104 research outputs found

    Active Disturbance Rejection Control of Thermal Power Unit Coordinated System based on Frequency Domain Analysis

    Get PDF
    For the multi-input and multi-output, strong-coupling nonlinear features of coordinated system for thermal power unit, it is difficult for traditional PID coordinated control scheme to meet the power grid demand which often participates in peak regulation and frequency modulation. In this paper, Inverse Nyquist array is employed to carry out frequency domain analysis of the plant model. Then Pseudo diagonalization is used to design the static decoupling compensation matrix of the system. Above on these, the linear active disturbance rejection controller of every channel in coordinated system can be designed repectively. Dynamic coupling and system unknown parts are observed by extended state observer of ADRC and is compensated to the system in time. The simulation tests show that the disturbance rejection results of the load and the main steam pressure for the coordinated control system under LADRC is better than that of PID control

    Zn⁺-O⁻ dual-spin surface states formation by modification of ZnO nanoparticles with diboron compounds

    Get PDF
    ZnO semiconductor oxides are versatile functional materials that are used in photoelectronics, catalysis, sensing, etc. The Zn⁺–O⁻ surface electronic states of semiconductor oxides were formed on the ZnO surface by Zn 4s and O 2p orbital coupling with the diboron compound’s B 2p orbitals. The formation of spin-coupled surface states was based on the spin–orbit interaction on the interface, which has not been reported before. This shows that the semiconductor oxide’s spin surface states can be modulated by regulating surface orbital energy. The Zn⁺–O⁻ surface electronic states were confirmed by electron spin resonance results, which may help in expanding the fundamental research on spintronics modulation and quantum transport

    Enhancing Vibrio vulnificus infection diagnosis for negative culture patients with metagenomic next-generation sequencing

    Get PDF
    ObjectiveTo evaluate the diagnostic value of metagenomic next-generation sequencing (mNGS) in Vibrio vulnificus (V. vulnificus) infection.MethodsA retrospective analysis of patients with V. vulnificus infection at the Fifth Affiliated Hospital of Sun Yat-Sen University from January 1, 2020 to April 23, 2023 was conducted. 14 enrolled patients were diagnosed by culture or mNGS. The corresponding medical records were reviewed, and the clinical data analyzed included demographics, epidemiology laboratory findings, physical examination, symptoms at presentation, antibiotic and surgical treatment, and outcome.ResultsIn this study, 78.6% (11/14) patients had a history of marine trauma (including fish stab, shrimp stab, crab splints and fish hook wounds), 7.1% (1/14) had eaten seafood, and the remaining 14.3% (2/14) had no definite cause. Isolation of V. vulnificus from clinical samples including blood, tissue, fester and secreta. 9 cases were positive for culture, 5 cases were detected synchronously by mNGS and got positive for V. vulnificus. 85.7% (12/14) cases accepted surgical treatment, with 1 patient suffering finger amputated. 14 enrolled patients received appropriate antibiotic therapy, and all of them had recovered and discharged. 9 strains V. vulnificus isolated in this study were sensitive to most beta-lactam antibiotics, aminoglycosides, quinolones, etc.ConclusionVibrio vulnificus infection is a common water-exposed disease in Zhuhai, which requires identification of a number of pathogens. Of severe infections with unknown pathogen, mNGS can be used simultaneously, and the potential to detect multiple pathogens is of great help in guiding treatment

    Modification of TiO_2 Nanoparticles with Organodiboron Molecules Inducing Stable Surface Ti^(3+) Complex

    Get PDF
    As one of the most promising semiconductor oxide materials, titanium dioxide (TiO_2) absorbs ultraviolet (UV) light but not visible light. To address this limitation, the introduction of Ti^(3+) defects represents a common strategy to render TiO_2 visible-light-responsive. Unfortunately, current hurdles in Ti^(3+) generation technologies impeded the widespread application of Ti^(3+) modified materials. Herein, we demonstrate a simple and mechanistically distinct approach to generating abundant surface-Ti^(3+) sites without leaving behind oxygen vacancy and sacrificing one-off electron donors. In particular, upon adsorption of organodiboron reagents onto TiO_2 nanoparticles, spontaneous electron injection from the dibron-bound O^(2-) site to adjacent Ti^(4+) site leads to an extremely stable blue surface Ti^(3+)β€’O^(-β€’) complex. Notably, this defect generation protocol is also applicable to other semiconductor oxides including ZnO, SnO_2, Nb_2O_5 and In_2O_3. Furthermore, the as-prepared photoelectronic device using this strategy affords 10^3 fold higher visible light response, and the fabricated perovskite solar cell shows an enhanced performance

    The incidence of liver injury in Uyghur patients treated for TB in Xinjiang Uyghur autonomous region, China, and its association with hepatic enzyme polymorphisms nat2, cyp2e1, gstm1 and gstt1.

