202 research outputs found

    A New Efficient ID-Based Authenticated Key Agreement Protocol

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    Recently Eun-Kyung Ryu, Eun-Jun Yoon, and Kee-Young Yoo proposed an efficient ID-based authenticated key agreement with paring.They argued that it is secure and efficient. In this paper, we show this protocol is doesn\u27t satisfy the Key-Compromise Impersonate property and it is not secure against key reveal attack. Then we propose our protocol from this protocol and shim\u27s protocol, its security and efficiency was analyzed

    Research on dynamics of sorting arms with high frequency reciprocating motion

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    The characters of high frequency reciprocating equipment are quick starting and stopping, short range, high frequency and multi-freedom reciprocating motion. The inertia introduced by the high frequency reciprocating motion of a LED chip sorter has complicated effects on the positional accuracy. It is necessary to obtain dynamics of the sorting arm to suppress the vibration of the high frequency operation. The positioning precision and positioning time are affected by the natural vibration of the sorting arm by analyzing the displacement response. The paper verifies that the inherent vibration of the sorting arm has a crucial effect on its positioning precision and positioning time. Under static condition, due to the additional mass of the accelerometers, the research results show that there is no obvious difference in the experimental modal analysis (EMA) based on multi-type sensors. The modal parameters identified by accelerometers and strain gauges are very close. The modal parameters are obtained through the modal analysis method, which combines the strain modal analysis and operational modal analysis (OMA), under high frequency reciprocating motion. The paper verifies that the modal parameters of lightweight structure are very different in the static and operation. The key points of each mode are found by analyzing the modal amplitudes at different speeds which provide the guiding principle and basis for the dynamic optimization of the sorting arm mechanism

    High resolution thermal microscopy

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    Journal ArticleA new high resolution thermal microscope has been demonstrated capable of imaging thermal fields with sub 1000 angstom resolution. It is based upon a non-contacting near field thermal probe. The thermal probe consists of a thermocouple sensor on the end of a tip with sub 1000 angstrom dimensions. The probe tip is scanned in close proximity to a solid or liquid surface and the local temperature is mapped with a resolution determined by the size of the tip. Material independent surface profiling has also been demonstrated with the thermal probe, providing a lateral resolution of approximately 300 angstroms. Temperature mapping and surface profiling results are presented on both electronic and biological materials

    Research on vibration suppression mode of sorting arm structure in high-frequency reciprocating motion

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    The sorting arm structure is under the inertia impact of high frequency reciprocating motion. The vibration characteristics are related to the operation process so that the precision of the chip sorting is uncertain. Thus, the accuracy of chips and efficiency of LED sorting machine are reduced. In the paper, the relationship between the vibration of the sorting arm and the positioning error of the chip has been studied. Besides, the correlation between the sorting arm structure’s vibration and the working precision of the separator are pointed out. The operation control is optimized based on the dynamics of the sorting arm and the operation parameters are optimized based on time sequence setting, in order to shorten the vibration attenuation time of the sorting arm for suppress vibration and provide efficiency. The incentives, which are introduced by variable structure and by the operation, can be effectively controlled. The array accuracy of chips and working efficiency of chip sorting machine are improved

    Divergence of Fecal Microbiota and Their Associations With Host Phylogeny in Cervinae

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    Gastrointestinal microbiota may shape the adaptation of their hosts to different habitats and lifestyles, thereby driving their evolutionary diversification. It remains unknown if gastrointestinal microbiota diverge in congruence with the phylogenetic relationships of their hosts. To evaluate the phylosymbiotic relationships, here we analyzed the compositions of fecal microbiota of seven Cervinae species raised in the Chengdu Zoo. All sampled animals were kept in the same environmental condition and fed identical fodder for years. Results showed that Firmicutes and Bacteroidetes were dominant in their fecal microbiota. Even though some bacteria (e.g., Ruminococcaceae) were found to be common in the feces of all investigated species, some genera (e.g., Sharpea and Succinivibrio) were only observed in animals with particular digestive systems. As for the intraspecies variations of microbial communities, only a few operational taxonomic units (OTUs) were shared among replicates of the same host species although they accounted for most of the total abundance. Correlation was observed between the fecal microbiota divergence and host phylogeny, but they were not congruent completely. This may shed new light on the coevolution of host species and their microbiota

    Influence of WeChat Use on the College Students Campus Life Satisfaction-A Perspective on Bridging Social Capital

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    The theories of social capital and Rosenberg's self-esteem scale were used to measure the campus life satisfaction of college students, this paper made an empirical analysis on the WeChat media use of 1000 college students from Hong Kong, Macao, Taiwan and mainland China (M=18.81 years old, SD=0.96) of a University in Guangdong province, and discussed the relationship among college students' social media use intensity, campus life satisfaction and social capital. The study found that there was a significant positive correlation between WeChat use intensity of college students and social capital, that the intensity of WeChat use had a direct effect on college students' satisfaction with campus life, and that self-esteem had a moderating effect between WeChat use intensity and social capital

    A nomogram model to predict the portal vein thrombosis risk after surgery in patients with pancreatic cancer

