoris and the muscle mass by the lower limb resistance training for males. There is a certain effect on the reduction of body FFM, but no significant improvement is found. The increase of whey protein supplementation may have little effect on body composition and muscle hypertrophy
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