1,833 research outputs found

    A Similarity Detection Method Based on Distance Matrix Model with Row-Column Order penalty Factor

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    Paper detection involves multiple disciplines, and making a comprehensive and correct evaluation of academic misconduct is quite a complex and sensitive issue. There are some problems in the existing main detection models, such as incomplete segmentation preprocessing specification, impact of the semantic orders on detection, near-synonym evaluation, slow paper backtrack and so on. This paper presents a sentence-level paper similarity comparison model with segmentation preprocessing based on special identifier. This model integrates the characteristics of vector detection, hamming distance and the longest common substring and carries out detection specific to near-synonyms, word deletion and changes in word order by redefining distance matrix and adding ordinal measures, making sentence similarity detection in terms of semantics and backbone word segmentation more effective. Compared with the traditional paper similarity retrieval, the present method adopts modular-2 arithmetic with low computation. Paper detection method with reliability and high efficiency is of great academic significance in word segmentation, similarity detection and document summarization

    Phenylboronic acid-diol crosslinked 6-<i>O</i>-vinylazeloyl-d-galactose nanocarriers for insulin delivery

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    A new block polymer named poly 3-acrylamidophenylboronic acid-b-6-O–vinylazeloyl-d-galactose (p(AAPBA-b-OVZG)) was prepared using 3-acrylamidophenylboronic acid (AAPBA) and 6-O-vinylazeloyl-D-galactose (OVZG) via a two-step procedure involving S-1-dodecyl-S-(α', α'-dimethyl-α″-acetic acid) trithiocarbonate (DDATC) as chain transfer agent, 2,2-azobisisobutyronitrile (AIBN) as initiator and dimethyl formamide (DMF) as solvent. The structures of the polymer were examined by Fourier transform infrared spectroscopy (FT-IR) and 1H NMR and the thermal stability was determined by thermal gravimetric analysis (TG/DTG). Transmission electron microscopy (TEM) and dynamic light scattering (DLS) were utilized to evaluate the morphology and properties of the p(AAPBA-b-OVZG) nanoparticles. The cell toxicity, animal toxicity and therapeutic efficacy were also investigated. The results indicate the p(AAPBA-b-OVZG) was successfully synthesized and had excellent thermal stability. Moreover, the p(AAPBA-b-OVZG) nanoparticles were submicron in size and glucose-sensitive in phosphate-buffered saline (PBS). In addition, insulin as a model drug had a high encapsulation efficiency and loading capacity and the release of insulin was increased at higher glucose levels. Furthermore, the nanoparticles showed a low-toxicity in cell and animal studies and they were effective at decreasing blood glucose levels of mice over 96 h. These p(AAPBA-b-OVZG) nanoparticles show promise for applications in diabetes treatment using insulin or other hypoglycemic proteins

    Dilute magnetic semiconductor and half metal behaviors in 3d transition-metal doped black and blue phosphorenes: a first-principles study

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    We present first-principles density-functional calculations for the structural, electronic, and magnetic properties of substitutional 3d transition metal (TM) impurities in two-dimensional black and blue phosphorenes. We find that the magnetic properties of such substitutional impurities can be understood in terms of a simple model based on the Hund's rule. The TM-doped black phosphorenes with Ti, V, Cr, Mn, Fe and Ni impurities show dilute magnetic semiconductor (DMS) properties while those with Sc and Co impurities show nonmagnetic properties. On the other hand, the TM-doped blue phosphorenes with V, Cr, Mn and Fe impurities show DMS properties, those with Ti and Ni impurities show half-metal properties, whereas Sc and Co doped systems show nonmagnetic properties. We identify two different regimes depending on the occupation of the hybridized electronic states of TM and phosphorous atoms: (i) bonding states are completely empty or filled for Sc- and Co-doped black and blue phosphorenes, leading to non-magnetic; (ii) non-bonding d states are partially occupied for Ti-, V-, Cr-, Mn-, Fe- and Ni-doped black and blue phosphorenes, giving rise to large and localized spin moments. These results provide a new route for the potential applications of dilute magnetic semiconductor and half-metal in spintronic devices by employing black and blue phosphorenes.Comment: 9 pages, 7 figure

    Sterigmatocystin limits plasmodium falciparum proliferation and transmission

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    As part of our drug discovery program against malaria, the Penicillium janthinellum ex-tract was discovered to inhibit P. falciparum proliferation in blood and transmission to mosquitoes. Bioactivity-guided fractionation of P. janthinellum extraction was carried out using chromatographic techniques. We determined the activities of fractions against Plasmodium falciparum asexual stage parasite proliferation in culture and sexual stage parasite transmission to mosquitoes using standard membrane feeding assays (SMFA). One active compound was isolated. Based on mass spectrom-etry and nuclear magnetic resonance profiles, the compound was structurally determined to be sterigmatocystin. Sterigmatocystin inhibited P. falciparum proliferation in the blood with an IC50 of 34 µM and limited the sexual parasites to infect mosquitoes with an IC50 of 48 µM. Meanwhile, sterigmatocystin did not show any acute toxicity to human kidney cells at a concentration of 64 µM or lower. Sterigmatocystin can be used as a drug lead for malaria control and as a probe to understand molecular mechanisms of malaria transmission

    Visualizing the intercity railway network in Mainland China

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    This study uses an equal population cartogram to plot the intercity railway network in Mainland China.Chinese Academy of Science

    Modeling the population and industry distribution impacts of urban land use policies in Beijing

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    Capable tools are desired for urban spatial policies planning in China to safeguard its sustainable development strategy. This study develops an activity-based Land Use/Transport Interaction (LUTI) model to forecast the urban activity impacts of the land-use policies. Essentially, its endogenized and interactive features in residential and employment distribution modeling mark it out from the traditional Lowry models. The LUTI model proposed consists of four models, i.e., a transport sub-model, a residential location model, an employment location model and a real estate rent model. It is then applied to the Beijing metropolitan area to characterize the urban activity evolution trend under the land use policies of recent years. The results show that with the increasing number of floorspace developed on the outskirts, more residents and employers are relocating there and sub-centers are formed to divide the service of central Beijing. This trend is consistent with the objective of government planning to develop more sub-centers around central Beijing by decentralizing industries to guide residential population growth patterns. The model provides a capable planning tool for urban spatial policy makers and demonstrates its first success in Beijing scenario
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