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    BackgroundPortal vein thrombosis (PVT) is a common postoperative complication in patients with pancreatic cancer (PC), significantly affecting their quality of life and long-term prognosis. Our aim is to establish a new nomogram to predict the risk of PVT after PC surgery.MethodWe collected data from 416 patients who underwent PC surgery at our hospital between January 2011 and June 2022. This includes 87 patients with PVT and 329 patients without PVT. The patients were randomly divided into a training group and a validation group at a ratio of 7:3. We constructed a nomogram model using the outcomes from both univariate and multivariate logistic regression analyses conducted on the training group. The nomogram’s predictive capacity was assessed using calibration curve, receiver operating characteristic (ROC) curve, and decision curve analysis (DCA).ResultsIn the study, the prevalence of PVT was 20.9%. Age, albumin, vein reconstruction and preoperative D-dimer were independent related factors. The model achieved a C-index of 0.810 (95% confidence interval: 0.752–0.867), demonstrating excellent discrimination and calibration performance. The area under the ROC curve of the nomogram was 0.829 (95% CI: 0.750–0.909) in the validation group. DCA confirmed that the nomogram model was clinically useful when the incidence of PVT in patients was 5%–60%.ConclusionWe have established a high-performance nomogram for predicting the risk of PVT in patients undergoing PC surgery. This will assist clinical doctors in identifying individuals at high risk of PVT and taking appropriate preventive measures

    Prognostic and recurrent significance of SII in patients with pancreatic head cancer undergoing pancreaticoduodenectomy

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    BackgroundTo investigate the clinical significance of preoperative inflammatory status in patients with pancreatic head carcinoma (PHC), we performed a single-center study to assess it.MethodWe studied a total of 164 patients with PHC undergoing PD surgery (with or without allogeneic venous replacement) from January 2018 to April 2022. Systemic immune-inflammation index (SII) was the most important peripheral immune index in predicting the prognosis according to XGBoost analysis. The optimal cutoff value of SII for OS was calculated according to Youden index based on the receiver operating characteristic (ROC) curve and the cohort was divided into Low SII group and High SII group. Demographic, clinical data, laboratory data, follow-up data variables were obtained and compared between the two groups. Kaplan-Meier curves, univariable and multivariable Cox regression models were used to determine the association between preoperative inflammation index, nutritional index and TNM staging system with OS and DFS respectively.ResultsThe median follow-up time was 16 months (IQR 23), and 41.4% of recurrences occurred within 1 year. The cutoff value of SII was 563, with a sensitivity of 70.3%, and a specificity of 60.7%. Peripheral immune status was different between the two groups. Patients in High SII group had higher PAR, NLR than those in Low SII group (P <0.01, <0.01, respectively), and lower PNI (P <0.01). Kaplan–Meier analysis showed significantly poorer OS and DFS (P < 0.001, <0.001, respectively) in patients with high SII. By using the multivariable Cox regression model, high SII (HR, 2.056; 95% CI, 1.082–3.905, P=0.028) was significant predictor of OS. Of these 68 high-risk patients who recurrence within one year, patients with widespread metastasis had lower SII and worse prognosis (P <0.01).ConclusionHigh SII was significantly associated with poor prognosis in patients with PHC. However, in patients who recurrence within one year, SII was lower in patients at TNM stage III. Thus, care needs to be taken to differentiate those high-risk patients

    Functional Expression of Spider Neurotoxic Peptide Huwentoxin-I in E. coli

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    The coding sequence of huwentoxin-I, a neurotoxic peptide isolated from the venom of the Chinese spider Ornithoctonus huwena, was amplified by PCR using the cDNA library constructed from the spider venom glands. The cloned fragment was inserted into the expression vector pET-40b and transformed into the E. coli strain BL21 (DE3). The expression of a soluble fusion protein, disulfide interchange protein (DsbC)-huwentoxin-I, was auto-induced in the periplasm of E. coli in the absence of IPTG. After partial purification using a Ni-NTA column, the expressed fusion protein was digested using enterokinase to release heteroexpressed huwentoxin-I and was further purified using RP-HPLC. The resulting peptide was subjected to gel electrophoresis and mass spectrometry analysis. The molecular weight of the heteroexpressed huwentoxin-I was 3750.69, which is identical to that of the natural form of the peptide isolated from spider venom. The physiological properties of the heteroexpressed huwentoxin-I were further analyzed using a whole-cell patch clamp assay. The heteroexpressed huwentoxin-I was able to block currents generated by human Nav1.7 at an IC50 of 640 nmole/L, similar to that of the natural huwentoxin-I, which is 630 nmole/L

    Transcriptional Regulation of PP2A-Aα Is Mediated by Multiple Factors Including AP-2α, CREB, ETS-1, and SP-1

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    Protein phosphatases-2A (PP-2A) is a major serine/threonine phosphatase and accounts for more than 50% serine/threonine phosphatase activity in eukaryotes. The holoenzyme of PP-2A consists of the scaffold A subunit, the catalytic C subunit and the regulatory B subunit. The scaffold subunits, PP2A-Aα/β, provide a platform for both C and B subunits to bind, thus playing a crucial role in providing specific PP-2A activity. Mutation of the two genes encoding PP2A-Aα/β leads to carcinogenesis and likely other human diseases. Regulation of these genes by various factors, both extracellular and intracellular, remains largely unknown. In the present study, we have conducted functional dissection of the promoter of the mouse PP2A-Aα gene. Our results demonstrate that the proximal promoter of the mouse PP2A-Aα gene contains numerous cis-elements for the binding of CREB, ETS-1, AP-2α, SP-1 besides the putative TFIIB binding site (BRE) and the downstream promoter element (DPE). Gel mobility shifting assays revealed that CREB, ETS-1, AP-2α, and SP-1 all bind to PP2A-Aα gene promoter. In vitro mutagenesis and reporter gene activity assays reveal that while SP-1 displays negative regulation, CREB, ETS-1 and AP-2Aα all positively regulate the promoter of the PP2A-Aα gene. ChIP assays further confirm that all the above transcription factors participate the regulation of PP2A-Aα gene promoter. Together, our results reveal that multiple transcription factors regulate the PP2A-Aα gene
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