Pure self-management model, pure aggregation business model and Self-support + aggregation model are three commonly used business modes on ride-hailing platforms. We use an analytical model to study ...these three business models and give the optimal business model decision of the platform. The research shows that the heterogeneity ratio of drivers, the cost of the platform under the Self-support model, the franchise fee received by the platform under the aggregation model and the dissatisfaction of the original users on the platform play a key role in the selection of the platform's business model. When the difference between the franchise fee under the aggregation mode and the platform cost under the Self-support mode fails to generate positive feedback on the platform profit, the platform should choose the pure Self-support mode. When riders are more sensitive to the heterogeneity of service quality of the platform and user stickiness can be ensured, the platform should choose the pure aggregation business model. When user stickiness can be guaranteed and the cost of the platform under the self-run model is controllable, the platform should choose the Self-support + aggregation business model.
A new potassium nitrate （KNO3）diatomite shape-stabilized composite phase change material （SS- CPCM） was prepared by the mixing and sintering method. KNO3 served as the phase change material （PCM） for ...thermal energy storage, while diatomite acted as the carrier matrix to provide the structural strength and prevent the leakage of PCM. It was found that KNO3 could be retained 65 wt% into pores and on surfaces of diatomite without the leakage of melted KNO3 from the SS-CPCM. The calculated filling rate of molten KNO3 that could enter into the disc-like shape pore of diatomite verified the scanning elec- tronic microscopy images of SS-CPCM. X-ray diffraction and Fourier transform infrared spectroscopy results showed that no reaction occurred between KNO3 and diatomite, performing good compatibility. Accord- ing to the differential scanning calorimetry results, after 50 thermal cycles, the phase change temperatures for melting and freezing of SS-CPCM with 65 wt% KNO3 were changed from 330.23 ℃ and 332.90 ℃ to 330.11 ℃ and 332.84 ℃ and corresponding latent heats varied from 60.52 J/g and 47.30 J/g to 54.64 J/g and 41.25 J/g, respectively. The KNO3/diatomite SS-CPCM may be considered as a potential storage media in solar power plants for thermal energy storage.
Mincle (macrophage-inducible C-type lectin, Clec4e) is a transmembrane pattern recognition receptor involving the innate immunity, but its role in kidney disease is still unexplored. In the ...obstructed kidney of the unilateral ureteral obstruction model of renal injury, Mincle was specifically detected in the infiltrating M1 macrophages (CD68+iNOS+ cells) on day one but was rapidly reduced following reduction of M1 macrophages during the progression of kidney injury. Interestingly, Mincle-expressing macrophages were progressively increased in the cisplatin-induced acute kidney injury model, where iNOS expression was detected in the CD68+ cells following Mincle induction. Adaptive transfer of Mincle+ M1 macrophages largely promoted cisplatin-induced renal inflammation, which was prevented by the knockdown of Mincle in the transferred cells. Mincle was tightly regulated by TLR4/NF-κB signaling as evidenced by the binding of NF-κB/p65 to the promoter region of Mincle in LPS-primed macrophages. Blocking TLR4 or NF-κB suppressed LPS-induced Mincle expression on macrophages. Importantly, Mincle was found to be essential for maintaining the inflammatory phenotypes of M1 macrophages through the Syk signaling pathway since knockdown of Mincle or inhibition of Syk suppressed LPS-induced IL-1β, MCP-1, and iNOS expression. Thus, Mincle is induced specifically on M1 macrophages, where Mincle-Syk signaling promotes and maintains inflammatory phenotypes of M1 macrophages in acute renal inflammation. Hence, targeting Mincle may be a novel therapy for acute kidney injury associated with M1 macrophages.
The Wnt signaling pathway is necessary for the development of the central nervous system and is associated with tumorigenesis in various cancers. However, the mechanism of the Wnt signaling pathway ...in glioma cells has yet to be elucidated. Small-molecule Wnt modulators such as ICG-001 and AZD2858 were used to inhibit and stimulate the Wnt/β-catenin signaling pathway. Techniques including cell proliferation assay, colony formation assay, Matrigel cell invasion assay, cell cycle assay and Genechip microarray were used. Gene Ontology Enrichment Analysis and Gene Set Enrichment Analysis have enriched many biological processes and signaling pathways. Both the inhibiting and stimulating Wnt/β-catenin signaling pathways could influence the cell cycle, moreover, reduce the proliferation and survival of U87 glioma cells. However, Affymetrix expression microarray indicated that biological processes and networks of signaling pathways between stimulating and inhibiting the Wnt/β-catenin signaling pathway largely differ. We propose that Wnt/β-catenin signaling pathway might prove to be a valuable therapeutic target for glioma.
