Molecular analyses of exosome-derived miRNAs revealed reduced expression of miR-184-3p and decreased exosome concentration in patients with alveolar echinococcosis.

Both E. multilocularis and host-derived exosomes are involved in the pathogenic process of alveolar echinococcosis (AE). Exosomes secrete miRNAs that have regulatory roles in host-pathogen interactions in multiple ways. In the present study, we collected and purified supernatants of E. multilocularis cultures, as well as human plasma exosomes. High-throughput sequencing showed the identities of 45 exosomal miRNAs in E. multilocularis. The lengths of these miRNAs ranged from 19 to 25 nucleotides (nt), with the majority (n = 18) measuring 22 nt. Notably, emu-let-7-5p emerged as the most abundant among these miRNAs, with a detected count of 33,097 and also length of 22 nt. Nanoparticle tracking analysis (NTA) showed that the concentration of exosomes in the plasma of AE patients was lower compared to that in the healthy individuals. This result suggested that the concentration of plasma exosomes was able to distinguish AE patients from healthy individuals. Using qRT-PCR to assess the relative expression of 10 miRNAs of E. multilocularis, we showed that the expression of miR-184-3p was downregulated significantly in the exosomes of plasma from AE patients compared to that in the control group. In summary, this study indicates that AE induces a reduction in the concentration of human plasma exosomes, as well as downregulating miR-184-3p in infected individuals.

Study on the Compositional Analysis, Extraction Process, and Hemostatic and Anti-Inflammatory Activities of Cirsium japonicum Fisch. ex DC.-Cirsium setosum (Willd.) MB Extracts.

Cirsium japonicum Fisch. ex DC. (CF) and Cirsium setosum (Willd.) MB (CS) are commonly used clinically to stop bleeding and eliminate carbuncles. Still, CF is mainly used for treating inflammation, while CS favors hemostasis. Therefore, the present study used UHPLC-MS to analyze the main chemical constituents in CF-CS extract. We optimized the extraction process using single-factor experiments and response surface methodology. Afterward, the hemostatic and anti-inflammatory effects of CF-CS extract were investigated by determining the clotting time in vitro, the bleeding time of rabbit trauma, and the induction of rabbit inflammation using xylene and lipopolysaccharide. The study of hemostatic and anti-inflammatory effects showed that the CF-CS, CF, and CS extract groups could significantly shorten the coagulation time and bleeding time of rabbits compared with the blank group (p < 0.01); compared with the model group, it could dramatically inhibit xylene-induced ear swelling in rabbits and the content of TNF-α, IL-6, and IL-1ß in the serum of rabbits (p < 0.01). The results showed that combined CF and CS synergistically increased efficacy. CF-CS solved the problem of the single hemostatic and anti-inflammatory efficacy of a single drug, which provided a new idea for the research and development of natural hemostatic and anti-inflammatory medicines.

Deciphering the molecular and cellular atlas of immune cells in septic patients with different bacterial infections.

BACKGROUND: Sepsis is a life-threatening organ dysfunction caused by abnormal immune responses to various, predominantly bacterial, infections. Different bacterial infections lead to substantial variation in disease manifestation and therapeutic strategies. However, the underlying cellular heterogeneity and mechanisms involved remain poorly understood. METHODS: Multiple bulk transcriptome datasets from septic patients with 12 types of bacterial infections were integrated to identify signature genes for each infection. Signature genes were mapped onto an integrated large single-cell RNA (scRNA) dataset from septic patients, to identify subsets of cells associated with different sepsis types, and multiple omics datasets were combined to reveal the underlying molecular mechanisms. In addition, an scRNA dataset and spatial transcriptome data were used to identify signaling pathways in sepsis-related cells. Finally, molecular screening, optimization, and de novo design were conducted to identify potential targeted drugs and compounds. RESULTS: We elucidated the cellular heterogeneity among septic patients with different bacterial infections. In Escherichia coli (E. coli) sepsis, 19 signature genes involved in epigenetic regulation and metabolism were identified, of which DRAM1 was demonstrated to promote autophagy and glycolysis in response to E. coli infection. DRAM1 upregulation was confirmed in an independent sepsis cohort. Further, we showed that DRAM1 could maintain survival of a pro-inflammatory monocyte subset, C10_ULK1, which induces systemic inflammation by interacting with other cell subsets via resistin and integrin signaling pathways in blood and kidney tissue, respectively. Finally, retapamulin was identified and optimized as a potential drug for treatment of E. coli sepsis targeting the signature gene, DRAM1, and inhibiting E. coli protein synthesis. Several other targeted drugs were also identified in other types of sepsis, including nystatin targeting C1QA in Neisseria sepsis and dalfopristin targeting CTSD in Streptococcus viridans sepsis. CONCLUSION: Our study provides a comprehensive overview of the cellular heterogeneity and underlying mechanisms in septic patients with various bacterial infections, providing insights to inform development of stratified targeted therapies for sepsis.

