100 research outputs found
Electrical transport across metal/two-dimensional carbon junctions: Edge versus side contacts
Metal/two-dimensional carbon junctions are characterized by using a nanoprobe
in an ultrahigh vacuum environment. Significant differences were found in bias
voltage (V) dependence of differential conductance (dI/dV) between edge- and
side-contact; the former exhibits a clear linear relationship (i.e., dI/dV
\propto V), whereas the latter is characterized by a nonlinear dependence,
dI/dV \propto V3/2. Theoretical calculations confirm the experimental results,
which are due to the robust two-dimensional nature of the carbon materials
under study. Our work demonstrates the importance of contact geometry in
graphene-based electronic devices
JujubeNet: A high-precision lightweight jujube surface defect classification network with an attention mechanism
Surface Defect Detection (SDD) is a significant research content in Industry 4.0 field. In the real complex industrial environment, SDD is often faced with many challenges, such as small difference between defect imaging and background, low contrast, large variation of defect scale and diverse types, and large amount of noise in defect images. Jujubes are naturally growing plants, and the appearance of the same type of surface defect can vary greatly, so it is more difficult than industrial products produced according to the prescribed process. In this paper, a ConvNeXt-based high-precision lightweight classification network JujubeNet is presented to address the practical needs of Jujube Surface Defect (JSD) classification. In the proposed method, a Multi-branching module using Depthwise separable Convolution (MDC) is designed to extract more feature information through multi-branching and substantially reduces the number of parameters in the model by using depthwise separable convolutions. What’s more, in our proposed method, the Convolutional Block Attention Module (CBAM) is introduced to make the model concentrate on different classes of JSD features. The proposed JujubeNet is compared with other mainstream networks in the actual production environment. The experimental results show that the proposed JujubeNet can achieve 99.1% classification accuracy, which is significantly better than the current mainstream classification models. The FLOPS and parameters are only 30.7% and 30.6% of ConvNeXt-Tiny respectively, indicating that the model can quickly and effectively classify JSD and is of great practical value
The Effect of Aging on the Dynamics of Reactive and Proactive Cognitive Control of Response Interference
Imidazole-dione conjugate induces apoptosis and inhibits proliferation of osteosarcoma cells via activation of p65NFκB
Purpose: To investigate the effect of imidazole-dione conjugate (IMC) on proliferation of MG63 osteosarcoma cells.
Methods: The effect of IMC on proliferation of MG63 osteosarcoma cells was determined using 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, while mRNA expressions of PTEN, FasL and FasR were assayed with real-time reverse transcription polymerase chain reaction (RT-PCR). Cell apoptosis was studied by flow cytometry. The protein expression level of IκBα was determined using western blotting.
Results: There were reductions in the proliferation of IMC-treated MG63 cells and Saos-2 cells at IMC dose of ≥ 4 μM (p < 0.05). Degree of proliferation of MG63 cells on exposure to 1, 2, 4, 6, 8 and 10 μM IMC was 99, 98, 76, 59, 34 and 21 %, respectively, relative to 100 % in untreated cultures. In MG63 cell cultures, treatment with 4, 6, 8 and 10 μM IMC led to 22, 39, 62 and 69 % apoptosis, respectively, when compared with 0.9 % apoptosis in control cell cultures (p < 0.05). Concentration-dependent increases were observed in PTEN, FasL and FasR mRNA in IMC-treated MG63 cells. Western blot assay showed a marked increase in the level of IκBα in MG63 cells following treatment with IMC. IMC treatment also caused a concentration-dependent increase in the expression of phospho-Ser536 p65NF-κB (p < 0.05).
Conclusion: IMC exerts inhibitory effect on the proliferation of MG63 cells via up-regulation of NF-κB phosphorylation. Thus, IMC may be useful as a therapeutic agent for osteosarcoma
Species-specific pharmacology of Trichloro(sulfanyl)ethyl benzamides as transient receptor potential ankyrin 1 (TRPA1) antagonists
Agonists of TRPA1 such as mustard oil and its key component AITC cause pain and neurogenic inflammation in humans and pain behavior in rodents. TRPA1 is activated by numerous reactive compounds making it a sensor for reactive compounds in the body. Failure of AITC, formalin and other reactive compounds to trigger pain behavior in TRPA1 knockout mice, as well as the ability of TRPA1 antisense to alleviate cold hyperalgesia after spinal nerve ligation, suggest that TRPA1 is a potential target for novel analgesic agents. Here, we have characterized CHO cells expressing human and rat TRPA1 driven by an inducible promoter. As reported previously, both human and rat TRPA1 are activated by AITC and inhibited by ruthenium red. We have also characterized noxious cold response of these cell lines and show that noxious cold activates both human and rat TRPA1. Further, we have used CHO cells expressing human TRPA1 to screen a small molecule compound library and discovered that 'trichloro(sulfanyl)ethyl benzamides' (AMG2504, AMG5445, AMG7160 and AMG9090) act as potent antagonists of human TRPA1 activated by AITC and noxious cold. However, trichloro(sulfanyl)ethyl benzamides' (TCEB compounds) displayed differential pharmacology at rat TRPA1. AMG2504 and AMG7160 marginally inhibited rat TRPA1 activation by AITC, whereas AMG5445 and AMG9090 acted as partial agonists. In summary, we conclude that both human and rat TRPA1 channels show similar AITC and noxious cold activation profiles, but TCEB compounds display species-specific differential pharmacology at TRPA1
Facile Synthesis of SiO2@C Nanoparticles Anchored on MWNT as High-Performance Anode Materials for Li-ion Batteries
