42 research outputs found

    A primary Rosai-Dorfman-Destombes disease of the scalp: case report and literature review

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    BackgroundRosai-Dorfman-Destombes disease (RDD) was first described in 1965 as a benign histiocytic proliferative disorder of unknown cause. Cases of RDD limited to cutaneous tissue have been reported over the past few decades, but single cutaneous RDD of the scalp is rare.Case presentationWe report a 31-year-old male with a lump on the parietal scalp without extranodal lesion lasting 1 month with gradual enlargement. The surgical incision ruptured with purulent after the first resection. Then the patient was treated with plastic surgery after disinfection and antibiotic treatment. Finally, he recovered well and discharged after 20 days.ConclusionsRDD of the scalp is rare. Surgical incision can cure the lesion but it may become infected because of increased lymphocytic infiltration. Early diagnosis and differential diagnosis of RDD are necessary. For treatment, individualized therapy is critical to patient prognosis

    Minimizing the programming power of phase change memory by using graphene nanoribbon edge-contact

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    Nonvolatile phase change random access memory (PCRAM) is regarded as one of promising candidates for emerging mass storage in the era of Big Data. However, relatively high programming energy hurdles the further reduction of power consumption in PCRAM. Utilizing narrow edge-contact of graphene can effectively reduce the active volume of phase change material in each cell, and therefore realize low-power operation. Here, we demonstrate that a write energy can be reduced to about ~53.7 fJ in a cell with ~3 nm-wide graphene nanoribbon (GNR) as edge-contact, whose cross-sectional area is only ~1 nm2. It is found that the cycle endurance exhibits an obvious dependence on the bias polarity in the cell with structure asymmetry. If a positive bias was applied to graphene electrode, the endurance can be extended at least one order longer than the case with reversal of polarity. The work represents a great technological advance for the low power PCRAM and could benefit for in-memory computing in future.Comment: 14 pages, 4 figure

    Effect of Heat Processing on the Functional Properties of Myosin in Three Kinds of Hairtail

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    Changes in the functional properties of myosin and the tissue microstructure of hooked, trawl-netted, and radar-netted hairtail (Trichiurus haumela) were investigated under different heating temperatures. Hairtails were water bathed at 30, 50, 70 or 90 ℃ and evaluated for cooking loss and water-holding capacity (WHC) as well as myosin turbidity, solubility, emulsifying capacity, foaming capacity and foam stability, and carbonyl content after 10 min. Besides, hematoxylin-eosin (HE) staining was used to analyze the effects of different heating temperatures on the tissue microstructure of hairtails. The results showed that as the heating temperature rose, the cooking loss and water-holding capacity of muscle decreased gradually for the three kinds of hairtail. Myosin turbidity and carbonyl content increased, and solubility, emulsifying activity index (EAI) and emulsion stability index (ESI), foaming capacity and foam stability decreased continuously. The decrease in muscle WHC and myosin solubility and the increase in myosin turbidity were all smaller in radar-netted hairtails than in the two other kinds. In addition, the HE staining results showed that with increasing heating temperature, the space between muscle fiber bundles in muscle tissues increased for all kinds of hairtail, and different degrees of breakage occurred. When the heating temperature was 50 ℃, the structure of collagen and muscle fibers was the most complete in the muscle tissue of radar-netted hairtail. Summarily, the muscle quality of all three kinds of hairtail decreased with the increase in heating temperature, and the muscle quality of radar-netted hairtail was the most stable

    Diverse Effects of the NTCP p.Ser267Phe Variant on Disease Progression During Chronic HBV Infection and on HBV preS1 Variability

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    The sodium taurocholate co-transporting polypeptide (NTCP) acts as a cellular receptor for the hepatitis B virus (HBV) infection on host hepatocytes. We aim to investigate how the NTCP p.Ser267Phe variant affects HBV-related disease progression and analyze viral genomic variability under a host genetic background carrying the p.Ser267Phe variant. A total of 3187 chronic hepatitis B (CHB) patients were enrolled and genotyped for the p.Ser267Phe variant. The variant's association with disease progression was evaluated by logistic regression analysis. We also enrolled 83 treatment-naive CHB patients to analyze the variability of the HBV preS1 region. The frequency of the NTCP p.Ser267Phe variant was significantly lower in patients diagnosed with acute-on-chronic liver failure [OR (95% CI) = 0.33 (0.18–0.58), P = 1.34 × 10−4], cirrhosis [OR (95% CI) = 0.47 (0.31–0.72), P = 4.04 × 10−4], and hepatocellular carcinoma [OR (95% CI) = 0.54 (0.34–0.86), P = 9.83 × 10−3] as compared with CHB controls under the additive model after adjustment. Furthermore, the percentage of amino acid mutations in HBV preS1 region was significantly higher in the NTCP p.Ser267Phe heterozygote group than in the NTCP wild type homozygote group (P < 0.05). We herein demonstrate that the NTCP p.Ser267Phe variant is a protective factor reducing CHB patient risk for liver failure, cirrhosis, and hepatocellular carcinoma. A host genetic background carrying NTCP p.Ser267Phe exerts selective pressure on the virus, leading to more variability

