Songorine inhibits oxidative stress-related inflammation through PI3K/AKT/NRF2 signaling pathway to alleviate lipopolysaccharide-induced septic acute lung injury.

OBJECTIVE: The present study aimed to investigate the protective action and mechanism of songorine on sepsis-induced acute lung injury (ALI). METHODS: The sepsis-induced ALI mouse and cell models were established by lipopolysaccharide (LPS) induction. Lung injury was assayed by hematoxylin and eosin staining, lung injury score, and lung wet-to-dry (W/D) weight ratio. Apoptosis in lung tissues was evaluated by TUNEL assay, and the expression of apoptosis-related markers (Bcl2, Bax, and caspase-3) was measured by western blotting. Levels of pro-inflammatory factors and oxidative stress markers in the bronchoalveolar lavage fluid (BALF) of mice were measured by ELISA and RT-qPCR. The expression of PI3K/AKT/NRF2 pathway-related proteins was analyzed by western blotting. RESULTS: Songorine treatment at 40 mg/kg mitigated sepsis-induced ALI, characterized by improved histopathology, lung injury score, and lung W/D weight ratio (p < 0.05). Moreover, songorine markedly attenuated sepsis-induced apoptosis in lung tissues; this was evidenced by an increase in Bcl2 levels and a decrease in Bax and caspase-3 levels (p < 0.01). Also, songorine reduced levels of proinflammatory cytokines (TNF-α, IL-6, IL-1ß and MPO) and oxidative stress regulators (SOD and GSH) in the BALF of LPS-induced sepsis mice and RAW264.7 cells (p < 0.05). In addition, songorine upregulated the PI3K/AKT/NRF2 pathway-related proteins in LPS-induced sepsis mice and RAW264.7 cells (p < 0.05). Furthermore, LY294002 (a PI3K inhibitor) treatment reversed the protective effect of songorine on sepsis-induced ALI. CONCLUSION: Songorine inhibits oxidative stress-related inflammation in sepsis-induced ALI via the activation of the PI3K/AKT/NRF2 signaling pathway.

Photon-counting-based underwater wireless optical communication employing orbital angular momentum multiplexing.

Underwater wireless optical communication (UWOC) is a critical technology for underwater communication, providing high speed, low latency, and security advantages. However, the strong attenuation in the water channel still limits the UWOC systems and their performances require further improvement. In this study, an orbital angular momentum (OAM) multiplexing UWOC system that uses photon-counting detection is experimentally demonstrated. By employing a single-photon counting module to receive photon signals, we analyze the bit error rate (BER) and photon-counting statistics by building a theoretical model that fits the real system, and demodulate the OAM states in single photon level and implement signal processing using field programmable gate array (FPGA) programming. Based on these modules, a 2-OAM multiplexed UWOC link is established over a water channel of 9 m. By using on-off keying modulation and 2-pulse position modulation, we achieve a BER of 1.26×10-3 with data rate of 20Mbps and 3.17×10-4 with data rate of 10Mbps respectively, which below the forward error correction (FEC) threshold of 3.8×10-3. The total transmission loss is 37 dB under an emission power of 0.5 mW, which is equivalent to the attenuation of 283 m Jerlov I type seawater from the perspective of energy loss. Our verified communication scheme will benefit the development of long-range and high-capacity UWOC.

Underwater wireless optical communication employing polarization multiplexing modulation and photon counting detection.

Wireless optical communication is a crucial direction for improving the data transmission rate in underwater environments. In order to improve the communication performance over the water channel, this paper studies underwater wireless optical communication (UWOC) employing polarization multiplexing modulation and photon counting detection. The improvements in bit error rates and communication capacities are analyzed theoretically by constructing the communication model of polarization multiplexing modulation UWOC based on photon counting. Under specific conditions, the polarization maintenance characteristics of photons over water channels are demonstrated by measuring the Mueller matrix, the fidelity of quantum states, depolarization ratio, and calculating the ratios of ballistic photons. Based on these results, by designing and developing the experimental system of UWOC with the polarization multiplexing modulation and photon counting detection, the data transmission rates of 14.58Mbps and 7.29Mbps are realized over a water channel of 92 m by using polarization on-off keying multiplexing modulation and polarization 2-pulse-position multiplexing modulation, respectively.

Optimizing ghost imaging via analysis and design of speckle patterns.