Carbon-coated silica nanoparticles anchored on multi-walled carbon nanotubes (SiO2@C/MWNT composite) were synthesized via a simple and facile sol-gel method followed by heat treatment. Scanning and transmission electron microscopy (SEM and TEM) studies confirmed densely anchoring the carbon-coated SiO2 nanoparticles onto a flexible MWNT conductive network, which facilitated fast electron and lithium-ion transport and improved structural stability of the composite. As prepared, ternary composite anode showed superior cyclability and rate capability compared to a carbon-coated silica counterpart without MWNT (SiO2@C). The SiO2@C/MWNT composite exhibited a high reversible discharge capacity of 744 mAh g−1 at the second discharge cycle conducted at a current density of 100 mA g−1 as well as an excellent rate capability, delivering a capacity of 475 mAh g−1 even at 1000 mA g−1. This enhanced electrochemical performance of SiO2@C/MWNT ternary composite anode was associated with its unique core-shell and networking structure and a strong mutual synergistic effect among the individual components
Susceptibility trends of zoliflodacin against multidrug-resistant Neisseria gonorrhoeae clinical isolates in Nanjing, China (2014-2018)
Previously, we reported potent activity of a novel spiropyrimidinetrione, zoliflodacin, against N. gonorrhoeae isolates from symptomatic men in Nanjing, China, collected in 2013. Here, we investigated trends of susceptibilities of zoliflodacin in 986 isolates collected from men between 2014 and 2018. N. gonorrhoeae isolates were tested for susceptibility to zoliflodacin and seven other antibiotics. Mutations in gyrA, gyrB, parC, parE and mtrR genes were determined by PCR and sequencing. The MICs of zoliflodacin ranged from \u3c /=0.002 to 0.25 mg/L; the overall MIC50s and MIC90s were 0.06 mg/L and 0.125mg/L in 2018, increasing two-fold from 2014. However, the percent of isolates with lower zoliflodacin MICs declined in each year sequentially while the percent with higher MICs increased yearly (P \u3c /=0.00001). All isolates were susceptible to spectinomycin but resistant to ciprofloxacin (MIC \u3e /=1 mg/L); 21.2% (209/986) were resistant to azithromycin ( \u3e /=1 mg/L), 43.4% (428/986) were penicillinase-producing (PPNG), 26.9% (265/986) tetracycline-resistant (TRNG) and 19.4% (191/986) were multi-drug resistant (MDR) isolates. Among 202 isolates tested, all were quinolone resistant with double or triple mutations in gyrA; One hundred ninety three (193/202; 95.5%) also had mutations in parC There were no D429N/A and/or K450T mutations in GyrB identified in the 143 isolates with higher zoliflodacin MICs; a S467N mutation in GyrB was identified in one isolate. We report that zoliflodacin continues to have excellent in vitro activity against clinical gonococcal isolates, including those with high-level resistance to ciprofloxacin, azithromycin and extended spectrum cephalosporins
Prevalence of syphilis infection in different tiers of female sex workers in China: implications for surveillance and interventions
<p>Abstract</p> <p>Background</p> <p>Syphilis has made a dramatic resurgence in China during the past two decades and become the third most prevalent notifiable infectious disease in China. Female sex workers (FSWs) have become one of key populations for the epidemic. In order to investigate syphilis infection among different tiers of FSWs, a cross-sectional study was conducted in 8 sites in China.</p> <p>Methods</p> <p>Serum specimens (n = 7,118) were collected to test for syphilis and questionnaire interviews were conducted to obtain socio-demographic and behavioral information among FSWs recruited from different types of venues. FSWs were categorized into three tiers (high-, middle- and low-tier FSWs) based on the venues where they solicited clients. Serum specimens were screened with enzyme-linked immunosorbent assay (ELISA) for treponemal antibody followed by confirmation with non-treponemal toluidine red unheated serum test (TRUST) for positive ELISA specimens to determine syphilis infection. A logistic regression model was used to determine factors associated with syphilis infection.</p> <p>Results</p> <p>Overall syphilis prevalence was 5.0% (95%CI, 4.5-5.5%). Low-tier FSWs had the highest prevalence (9.7%; 95%CI, 8.3-11.1%), followed by middle-tier (4.3%; 95%CI, 3.6-5.0%, <it>P </it>< 0.001) and high-tier FSWs (2.2%; 95%CI, 1.6-2.9%, <it>P </it>< 0.001). Factors independently associated with syphilis infection included older age, lower education level, geographic location, lower tier of typology, and injection drug use.</p> <p>Conclusions</p> <p>This multi-site survey showed a high prevalence of syphilis infection among FSWs and substantial disparities in syphilis prevalence by the tier of FSWs. The difference in syphilis prevalence is substantial between different tiers of FSWs, with the highest rate among low-tier FSWs. Thus, current surveillance and intervention activities, which have low coverage in low-tier FSWs in China, should be further examined.</p
Intervention-induced enhancement in intrinsic brain activity in healthy older adults
This study examined the effects of a multimodal intervention on spontaneous brain activity in healthy older adults. Seventeen older adults received a six-week intervention that consisted of cognitive training, Tai Chi exercise, and group counseling, while 17 older adults in a control group attended health knowledge lectures. The intervention group demonstrated enhanced memory and social support compared to the control group. The amplitude of low frequency fluctuations (ALFF) in the middle frontal gyrus, superior frontal gyrus, and anterior cerebellum lobe was enhanced for the intervention group, while the control group showed reduced ALFF in these three regions. Moreover, changes in trail-making performance and well-being could be predicted by the intervention-induced changes in ALFF. Additionally, individual differences in the baseline ALFF were correlated with intervention-related changes in behavioral performance. These findings suggest that a multimodal intervention is effective in improving cognitive functions and well-being and can induce functional changes in the aging brain. The study extended previous training studies by suggesting resting-state ALFF as a marker of intervention-induced plasticity in older adults
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