Antagonistic Activity of Volatile Organic Compounds Produced by Acid-Tolerant Pseudomonas protegens CLP-6 as Biological Fumigants To Control Tobacco Bacterial Wilt Caused by Ralstonia solanacearum.

Tobacco bacterial wilt, which is caused by Ralstonia solanacearum, is a devastating soilborne disease of tobacco worldwide and is widespread in the continuously acidic fields of southern China. Here, the fumigation activity under different pH conditions, component identification, and bioactivity of the volatile organic compounds (VOCs) produced by an acid-tolerant strain, Pseudomonas protegens CLP-6, were investigated. There was a wide antimicrobial spectrum of the VOCs against phytopathogens, including four bacteria, eight fungi, and two oomycetes. The antagonistic activity of the VOCs against R. solanacearum was proportionally correlated with the concentration of the inoculum, amount, culture time, and culture pH for CLP-6. The number of gene copies of R. solanacearum was significantly inhibited by VOCs produced at pH 5.5 in vivo. The control effect of VOCs emitted at pH 5.5 was 78.91% for tobacco bacterial wilt, which was >3-fold greater than that at pH 7.0. Finally, the main volatile compounds were identified by solid-phase microextraction (SPME)-gas chromatography-mass spectroscopy (GC-MS) as S-methyl thioacetate, methyl thiocyanate, methyl disulfide, 1-decene, 2-ethylhexanol, 1,4-undecadiene, 1-undecene, 1,3-benzothiazole, and 2,5-dimethylpyrazine, and the inhibition rates of 1,3-benzothiazole, 2-ethylhexanolmethyl thiocyanate, dimethyl disulfide, and S-methyl thioacetate were 100%, 100%, 88.91%, 67.64%, and 53.29%, respectively. S-Methyl thioacetate was detected only at pH 5.5. In summary, VOCs produced by P. protegens CLP-6 had strong antagonistic activities against phytopathogens, especially R. solanacearum, under acidic conditions and could be used to develop a safe and additive fumigant against R. solanacearum on tobacco and even other Solanaceae crop bacterial wilt diseases in acidic fields. IMPORTANCE VOCs produced by beneficial bacteria penetrate the rhizosphere to inhibit the growth of plant-pathogenic microorganisms; thus, they have the potential to be used as biological agents in controlling plant diseases. Tobacco bacterial wilt, which is caused by the acidophilic pathogen R. solanacearum, is a major bacterial disease in southern China and is prevalent in acidic soil. In this study, we discovered that the VOCs produced by P. protegens CLP-6 had excellent inhibitory effects on important plant pathogens. Moreover, two of the VOCs, namely, 1,3-benzothiazole and 2-ethylhexanol, had excellent inhibitory effect on R. solanacearum, and another VOC substance, methyl thiocyanate, was produced only at pH 5.5. The VOCs produced by the acid-tolerant strain P. protegens CLP-6 may have potential as environment-friendly microbial fumigant agents for bacterial wilt of tobacco or even other Solanaceae crops in acidic soils in China.

Ultra-broad bandwidth low-dispersion mirror with smooth dispersion and high laser damage resistance.