In this paper, a sensorless control strategy of permanent magnet synchronous motor (PMSM) based on fuzzy sliding mode observer (FSMO) is proposed. On the premise of satisfying the Lyapunov stability ...condition, a sliding mode observer (SMO) is constructed. The sigmoid function is used instead of the sign function as the switching function. The parameters of sigmoid function are adjusted in real time by establishing fuzzy rules to change the convergence characteristics of sigmoid function, so as to improve the observation performance. The back EMF signal extracted by the SMO can be made smoother by using the back EMF adaptive law, which reduces the chattering of the system and the observation error. In order to solve the problem that the traditional phase locked loop (PLL) can not be used when the positive and negative speed of the motor is switched, a tangent function PLL is proposed in this paper. Through the use of tangent function, the value and symbol of back EMF are avoided from entering the system, so as to realize the accurate estimation of rotor speed and rotor position under the condition of positive and negative speed switching. The designed Fuzzy Sliding Mode Observer is simulated in Matlab/Simulink, and the experimental verification is carried out on the 2kW surface mounted PMSM vector control platform with TMS320F28335 as the main control chip. Simulation and experimental results show that this method can effectively track the changes of rotor speed and position when the motor is switched between positive and negative speed, and has the characteristics of fast convergence, small chattering and good robustness.
The dynamic map is applied instead of traditional static maps in the teaching of geographic information science (GIS)‐related majors so as to meet the need for teaching animations and teaching ...interaction in new teaching methods such as mobile personalized learning, massive open online course, and Flipped Classroom. The research introduces the concept and the making tools of dynamic maps, studies the making principles and key technologies of dynamic maps, and constructs the relevant theories such as the “frame” model based on time granularity, the dynamic interpolation algorithm based on spatial characteristics, dynamic symbolic logic model, and algorithm. Based on the above principles and theories, taking a dynamic map of the change in the population of each city in Shandong province as an example, the research demonstrates the making method and process of the dynamic maps for teaching with Flash MX. At last, it analyzes the role of dynamic map in GIS‐related courses teaching and evaluates the teaching effect of dynamic maps.
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•Prenatal PFOA and PFOS exposures were adversely associated with communication domains of infants at 6 months of age.•PFHxS and 6:2Cl-PFESA were associated with poor scores of ...communication domain at 6 months.•PFOA, PFOS, and PFHxS can affect the communication domain's trajectory in infancy.•Boys were more sensitive to PFOA, PFOS, and PFHxS than girls.•The impacts of PFAS mixtures were greater than effects induced by individual PFAS.
Epidemiological data on the effects of perfluoroalkyl and polyfluoroalkyl substances (PFAS) on infant neurodevelopment trajectories are far from being sufficiently addressed. In this study, 1285 mother–child pairs were recruited during 2016–2017. A high-performance liquid chromatography-triple quadrupole mass spectrometer was used to measure 16 PFAS levels in cord serum. Ages and Stages Questionnaires were used to examine children's neurodevelopment at 2, 6, 12, and 24 months of age. Group-based trajectory models were applied to derive the neurodevelopmental trajectories. Children with relatively low scores from 2 to 24 months were classified into a low-score group and were used as a risk group in each domain. Multiple linear regression, logistic regression, and quantile-based g-computation were performed to assess associations of single or mixture PFAS exposures with neurodevelopment and trajectories. Perfluorooctane sulphonate (PFOS), perfluorooctanoic acid (PFOA), perfluorohexanesulfonic acid (PFHxS), and 6:2 chlorinated polyfluorooctane ether sulfonate (6:2Cl-PFESA) were detected in over 90 % samples. PFOA had the highest concentration (median: 4.61 μg/L). Each ln-unit (μg/L) increase of PFAS (e.g., PFOA, PFOS, PFHxS, 6:2Cl-PFESA) was associated with poor scores of communication domain at 6 months, with the effect size ranging from −0.69 to −0.44. PFOS (OR: 1.14, (1.03, 1.26), PFDA (OR:1.08, (1.02, 1.15)), PFHxS (OR:1.31, (1.12, 1.56)), and 6:2Cl-PFESA (OR:1.08, (1.00, 1.16)) were associated with an increased risk of being in the low-score group in the early childhood communication domain's trajectory. Each mixture quartile increment was associated with a 1.60 (−2.76, −0.45) decrease in communication domain scores of 6-month-old infants, and the mixture effect was mainly attributed to PFOS. Each mixture quartile increase was associated with a 1.23-fold (1.03, 1.46) risk of being in the low-score group of the communication domain, and the mixture effect was mainly attributed to PFOS. In conclusion, PFAS and their mixtures might adversely affect childhood neurodevelopment. The gender-specific associations existed in the above associations.