    SN 2014J in M82: New Insights On the Spectral Diversity of Type Ia Supernovae

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    We present extensive spectroscopic observations for one of the closest type Ia supernovae (SNe Ia), SN 2014J discovered in M82, ranging from 10.4 days before to 473.2 days after B-band maximum light. The diffuse interstellar band (DIB) features detected in a high-resolution spectrum allow an estimate of line-of-sight extinction as Av=1.9+/-0.6 mag. Spectroscopically, SN 2014J can be put into the high-velocity (HV) subgroup in Wang's classification with a velocity of Si~II 6355 at maximum light as about 12200 km/s, but has a low velocity gradient (LVG, following Benetti's classification) as 41+/-2 km/s/day, which is inconsistent with the trend that HV SNe Ia generally have larger velocity gradients. We find that the HV SNe Ia with LVGs tend to have relatively stronger Si III (at ~4400 Angstrom) absorptions in early spectra, larger ratios of S II 5468 to S II 5640, and weaker Si II 5972 absorptions compared to their counterparts with similar velocities but high velocity gradients. This shows that the HV+LVG subgroup of SNe Ia may have intrinsically higher photospheric temperature, which indicates that their progenitors may experience more complete burning in the explosions relative to the typical HV SNe Ia.Comment: Accepted by MNRAS, 13 figure

    Properties and Asteroseismological analysis of a new ZZ ceti discovered by TMTS

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    Tsinghua university-Ma Huateng Telescope for Survey (TMTS) aims to discover rapidly evolving transients by monitoring the northern sky. The TMTS catalog is cross-matched with the white dwarf (WD) catalog of Gaia EDR3, and light curves of more than a thousand WD candidates are obtained so far. Among them, the WD TMTS J23450729+5813146 (hereafter J2345) is one interesting common source. Based on the light curves from the TMTS and follow-up photometric observations, periods of 967.113 s, 973.734 s, 881.525 s, 843.458 s, 806.916 s and 678.273 s are identified. In addition, the TESS observations suggest a 3.39 h period but this can be attributed to the rotation of a comoving M dwarf located within 3". The spectroscopic observation indicates that this WD is DA type with Teff = 11778+/-617K,log g = 8.38+/-0.31,mass=0.84+/-0.20Msun and age=0.704+/-0.377 Gyrs. Asteroseismological analysis reveals a global best-fit solution of Teff =12110+/-10K and mass=0.760+/-0.005Msun,consistent with the spectral fitting results, and Oxygen and Carbon abundances in the core center are 0.73 and 0.27, respectively. The distance derived from the intrinsic luminosity given by asteroseismology is 93 parsec, which is in agreement with the distance of 98 parsec from Gaia DR3. Additionally, kinematic study shows that this WD is likely a thick disk star. The mass of its zero-age main-sequence mass is estimated to be 3.08 Msun and has a main-sequence plus cooling age of roughly 900 Myrs.Comment: 10 pages, 10 figures, accepted for publication in MNRA

    Variable white dwarfs in TMTS: Asteroseismological analysis of a ZZ Ceti star, TMTS J17184064+2524314