Low-dispersion mirrors (LDMs), which require a broad bandwidth, low dispersion, and high damage threshold, are essential optics in ultra-intense and ultra-short laser devices. Bragg mirrors and chirped LDMs do not satisfy these requirements simultaneously. We propose a novel LDM (NLDM) based on the hump-like structure and quarter wavelength optical thickness (QWOT) structure to achieve a broad bandwidth, smooth dispersion, and high robustness. The spectral and dispersion characteristics of the two structures compensate for each other, which makes up for the deficiency that the dispersion bandwidth of the sinusoidal modulation structure cannot be broadened. Based on this structure, the LDM can achieve a design bandwidth of 240 nm and support the transmission of sub-11-fs pulses. The accuracy of the NLDM is experimentally evaluated. The structure shows the potential for broad-spectrum laser damage performance due to the low electric field intensity. The NLDM improves the mirror performance and paves the way for a new generation of ultra-intense and ultra-short laser devices.

Optical vortex switch based on multiplexed volume gratings with high diffraction efficiency.

Systems of controllable orbital angular momentum (OAM) require more compact, higher conversion efficiency and more tolerable wavelength or polarization. We introduce an optical vortex switch based on a multiplexed volume grating (MVG). The MVG recorded in a piece of photo-thermo-refractive (PTR) glass exhibits high diffraction efficiency (DE, also known as conversion efficiency in transporting), sensitive angular selectivity, and polarization-insensitivity. The effects of the incident divergence angle and polarization on the DE and the far-field diffraction profiles are demonstrated and investigated. It turns out that the divergence angle of the probe beam can greatly affect the DE. The fluctuation of the DE caused by polarization variation is less than 1.59%. This switch can be potentially applied in vortex tweezers, optical communication, and high power systems.

Accurate temperature measurement of a spectral beam combination grating based on VO2 film.

In a spectral beam combination system, temperature increase of the multilayer dielectric grating (MDG) worsens the far-field beam quality of the output laser. To accurately monitor the surface temperature of the MDG, this study deposits VO2 phase-change film on the lowest layer of multilayer dielectric films in the MDG and tests the transmittance with a probe laser. Based on this measurement, the surface temperature of the MDG can be calculated. Additionally, the study analyzes the influence of VO2 film on the surface electric field and the -1 diffraction efficiency of the MDG and presents a specific example of using VO2 film to test high reflector temperature. The study concludes that VO2 film is a feasible method of measuring temperature and better than an infrared thermal imager.

Eliminating imidacloprid and its toxicity by permanganate via highly selective partial oxidation.

Imidacloprid is a widely used neonicotinoid insecticide worldwide, and has attracted great concerns due to its potential threat to human and environment. Much effort was thus spent on developing the effective way for removing imidacloprid from water, but might also produce various degradation products with unknown risks. The hypothesis was then proposed that permanganate oxidation was probably the appropriate tool for eliminating imidacloprid and its toxicity through selective oxidation of specific groups. To that end, we studied the kinetics of permanganate/imidacloprid reaction by considering the effects of pH (5.0-9.0), temperature (15-35 °C), ionization strength (0.05-0.20 M), typical anions (Cl-, Br-, I-) and humic acid. Based on the identified products from mass spectrometer, the main reaction pathway was found to be the hydroxylation of C-H bond at imidazole ring, leading to the decreased toxicity evaluated by ECOSAR program. Our results demonstrate that permanganate oxidation should be a very promising technique for controlling imidacloprid contamination by effective detoxification through highly selective partial oxidation. Moreover, this study has also paved the way toward applying permanganate oxidation for in situ chemical remediation of imidacloprid, though the corresponding standards need to be established in advance.

Adsorption Properties of Pd3-Modified Double-Vacancy Defect Graphene toward SF6 Decomposition Products.

In this study, we investigate Pd3-cluster-modified 555-777 graphene (Pd3-graphene) as a novel resistor-type gas sensor to detect SF6 decomposition products based on density functional theory calculations. We obtained and minutely analyzed the relevant parameters of each most stable adsorption configuration to explore the microscopic mechanism during gas adsorption. Theoretical results reveal that Pd3-graphene shows great adsorption capacity and sensitivity toward those decompositions. High adsorption energies and abundant charge transfer amounts could guarantee a stable adsorption structure of decomposition gases on Pd3-graphene surface. The complex change of density of states verifies a strong chemical reaction between the gases and the surface. Moreover, the conductivity of Pd3-graphene would improve due to the decrease of energy gap, and the sensitivity was calculated as SOF2 > H2S > SO2 > SO2 F2. This work provides an effective method to evaluate the operation status of SF6 gas-insulated equipment.