Diatomite, a natural clay mineral, is mainly composed of silica and contains a large number of fine microscopic pores. In the present work, a series of porous Si/C composites are successfully ...synthesized by employing diatomite as a raw material, followed by low temperature magnesiothermic reduction, impregnation and carbonization of phenolic resin. The obtained Si/C composites are consisted of porous Si coated with a 15 nm thick amorphous layer of carbon. Porous Si/C composites with different ratios of Si and C are investigated as anode materials for Li-ion batteries. The porous Si/C composite containing 33% carbon exhibits the highest reversible capacity of about 1628 mAh g−1 at the first cycle with excellent capacity retention in the following cycles. Moreover, the porous Si/C composites display the excellent rate performance at high current densities such as 1 and 2 A g−1. The optimum electrochemical performance could also be tuned by varying the proportions of porous Si and carbon precursors during the preparation process. The results indicate that the natural pore structures of Si and C are conducive to the electrochemical performance and clay mineral diatomite could be considered as a promising raw material for Si/C composites for lithium-ion batteries.
► Diatomite was used as a raw material for the preparation of porous Si/C composite. ► The pore structure of diatomite could be well retained in the prepared porous Si. ► The porous Si/C composite exhibits high electrochemical performance.
Unresolved inflammation can lead to tissue fibrosis and impaired organ function. Macrophage–myofibroblast transition (MMT) is one newly identified mechanism by which ongoing chronic inflammation ...causes progressive fibrosis in different forms of kidney disease. However, the mechanisms underlying MMT are still largely unknown. Here, we discovered a brain-specific homeobox/POU domain protein Pou4f1 (Brn3a) as a specific regulator of MMT. Interestingly, we found that Pou4f1 is highly expressed by macrophages undergoing MMT in sites of fibrosis in human and experimental kidney disease, identified by coexpression of the myofibroblast marker, α-SMA. Unexpectedly, Pou4f1 expression peaked in the early stage in renal fibrogenesis in vivo and during MMT of bone marrow-derived macrophages (BMDMs) in vitro. Mechanistically, chromatin immunoprecipitation (ChIP) assay identified that Pou4f1 is a Smad3 target and the key downstream regulator of MMT, while microarray analysis defined a Pou4f1-dependent fibrogenic gene network for promoting TGF-β1/Smad3-driven MMT in BMDMs at the transcriptional level. More importantly, using two mouse models of progressive renal interstitial fibrosis featuring the MMT process, we demonstrated that adoptive transfer of TGF-β1-stimulated BMDMs restored both MMT and renal fibrosis in macrophage-depleted mice, which was prevented by silencing Pou4f1 in transferred BMDMs. These findings establish a role for Pou4f1 in MMT and renal fibrosis and suggest that Pou4f1 may be a therapeutic target for chronic kidney disease with progressive renal fibrosis.
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•Assessment of 63 compounds in roasted beans of 12 Arabica coffee cultivars.•Principal component analysis clustered the 12 coffee cultivars into four groups.•Revealing the quality ...characteristics of different lineage coffee cultivars.•Some introgressed cultivars also have the potential to produce high-quality coffee.
This work aimed to study the composition differences of roasted beans between 12 coffee cultivars (Catimor 7963, HIBRIDO DE TIMOR, Ruiru 11, Castillo, DTARI 296, DTARI 366, DTARI 392, DTARI 585, SL28, SL34, Catuai-Amarelo and Catuai-Vermelho) from Bourbon-Typica group and Introgressed group under subtropical humid monsoon climate. The water-soluble compounds of roasted coffee beans were characterized by proton nuclear magnetic resonance spectroscopy (1H NMR), and the aroma components were analyzed by static headspace gas chromatography mass spectrometry (SHS-GC/MS). In total, 20 water soluble compounds and 43 volatile compounds were identified. Both water-soluble and volatile compounds are rich in acidic substances, and the content varied depending on the cultivars. Furthermore, principal component analysis (PCA) clustered 12 coffee cultivars into four groups. The four different chemically defined clusters of Arabica cultivars produced by chemical differences cannot reflect the traditional grouping based on introgressed, and it is one-sided to judge coffee quality based on lineage. These results give further insight into the quality characteristics of different coffee cultivars, which is of great significance for guiding the adjustment of cultivars' structure and the breeding of new cultivars.
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