We study the influence rules of the speckle size of a light source on ghost imaging, and propose a type of speckle pattern to improve the quality of ghost imaging. The results show that image quality will first increase and then decrease with the increase in speckle size, and there is an optimal speckle size for a specific object. At the same time, by using a random distribution of speckle positions, a type of displacement speckle pattern is designed, and the imaging quality is better than that of random speckle patterns. These results are of great significance for finding the best speckle patterns suitable for detecting targets, which further promotes practical applications of ghost imaging.

Practical underwater quantum key distribution based on decoy-state BB84 protocol.

Polarization encoding quantum key distribution has been proven to be a reliable method to build a secure communication system. It has already been used in an inter-city fiber channel and near-Earth atmosphere channel, leaving an underwater channel the last barrier to conquer. Here we demonstrate a decoy-state BB84 quantum key distribution system over a water channel with a compact system design for future experiments in the ocean. In the system, a multiple-intensity modulated laser module is designed to produce the light pulses of quantum states, including signal state, decoy state, and vacuum state. Classical communication and synchronization are realized by wireless optical transmission. Multiple filtering techniques and wavelength division multiplexing are further used to avoid cross talk of different lights. We test the performance of the system and obtain a final key rate of 245.6 bps with an average quantum bit error rate of 1.91% over a 2.4 m water channel, in which the channel attenuation is 16.35 dB. Numerical simulation shows that the system can tolerate up to 21.7 dB total channel loss and can still generate secure keys in 277.9 m Jerlov type I ocean channel.

Myrislignan Induces Redox Imbalance and Activates Autophagy in Toxoplasma gondii.

Toxoplasma gondii (T. gondii) is an important health problem in human and animals, and the highlighting side effects of launched therapeutic chemicals cannot be ignored. Thus, it is urgent to develop new drugs to against the infection. Myrislignan originated from nutmeg exhibited excellent anti-T. gondii activity in vitro and in vivo, and was able to destroy mitochondrial function. However, the exact mechanism of action is still unknown. In this study, combining RNAs deep-sequencing analysis and surface plasmon resonance (SPR) analysis, the differentially expressed genes (DEGs) and high affinity proteins suggested that myrislignan may affect the oxidation-reduction process of T. gondii. Furthermore, the upregulating ROS activity after myrislignan incubation verified that myrislignan destroyed the oxidant-antioxidant homeostasis of tachyzoites. Transmission electron microscopy (TEM) indicated that myrislignan induced the formation of autophagosome-like double-membrane structure. Moreover, monodansyl cadaverine (MDC) staining and western blot further illustrated autophagosome formation. Myrislignan treatment induced a significant reduction in T. gondii by flow cytometry analysis. Together, these findings demonstrated that myrislignan can induce the oxidation-reduction in T. gondii, lead to the autophagy, and cause the death of T. gondii.

The Effects of Pulmonary Physical Therapy on the Patients with Respiratory Failure.

BACKGROUND: We aimed to investigate the application effects of pulmonary physical therapy on the patients with respiratory failure. METHODS: Overall, 132 patients with respiratory failure admitted into the Affiliated Hospital of Medical Collage of Ningbo University from 2013-2017 were enrolled and divided into control group (n=66) and observation group (n=66). Patients in the two groups received conventional physical therapy but those in observation group received pulmonary physical therapy additionally. The ventilation and air-exchanging functions, scores of acute physiology and chronic health evaluation II (APACHE II) and occurrence of complications in patients in the two groups were compared. RESULTS: PaO2, PaCO2, PaO2/FiO2 and estimated FEV2% were greatly improved in patients in the two groups after treatment and those in patients in observation group were better than those in patients in control group; the differences were statistically significant (P=0.014). There were no statistically significant differences in the scores of APACHE II in patients in the two groups before treatment and at 2 days and 3 days after treatment. Scores of APACHE II of patients in observation group were obviously lower than those of other group at 4 days and 7 days after treatment and the differences were statistically significant (P=0.015, 0.029). The total incidence rates of complications in patients in observation group and control group were 7.57% and 39.39%, respectively, and the difference was statistically significant (P=0.021). CONCLUSION: The treatment of respiratory failure patients with pulmonary physical therapy can greatly improve the ventilation and air-exchanging functions, avoid the occurrence of complications and improve the health condition.