RESUMEN
Plant health states may influence the distribution of rhizosphere microorganisms, which regulate plant growth and development. In this study, the response of rhizosphere bacteria and fungi of healthy and diseased plants compared to bulk microbes was analyzed using high-throughput sequencing. Plant adaptation strategies of plants under potato virus Y (PVY) infection have been studied from a microbial perspective. The diversity and community structure of bacteria and fungi varied between bulk and rhizosphere soils, but not between healthy and diseased rhizosphere soils. A LEfSe analysis revealed the significant differences between different treatments on bacterial and fungal community compositions and identified Roseiflexaceae, Sphingomonas, and Sphingobium as the bacterial biomarkers of bulk (BCK), healthy rhizosphere (BHS), and diseased rhizosphere (BIS) soils, respectively; Rhodotorula and Ascomycota_unidentified_1_1 were identified as the fungal biomarkers of bulk (FCK) and healthy rhizosphere (FHS) soils. Bacterial networks were found to be more complex and compact than fungal networks and revealed the roles of biomarkers as network keystone taxa. PVY infection further increased the connectedness among microbial taxa to improve rhizosphere microbial community stability and resistance to environmental stress. Additionally, water content (WC) played an apparent influence on bacterial community structure and diversity, and pH showed significant effects on fungal community diversity. WC and pH greatly affected the biomarkers of bacterial rhizosphere communities, whereas the biomarkers of bulk bacterial communities were significantly affected by soil nutrients, especially for Sphingobium. Overall, the rhizosphere microbial community enrichment processes were different between healthy and diseased plants by changing the community compositions and identifying different biomarkers. These findings provide insight into the assemblage of rhizosphere microbial communities and soil physicochemical properties, which contributes to a deeper understanding of the establishment of an artificial core root microbiota to facilitate plant growth and bolstering resistance mechanisms. This knowledge contributes to a deeper understanding of the establishment of an artificial core root microbiota, thereby facilitating plant growth and bolstering resistance mechanisms.
RESUMEN
We report a single-frequency Q-switched Er:YAG all-solid-state laser with a pulse repetition rate of up to 10 kHz. The single-frequency feature is ensured by injecting the seed laser into a Q-switched ring cavity, and the pulse repetition rate is increased by combing the Pound-Drever-Hall method and optical feedback. Peak power of 4.12 kW with an average pulse energy of 1.35 mJ single-frequency 1645 nm laser pulses is achieved at a pulse repetition rate of 10 kHz, which matches an average power of 13.5 W.
RESUMEN
A wavelength tunable single-longitudinal-mode (SLM) Er:YAG ring laser around 1.6 µm is demonstrated. By using an acousto-optic modulator (AOM) to force unidirectional operation, up to 10.4 W and 8.7 W SLM laser output power are obtained at 1645.22 nm and 1617.33 nm, with corresponding slope efficiencies of 45% and 40%, respectively. Besides, stable dual-wavelength operation at both 1645 nm and 1617 nm is also achieved with the maximum power of 9.1 W. By rotating the birefringent filter (BRF) in the ring cavity, the wavelength could be tuned from 1616.77 nm to 1617.51 nm and 1644.51 nm to 1646.12 nm. The line width is measured to be 125 kHz at 1617 nm and 131 kHz at 1645 nm via the time-delayed self-heterodyne method. As far as we know, 8.7 W is the highest continuous-wave SLM output power at 1617 nm.
RESUMEN
We present an injection-seeding Q-switched 1645 nm Er:YAG ceramic laser with high frequency stability and energy stability by combining the injection-seeding technique and Pound-Drever-Hall technique. 10.31 mJ single-frequency pulses with optimal frequency stability (525 kHz) and relative energy stability (0.52%) at a high pulse repetition rate of 1 kHz are obtained. To the best of our knowledge, this is the highest frequency stability and energy stability so far in a high pulse repetition frequency, large pulse energy, single-frequency Q-switched Er-doped solid laser. This single frequency laser with high stability provides an excellent light source for a coherent lidar system.
RESUMEN
Solid-state single-frequency lasers around 1.6 µm are ideal sources for coherent Doppler wind lidars (CDWLs). A CDWL system with 1645 nm sing-frequency, injection-seeded Er:YAG ceramic laser is demonstrated. The Er:YAG laser based on an "M-shaped" ring resonator operates at pulse repetition frequencies (PRFs) of 300-1000 Hz at room temperature. The maximum single-frequency output energy is 10.1 mJ with a pulse width of 179 ns at 300 Hz. The 1645 nm Er:YAG laser is first used in a long-range CDWL system, and a line of sight (LOS) wind velocity up to 25â km is detected with 90 m range resolution in 0.5 s observation. To verify the reliability of the measurement results, the relationship between detection range, pulse energy, and accumulated numbers is also demonstrated.
