Streptococcus suis prophage lysin as a new strategy for combating streptococci-induced mastitis and Streptococcus suis infection.

OBJECTIVES: The genus Streptococcus contains species of important zoonotic pathogens such as those that cause bovine mastitis. Unfortunately, many Streptococcus species have developed antibiotic resistance. Phage lysins are considered promising alternatives to antibiotics because it is difficult for bacteria to develop lysin resistance. However, there remains a lack of phage lysin resources for the treatment of streptococci-induced mastitis. METHODS: We identified the prophage lysin Lys0859 from the genome of the Streptococcus suis SS0859 strain. Lys0859 was subsequently characterized to determine its host range, MIC, bactericidal activity in milk, and ability to clear biofilms in vitro. Finally, to determine the effects of Lys0859 on the treatment of both bovine mastitis and S. suis infection in vivo, we established models of Streptococcus agalactiae ATCC 13813-induced mastitis and S. suis serotype 2 SC19 systemic infection. RESULTS: Our results demonstrate that Lys0859 possesses broad-spectrum lytic activity against Streptococcus and Staphylococcus species isolated from animals with bovine mastitis and 15 serotypes of S. suis isolated from swine. Intramammary and intramuscular injection of Lys0859 reduced the number of bacteria in mammary tissue by 3.75 and 1.45 logs compared with the PBS group, respectively. Furthermore, 100 µg/mouse of Lys0859 administered intraperitoneally at 1 h post-infection protected 83.3% (5/6) of mice from a lethal dose of S. suis infection. CONCLUSIONS: Overall, our results enhance the understanding and development of new strategies to combat both streptococci-induced mastitis and S. suis infection.

[Research on the Distribution of Broad-Band Correlated Photon Spectra and the Measurement of Time-Correlation].

The correlated photon technique makes it possible to achieve a radiation calibration processing without chain transferring. The study of the spectral radiation character and time correlation of the photon is of great significance for broad-band radiometric calibration. To absolutely calibrate quantum efficiency of photoelectric detector, it is necessary to extend calibration band from single band to more bands. According to the phase-matching condition of the spontaneous parametric down-conversion, non-collinear angle formula of correlated photon in the crystal is derived. The distribution of the photon spectrum is simulated. Meanwhile, the phase-matching angle of the crystal is optimized. The photon generated by the spontaneous parameters down-conversion has a broad spectral distribution and the correlated photon wavelength is corresponding to its emission angle. Based on the result of the simulation, the experimental measurement system of the spectral distribution and time-correlation of the correlated photon is established. The spectral distribution, the time-correlation and the polarization properties of the four pair photon were measured by using this system. The experimental results show that, (1) the spectral distribution of the measurements is 633~808 nm, where the maximum spectral distribution measurement bias is 1.51 mm. The experiment result is highly consistent with theoretical ones; (2) the correlation time of four pairs correlated photon is measured, during which "three coincidence-peaks" is observed and the minimum correlation time was 0.32 ns; (3) single photon count rate along with coincidence count rate of correlated photon vary with the polarization direction of the pump as sine function. The experimental result is shown that the correlated photon pairs are ranging from the visible to near infrared band distribution, and that the spectrum has time-correlation and polarization characteristic. The research result is firstly reported at home and abroad, and the results are promising for the application of the photoelectric detector in the multi-band radiometric calibration.

Target-based deep learning network surveillance of non-contrast computed tomography for small infarct core of acute ischemic stroke.

