A novel label-free capillary electrophoresis LED-induced fluorescence platform based on catalytic hairpin assembly for sensitive detection of multiple circulating tumor DNA.

Circulating tumor DNA (ctDNA) is a highly promising biomarker for the early diagnosis and treatment of gastric cancer (GC). However, there is still a lack of effective and practical ctDNA detection methods. In this work, a simple and economical capillary non-gel sieving electrophoresis-LED induced fluorescence detection (NGCE-LEDIF) platform coupled with catalytic hairpin assembly (CHA) as the signal amplification strategy is proposed for quantitative detection of PIK3CA E542K and TP53 (two types of ctDNA associated with GC). We have reasonably designed two pairs of programmable oligonucleotide hairpin probes for PIK3CA E542K and TP53. Using a one-pot reaction, the presence of ctDNA triggers the cyclic amplification of CHA, forming numerous thermodynamically stable H1/H2 double-strands. The H1/H2 double-stranded DNA catalyzed by PIK3CA E542K and TP53 can be easily separated by NGCE due to their different lengths, enabling simultaneous detection of both ctDNAs. Under optimal experimental conditions, the detection limits of this strategy for detecting GC-related biomarkers PIK3CA E542K and TP53 are 20.35 pM and 19.61 pM, respectively, and can achieve 730-fold signal amplification. This strategy has a good recovery in the serum matrix. The results of this study show that this strategy has significant advantages such as high selectivity, a simple process, no special instruments and equipment, no need for fluorescence modification of hairpin probes in advance, high automation, low cost, and minimal sample consumption. This provides a powerful method for the detection of trace cancer biomarkers in the serum matrix with good application prospects.

First Report on Choanephora cucurbitarum Causing Choanephora Rot in Chenopodium Plants and Its Sensitivity to Fungicide.

Choanephora rot of Chenopodium plants (CRC) was observed at the flowering stages in seven plantations of Shanxi Province, China. CRC had caused leaf, stem, and panicle neck rot of C. quinoa, panicle neck and stem rot of C. formosanum, and stem rot of C. album. Typical symptoms included water-soaked, rapid soft rotting, and abundant sporulation on the whole panicle necks, stems, and leaves. Based on morphological characteristics, phylogenetic analyses, and pathogenicity tests, the pathogens were identified as Choanephoraceae cucurbitarum. Sporangiola and sporangiospore of C. cucurbitarum germinated at 30 °C and were able to germinate by two h post-inoculation (hpi). The germination rates of sporangiola and sporangiospore significantly increased at 3 to 4 hpi, and the germination rates ranged from 91.53 to 97.67%. The temperature had a significant effect on the pathogenicity of C. cucurbitarum the optimum pathogenic temperatures for stems of C. quinoa, C. formosanum and C. album were 30 °C after one day post-inoculation. Choanephoraceae cucurbitarum could infect white and red quinoa panicle necks between 20 and 30 °C, and the average lesion lengths were 0.21 to 3.62 cm. Among the five tested fungicides (boscalid, dimethomorph, isopyrazam, propiconazole, and tebuconazole), isopyrazam showed higher sensitivity to sporangiola germination of C. cucurbitarum, with an EC50 value of 0.6550 µg/mL. Isopyrazam and tebuconazole strongly inhibited the sporangiospore germination of C. cucurbitarum, which showed EC50 values of 0.4406 and 0.3857 µg/mL. To our knowledge, the present study found for the first time that C. cucurbitarum is a pathogen causing panicle neck of C. formosanum and stem rot of C. formosanum and C. album, while CRC first appeared in the quinoa panicle necks, and gradually expanded to stems and leaves.

Rhodotron and rotating target: A solution towards micro-spot for high energy and high dose rate bremsstrahlung sources.