RESUMEN
In an actual setup of squeezed state generation, the stability of a squeezing factor is mainly limited by the performance of the servo-control system, which is mainly influenced by the shot noise and gain of a photodetector. We present a unique transformer-coupled LC resonant amplifier as a photodetector circuit to reduce the electronic noise and increase the gain of the photodetector. As a result, we obtain a low-noise, high gain photodetector with the gain of more than 1.8×105 V/A, and the input current noise of less than 4.7 pA/Hz. By adjusting the parameters of the transformer, the quality factor Q of the resonant circuit is close to 100 in the frequency range of more than 100 MHz, which meets the requirement for weak power detection in the application of squeezed state generation.
RESUMEN
Based on the requirement of squeezed state generation, we build the phase relationship between two electronic local oscillators for the cavity- and phase-locking branches, and a 2-way 90° power splitter is adopted to satisfy the phase relationship simultaneously, which greatly simplifies the experimental setup and adjusting process. A LC parallel resonant circuit, which is composed by the inherent capacitance of a photodiode and an extra inductor, is adopted in the resonant photodetector to improve the gain factor at the expected frequency. The gain of the resonant photodetector is about 30 dB higher than that of the broadband photodetector at the resonant frequency. The peak-to-peak value of the error signal for cavity-locking (phase-locking) with the resonant photodetector is 240 (260) times of that with the broadband photodetector, which can improve the locking performance on the premise of not affecting the squeezing degree.
RESUMEN
A balanced homodyne detector, with a maximum common mode rejection ratio and clearance of 75.2 dB and 37 dB, is experimentally obtained with two arbitrary photodiodes of the same model. On the basis of self-subtraction photodetector scheme, we divide the influence of photodiodes on the common mode rejection ratio into two parts, including magnitude and phase of output signal. The discrepancy of quantum efficiency and dark current affects magnitude of output signal of photodiodes, which is compensated by adjusting the splitter ratio. The difference of the equivalent capacitance and resistance affects the phase of output signal of photodiodes, which is compensated by the differential fine tuning circuit and adjustable bias voltage circuit. With these designs, the developed homodyne detector can be used for measuring accurately the squeezed state.
RESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Valeriana jatamansi Jones named Zhizhuxiang in China is one of the most popular traditional medicine for varied ailments related to malaise, abdominal distention, insomnia, and rheumatism. AIM OF THE STUDY: Evaluate the safety of iridoids rich fraction from V. jatamansi Jones (IRFV) and to provide data for clinical application. MATERIALS AND METHODS: The acute and sub-chronic toxicity of IRFV were investigated by employing established methods. The acute toxicity study was conducted through oral administration of a single dose (3,200 mg/kg body weight) of IRFV to adult mice. The vehicle used for dilution of the IRFV was a mixture of 0.5% CMC-Na and 99.5% water. The weight, diet, toxic reaction, and death after 14 days were observed. In the sub-chronic toxicity study, low doses (240 mg/kg bw), middle doses (960 mg/kg bw), and high doses (1,200 mg/kg bw) of IRFV were administered daily to adult rats for 6 days a week (except Sunday) for 3 months. The general behavior of the rats was observed and recorded daily. The weight and food consumption of rats were tested weekly. The effect on organs, the hematological and blood biochemical parameters, and the histopathology were assessed after 1.5 months (five males and five females) and after 3 months (10 males and 10 females).The remaining 10 rats (five males and five females) in each group were fed for 2 weeks to observe reversible and delayed toxicity after the medicine was administered. RESULTS: In the acute toxicity study, no significant difference was found in the body weight of the mice in the control group and those in the drug group (p>0.05). The maximum tolerated dose of IRFV on mice was 3,200 mg/kg, which is 2666 times of the clinical adult daily dose. In the sub-chronic toxicity study on rats, the daily single oral doses of the IRFV did not result in death nor affected the general behavior, including appearance, activities, discharge, and waste at all tested doses. Moreover, no significant difference was found (p>0.05) between the body weights of the rats from the drug groups and those from the control group. Food consumption was significantly affected (p<0.05) only in the first 3 weeks. No statistically significant differences (p>0.05) were observed in the hematological and blood biochemical parameters, and no abnormality of other organs were noted in both gross and histopathological examinations, except several animal transients (p<0.05) or spontaneous lesions (abnormality). CONCLUSION: IRFV is extremely safe in the usual clinical dose, and may not have any single dose toxicity. The lethal dose with 50% mortality rate (LD50) on mice is over 2,000 mg/kg bw. The no-observed adverse effects level is 1,200 mg/kg/day for rats. No direct correlation was found between the hematology, blood biochemical indexes, and organ coefficient of tested rats and the toxicity of IRFV.
