Behaviors of laser-induced damage of dye cell windows at low fluences and their mechanism analysis.

In most liquid dye lasers, dye cell windows are the optical components most susceptible to laser damage even at very low fluences. Although various mechanisms and mitigation techniques have been explored, damage still occurs at some point, and some behaviors of the process cannot be effectively explained. In this work, we investigated three special behaviors of dye cell window damage which cannot be explained by ordinary laser-induced damage mechanisms. We proposed that damage to dye cell windows can be caused by a contamination process similar to laser-induced contamination (LIC) on space optics, and used the LIC mechanism to analyze the cause of those damage behaviors. Additional experiments and calculations were conducted, providing more evidence in support of the analysis. In addition, it was found that dye molecules, which are necessary for dye lasers, are the primary contaminants in the LIC process. This explains the inevitable damage to dye cell windows.

Impact of surface ultraviolet radiation intensity on hospital admissions for ischemic and hemorrhagic stroke: A large-scale database study using distributed lag nonlinear analysis, 2015-2022, in Harbin, China.

OBJECTIVES: Our aim is to evaluate the impact of surface ultraviolet radiation intensity on hospital admissions for stroke and to compare the correlation and differences among different subtypes of strokes. MATERIALS AND METHODS: We collected daily data on surface ultraviolet radiation intensity, temperature, air pollution, and hospital admissions for stroke in Harbin from 2015 to 2022. Using a distributed lag non-linear model, we determined the correlation between daily surface ultraviolet radiation intensity and the stroke admission rate. Relative risks (RR) with 95% confidence intervals (CI) and attributable fractions (AF) with 95% CI were calculated based on stroke subtypes, gender, and age groups. RESULTS: A total of 132,952 hospitalized stroke cases (including hemorrhagic and ischemic strokes) were included in the study. We assessed the non-linear effects of ultraviolet intensity on hospitalized patients with ischemic and hemorrhagic strokes. Compared to the maximum morbidity benchmark ultraviolet intensity (19.2 × 10^5 for ischemic stroke and 20.25 for hemorrhagic stroke), over the 0-10 day lag period, the RR for extreme low radiation (1st percentile) was 0.86 (95% CI: 0.77, 0.96), and the RR for extreme high radiation (99th percentile) was 0.86 (95% CI: 0.77, 0.96). In summary, -4.842% (95% CI: -7.721%, -2.167%) and -1.668% (95% CI: -3.061%, -0.33%) of ischemic strokes were attributed to extreme low radiation intensity with a lag of 0 to 10 days and extreme high radiation intensity with a lag of 0 to 5 days, respectively. The reduction in stroke hospitalization rates due to low or high ultraviolet intensity was more pronounced in females and younger individuals compared to males and older individuals. None of the mentioned ultraviolet intensity intensities and lag days had a statistically significant impact on hemorrhagic stroke. CONCLUSIONS: Our study fundamentally suggests that both lower and higher levels of surface ultraviolet radiation intensity in Harbin, China, contribute to a reduced incidence of ischemic stroke, with this effect lasting approximately 10 days. This finding holds significant potential for public health and clinical relevance.

Two-dimensional simulation of near-longitudinally pumped dye laser amplifiers.

Simulations of near-longitudinally pumped dye laser amplifiers are demonstrated in this paper. We developed a two-dimensional model that considers the amplified spontaneous emission (ASE). The influence of the angle between the input beam and pump beam on the extraction efficiency, ASE, and heating process of the amplifiers is investigated. It was found that for the main amplifiers with high pump and input powers, both the extraction efficiency and the ASE are insensitive to variations in the pump angle. However, for preamplifiers with a low input power, the increase in the angle causes a more significant loss in efficiency and a higher ASE generation. For the heating caused by light, the influence of the pump angle is insignificant. The results suggest that near-longitudinal pumping is appropriate for main amplifiers but not for preamplifiers.

Flavonoids and biphenylneolignans with anti-inflammatory activity from the stems of Millettia griffithii.

Five new flavonoids, griffinones A-E (1-5), a new biphenylneolignan, griffilignan A (6) and ten known compounds were isolated from the n-hexane and EtOAc extracts of Millettia griffithii. The structures of the new compounds were determined by 1D and 2D NMR, and by HRMS. The anti-inflammatory activity of the isolated compounds was evaluated on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 cells. Among the isolated compounds, compounds 1, 2 and 14 showed significant anti-inflammatory activity with IC50 values of 20.4, 2.1 and 35.7µM, respectively and no obvious toxicities were observed at 100µM. Western blot and PCR assay further showed that inhibition of nitric oxide production by compound 2 was associated with suppression of iNOS expression. Modeling studies suggested that the amino group, phenyl ring as well as the isopentenyl tails of compound 2 could help bind to iNOs.

[Metabolic stability and metabolic enzyme phaenotypes of lanceolatin B in liver microsomes of different species by UPLC-MS/MS].

To investigate the metabolic stability and parameters in vitro of lanceolatin B in liver microsomes of rats, human, Beagle dogs, and monkeys, and to identify the phaenotypes of CYP enzymes of lanceolatin B by using the liver microsome incubation system in vitro. After incubated with different species of liver microsomes, lanceolatin B was quantified by UPLC-MS/MS method to evaluate its metabolic stability and metabolic kinetic parameters in vitro. Lanceolatin B was incubated with specific inhibitors of CYP450 isoforms (CYP2E1, 2C19, 1A2, 2D6, 2C9, 3A4, and 2A1) to determine the phaenotypes of metabolic enzymes. The results showed that lanceolatin B was metabolized in the liver microsomes of rats and monkeys but not in the human and Beagle dogs. Their in vitro half-life T1/2 and intrinsic clearance rate CLint in rat and monkey liver microsomes were 11.57,8.07 min, and 0.12,0.17 mL•min⁻¹â€¢mg⁻¹ without significant difference. The results of metabolic phenotyping indicated that CYP1A2 was mainly involved in the metabolism of lanceolatin B. There existed a difference in the metabolism of lanceolatin B in different types of liver microsomes. Several of CYP450 isoforms metabolized lanceolatin B together in liver microsomes of rats, in which CYP1A2 was the major enzyme mainly responsible for the metabolism of lanceolatin B.