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    The Tsinghua University-Ma Huateng Telescope for Survey (TMTS) has been constantly monitoring the northern sky since 2020 in search of rapidly variable stars. To find variable white dwarfs (WDs), the TMTS catalog is cross-matched with the WD catalog of Gaia EDR3, resulting in over 3000 light curves of WD candidates. The WD TMTS J17184064+2524314 (hereafter J1718) is the second ZZ~Ceti star discovered among these common sources. Based on the light curves from TMTS, follow-up photometric observations, and TESS, 10 periods and 3 combination periods are detected. A rotation period of 25.12±0.1825.12\pm0.18 hr is derived, according to the identified rotational splitting. Our spectroscopic observation indicates that this WD belongs to DA type with Teff=11,670±604T_{\rm eff}=11,670\pm604 K, log g=8.16±0.36g=8.16\pm0.36, M=0.70±0.23M = 0.70\pm0.23 M⊙_{\odot}, and age=0.51±0.340.51\pm0.34 Gyr. Based on core-parameterized asteroseismological model grids (⩾\geqslant 14 million), we derive a best-fit solution of Teff=11,640±20T_{\rm eff}=11,640\pm20 K, log g=8.267±0.008g=8.267\pm0.008, and M=0.750±0.005M = 0.750\pm0.005 M⊙_{\odot} for J1718, consistent with the spectral fitting results. For this WD, the corresponding carbon and oxygen abundances in the core are 0.43 and 0.57, respectively. The distance derived from the intrinsic luminosity given by asteroseismology is 64±1564\pm15 pc, in accord with the distance of 70.1±0.270.1\pm0.2 pc from Gaia DR3 within the uncertainties.Comment: 11 pages, 8 figures, Accepted for publication in MNRAS. arXiv admin note: text overlap with arXiv:2305.1158

    Evolutionary Game Analysis of Government and Enterprise Behavior Strategies in Public-Private-Partnership Farmland Consolidation

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    To improve the implementation effect of farmland consolidation (FC) and promote the development of agricultural modernization, the Chinese government has vigorously promoted the application of the public-private-partnership for farmland consolidation (PPP-FC). However, many conflicts of interest among stakeholders exist in PPP-FC. Especially in the implementation stage of PPP-FC, most private enterprises probably prefer to decrease the costs of construction to increase the profits when government incentives and supervision are insufficient. Based on this, this paper constructs an evolutionary game model between the government and the enterprises to explore the motivations of the enterprises’ speculative behaviors, the interaction mechanism and the evolutionary stability strategies of both parties and uses numerical simulations to visually analyze the effectiveness of the incentive mechanism and the strategic change of both sides. Our results show that (1) the enterprise’s farmland operating income is the decisive factor that affects behavioral choices: the situation for the income of a low-effort strategy is greater than that of a high-effort strategy is the root cause of speculative behavior; (2) the incentive mechanism can simultaneously affect the decision-making direction and speed of both the government and the enterprises, especially punishment which can effectively regulate the behaviors of the enterprises; (3) government regulation costs and officials’ desire for promotion are important factors affecting their strategic choices: regulation costs negatively impact the government’s plans to adopt an incentive strategy and the promotion desire positively promotes the government implementing incentive measures for the enterprises; and (4) the supervision level of farmers is an important factor that affects the strategic choices of both the government and the enterprises: farmers supervision is an effective remedy for inadequate government regulation and constrains the government’s behavior. Finally, the paper proposes corresponding policy recommendations to improve the implementation effect of PPP-FC and also provides an important reference for other developing countries to formulate PPP-FC incentive mechanisms

    The Effect of Carbon Doping on the Crystal Structure and Electrical Properties of Sb2Te3

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    As a new generation of non-volatile memory, phase change random access memory (PCRAM) has the potential to fill the hierarchical gap between DRAM and NAND FLASH in computer storage. Sb2Te3, one of the candidate materials for high-speed PCRAM, has high crystallization speed and poor thermal stability. In this work, we investigated the effect of carbon doping on Sb2Te3. It was found that the FCC phase of C-doped Sb2Te3 appeared at 200 °C and began to transform into the HEX phase at 25 °C, which is different from the previous reports where no FCC phase was observed in C-Sb2Te3. Based on the experimental observation and first-principles density functional theory calculation, it is found that the formation energy of FCC-Sb2Te3 structure decreases gradually with the increase in C doping concentration. Moreover, doped C atoms tend to form C molecular clusters in sp2 hybridization at the grain boundary of Sb2Te3, which is similar to the layered structure of graphite. And after doping C atoms, the thermal stability of Sb2Te3 is improved. We have fabricated the PCRAM device cell array of a C-Sb2Te3 alloy, which has an operating speed of 5 ns, a high thermal stability (10-year data retention temperature 138.1 °C), a low device power consumption (0.57 pJ), a continuously adjustable resistance value, and a very low resistance drift coefficient
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