X-ray Astronomy in the Laboratory with a Miniature Compact Object Produced by Laser-Driven Implosion

Laboratory spectroscopy of non-thermal equilibrium plasmas photoionized by intense radiation is a key to understanding compact objects, such as black holes, based on astronomical observations. This paper describes an experiment to study photoionizing plasmas in laboratory under well-defined and genuine conditions. Photoionized plasma is here generated using a 0.5-keV Planckian x-ray source created by means of a laser-driven implosion. The measured x-ray spectrum from the photoionized silicon plasma resembles those observed from the binary stars Cygnus X-3 and Vela X-1 with the Chandra x-ray satellite. This demonstrates that an extreme radiation field was produced in the laboratory, however, the theoretical interpretation of the laboratory spectrum significantly contradicts the generally accepted explanations in x-ray astronomy. This model experiment offers a novel test bed for validation and verification of computational codes used in x-ray astronomy.Comment: 5 pages, 4 figures are included. This is the original submitted version of the manuscript to be published in Nature Physic

Automatic segmentation of coronary angiograms based on fuzzy inferring and probabilistic tracking

<p>Abstract</p> <p>Background</p> <p>Segmentation of the coronary angiogram is important in computer-assisted artery motion analysis or reconstruction of 3D vascular structures from a single-plan or biplane angiographic system. Developing fully automated and accurate vessel segmentation algorithms is highly challenging, especially when extracting vascular structures with large variations in image intensities and noise, as well as with variable cross-sections or vascular lesions.</p> <p>Methods</p> <p>This paper presents a novel tracking method for automatic segmentation of the coronary artery tree in X-ray angiographic images, based on probabilistic vessel tracking and fuzzy structure pattern inferring. The method is composed of two main steps: preprocessing and tracking. In preprocessing, multiscale Gabor filtering and Hessian matrix analysis were used to enhance and extract vessel features from the original angiographic image, leading to a vessel feature map as well as a vessel direction map. In tracking, a seed point was first automatically detected by analyzing the vessel feature map. Subsequently, two operators [e.g., a probabilistic tracking operator (PTO) and a vessel structure pattern detector (SPD)] worked together based on the detected seed point to extract vessel segments or branches one at a time. The local structure pattern was inferred by a multi-feature based fuzzy inferring function employed in the SPD. The identified structure pattern, such as crossing or bifurcation, was used to control the tracking process, for example, to keep tracking the current segment or start tracking a new one, depending on the detected pattern.</p> <p>Results</p> <p>By appropriate integration of these advanced preprocessing and tracking steps, our tracking algorithm is able to extract both vessel axis lines and edge points, as well as measure the arterial diameters in various complicated cases. For example, it can walk across gaps along the longitudinal vessel direction, manage varying vessel curvatures, and adapt to varying vessel widths in situations with arterial stenoses and aneurysms.</p> <p>Conclusions</p> <p>Our algorithm performs well in terms of robustness, automation, adaptability, and applicability. In particular, the successful development of two novel operators, namely, PTO and SPD, ensures the performance of our algorithm in vessel tracking.</p

Exploration of the Protection of Riboflavin Laurate on Oral Mucositis Induced by Chemotherapy or Radiotherapy at the Cellular Level: What Is the Leading Contributor?

Oral or gastrointestinal mucositis is a frequent phenomenon in cancer patients receiving chemotherapy or radiotherapy. In addition, several clinical investigations have demonstrated in recent years that riboflavin laurate has the potential to protect the patients from the disease induced by chemotherapy or radiotherapy. In our studies, it is observed that riboflavin laurate can ameliorate either chemotherapy- or radiotherapy-induced toxicities on Helf cells, and the effect is greater than that of riboflavin. In addition, riboflavin laurate is able to transport through the Caco-2 cell monolayer as the prototype, indicating the protective effects may be produced by the prototype of riboflavin laurate, rather than simply by the released riboflavin