High energy over MeV bremsstrahlung sources that employ normal conducting radio frequency linear accelerators have expanding applications in industrial computerized tomography (CT) for non-destructive inspection and evaluation. The X-ray spot size that mainly affects the imaging quality is yet limited by the electron beam width in the high resolution CT systems. In a short exposure time, high beam power is required to generate sufficient photons to improve the signal to noise ratio of imaging. However, with ∼kW level of average beam power these linear accelerators usually have a beam spot size over 1 mm since the temperature rising due to the beam energy deposition in the target should be far below its melting point. We propose a concept of using a Rhodotron-based accelerator to provide high power electron beams in a long duration pulse and a rotating target to mitigate the overheating issue, such that the gap between micro-spot and high dose rate can be bridged in the high energy bremsstrahlung sources. This article presents an in-depth simulation work to discuss and evaluate this scheme of X-ray source. The simulations of beam dynamics in the accelerator and bremsstrahlung process in the target predict the generated X-rays with a spot size as small as 68 µm at full-width half-maximum and a dose rate as high as 4700 cGy/min from a 9 MeV electron beam interacting with a 1 mm thickness tantalum target. Further thermal analysis in the rotating target indicates a significant improvement of beam power handling in comparison with the conventional stationary one.

Single-shot characterization of strongly focused coherent XUV and soft X-ray beams.

In this Letter, we present a novel, to the best of our knowledge, single-shot method for characterizing focused coherent beams. We utilize a dedicated amplitude-only mask, in combination with an iterative phase retrieval algorithm, to reconstruct the amplitude and phase of a focused beam from a single measured far-field diffraction pattern alone. In a proof-of-principle experiment at a wavelength of 13.5 nm, we demonstrate our new method and obtain an RMS phase error of better than λ/70. This method will find applications in the alignment of complex optical systems, real-time feedback to adaptive optics, and single-shot beam characterization, e.g., at free-electron lasers or high-order harmonic beamlines.

Chrysin Alleviates Monocrotaline-Induced Pulmonary Hypertension in Rats Through Regulation of Intracellular Calcium Homeostasis in Pulmonary Arterial Smooth Muscle Cells.

Chrysin (CH) is the main ingredient of many medicinal plants. Our previous study showed that CH could suppress hypoxia-induced pulmonary arterial smooth muscle cells proliferation and alleviate chronic hypoxia-induced pulmonary hypertension by targeting store-operated Ca entry (SOCE)-[Ca]i pathway. In this study, we investigated the effect of CH on monocrotaline-induced pulmonary hypertension (MCTPH) and the mechanism behind it. Results show that, in MCTPH model rats, (1) CH significantly reduced the enhancement of right ventricular pressure, right ventricular hypertrophy, and pulmonary vascular remodeling; (2) CH markedly suppressed the promotion of SOCE and [Ca]i in pulmonary arterial smooth muscle cells; and (3) CH obviously inhibited the MCT-upregulated proliferating cell nuclear antigen, TRPC1, TRPC4, and TRPC6 expression in distal pulmonary arteries. These results demonstrate that CH likely alleviates MCTPH by targeting TRPC1,4,6-SOCE-[Ca]i pathway.

Astragaloside inhibits IL-1ß-induced inflammatory response in human osteoarthritis chondrocytes and ameliorates the progression of osteoarthritis in mice.

Background: Osteoarthritis (OA) is a chronic joint-degeneration disease and accounts for the most frequent arthritis in aging people. OA is characterized by the degeneration of articular cartilage, subchondral bone sclerosis and synovitis. Inflammation as an important role in OA progression, in that anti-inflammatory agents could effectively inhibit the development of OA with minimal side effects, therefore developing a nature anti-inflammatory compound will be a promising therapy for treating OA. Methods: We treated patient-derived chondrocytes and mouse models of OA with astragaloside, an effective component of astragalus membranaceus, and measured its effect on pro-inflammatory cytokines and OA progression in mice. Results: In vitro, astragaloside induced a dose-dependent inhibition of IL-1ß-induced the production of inflammatory factors, including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), nitric oxide (NO), prostaglandin E2 (PGE2), expression of MMP 13 and ADAMTS-5, and the activation of NF-κB signaling. In vivo, astragaloside ameliorate the degeneration of cartilage in mouse model of OA. Conclusion: Astragaloside potentially serve as a promising and effective therapeutic agent for treating OA patients.

Measurement of yield and spectrum of secondary electron emission and their characteristics under modification of conductive materials.

