Identification and Functional Analysis of Lysine 2-Hydroxyisobutyrylation in Cyanobacteria.

Cyanobacteria are the oldest prokaryotic photoautotrophic microorganisms and have evolved complicated post-translational modification (PTM) machinery to respond to environmental stress. Lysine 2-hydroxyisobutyrylation (Khib) is a newly identified PTM that is reported to play important roles in diverse biological processes, however, its distribution and function in cyanobacteria have not been reported. Here, we performed the first systematic studies of Khib in a model cyanobacterium Synechococcus sp. strain PCC 7002 (Syn7002) using peptide prefractionation, pan-Khib antibody enrichment, and high-accuracy mass spectrometry (MS) analysis. A total of 1875 high-confidence Khib sites on 618 proteins were identified, and a large proportion of Khib sites are present on proteins in the cellular metabolism, protein synthesis, and photosynthesis pathways. Using site-directed mutagenesis and functional studies, we showed that Khib of glutaredoxin (Grx) affects the efficiency of the PS II reaction center and H2O2 resistance in Syn7002. Together, this study provides novel insights into the functions of Khib in cyanobacteria and suggests that reversible Khib may influence the stress response and photosynthesis in both cyanobacteria and plants.

The relationship between psychological capital, patient's contempt, and professional identity among general practitioners during COVID-19 in Chongqing, China.

General practitioners are crucial in the primary healthcare system as well as for epidemic prevention and control. However, few researchers have examined their professional identity. This study investigated the current status of the professional identity of general practitioners in Chongqing, China and explored the effects of psychological capital and patient's contempt on their professional identity. From December 2021 to January 2022, randomized cluster sampling was used to conduct a cross-sectional online self-assessment questionnaire survey among general practitioners in Chongqing. In total, 2,180 general practitioners working for more than one year were selected. General practitioners' sense of professional identity, mental health, and sense of patients' disrespect were measured using the Professional Identity Scale, Psychological Capital Questionnaire, and Patient's Contempt Questionnaire. Sociodemographic characteristics were also collected. A multiple linear regression model was used to analyze the association between professional identity, psychological capital, and patient's contempt. The average score for professional identity among general practitioners was 53.59 (SD = 6.42). The scores for self-efficacy, hope, resilience, and optimism (subscales of psychological capital) were 26.87 (SD = 5.70), 26.47 (SD = 5.74), 26.97 (SD = 5.55), and 26.86 (SD = 5.59), respectively. The score for perceived contempt was 34.19 (SD = 7.59). An average monthly income greater than CNY 8,000 (ß = 1.018, p < 0.001), work tenure of more than 15 years (ß = 0.440, p = 0.001), hope (ß = 0.249, p < 0.001) and a higher optimism score (ß = 0.333, p < 0.001) were positively correlated with professional identity. Having a bachelor's degree and above (ß = -0.720, p = 0.014), an administrative role (ß = -1.456, p < 0.001), self-efficacy (ß = -0.122, p < 0.001), and higher patient's contempt (ß = -0.103, p < 0.001) were negatively associated with professional identity. General practitioners in Chongqing demonstrated high professional identity and a strong psychological status during the COVID-19 pandemic. Psychological capital and patient's contempt were associated with professional identity. To improve general practitioners' professional identity, stakeholders should promote practitioners' mental health and physician-patient relationships in China.

The use of 5-fluorouracil-loaded nanobubbles combined with low-frequency ultrasound to treat hepatocellular carcinoma in nude mice.

OBJECTIVE: This study aimed to investigate the therapeutic effects of 5-fluorouracil (5-FU)-loaded nanobubbles irradiated with low-intensity, low-frequency ultrasound in nude mice with hepatocellular carcinoma (HCC). METHODS: A transplanted tumor model of HCC in nude mice was established in 40 mice, which were then randomly divided equally into four groups: group A (saline), group B (5-FU-loaded nanobubbles), group C (5-FU-loaded nanobubbles with non-low-frequency ultrasound), and group D (5-FU-loaded nanobubbles with low-frequency ultrasound). The tumor size in each mouse was observed via ultrasound before and after the treatments. Inhibition of the tumor growth in each group was compared, and survival curves were generated. Tumor tissues were removed to determine the apoptotic index using the TUNEL method and quantitative analysis. Tumor tissues with CD34-positive microvessels were observed by immunohistochemistry, and the tumor microvessel densities were calculated. RESULTS: The growth rate of the tumor volumes in group D was significantly slower than that in the other groups, while the tumor inhibition rates and apoptotic index in group D were significantly higher than those of the other groups. The number of microvessels staining positive for CD34 was decreased in group D. Therefore, group D presented the most significant inhibitory effects. CONCLUSIONS: Therefore, 5-FU-loaded nanobubbles subjected to irradiation with low-frequency ultrasound could further improve drug targeting and effectively inhibit the growth of transplanted tumors, which is expected to become an ideal drug carrier and targeted drug delivery system for the treatment of HCC in the future.

Novel Visual Nasogastric Tube Insertion System: A Feasibility and Efficiency Study in a Manikin.

Background. Conventional nasogastric tube placement is an essential clinical procedure; however, complications may arise from blind manipulation. We tested the feasibility and efficiency of a visual nasogastric tube insertion system (VNGS) using a manikin. Methods. A microimaging fiber (0.8 mm) was integrated into the nasogastric tube to create the VNGS. Twenty inexperienced physicians were enrolled and assigned to the visual or conventional group. Each physician performed 10 repeated nasogastric tube insertions with visual guidance or the conventional method; another 20 inexperienced medical students received nasogastric tube insertion training using visual guidance or the conventional method. Results. The nasogastric tube successfully reached the stomach and the narrow anatomic structures were visualized with the VNGS. Time required for insertion was significantly shorter in the visual group compared to the conventional group (22.56 ± 3.08 versus 37.30 ± 4.12 seconds, P < 0.001). Tube misplacement was observed in 19/100 cases (19%) in the conventional group; no misplacement was observed in the visual group. Less mucosal damage was noted in the visual group (3.43 ± 1.63 versus 9.86 ± 2.31 cm2). Medical students performed better NGT insertions (shorter insertion time and less procedure-related complications) after undergoing the visual guidance training. Conclusions. The VNGS may provide a new technique for nasogastric tube insertion applicable to clinical use or simulation training.