Online Ridesharing with Meeting Points [Technical Report]

Nowadays, ridesharing becomes a popular commuting mode. Dynamically arriving riders post their origins and destinations, then the platform assigns drivers to serve them. In ridesharing, different groups of riders can be served by one driver if their trips can share common routes. Recently, many ridesharing companies (e.g., Didi and Uber) further propose a new mode, namely "ridesharing with meeting points". Specifically, with a short walking distance but less payment, riders can be picked up and dropped off around their origins and destinations, respectively. In addition, meeting points enables more flexible routing for drivers, which can potentially improve the global profit of the system. In this paper, we first formally define the Meeting-Point-based Online Ridesharing Problem (MORP). We prove that MORP is NP-hard and there is no polynomial-time deterministic algorithm with a constant competitive ratio for it. We notice that a structure of vertex set, $k$-skip cover, fits well to the MORP. $k$-skip cover tends to find the vertices (meeting points) that are convenient for riders and drivers to come and go. With meeting points, MORP tends to serve more riders with these convenient vertices. Based on the idea, we introduce a convenience-based meeting point candidates selection algorithm. We further propose a hierarchical meeting-point oriented graph (HMPO graph), which ranks vertices for assignment effectiveness and constructs $k$-skip cover to accelerate the whole assignment process. Finally, we utilize the merits of $k$-skip cover points for ridesharing and propose a novel algorithm, namely SMDB, to solve MORP. Extensive experiments on real and synthetic datasets validate the effectiveness and efficiency of our algorithms.Comment: 18 page

Mechanisms of the Traditional Chinese Herb

Atractylodes lancea (Thunb.) DC. (AL) has been proven to be effective in the treatment of coronavirus disease 2019 (COVID-19). In this study, TCMSP, TCMID, OMIM, GeneCards, PharmMapper and SwissTargetPrediction were used to collect potential targets for AL against COVID-19. The online STRING analysis platform and Cytoscape were used for generating a (protein-protein interaction) PPI network. The Cytoscape and Autodock software were used for determining hub genes and key compounds. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed via DAVID database. A total of 84 common targets were obtained. The antiviral pathways were main pathways in traetment. 10 hub genes and key compounds were screened by CytoHubba. We found that AL2, AL6 and AL38 had lower binding energy with key proteins. Our study demonstrated that AL might be used to treat COVID-19 by improving the "cytokine storm", regulating some antiviral pathways, and inhibiting the key protein through which the SARS-CoV-2 invades the host cell. These findings give a pharmacological basis and support for treating COVID-19 with AL

Dual regulation of Akt and glutathione caused by isoalantolactone effectively triggers human ovarian cancer cell apoptosis

Ovarian cancer is one of leading causes of cancer death in gynecological tumor. Isoalantolactone (IL), present in several medicinal plants, exhibits various biological activities, and its mechanism underlying anti-ovarian cancer activity needs to be further investigated. Here, we find that IL inhibits the proliferation of SKOV-3 and OVCAR-3 cells by causing G2/M phase arrest and inducing apoptosis. Moreover, IL decreases intracellular glutathione (GSH) level, and induces reactive oxygen species (ROS) generation in SKOV-3 cells. Furthermore, IL induces inactivation of Akt which is required for the cytotoxicity of IL. In addition, overexpression of Akt attenuates the IL-induced growth inhibition and ROS generation. GSH supplementation moderately increases the expression of phospho-Akt. Further investigation reveals that pretreatment with L-buthionine-sulfoximine (a GSH biosynthesis inhibitor) restores the Akt-mediated attenuation of growth inhibition induced by IL. Moreover, co-treatment with IL and wortmannin (an Akt pathway inhibitor) increases the growth inhibition attenuated by pretreatment with N-acetyl-L-cysteine (a precursor for GSH biosynthesis). These results indicate that inactivation of Akt and downregulation of GSH level induced by IL are related to each other. In conclusion, combined targeting Akt and GSH is an effective strategy for cancer therapy and IL can be a promising anticancer agent for further exploration

Effect of Residence Time on Hydrothermal Carbonization of Corn Cob Residual

Hydrothermal carbonization is a promising technique for conversion of industrial waste into valuable products. Producing hydrochar from corn cob residual (CCR) in a cost-effective way is key, from an economic standpoint. For this purpose, the effect of residence time in the range of 0.5 to 6 h was studied under the optimal temperature of 250 °C. Results showed that the higher heating value (HHV) of hydrochar increased approximately 40% in comparison to that of the raw material; however, prolonging the residence time beyond 0.5 h had a negligible effect on the HHV increase. Chemical compositions and H/C and O/C ratios of hydrochars revealed a minimal effect of longer residence time. Furthermore, thermogravimetric and derivative thermogravimetric analysis (TG/DTG), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) analysis of hydrochars also verified that the pyrolysis behavior and chemical structure of hydrochars with various residence times were similar

