24 research outputs found
Estimating Direction of Arrival by Using Two-Dimensional State-Space Balance Method
A study of a two-dimensional state-space balance (2D SSB) method for estimating direction of arrival (DOA) for uniform rectangular array (URA) is presented in this letter. The comprehensive utilization of controllability and observability matrices and automatic pairing technique are considered in this method by using the single snapshot. Therefore, the DOAs of elevation angle and azimuth angle can pair automatically and acquire better estimation performance compared with 2D matrix pencil method or unitary matrix pencil method. In addition, the proposed method can handle correlated signals directly without preprocessing. Simulation is conducted to verify the effectiveness of the proposed method
Insight on the heterogeneously activated H2O2 with goethite under visible light for cefradine degradation: pH dependence and photoassisted effect
The iron mineral-catalyzed degradation of cephalosporin antibiotics with H2O2 occurs ubiquitously in nature. Despite numerous studies, the effects of environmental conditions on reactive species production and degradation processes of cephalosporins remain unclear. Here, we report the iron mineral of goethite as the efficient and heterogenous catalyst for the degradation of cefradine (CRD) via H2O2 activation under different conditions involving pH and visible light irradiation. Results show that the CRD removal rate is highly dependent on pH and visible light irradiation. Interestingly, when the pH ranges from 4.0 to 7.0, the degradation intermediates of CRD under dark are the same as under visible light conditions in the goethite/H2O2 system. And, the ratio of CRD degradation rate constant (kLight/kDark) reaches a maximum at pH 5.0, suggesting that CRD existing as zwitterion species is preferable for its removal with photoassistance. The mechanism investigation reveals that both •OH and ≡[FeIVO]2+ oxidants are generated during the reaction process, and •OH is the major oxidant at acidic pH, while ≡[FeIVO]2+ is more likely to be formed with photoassistance at near-neutral pH. According to UPLC–MS/MS analysis, CRD degradation likely happens via hydrogen atom abstraction from cyclohexadienyl by •OH, thioether and olefin oxidation by ≡[FeIVO]2+, and FeIII-catalyzed hydrolytic cleavage of β-lactam ring. These findings highlight the vital roles of pH and photoassistance in the heterogeneously activated H2O2 with goethite for CRD degradation.</p
CALCULATION OF CATALYTIC REACTIVITY FOR PREPARING DICHLORODIMETHYLSILANE UTILIZING PRE- AND POST-MODIFIED 24T AlCl3/ZSM-5
Dichlorodimethylsilane is the most important raw material for the preparation of organic silicon materials. Currently, the preparation of dichlorodimethylsilane is mainly based on disproportionation method. This method can turn wastes (by-products) into treasures but the mechanism is still indeterminate. In this study, MP2/6-311++G (3df, 2pd) basis set was used to study the mechanism of the disproportionation for producing dichlorodimethylsilane. Dichlorodimethylsilane is catalyzed by 24T cluster AlCl3/ZSM-5 catalyst and modified by (AlCl2)+, and (BCl2)+. The calculation results show that the rate-determining step is the reaction of the catalyst with trimethylchlorosilane . The activation energy of the rate-determining step of main reaction is: 393.83, 427.73, and 527.61 kJ mol-1, respectively. The structure analysis, activation energy analysis and LOL analysis for different catalysts all show that the catalytic effect of unmodified AlCl3/ZSM-5 is better
Trajectory Optimization for Multitarget Tracking Using Joint Probabilistic Data Association Filter
Impact of CYP2A6 gene polymorphism on the pharmacokinetics of dexmedetomidine for premedication
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Phototherapy with Cancer-Specific Nanoporphyrin Potentiates Immunotherapy in Bladder Cancer.
PurposeImmune checkpoint inhibitors (ICI) in general have shown poor efficacy in bladder cancer. The purpose of this project was to determine whether photodynamic therapy (PDT) with bladder cancer-specific porphyrin-based PLZ4-nanoparticles (PNP) potentiated ICI.Experimental designSV40 T/Ras double-transgenic mice bearing spontaneous bladder cancer and C57BL/6 mice carrying syngeneic bladder cancer models were used to determine the efficacy and conduct molecular correlative studies.ResultsPDT with PNP generated reactive oxygen species, and induced protein carbonylation and dendritic cell maturation. In SV40 T/Ras double-transgenic mice carrying spontaneous bladder cancer, the median survival was 33.7 days in the control, compared with 44.8 (P = 0.0123), 52.6 (P = 0.0054), and over 75 (P = 0.0001) days in the anti-programmed cell death-1 antibody (anti-PD-1), PNP PDT, and combination groups, respectively. At Day 75 when all mice in other groups died, only 1 in 7 mice in the combination group died. For the direct anti-tumor activity, compared with the control, the anti-PD-1, PNP PDT, and combination groups induced a 40.25% (P = 0.0003), 80.72% (P < 0.0001), and 93.03% (P < 0.0001) tumor reduction, respectively. For the abscopal anticancer immunity, the anti-PD-1, PNP PDT, and combination groups induced tumor reduction of 45.73% (P = 0.0001), 54.92% (P < 0.0001), and 75.96% (P < 0.0001), respectively. The combination treatment also diminished spontaneous and induced lung metastasis. Potential of immunotherapy by PNP PDT is multifactorial.ConclusionsIn addition to its potential for photodynamic diagnosis and therapy, PNP PDT can synergize immunotherapy in treating locally advanced and metastatic bladder cancer. Clinical trials are warranted to determine the efficacy and toxicity of this combination
Flavonoid biosynthesis controls fiber color in naturally colored cotton
The existence of only natural brown and green cotton fibers (BCF and GCF, respectively), as well as poor fiber quality, limits the use of naturally colored cotton (Gossypium hirsutum L.). A better understanding of fiber pigment regulation is needed to surmount these obstacles. In this work, transcriptome analysis and quantitative reverse transcription PCR revealed that 13 and 9 phenylpropanoid (metabolic) pathway genes were enriched during pigment synthesis, while the differential expression of phenylpropanoid (metabolic) and flavonoid metabolic pathway genes occurred among BCF, GCF, and white cotton fibers (WCF). Silencing the chalcone flavanone isomerase gene in a BCF line resulted in three fiber phenotypes among offspring of the RNAi lines: BCF, almost WCF, and GCF. The lines with almost WCF suppressed chalcone flavanone isomerase, while the lines with GCF highly expressed the glucosyl transferase (3GT) gene. Overexpression of the Gh3GT or Arabidopsis thaliana 3GT gene in BCF lines resulted in GCF. Additionally, the phenylpropanoid and flavonoid metabolites of BCF and GCF were significantly higher than those of WCF as assessed by a metabolomics analysis. Thus, the flavonoid biosynthetic pathway controls both brown and green pigmentation processes. Like natural colored fibers, the transgenic colored fibers were weaker and shorter than WCF. This study shows the potential of flavonoid pathway modifications to alter cotton fibers’ color and quality