Erbium-doped fiber amplifier (EDFA)-assisted laser heterodyne radiometer (LHR) working in the shot-noise-dominated regime.

A near-infrared (NIR) laser heterodyne radiometer (LHR) using a 1603 nm distributed feedback (DFB) laser, associated with an erbium-doped fiber amplifier (EDFA), used as a local oscillator (LO) was developed. The EDFA was customized for automatic power control to amplify and stabilize the LO DFB laser power, which allowed to reduce baseline fluctuation and thus make the processed atmospheric transmission spectrum with higher precision. The operation of the EDFA-assisted LHR with a shot-noise-dominated performance was analyzed and experimentally achieved by optimizing the LO power. The performance of the developed LHR was evaluated and verified by measuring an atmospheric CO2 absorption spectrum, and the atmospheric CO2 column abundances were then retrieved based on the optimal estimation method (OEM). The results were in good agreement with the Greenhouse Gas Observation Satellite (GOSAT) data. The EDFA-assisted LHR firstly reported in this Letter has a potential to further improve the measurement precision of atmospheric greenhouse gases using ground-based LHR remote sensing.

DBALM: A novel method for identifying ornamental flowering plants based on DNA barcodes-leaf morphology.

Whereas the presence of flowers on ornamental flowering plants is essential for their identification via traditional methods, ornamental flowering plants cannot be reliably identified in non-flowering stages likewise. Here, DBALM (DNA Barcodes-Leaf Morphology), a new approach that combines DNA barcoding data with micromorphological features of the leaf epidermis and that is not limited by the flowering stage, was used to identify 16 evergreen rhododendron cultivars. First, the sequences of DNA barcodes, ITS, matK, psbA-trnH, and rbcL, were obtained from the DNA of leaves. Phylogenetic analysis was conducted to clarify the groupings among all the samples based on the four markers. Then, microscopic features of the leaf epidermis were used to further distinguish individuals from the same clade. DNA barcoding permitted the 16 cultivars to be divided into eight groups. The microscopic features of the leaf epidermis permitted cultivars within the same clade to be distinguished. The matK + psbA-trnH combination was the most effective barcode combination in this study. In addition, the new primer matK-Rh_R was designed, and it increased the amplification rate of evergreen rhododendron cultivars to 100%. In sum, DBALM was capable of accurately identifying the 16 evergreen rhododendron cultivars using data collected from a single leaf in the vegetative growth stage. This method can greatly facilitate the identification and breeding of ornamental flowering plants.

External-cavity diode laser-based near-infrared broadband laser heterodyne radiometer for remote sensing of atmospheric CO2.

A near-infrared broadband (1500-1640 nm) laser heterodyne radiometer (LHR) with a tunable external-cavity diode laser as the local oscillator is developed and the relative transmittance, which represents the absolute relationship between the measured spectral signals and the atmospheric transmittance, is derived. High-resolution (0.0087 cm-1) LHR spectra in the spectral region of 6248.5-6256 cm-1 were recorded for the observation of atmospheric CO2. Combined with the relative transmittance, the preprocessed measured LHR spectra, the optimal estimation method, and the Python scripts for computational atmospheric spectroscopy, the column-averaged dry-air mixing ratio of CO2 of 409.09 ± 8 ppmv in Dunkirk, France on February 23, 2019, was retrieved, which is consistent with GOSAT and TCCON data. The near-infrared external-cavity LHR demonstrated in the present work has a high potential for use in developing a robust, broadband, unattended, and all-fiber LHR for spacecraft and ground-based atmospheric sensing that offers more channel selection for inversion.

High-resolution oxygen-corrected laser heterodyne radiometer (LHR) for stratospheric and tropospheric wind field detection.

We developed a near-infrared (NIR) dual-channel oxygen-corrected laser heterodyne radiometer (LHR) in the ground-based solar occultation mode for measuring vertical profile of wind field in the troposphere and low stratosphere. Two distributed feedback (DFB) lasers centered at 1.27 µm and 1.603 µm were used as local oscillators (LO) to probe absorption of oxygen (O2) and carbon dioxide (CO2), respectively. High-resolution atmospheric O2 and CO2 transmission spectra were measured simultaneously. The atmospheric O2 transmission spectrum was used to correct the temperature and pressure profiles based on a constrained Nelder-Mead's simplex method. Vertical profiles of atmospheric wind field with an accuracy of ∼5 m/s were retrieved based on the optimal estimation method (OEM). The results reveal that the dual-channel oxygen-corrected LHR has high development potential in portable and miniaturized wind field measurement.

Performance Characterization of a Fully Transportable Mid-Infrared Laser Heterodyne Radiometer (LHR).

A fully transportable laser heterodyne radiometer (LHR), involving a flexible polycrystalline mid-infrared (PIR) fiber-coupling system and operating around 8 µm, was characterized and optimized with the help of a calibrated high temperature blackbody source to simulate solar radiation. Compared to a mid-IR free-space sunlight coupling system, usually used in a current LHR, such a fiber-coupling system configuration makes the mid-infrared (MIR) LHR fully transportable. The noise sources, heterodyne signal, and SNR of the MIR LHR were analyzed, and the optimum operating local oscillator (LO) photocurrent was experimentally obtained. The spectroscopic performance of the MIR LHR was finally evaluated. This work demonstrated that the developed fully transportable MIR LHR could be used for ground-based atmospheric sounding measurements of multiple trace gases in the atmospheric column. In addition, it also has high potential for applications on spacecraft or on an airborne platform.