Preparation of Dissolving Pulp by Combined Mechanical and Deep Eutectic Solvent Treatment

Grasses are potential candidate to replace wood as a raw material for pulping and paper making, and several processes have been developed to produce grass pulp. In this study, wheat straw was used as raw material, and the possibility of sequential treatment with a mechanical method and deep eutectic solvent (DES) to prepare high-quality dissolving pulp was explored. Firstly, the wheat straw was mechanically treated, and then the wheat straw was delignified using a choline chloride–lactic acid deep eutectic solvent. The results showed that the optimal treatment conditions of deep eutectic solvent were 110 °C, 6 h, and a solid–liquid ratio (ratio of pulp to DES) of 1:40. The removal rate of lignin was 82.92%, the glucose content of pulp was increased by 11.42%. The DES recovery rate was further calculated, and the results showed that the DES recovery rate was more than 50% with rotary evaporation. The pulp viscosity after bleaching was 472 mL/g, and the α-cellulose accounted for 81.79%. This treatment has advantages in biomass refining, and the total utilization rate of wheat straw reaches 72%. This study confirmed that combined mechanical and deep eutectic solvent treatment can effectively remove lignin from wheat straw to produce high-quality wheat straw dissolving pulp

Structural Characterization and Antioxidant Activity of Milled Wood Lignin from Xylose Residue and Corncob

Xylose residue (XR), after diluted acid treatment of corncob, consists of cellulose and lignin. However, structural changes of XR lignin have not been investigated comprehensively, and this has seriously hindered the efficient utilization of lignin. In this study, corncob milled wood lignin (CC MWL), and xylose residue milled wood lignin (XR MWL) were isolated according to the modified milled wood lignin (MWL) method. The structural features of two lignin fractions were thoroughly investigated via fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), thermogravimetric analysis (TGA) and two dimensional nuclear magnetic resonance (2D NMR) spectroscopy techniques. XR MWL with higher yield and lower bound carbohydrate contents presented more phenolic OH contents than CC MWL due to partial cleavage of β-O-4. Furthermore, the molecular weights of XR MWL were increased, possibly because of condensation of the lignin during the xylose production. A study on antioxidant activity showed that XR lignin had better radical scavenging ability than that of 2,6-Di-tert-butyl-4-methyl-phenol (BHT) and CC MWL. The results suggested that the lignin in xylose residue, showing great antioxidant properties, has potential applications in food additives

Highly Active N, S Codoped Porous Carbon Derived from Lignin-Rich Pulping Waste Liquor for Supercapacitors and Oxygen Reduction Reaction

Heteroatom-doped porous carbon has become a key material in the field of supercapacitors (SCs) and the oxygen reduction reaction (ORR). Here, eucalyptus pulping red liquor was used as the starting material for a straightforward one-step NH4Cl-assisted carbonization technique that produced a nitrogen and sulfur codoped bifunctional porous carbon material. The sulfur in sodium lignosulfonate was used as a S atom dopant. NH4Cl added to the red liquor can not only produce NaCl as a template but also as a nitrogen source. The resulting carbons possess rich hierarchical porous structures and high specific surface area (1092 m2 g–1) and ID/IG ratio (1.04), leading to remarkable electrocatalytic activity with a specific capacitance of 326 F g–1 at 0.5 A g–1 for capacitance and an identical onset and half-wave potentials of 0.988 V vs reversible hydrogen electrode (RHE) and 0.847 V vs RHE for the ORR, as compared with the benchmark Pt/C catalyst. Furthermore, when BLC-N/S-1000 was used as an electrocatalyst in an air electrode of a zinc–air battery, it showed superior long-term stability for 356 h at 5 mA cm–2 and 20 min/cycle. Results in the present work pave a new green method to convert abundant low-cost biomass into high-end heteroatom-doped carbons with rich hierarchical porous structures for electrochemical energy devices

DataSheet1_High performance bio-supercapacitor electrodes composed of graphitized hemicellulose porous carbon spheres.DOCX

A template-free and one-step carbonization process was developed for fabricating graphitic porous carbon spheres (GPCSs) on hemicelluloses as the electrode material for supercapacitors. This method is green, low-energy, and less time consuming compared to the conventional two-step process (pore-forming and graphitizing). It uses K2FeO4, a mild activating agent that fulfills synchronous activation and graphitization. The GPCSs is regular spherical shape, have high nanoporosity, a large specific surface area (1,250 m2 g−1), and have a high graphitization degree. A unique structural advantage includes a rich interconnected conductive network for electron transfer that shortens the ion transport distance of the electrolyte. Remarkably, the GPCSs electrode displays outstanding electrochemical performance including high specific capacitance (262 F g−1 at 1.0 A g−1), rate capability energy (80%, 20 A g−1), and excellent cycling stability (95%, 10,000 cycles). This work represents a powerful methodology to develop sustainable and low-cost energy storage devices from hemicellulose.</p