DFT investigation of the DDQ-catalytic mechanism for constructing C-O bonds.

In this study, we investigated the photo-catalytic mechanisms for the construction of C-O bonds from arenes (benzene, 2',6'-dimethyl-[1,1'-biphenyl]-2-carboxylic acid, or 2,4-dichloro-1-fluorobenzene), catalyzed by 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ). All the structures for the Gibbs free surfaces were calculated at the M06-2X-D3/ma-def2-SVP level in the SMD solvent model. Also, TDDFT calculations of DDQ were performed at the PBE1PBE-D3/ma-def2-SVP level in the SMD solvent model. The computational results indicated that DDQ, serving as a photo-catalyst, would be excited under visible light of 450 nm, aligning well with experimental observations as reflected in the UV-vis spectrum. Gibbs free energy surface analyses of the three reactions suggested that the path involving 3DDQ* activating the reactant (-COOH, H2O, or CH3OH) is favorable. Additionally, the role of O2 was investigated, revealing that it could facilitate the recycling of DDQ by lowering the energy barrier for the conversion of the DDQH˙ radical (not DDQH2) into DDQ. The use of ρhole and ρele can reveal the photo-catalytic reaction and charge transfer processes, while localized orbital locator isosurfaces and electron spin density isosurface graphs were employed to analyze structures and elucidate the single electron distribution. These computational results offer valuable insights into the studied interactions and related processes, shedding light on the mechanisms governing C-O bond formation from arenes catalyzed by DDQ.

Outcomes in pediatric extracorporeal cardiopulmonary resuscitation: A single-center retrospective study from 2007 to 2022 in China.

OBJECTIVE: We aimed to investigate the prognostic factors of pediatric extracorporeal cardiopulmonary resuscitation (ECPR). METHODS: The retrospective study included a total of 77 pediatric cases (7 neonates and 70 children) who underwent ECPR after in-hospital and out-of-hospital cardiac arrest between July 2007 and December 2022. Primary endpoints were complications, while secondary endpoints included all-cause in-hospital mortality. RESULTS: Among the 45 cases experiencing complications, 4 neonates and 41 children had multiple simultaneous complications, primarily neurological issues in 25 cases. Additionally, organ failure occurred in 11 cases, and immunodeficiency was present in two cases. Furthermore, 9 cases experienced bleeding events, and 13 cases showed thrombosis. Patients with complications had lower weight, shorter ECMO durations, and longer CPR durations. Non-survivors had longer CPR durations and shorter durations of ECMO, ICU stay, and mechanical ventilation compared to survivors. Complications were more prevalent in non-survivors, particularly organ failure and bleeding events. CONCLUSION: Weight, CPR duration, and ECMO duration were associated with complications, suggesting areas for treatment optimization. The higher occurrence of complications in non-survivors underscores the importance of early detection and management to improve survival rates. Our findings suggest clinicians consider these factors in prognostic assessments to enhance the effectiveness of ECPR programs.

Synthesis, Characterization, and Antifungal Activity of Benzimidazole-Grafted Chitosan against Aspergillus flavus.

Aspergillus flavus contamination in agriculture and food industries poses threats to human health, leading to a requirement of a safe and effective method to control fungal contamination. Chitosan-based nitrogen-containing derivatives have attracted much attention due to their safety and enhanced antimicrobial applications. Herein, a new benzimidazole-grafted chitosan (BAC) was synthesized by linking the chitosan (CS) with a simple benzimidazole compound, 2-benzimidazolepropionic acid (BA). The characterization of BAC was confirmed by Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance spectroscopy (1H and 13C NMR). Then, the efficiency of BAC against A. flavus ACCC 32656 was investigated in terms of spore germination, mycelial growth, and aflatoxin production. BAC showed a much better antifungal effect than CS and BA. The minimum inhibitory concentration (MIC) value was 1.25 mg/mL for BAC, while the highest solubility of CS (16.0 mg/mL) or BA (4.0 mg/mL) could not completely inhibit the growth of A. flavus. Furthermore, results showed that BAC inhibited spore germination and elongation by affecting ergosterol biosynthesis and the cell membrane integrity, leading to the permeabilization of the plasma membrane and leakage of intracellular content. The production of aflatoxin was also inhibited when treated with BAC. These findings indicate that benzimidazole-derived natural CS has the potential to be used as an ideal antifungal agent for food preservation.

SLPA-Net: A Real-Time Recognition Network for Intelligent Stomata Localization and Phenotypic Analysis.

Plant stomatal phenotype traits play an important role in improving crop water use efficiency, stress resistance and yield. However, at present, the acquisition of phenotype traits mainly relies on manual measurement, which is time-consuming and laborious. In order to obtain high-throughput stomatal phenotype traits, we proposed a real-time recognition network SLPA-Net for stomata localization and phenotypic analysis. After locating and identifying stomatal density data, ellipse fitting is used to automatically obtain phenotype data such as apertures. Aiming at the problems of small stomata and high similarity to background, we introduced ECANet to improve the accuracy of stoma and aperture location. In order to effectively alleviate the unbalance problem in bounding box regression, we replaced the Loss function with a more effective Focal EIoU Loss. The experimental results show that SLPA-Net has excellent performance in the migration generalization and robustness of stomata and apertures detection and identification, as well as the correlation between stomata phenotype data obtained and artificial data.

YMDD motif mutations in chronic hepatitis B antiviral treatment naïve patients: a multi-center study

OBJECTIVE: This study aimed to determine the natural prevalence of variants of tyrosine-methionine-aspartic acid-aspartic acid (YMDD) motif in patients with chronic hepatitis B (CHB), and to explore its relation with demographic and clinical features, hepatitis B virus (HBV) genotypes, and HBV DNA levels. METHODS: A total of 1,042 antiviral treatment naïve CHB patients (including with lamivudine [LAM]) in the past year were recruited from outpatient and inpatient departments of six centers from December 2008 to June 2010. YMDD variants were analyzed using the HBV drug resistance line probe assay (Inno-Lipa HBV-DR). HBV genotypes were detected with polymerase chain reaction (PCR) microcosmic nucleic acid cross-ELISA, and HBV deoxyribonucleic acid (DNA) was quantitated with real-time PCR. All serum samples underwent tests for HBV, HCV, and HDV with ELISA. RESULTS: YMDD variants were detected in 23.3% (243/1042) of CHB patients. YMDD mutation was accompanied by L180M mutation in 154 (76.9%) patients. Both wild-type HBV and YMDD variant HBV were present in 231 of 243 patients. Interestingly, 12 patients had only YIDD and/or YVDD variants without wild YMDD motif. In addition, 27.2% (98/359) of HbeAg-positive patients had YMDD mutations, which was higher than that in HbeAg-negative patients (21.2%, 145/683). The incidence of YMDD varied among patients with different HBV genotypes, but the difference was not significant. Moreover, the incidence of YMDD in patients with high HBV DNA level was significantly higher than that in those with low HBV DNA level. CONCLUSION: Mutation of YMDD motif was detectable at a high rate in CHB patients in this study. The incidence of YMDD may be correlated with HBeAg and HBV DNA level.