A comparison of drying methods on the quality for bryophyte molecular specimens collected in the field.

A major challenge in extracting high-quality DNA from bryophytes is the treatment of bryophyte material in the field. The existing and commonly used treatment methods in the field have several shortcomings. Natural drying methods can lead to DNA breaks. In addition, it is highly cumbersome to carry large quantities of silica gel in the field due to its weight and high risk of contamination among samples. In this study, we explored more convenient drying methods to treat bryophyte specimens and promote more efficient DNA recovery. The quantity and quality of genomic DNA extracted from every bryophyte species using different drying methods, including hot-air drying methods (150°C, 80°C, and 40°C), natural drying method, and silica gel drying method, were measured. Spectrophotometry, electrophoresis, and PCR amplification were performed to assess the effects of different drying methods. The results of total DNA purity, total DNA concentration, PCR success, and OD 260/230 ratios suggested that the hot-air drying (40-80°C) was the best method. The morphological comparison revealed that hot-air drying at 40°C and 80°C exerted no significant adverse effects on plant morphology and taxonomic studies. Thus, this method prevents rapid DNA degradation and silica gel pollution and saves the workforce from carrying large amounts of silica gel to the field. Several inexpensive devices, such as portable hairdryers, fan heaters, and electric blankets, are available that can be easily carried to the field for drying molecular specimens.

A MEMS modulator-based dual-channel mid-infrared laser heterodyne radiometer for simultaneous remote sensing of atmospheric CH4, H2O and N2O.

The performance of a micro-electro-mechanical system (MEMS) modulator-based dual-channel mid-infrared laser heterodyne radiometer (MIR-LHR) was demonstrated in ground-based solar occultation mode for the first time. A MEMS mirror was employed as an alternative modulator to the traditional mechanical chopper, which makes the system more stable and compact. Two inter-band cascade lasers (ICL) centered at 3.53 µm and 3.93 µm, were employed as local oscillators (LO) to probe absorption lines of methane (CH4), water vapor (H2O) and nitrous oxide (N2O). The system stability greater than 1000 s was evaluated by Allan variance. The experimental MIR-LHR spectra (acquired at Hefei, China, on February 24th 2022) of two channels were compared and were in good agreement with simulation spectra from atmospheric transmission modeling. The mixing ratio of CH4, H2O and N2O were determined to be ∼1.906 ppm, 3069 ppm and ∼338 ppb, respectively. The reported MEMS modulator-based dual-channel MIR-LHR in this manuscript has great potential to be a portable and high spectral resolution instrument for remote sensing of multi-component gases in the atmospheric column.

[Electroacupuncture at Siguan points for migraine of liver yang hyperactivity: a randomized controlled trial].

OBJECTIVE: To compare the clinical effect of electroacupuncture at Siguan points and flunarizine hydrochloride capsule on migraine of liver yang hyperactivity. METHODS: A total of 110 patients with migraine of liver yang hyperactivity were randomly divided into an electroacupuncture group (55 cases, 2 cases dropped off) and a western medication group (55 cases, 2 cases dropped off). In the electroacupuncture group, electroacupuncture was applied at Siguan points (Hegu [LI 4] and Taichong [LR 3]), with disperse-dense wave of 2 Hz/100 Hz in frequency and current intensity of 0.1-1 mA, 30 min each time, once a day, 5 times per week for 4 weeks. Flunarizine hydrochloride capsule was given orally in the western medication group, 10 mg a day for 4 weeks. The visual analogue scale (VAS) score and the migraine attack days were observed before and after treatment, during follow-up of 1, 3 and 6 months, and the migraine symptom score was observed before and after treatment in the two groups. RESULTS: After treatment, during follow-up of 1, 3 and 6 months, the VAS scores and the migraine attack days in the two groups were decreased compared with before treatment (ï¼°<0.05), and above indexes in the electroacupuncture group were lower than the western medication group (ï¼°<0.05). After treatment, the migraine symptom scores in the two groups were decreased (ï¼°<0.05), the change in the electroacupuncture group was greater than the western medication group (ï¼°<0.05). CONCLUSION: Electroacupuncture at Siguan points could effectively reduce headache intensity and migraine attack days, relieve migraine symptoms in patients with migraine of liver yang hyperactivity, and the efficacy is superior to oral flunarizine hydrochloride capsules.

The complete chloroplast genome of Rhodobryum laxelimbatum (Hampe ex Ochi) Z. Iwatsuki and T. J. Koponen.