Fabrication of high-precision reflective volume Bragg gratings.

Reflecting Bragg gratings (RBGs) recorded in photo-thermo-refractive (PTR) glasses have been widely used in narrowing and stabilization of the laser emission spectrum. As the center wavelength of RBGs determines the final output wavelength of lasers, it is necessary to carefully control the center wavelength of RBGs during the fabrication process. In this paper, the fabrication process of high-precision RBGs was investigated. We developed a two-step method and demonstrated both theoretically and experimentally that it is effective and can be used to guide the fabrication process of high-precision RBGs. The experimental results show that the center wavelength of the fabricated RBG deviates from the target center wavelength within ±10 pm.

Continuous-wave laser damage mechanism of a spectral combining grating.

With increased power of spectral beam combination, surface heat distortion of multilayer dielectric gratings (MDGs) could occur. In this study, the damage morphology of MDGs was initially analyzed under a continuous-wave laser irradiation. Subsequently, the surface distortion and temperature rise of different MDGs were tested experimentally. The experimental results showed that the initial damage of MDGs was caused by the thermal stress. Further, the thermal stress of the multilayer dielectric films on the MDG surface was analyzed theoretically. The calculated results were in good agreement with the experimental results. The conclusions indicated that with the increase of the MDG surface temperature, the stress in the HfO2 layers initially reached the stress damage threshold of the dielectric films and, therefore, the damage occurred.

Design and fabrication of multiplexed volume Bragg gratings as angle amplifiers in high power beam scanning system.

In this study, the realization of multiplexed volume Bragg gratings (VBGs) working as angle amplifiers in high power beam scanning system is theoretically and experimentally investigated. The design of the multiplexed VBG for the working wavelength of 1064 nm is described. We propose a cascaded multiplexed VBGs scheme that consists of 12 grating channels. Three 4-channel multiplexed VBGs were fabricated inside photo-thermo-refractive (PTR) glasses by multiple exposures and subsequent heat treatment. The test results show that this angle amplifier can achieve discrete angle deflection ranging from -45° to + 45°. The relative diffraction efficiency of all the grating channels is more than 80% and is almost polarization independent.

Study of the key factors affecting temperature of spectral-beam-combination grating.

Spectral beam combination is a promising method for high-radiance lasers with a good beam quality. With the increase of the combination power, the temperature of the multilayer dielectric grating (MDG) unavoidably increases, leading to surface heat distortion of the MDG. In this study, the temperature field equation of the MDG is derived, and the key factors influencing the MDG temperature are investigated. Furthermore, experiments are performed to confirm the calculation results. The results reveal that the increase of the thickness of the substrate can improve the power tolerance of the MDG but delays the stable output of beam laser; use of a substrate material with a large thermal conductivity can greatly reduce the temperature of the MDG.

Method for precise evaluation of refractive index modulation amplitude inside the volume Bragg grating recorded in photo-thermo-refractive glass.

In this paper, we present a method for achieving precise evaluation of amplitude of refractive index modulation (RIM) inside the volume Bragg grating (VBG) recorded in photo-thermo-refractive (PTR) glasses. The Gaussian divergence characteristics of the incident beam is theoretically considered when calculating the angular selectivity of VBG, and the profiles of experimental angular selectivity curves are utilized to determine the value of RIM with one step. The effectiveness of our proposed method is experimentally verified. This method is applicable even if the full width at half maximum (FWHM) of VBG's angular selectivity curve has the same order of magnitude as or is less than the beam divergence.

Effects of metalaxyl enantiomers stress on root activity and leaf antioxidant enzyme activities in tobacco seedlings.