Compact gain-saturated x-ray lasers down to 6.85 nm and amplification down to 5.85 nm

Includes bibliographical references (pages 261-262).Plasma-based x-ray lasers allow single-shot nano-scale imaging and other experiments requiring a large number of photons per pulse to be conducted in compact facilities. However, compact repetitively fired gain-saturated x-ray lasers have been limited to wavelengths above λ = 8.85 nm. Here we extend their range to λ = 6.85 nm by transient traveling wave excitation of Ni-like Gd ions in a plasma created with an optimized pre-pulse followed by rapid heating with an intense sub-picosecond pump pulse. Isoelectronic scaling also produced strong lasing at 6.67 nm and 6.11 nm in Ni-like Tb and amplification at 6.41 nm and 5.85 nm in Ni-like Dy. This scaling to shorter wavelengths was obtained by progressively increasing the pump pulse grazing incidence angle to access increased plasma densities. We experimentally demonstrate that the optimum grazing incidence angle increases linearly with atomic number from 17 deg for Z = 42 (Mo) to 43 deg for Z = 66 (Dy). The results will enable applications of sub-7 nm lasers at compact facilities

Effects of different application ratios of biochar-organic compound fertilizers and chemical fertilizers on soil nutrition content and yield of maize

Overuse of traditional chemical fertilizers may result in environmental pollution and a decrease in the quality of farm produce. By contrast, applying biochar-organic compound fertilizers can enhance soil structure, increase soil fertility, and mitigate pollution levels. This study explores the intricate mechanisms of the combined application of biochar-organic compound fertilizers and chemical fertilizers on soil chemical properties and corn growth. The aim is to elucidate the theoretical foundations supporting the widespread adoption of biochar-organic compound fertilizers. A total of 6 treatments were set up, among which the CK treatment did not apply fertilizer, the CF treatment used bovine excrement organic fertilizer combined with chemical fertilizer, the T1 to T4 treatments used biochar-organic compound fertilizers and replaced 40%, 60%, 80%, and 100% bovine excrement organic fertilizer combined with chemical fertilizer. The results showed that applying biochar-organic compound fertilizers enhanced the slow-release properties of soil available nutrients, increased corn yield, and improved grain quality. Notably, when biochar-organic compound fertilizers were employed instead of 100% bovine excrement organic fertilizer, the yield surpassed that of other treatments, exhibiting a remarkable 9.30% increase compared to the CF treatment. Through comprehensive analysis, it was determined that using biochar-organic compound fertilizer to replace 60% of bovine excrement organic fertilizer is a scheme that can balance both fertilizer efficacy and cost and is recommended to farmers. This research can contribute to promoting the green transformation of agriculture and help achieve the goal of "carbon neutrality"

A Missing Key to Understand the Electrical Resonance and the Mechanical Property of Neurons: a Channel-Membrane Interaction Mechanism

The recent study of the interaction between the fatty acyl tails of lipids and the K+ channel establishes the connection between flexoelectricity and the ion channel's dynamics, named Channel-Membrane Interaction (CMI), that may solve the electrical resonance in neurons

0.85 PW laser operation at 3.3 Hz and high-contrast ultrahigh-intensity λ = 400 nm second-harmonic beamline

Includes bibliographical references (page 3831).We demonstrate the generation of 0.85 PW, 30 fs laser pulses at a repetition rate of 3.3 Hz with a record average power of 85 W from a Ti:sapphire laser. The system is pumped by high-energy Nd:glass slab amplifiers frequency doubled in LiB3O5 (LBO). Ultrahigh-contrast λ = 400 nm femtosecond pulses were generated in KH2PO4 (KDP) with>40% efficiency. An intensity of 6.5 × 1021 W∕cm2 was obtained by frequency doubling 80% of the available Ti:sapphire energy and focusing the doubled light with an f∕2 parabola. This laser will enable highly relativistic plasma experiments to be conducted at high repetition rate