Rhodobryum laxelimbatum (Bryophyta, Bryaceae) is one of the folk medicine resources in Southwest China, which has excellent potential for application in treating cardiovascular diseases. In this study, R. laxelimbatum was sequenced by high-throughput sequencing technology. The complete chloroplast genome is 124,632 bp in length with a quadripartite structure. Two inverted repeat regions are 9837 bp, separated by a large single copy region of 86,444 bp and a small single copy region of 18,514 bp. It encodes 118 unique genes, including 82 protein-coding genes, 32 tRNA genes, and four rRNA genes. The phylogenetic tree was constructed based on the complete chloroplast genome sequences of 18 bryophytes, downloaded from GenBank and acquired in this study. The phylogenetic analysis strongly indicated that R. laxelimbatum was the sister group of the clade which consists of Mnium marginatum, Pohlia cruda and Pohlia nutans. The R. laxelimbatum chloroplast genome sequence provides new genomic resources, which will improve its research, conservation, and application in the future.

Transportable mid-infrared laser heterodyne radiometer operating in the shot-noise dominated regime.

A transportable laser heterodyne radiometer (LHR) based on an external cavity quantum cascade laser, operating in the mid-infrared (mid-IR) around 8 µm, was developed for ground-based remote sensing of multiple greenhouse gases. A newly available novel flexible mid-IR polycrystalline fiber was first exploited to couple solar radiation, real-time captured using a portable sun-tracker, to the LHR receiver. Compared to free space coupling of sunlight, the technique usually used nowadays in the mid-IR, such fiber coupling configuration makes the LHR system readily more stable, simpler, and robust. Operation of the LHR with quasi-shot-noise limited performance was analyzed and experimentally achieved by optimizing local oscillator power. To the best of our knowledge, no such performance approaching the fundamental limit has been reported for a transportable LHR operating at a long mid-IR wavelength around 8 µm. CH4 and N2O were simultaneously measured in the atmospheric column using the developed mid-IR LHR. The experimental LHR spectrum of CH4 and N2O was compared and is in good agreement with a referenced Fourier-transform infrared spectrum from the Total Carbon Column Observing Network observation site and with a simulation spectrum from atmospheric transmission modeling.

The complete chloroplast genome of Mnium marginatum (With.) P. Beauv.

Mnium is the type genus of the family Mniaceae, the species' richest family of order Bryales (Bryophyte). Mnium marginatum is widely distributed worldwide. The complete chloroplast genome of M. marginatum was sequenced by high-throughput sequencing technology. The chloroplast genome is 124,935 bp in length with a quadripartite structure. The two inverted repeat regions are 9,910 bp long and separated by a large single-copy region of 86,572 bp and a small single-copy region of 18,543 bp. Based on the chloroplast genome data of 11 bryophytes downloaded from GenBank and one acquired in this study, phylogenetic trees were constructed.

Investigation of catalysts M/CeO2 (M = Pt, Rh, or Pd) for purification of CO2 derived from oxycombustion in the absence or presence of water.

Oxyfuel combustion is a promising technology to produce a CO2-rich flue gas ready suitable for sequestration or valorization. But its storage as well as its further valorization requires to increase the CO2 purification as a small amount of CO and NOx are produced during combustion. Based on the technology developed for three-way converters, similar systems, i.e., M/CeO2 where M is Pt, Pd, or Rh, were studied for NO-CO abatement in a gas stream similar to those obtained when an oxyfuel combustion is performed. The results evidenced that the role of the metal nature influences the performances obtained on NO-CO abatement, platinum supported on ceria being the most efficient catalyst. We also measured the impact of the presence of water in the reaction stream on the catalytic activity of these materials. It appears that the presence of water has a beneficial effect on the different reactions due to a water gas shift reaction that increases the reduction of the NO and favors the formation of N2. The study pointed out that platinum supported on ceria remained the best catalyst, under these wet operating conditions close to industrial ones, for purification of oxyfuel combustion exhausts.

[Professor ZHANG Ren's clinical experience of acupuncture for glaucoma].

Professor ZHANG Ren's clinical experience of acupuncture for glaucoma is summarized. Professor ZHANG believes that key pathogenesis of glaucoma is stagnation of qi and blood in the eyes, obstruction of xuanfu in the eyes, and obstruction of meridians. The treatment should focus on the eye, with smoothing the liver and keeping functional state of six-fu as priority; he also emphasizes the acupoint selection based on the combination of disease differentiation and syndrome differentiation, and pays attention to the application of acupuncture method of promoting qi circulation and inducting qi movement. Professor ZHANG proposes that the patients should be treated according to different types, and stresses the importance of using comprehensive treatment and emotional adjustment method, as well as early intervention, long-term adherence and regular treatment.

The complete chloroplast genome sequence of Pohlia cruda (Hedw.) Lindb.

Pohlia is a genus with many taxonomic and systematic controversies. In this study, the complete chloroplast genome of Pohlia cruda (Bryales, Bryophyte) was sequenced by high-throughput sequencing technology and described. The complete chloroplast genome is 125,114 bp in length and has a quadripartite structure. The two inverted repeat (IR) regions are 9921 bp long and separated by a large single-copy (LSC) region of 86,727 bp and a small single-copy (SSC) region of 18,545 bp. Phylogenetic trees were constructed based on the complete chloroplast genome sequences of 10 bryophytes downloaded from GenBank and one acquired in this study.