Surface modification technique of secondary electron emission (SEE) characteristics of materials, which is utilized to suppress or promote the SEE from material surface under electron bombardment, has extensive applications in a variety of fields. Measurement of the secondary electron yield (SEY) and the secondary electron spectrum (SES) before and after surface modification is essential for the evaluation of effectiveness and the investigation of mechanism of material modification. A SEY and SES measurement system is reported in this article. The comparative measurements of the total SEY, the true SEY, the backscattered electron yield, and the SES of nickel and free-standing vertical graphene, which was grown in situ on the surface of nickel substrate by plasma enhanced chemical vapor deposition, were performed using this system. The measurement results demonstrate that this system could facilitate the study of surface modification on the SEE characteristics of conductive materials.

Insights on UNC-104-dynein/dynactin interactions and their implications on axonal transport in Caenorhabditis elegans.

Bidirectional cargo transport in neurons can be explained by two models: the "tug-of-war model" for short-range transport, in which several kinesin and dynein motors are bound to the same cargo but travel in opposing directions, and by the "motor coordination model" for long-range transport, in which small adaptors or the cargo itself activates or deactivates opposing motors. Direct interactions between the major axonal transporter kinesin-3 UNC-104(KIF1A) and the dynein/dynactin complex remains unknown. In this study, we dissected and evaluated the interaction sites between UNC-104 and dynein as well as between UNC-104 and dynactin using yeast two-hybrid assays. We found that the DYLT-1(Tctex) subunit of dynein binds near the coiled coil 3 (CC3) of UNC-104, and that the DYRB-1(Roadblock) subunit binds near the CC2 region of UNC-104. Regarding dynactin, we specifically revealed strong interactions between DNC-6(p27) and the FHA-CC3 stretch of UNC-104, as well as between the DNC-5(p25) and the CC2-CC3 region of UNC-104. Motility analysis of motors and cargo in the nervous system of Caenorhabditis elegans revealed impaired transport of UNC-104 and synaptic vesicles in dynein and dynactin mutants (or in RNAi knockdown animals). Further, in these mutants UNC-104 clustering along axons was diminished. Interestingly, when dynamic UNC-104 motors enter a stationary UNC-104 cluster their dwelling times are increased in dynein mutants (suggesting that dynein may act as an UNC-104 activator). In summary, we provide novel insights on how UNC-104 interacts with the dynein/dynactin complex and how UNC-104 driven axonal transport depends on dynein/dynactin in C. elegans neurons.

[Effects of salinity and adhesive materials on the growth and adhesion of Amphora sp. HN08 under static conditions].

OBJECTIVE: To optimize the cultural conditions including adhesive materials and salinity for one tropical benthic diatom (Amphora sp. HN08). METHODS: Two experiments were performed: (1) five adhesive materials including agar, glass, PVC plate, plastic film and nylon net were used to culture Amphora sp. HN08 HN08; (2) Amphora sp. HN08 was cultured under 6 salinity levels from 1 through 6%. The algal cells were harvested after 9 days treatments, and the biomass productivity, adhesive strength and pigments content of cells were examined. RESULTS: For the adhesive materials experiment, cultures with glass and plastic plate showed the highest biomass production and the dry weight of cells reached to 3.64 g/m2. The adhesion strength level of cells on the glass plate was III degree, which means the cells were easy to be separated from the glass and dewatered by centrifugation. Salinity did not contribute significantly to the biomass production, while it significantly influenced the cells adhesion and pigments concentration. The adhesive strength levels of the cells under 3% or 4% salinity was IV degree, which led to an easy harvest process. While the. cells cultured under high salinity (5% and 6%) usually suspended in the medium and were difficult to be dewatered by centrifugation. Both chlorophyll a and carotenoid content of cells cultured with higher salinity (≥ 3%) are extremely higher (p < 0.01) than that with lower salinity (1% and 2%). Chlorophyll a and carotenoid content of cells under 5% salinity was 26.27% and 11.11% by dry weight, respectively. CONCLUSION: Taking the harvest and biomass production together, we think the optimal salinity for Amphora sp. HN08 was between 3% and 4%, and the glass plate was suitable for adhesive material. However, considering the cost and safety, the PVC plate is suggested to be used for biomass production.