Clinical analysis of rituximab for adult refractory primary membranous nephropathy

Objective·To evaluate clinical efficacy and safety of rituximab (RTX) in the patients with refractory primary membranous nephropathy (PMN).Methods·A retrospective analysis was carried out on the patients with refractory PMN, who had recurred or had not achieved clinical remission after more than 1 year of treatment with glucocorticoid and cyclosporine, cyclophosphamide or tacrolimus, admitted to the Department of Nephrology, Qingpu Branch of Zhongshan Hospital, Fudan University from July 2018 to April 2022. They received 2 doses of RTX. The single dose of RTX was 1 000 mg, and the interval between the two doses was 2 weeks. After 6 months, the numbers of peripheral blood B cells of the patients were detected. If the count of peripheral blood B cells were greater than 5 cell/µL, another 1 000 mg RTX would be added. The main indicators were serum albumin, serum creatinine, urinary protein/creatinine ratio (UPCR), blood antibody against phospholipase A2 receptor (PLA2R) antibody, peripheral blood B cell count, and serum total IgG level. The clinical efficacy and safety of the treatment regimen were evaluated by observing the change of the main indicators of patients and adverse reactions.Results·A total of 18 patients were included, with an average age of (58.17±16.73) years, including 11 males. The total dose of RTX was (2 222.22±485.07) mg, and the follow-up time after RTX treatment was (14.9±4.9) months. At the last follow-up, the serum albumin level was significantly higher than that before RTX treatment [(36.50±5.33) g/L vs (27.61±8.59) g/L, P=0.009]; the serum creatinine level was stable (P>0.05); the value of UPCR decreased significantly [863.30 (203.20, 2 291.75) mg/g vs 2 954.00 (1 458.00, 7 260.75) mg/g, P=0.047]; the PLA2R antibody decreased significantly [(44.32±33.71) RU/mL vs (168.40±88.40) RU/mL, P=0.015]; the peripheral blood B cell count decreased significantly [(37.89±12.43) cell/µL vs (246.40±239.98) cell/µL, P=0.009]; the total blood IgG level was stable (P>0.05). After RTX treatment, 8 patients achieved complete remission (44.4%), 7 patients achieved partial remission (38.9%), and the overall effective rate was 83.3%; only 3 patients were unrelieved (16.7%). In terms of adverse reactions, 1 patient had transfusion allergy reaction, and 1 patient had pulmonary infection.Conclusion·For the patients with refractory PMN who have relapse or do not relieve after traditional immunosuppressive therapy, RTX treatment can effectively induce clinically complete remission or partial remission with good safety

Morphology and metabolism of storage substances contribution to alkali stress responses in two contrasting barley cultivars during germination stage

Abstract: Barley (Hordeum vulgare L.) is a globally significant crop and serves as a pioneer crop for improving saline-alkaline soils due to its salt-alkali tolerant properties. However, the response mechanism of barley to alkali stress remains unclear. In this study, two barley genotypes with contrasting performance under alkali stress were selected: the alkali-tolerant SCMS and the alkali-sensitive QT9919. The morphological and physiological mechanisms of these two barley cultivars in response to alkali stress were elucidated. Results showed that alkali stress inhibited germination in QT9919, leading to significant decreases in germination vigor, plant height and root length. On the other hand, SCMS presented stronger water absorbing capacity than QT9919 under all circumstances. Furthermore, starch degradation and sugar metabolism were suppressed by alkali stress in both barley cultivars through down-regulation of genes expression and reduction of enzymes activities involved in the processes of EMP (Embden-Meyerhof-Parnas), tricarboxylic acid cycle (TCA), and pentose phosphate pathway (PPP). Notably, enzyme activity of hexokinase (HK) and malic dehydrogenase (MDH) showed significant changes under alkali stress between the two barley genotypes. This study provides insights into screening barley germplasm with strong alkali-tolerance and holds significant implications for improving and utilizing of saline-alkaline soils