Purpose: Rapid diagnosis of acute ischemic stroke (AIS) is critical to achieve positive outcomes and prognosis. This study aimed to construct a model to automatically identify the infarct core based on non-contrast-enhanced CT images, especially for small infarcts. Methods: The baseline CT scans of AIS patients, who had DWI scans obtained within less than 2 h apart, were included in this retrospective study. A modified Target-based deep learning model of YOLOv5 was developed to detect infarctions on CT. Randomly selected CT images were used for testing and evaluated by neuroradiologists and the model, using the DWI as a reference standard. Intraclass correlation coefficient (ICC) and weighted kappa were calculated to assess the agreement. The paired chi-square test was used to compare the diagnostic efficacy of physician groups and automated models in subregions. p < 0.05 was considered statistically significant. Results: Five hundred and eighty four AIS patients were enrolled in total, finally 275 cases were eligible. Modified YOLOv5 perform better with increased precision (0.82), recall (0.81) and mean average precision (0.79) than original YOLOv5. Model showed higher consistency to the DWI-ASPECTS scores (ICC = 0.669, κ = 0.447) than neuroradiologists (ICC = 0.452, κ = 0.247). The sensitivity (75.86% vs. 63.79%), specificity (98.87% vs. 95.02%), and accuracy (96.20% vs. 91.40%) were better than neuroradiologists. Automatic model had better diagnostic efficacy than physician diagnosis in the M6 region (p = 0.039). Conclusion: The deep learning model was able to detect small infarct core on CT images more accurately. It provided the infarct portion and extent, which is valuable in assessing the severity of disease and guiding treatment procedures.

Effectiveness and safety of brucea javanica oil assisted TACE versus TACE in the treatment of liver cancer: a systematic review and meta-analysis of randomized controlled trials.

Background: The effectiveness and safety of using Brucea javanica oil (BJO) in combination with Transarterial Chemoembolization (TACE) for liver cancer treatment are subjects of debate. This study aims to assess the comparative effectiveness and safety of BJO-assisted TACE versus TACE alone and quantifies the differences between these two treatment methods. Methods: A systematic search was conducted in multiple databases including PubMed, Cochrane, CNKI, and Wanfang, until 1 July 2023. Meta-analysis was conducted, and the results were presented as mean difference (MD), risk ratio (RR), and 95% confidence intervals (CI). Results: The search yielded 11 RCTs, with a combined sample size of 1054 patients. Meta-analysis revealed that BJO-assisted TACE exhibited superior outcomes compared to standalone TACE. Specific data revealed that BJO-assisted TACE improves clinical benefit rate by 22% [RR = 1.22, 95% CI (1.15, 1.30)], increases the number of people with improved quality of life by 32%, resulting in an average score improvement of 9.53 points [RR = 1.32, 95% CI (1.22, 1.43); MD = 9.53, 95% CI (6.95, 12.10)]. Furthermore, AFP improvement rate improved significantly by approximately 134% [RR = 2.34, 95% CI (1.58, 3.46)], accompanied by notable improvements in liver function indicators, with an average reduction of 27.19 U/L in AST [MD = -27.19, 95% CI (-40.36, -14.02)], 20.77 U/L in ALT [MD = -20.77, 95% CI (-39.46, -2.08)], 12.17 µmol/L in TBIL [MD = -12.17, 95% CI (-19.38, -4.97)], and a decrease of 43.72 pg/mL in VEGF [MD = -43.72, 95% CI (-63.29, -24.15)]. Most importantly, there was a 29% reduction in the occurrence of adverse reactions [RR = 0.71, 95% CI (0.60, 0.84)]. Conclusion: These findings indicate that BJO-assisted TACE may be considered as a potentially beneficial treatment option for liver cancer patients when compared to standalone TACE. It appears to contribute to improved treatment outcomes, enhanced quality of life, and potentially reduced adverse reactions, suggesting it warrants further investigation as a promising approach for liver cancer treatment. Systematic Review Registration: identifier CRD42023428948.

Spectroscopic evidence for a large spot on the dimming Betelgeuse.

During October 2019 and March 2020, the luminous red supergiant Betelgeuse demonstrated an unusually deep minimum of its brightness. It became fainter by more than one magnitude and this is the most significant dimming observed in the recent decades. While the reason for the dimming is debated, pre-phase of supernova explosion, obscuring dust, or changes in the photosphere of the star were suggested scenarios. Here, we present spectroscopic studies of Betelgeuse using high-resolution and high signal-to-noise ratio near-infrared spectra obtained at Weihai Observatory on four epochs in 2020 covering the phases of during and after dimming. We show that the dimming episode is caused by the dropping of its effective temperature by at least 170 K on 2020 January 31, that can be attributed to the emergence of a large dark spot on the surface of the star.