The objective of this experiment was to study the effects of metalaxyl enantiomers on the activity of roots and antioxidative enzymes in tobacco seedlings. Water culture experiment was conducted to analyze the effects of different concentrations of metalaxyl enantiomers (30 and 10 mg L-1 ) on root activity and leaf superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities and malondialdehyde (MDA) content of tobacco seedlings. The results showed that metalaxyl significantly inhibited root activity and significantly improved leaf SOD, POD, and CAT activities and MDA content. A better physiological response in tobacco seedlings was observed at 30 mg L-1 than at 10 mg L-1 metalaxyl. The stereoselectivity for different enantiomers had no obvious effect on root activity and the leaf POD activity, but it affected significantly the SOD and CAT activities and MDA content. The SOD activity was promoted more by R-enantiomer than by S-enantiomer at 30 mg L-1 metalaxyl, and the same effect was observed on CAT activity from the beginning to the end of the stress period. The MDA content under the stress by R-enantiomer was higher than that under the stress by S-enantiomer at 10 mg L-1 metalaxyl.

Dependence of temperature and far-field beam quality on substrate thickness of a spectral beam combining grating with 13.4 kW/cm2laser irradiation.

In previous research, the thermal distortion and far-field beam quality of a spectral beam combining grating were analyzed by theory and experiment under the irradiation of a high-power continuous-wave laser. It was concluded that the thermal expansion of the substrate was the main cause of the grating distortion and decrease in the beam quality. However, there was no further study to determine a method to decrease the heat deposition on the grating surface and far-field beam quality factor, M2. In this paper, we theoretically simulate the influence of the substrate thickness on the temperature field distribution and far-field beam quality of a multilayer dielectric grating. An experimental setup is proposed to verify the theoretical calculations. The experimental results are in good agreement with the calculations. The conclusions indicate that the temperature rise of the grating and M2 are effectively reduced by increasing the thickness of the substrate.

Polarization-independent almost-perfect absorber controlled from narrowband to broadband.

Achieving perfect absorption and controlling the absorption bandwidth are highly desirable for many applications. In this work, we design a narrowband almost-perfect absorber by using a metal-insulator-metal thin-film stack with absorption up to 99.67% at 0.58µm incident wavelength. The peak of absorption can be totally controlled by adjusting the thickness of the insulator layer. When the top metal layer is patterned by crossed grating nanostructure with optimized parameters, the absorber becomes broadband over 150nm bandwidth with average absorption exceeding 97% from 0.5µm to 0.65µm in the visible region. Both the narrowband and broadband absorbers are independent on polarization in specific incident angle range. This work opens up a promising new approach to control bandwidth of perfect absorption, which implicates many potential applications.

Polarization-independent broadband beam combining grating with over 98% measured diffraction efficiency from 1023 to 1080 nm.

We report a grating solution for achieving broadband and polarization-independent properties that brings a laser combining system to much higher power levels. The grating, with a high-refractive-index-contrast bilayer ridge, was designed and successfully fabricated based on high-power laser coatings, lithography, and ion-beam etching technology. The measured -1st order non-polarized reflective diffraction efficiency of the grating exceeds 98% over the wavelength range of 1.023-1.08 µm, and the highest value is 99.15%.

Beam modulation due to thermal deformation of grating in a spectral beam combining system.

As the power of a spectral beam combining (SBC) system increases, the temperature of the multilayer dielectric grating (MDG) inevitably rises under the influence of high-power continuous-wave (CW) laser irradiation. Hence, thermal deformation of the MDG occurs, along with degeneration of the combined beam properties. In this study, we experimentally and theoretically investigate the influence of the MDG thermal deformation on the combined beam properties. An experimental setup is first proposed, in which beam quality M2, beam profile, and MDG wavefront deformation are investigated. The experimental results indicate that the beam quality clearly degrades and the MDG wavefront deformation becomes more significant with increasing pump-CW power density. On this basis, a calculation model for MDG thermal deformation in SBC systems is proposed. The results indicate that MDG wavefront deformation becomes more significant, combined beam profile becomes deformed, and beam quality of the combined beam degrades with increasing power density. Further, thermal expansion of the substrate is a crucial factor that induces MDG wavefront deformation and far-field intensity modulation.