77,932 research outputs found
Sublytic complement C5b-9 complexes induce thrombospondin-1 production in rat glomerular mesangial cells via PI3-k/Akt: association with activation of latent transforming growth factor-beta1
No full textMesangial cell proliferation is a common cellular response to a variety of different types of glomerular injury. Complement C5b‐9 is a prime candidate to mediate mesangial cell proliferation, especially sublytic C5b‐9, which can induce the production of multiple inflammatory factors and cytokines. Transforming growth factor (TGF)‐β1 plays a major role in the accumulation of extracellular matrix (ECM), while thrombospondin (TSP)‐1 has been identified as an activator of latent TGF‐β1 in an in vitro system. Using rat glomerular mesangial cells (GMCs) as a model system, we assessed the effect of sublytic C5b‐9 on the expression of TSP‐1 and TGF‐β1 and explored the relevant pathway of signal transduction. First, we ensured the concentrations of anti‐Thy1 antibody and complement, which were regarded as a sublytic C5b‐9 dose, and examined whether the sublytic C5b‐9 induced expression of TSP‐1 in rat GMCs which, in turn, activated latent TGF‐β1 by real‐time polymerase chain reaction (PCR) and enzyme‐linked immunosorbent assay (ELISA), respectively. Then, we investigated the role of the PI3‐k/Akt pathway in sublytic C5b‐9‐induced TSP‐1 production in rat GMCs by Western blot analysis. The addition of sublytic C5b‐9 (5% anti‐Thy1 antibody and 4% normal serum) to rat GMCs induced activation of latent TGF‐β1 via TSP‐1. The addition of sublytic C5b‐9 apparently increased the protein of Akt phosphorylation, whereas PI3‐k inhibitor LY294002 could clearly reduce the increase of TSP‐1 induced by sublytic C5b‐9. These results indicate that TSP‐1 is an activator of latent TGF‐β1 in sublytic C5b‐9‐induced rat GMCs; furthermore, the PI3‐k/Akt signal transduction pathway may play a key role in sublytic C5b‐9‐induced TSP‐1 production
Measurement of surface potential decay of corona-charged polymer films using the pulsed electroacoustic method
No full textIn this paper, the pulsed electroacoustic (PEA) technique that allows the determination of space charge in a dielectric material has been used to monitor the electrical potential decay of corona-charged polyethylene films of different thicknesses. To prevent possible disturbance on the surface charge during the PEA measurements, two thin polyethylene films were placed on both sides of the corona-charged sample. Charge profiles measured at different times were used to calculate the potential across the sample. The obtained potential decay was compared with the potential measured using the conventional method. A good agreement has been obtained. More importantly, the charge profile obtained using the PEA technique indicates that bipolar charge injection has taken place
Arxiella longispora Yue Xu, T. Qiu, S. Gao, W. Meng & L. J. Xu. 2023, sp. nov.
No full text<i>Arxiella longispora</i> Yue Xu, T. Qiu, S. Gao, W. Meng & L.J. Xu. <i>sp</i>. <i>nov</i>. (FIGURE 3) <p>Mycobank No.: MB838820</p> <p> <b>Type:</b> — CHINA. HEILONGJIANG: Greater Hinggan Mountains, 52.33°N, 124.7°E, alt. Ex leaves <i>(Populus davidiana</i>., <i>Betula platyphylla</i>, <i>Larix gmelinii</i>. and <i>Pinus Sylvestris</i>) litter (MEFL706), 10 Oct, 2017, J. Liang, B. Liu, W. Meng, Q. Wang & L. Xu, HMPHU 1245 (holotype). Ex-type living culture CCTCC M 2021101 (SGSF 303). GenBank: ITS = MT 921658; LSU = MW 519910; <i>rpb2</i> = MW 717995; <i>tef1</i> = MW 883564.