    Get PDF
    BACKGROUND AND OBJECTIVE: Of three first-line anti-tuberculosis (anti-TB) drugs, isoniazid is most commonly associated with hepatotoxicity. Differences in INH-induced toxicity have been attributed to genetic variability at several loci, NAT2, CYP2E1, GSTM1and GSTT1, that code for drug-metabolizing enzymes. This study evaluated whether the polymorphisms in these enzymes were associated with an increased risk of anti-TB drug-induced hepatitis in patients and could potentially be used to identify patients at risk of liver injury. METHODS AND DESIGN: In a cross-sectional study, 2244 tuberculosis patients were assessed two months after the start of treatment. Anti-TB drug-induced liver injury (ATLI) was defined as an ALT, AST or bilirubin value more than twice the upper limit of normal. NAT2, CYP2E1, GSTM1 and GSTT1 genotypes were determined using the PCR/ligase detection reaction assays. RESULTS: 2244 patients were evaluated, there were 89 cases of ATLI, a prevalence of 4% 9 patients (0.4%) had ALT levels more than 5 times the upper limit of normal. The prevalence of ATLI was greater among men than women, and there was a weak association with NAT2*5 genotypes, with ATLI more common among patients with the NAT2*5*CT genotype. The sensitivity of the CT genotype for identifying patients with ATLI was 42% and the positive predictive value 5.9%. CT ATLI was more common among slow acetylators (prevalence ratio 2.0 (95% CI 0.95,4.20) )compared to rapid acetylators. There was no evidence that ATLI was associated with CYP2E1 RsaIc1/c1genotype, CYP2E1 RsaIc1/c2 or c2/c2 genotypes, or GSTM1/GSTT1 null genotypes. CONCLUSIONS: In Xinjiang Uyghur TB patients, liver injury was associated with the genetic variant NAT2*5, however the genetic markers studied are unlikely to be useful for screening patients due to the low sensitivity and low positive predictive values for identifying persons at risk of liver injury

    A COVID-19 Risk Score Combining Chest CT Radiomics and Clinical Characteristics to Differentiate COVID-19 Pneumonia From Other Viral Pneumonias

    Get PDF
    With the continued transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) throughout the world, identification of highly suspected COVID-19 patients remains an urgent priority. In this study, we developed and validated COVID-19 risk scores to identify patients with COVID-19. In this study, for patient-wise analysis, three signatures, including the risk score using radiomic features only, the risk score using clinical factors only, and the risk score combining radiomic features and clinical variables, show an excellent performance in differentiating COVID-19 from other viral-induced pneumonias in the validation set. For lesion-wise analysis, the risk score using three radiomic features only also achieved an excellent AUC value. In contrast, the performance of 130 radiologists based on the chest CT images alone without the clinical characteristics included was moderate as compared to the risk scores developed. The risk scores depicting the correlation of CT radiomics and clinical factors with COVID-19 could be used to accurately identify patients with COVID-19, which would have clinically translatable diagnostic and therapeutic implications from a precision medicine perspective

    EBV-Encoded LMP1 Upregulates IgΞΊ 3β€²Enhancer Activity and IgΞΊ Expression in Nasopharyngeal Cancer Cells by Activating the Ets-1 through ERKs Signaling

    Get PDF
    Accumulating evidence indicates that epithelial cancer cells, including nasopharyngeal carcinoma (NPC) cells, express immunoglobulins (Igs). We previously found that the expression of the kappa light chain protein in NPC cells can be upregulated by the EBV-encoded latent membrane protein 1 (LMP1). In the present study, we used NPC cell lines as models and found that LMP1-augmented kappa production corresponds with elevations in ERKs phosphorylation. PD98059 attenuates LMP1-induced ERKs phosphorylation resulting in decreased expression of the kappa light chain. ERK-specific small interfering RNA blunts LMP1-induced kappa light chain gene expression. Luciferase reporter assays demonstrate that immunoglobulin ΞΊ 3β€² enhancer (3β€²EΞΊ) is active in IgΞΊ-expressing NPC cells and LMP1 upregulates the activity of 3β€²EΞΊ in NPC cells. Moreover, mutation analysis of the PU binding site in 3β€²EΞΊ and inhibition of the MEK/ERKs pathway by PD98059 indicate that the PU site is functional and LMP1-enhanced 3β€²EΞΊ activity is partly regulated by this site. PD98059 treatment also leads to a concentration-dependent inhibition of LMP1-induced Ets-1 expression and phosphorylation, which corresponds with a dose-dependent attenuation of LMP1-induced ERK phosphorylation and kappa light chain expression. Suppression of endogenous Ets-1 by small interfering RNA is accompanied by a decrease of Ig kappa light chain expression. Gel shift assays using nuclear extracts of NPC cells indicate that the transcription factor Ets-1 is recruited by LMP1 to the PU motif within 3β€²EΞΊ in vitro. ChIP assays further demonstrate Ets-1 binding to the PU motif of 3β€²EΞΊ in cells. These results suggest that LMP1 upregulates 3β€²EΞΊ activity and kappa gene expression by activating the Ets-1 transcription factor through the ERKs signaling pathway. Our studies provide evidence for a novel regulatory mechanism of kappa expression, by which virus-encoded proteins activate the kappa 3β€² enhancer through activating transcription factors in non-B epithelial cancer cells
    • …
    corecore