</p> <p> <i>Colonies</i> on PDA, and MEA, reaching 22.00– 22.33 mm after 12 d, smooth, velvet, firstly off-white hyphae, becoming grayish-brown on PDA or grayish-green on MEA after 1 wk; reverse amber, with off-white, smooth, even margin; exudate clear. <i>Colonies</i> on OA reaching 22.00 mm after 12 d, smooth with white hyphae, light yellow to light brown plaques; aerial hyphae sparse, with wavy edge after 3 wk; reverse milk white (Fig. S1). <i>Colonies</i> on CMA reaching 16 mm after 12 d; aerial hyphae dense, becoming grayish towards the outside with black secretions; reverse dark gray (FIGURE S1).</p> <p> <i>Hyphae</i> septate, branched, hyaline to brown, 1.5–5 μm diam. <i>Conidiophores</i> filamentous, smooth, unbranched, or dichotomously branched, ovoid, clavate, cylindrical or irregular. <i>Conidia</i> (13–)14–22(–24) × 3–4 μm (x̄ = 17.8 × 3.5 μm, n = 100), reniform or cylindrical, hyaline, smooth, guttulate, solitary or occasionally interconnected, medianly 1-septate or no septate, inner plane with apical and basal horn-like appendages, with or without a slightly raised hilum near the base of one of the appendages. <i>Chlamydospores</i> absent. <i>Sexual morph</i> absent.</p> <p>The optimal temperatures for the colony growth of SGSF 303 on PDA were in the range of 20 ℃ to 25 ℃ where the colony reached around 22 mm diam. in 12 d (FIGURE S2). Growth rates were similar between pH 5 and 10 on PDA for 12 d, but at the pH 4 the fungus had significantly reduced growth speed (5.67 mm, FIGURE S2).</p> <p> <b>Diagnosis:</b> — <i>Colonies</i> grayish brown on surface; <i>conidiophore</i> hyaline, dichotomously branched; <i>conidia</i> up to more than 20 μm long, hyaline, reniform or cylindrical, inner plane with apical and basal horn-like appendages, medianly 1-septate.</p> <p> <b>Etymology:</b> —Referring to its long spores.</p> <p> <b>Habitat:</b> —Forest litters.</p> <p> <b>Known Distribution:</b> —Greater Hinggan mountains, Heilongjiang province, China.</p> <p> <b>Additional isolates examined:</b> — CHINA, Heilongjiang province, Maoershan, leaves (<i>Populus davidiana</i>, <i>Betula platyphylla</i>) litter and soil, September 2018, Siyu Gao SGSF411, <i>ibid.</i> SGSF573.</p> <p> <b>Notes:</b> — <i>Arxiella longispora</i> is distinct from three asexual morphs in <i>Arxiella</i>, <i>A. dolichandrae</i>, <i>A. lunata</i>, and <i>A. terrestris</i>, by having longer conidia (up to 24 μm long) with a larger length-to-width ratio (>5) (TABLE 2). The closest taxa of <i>A. longispora</i> is <i>A. terrestris</i> based on the similarity of different DNA sequences. The ITS, <i>rpb2</i> and <i>tef1</i> sequences of <i>A. longispora</i> showed 97.73%, 94.42%, and 98.61% similarity to <i>A. terrestris</i>, respectively (TABLE S2). Morphologically, <i>A. longispora</i> is closer to <i>A. terrestris</i> and <i>A. dolichandrae</i> due to shape of the conidia which have a straight inner side. In comparison, <i>A. lunata</i> has conidia with a curved inner side. The black-brown colonies of <i>A. longispora</i> on PDA was different with <i>A. terrestris</i>, which shows black-green colonies on PDA. In addition, <i>A. longispora</i> produces unique conidia as mentioned above, but <i>A</i>. <i>celtidis</i> as the only sexual morph do not produce any asexual morph in the culture.</p>Published as part of <i>Xu, Yue, Du, Tingting, Liu, Yao, Qiu, Tianyi, Gao, Siyu, Meng, Wei & Xu, Lijian, 2023, Arxiella longispora (Muyocopronaceae), a new fungal species from forest litters in Northeast China, pp. 160-168 in Phytotaxa 616 (2)</i> on pages 164-166, DOI: 10.11646/phytotaxa.616.2.5, <a href="http://zenodo.org/record/8389607">http://zenodo.org/record/8389607</a>
Serum ACTH and Cortisol Level is Associated with the Acute Gastrointestinal Injury Grade in ICU Patients [Erratum]
No full textXu W, Qiu Y, Qiu H, Zhong M, Li L. Int J Gen Med. 2024;17:127–134.
On page 127, the third author’s name should read from “Hongping Qiu” to “Hongping Qu”.
This error was introduced by the Editorial staff during the publication process
Dimensions optimization design of a low-speed wind tunnel for an expanded test section with limited overall space
No full textIn this paper, a novel multi-objective optimization framework is proposed for the global dimensions of the low-speed wind tunnel supported by the Belt and Road Joint Laboratory (BRJL-LWT). Three indexes are considered in the process: the flow quality index, the total pressure loss index and the test section volume index. The flow quality is taken as a constraint on the aerodynamic requirements, while pursuing a larger test section space and lower total pressure loss. A multi-objective optimization algorithm is adopted as the solver for the optimization process at four initial flow velocities. The results show that the flow quality of the optimized large test section fully meets the target requirements for structure fluid testing. The total pressure loss index is inversely proportional to the test section volume index for all initial flow velocities. Finally, the optimal BRJL-LWT dimensions are determined and the optimal BRJL-LWT model is developed. The fluid analyses are performed to assess the flow uniformity and turbulence intensity of the fluid within the test section. This optimization framework not only enables the designed wind tunnel to produce the required flow field conditions, but also makes efficient use of the test section space and reduces the facility's operational energy consumption, which significantly extends the applicability of the wind tunnel design
Origin of the Placer Gold of the Barkerville Area, Cariboo District, British Columbia, Canada:
No full textW. L. Uglow and W. A. Johnston.In: Economic Geology. -- Vol. 18. no 6 (1923)
Ant-colony-based multiuser detection for multifunctional-antenna-array-assisted MC DS-CDMA systems
No full textA novel Ant Colony Optimization (ACO) based Multi-User Detector (MUD) is designed for the synchronous Multi-Functional Antenna Array (MFAA) assisted Multi-Carrier Direct-Sequence Code-Division Multiple-Access (MC DS-CDMA) uplink (UL), which supports both receiver diversity and receiver beamforming. The ACO-based MUD aims for achieving a bit-error-rate (BER) performance approaching that of the optimum maximum likelihood (ML) MUD, without carrying out an exhaustive search of the entire MC DS-CDMA search space constituted by all possible combinations of the received multi-user vectors. We will demonstrate that regardless of the number of the subcarriers or of the MFAA configuration, the system employing the proposed ACO based MUD is capable of supporting 32 users with the aid of 31-chip Gold codes used as the T-domain spreading sequence without any significant performance degradation compared to the single-user system. As a further benefit, the number of floating point operations per second (FLOPS) imposed by the proposed ACO-based MUD is a factor of 108 lower than that of the ML MUD. We will also show that at a given increase of the complexity, the MFAA will allow the ACO based MUD to achieve a higher SNR gain than the Single-Input Single-Output (SISO) MC DS-CDMA system. Index Terms—Ant Colony Optimization, Multi-User Detector, Multi-Functional Antenna Array, Multi-Carrier Direct-Sequence Code-Division Multiple-Access, Uplink, Near-Maximum Likelihood Detection
Molecular engineering of copolymers with donor-acceptor structure for bulk heterojunction photovoltaic cells toward high photovoltaic performance
No full textA series of donor-acceptor (D-A) conjugated copolymers with benzo[1,2-b:4,5-b-]dithiophene (BDT) as donor and two different electron-accepting groups bithiophenevinyl-2-pyran-4-ylidenemalononitrile (TVM) and benzothiadiazole (BT) moieties as acceptors is designed and synthesized. The optical and electrochemical properties show that the band gaps of the copolymers are in the range of 1.70-1.84 eV, and the HOMO and LUMO energy levels can be tuned effectively by controlling the varied ratios between TVM and BT because of the change of the ICT interaction between donor and acceptor, the electron delocalization degree, and the electron cloud density distribution of the copolymers. Bulk heterojunction photovoltaic devices are fabricated by using the copolymers as donors and (6,6)-phenyl-C61-butyric acid methyl ester (PC61BM) or (6,6)-phenyl-C71-butyric acid methyl ester (PC71BM) as acceptors. The optimized photovoltaic performances show that the open-circuit voltage (Voc) was gradually increased from 0.7 to 0.94 V when decreasing the HOMO energy levels of copolymers, and the short-circuit current density (Jsc) is greatly improved by increasing the absorption spectrum in the visible region, increasing the hole mobility and optimizing the morphologies of blend films between copolymers and PCBM. The optimized photovoltaic performance with a Voc of 0.78 V, J sc of 5.47 mA/cm2, fill factor (FF) of 0.40, and power conversion efficiency (PCE) of 1.67% under simulated AM 1.5 solar irradiation of 100 mW/cm2 is obtained by the copolymer PM50 (PM50:PC 61BM, 1:3 w/w, in CB solution). This is due to its high hole mobility and interpenetrating network morphology of PM50:PC61BM blend film. The photovoltaic device based on PM50:PC71BM shows a Jsc of 8.32 mA/cm2 and a PCE of 2.89%
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