23 research outputs found

    Effect of Earth-Moon's gravity on TianQin's range acceleration noise. II. Impact of orbit selection

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    The paper is a sequel to our previous work (Zhang et al. Phys. Rev. D 103, 062001 (2021)). For proposed geocentric space-based gravitational wave detectors such as TianQin, gLISA, and GADFLI, the gravity-field disturbances, i.e., the so called ``orbital noise'', from the Earth-Moon system on the sensitive intersatellite laser interferometric measurements should be carefully evaluated and taken into account in the concept studies. Based on TianQin, we investigate how the effect, in terms of frequency spectra, varies with different choices of orbital orientations and radii through single-variable studies, and present the corresponding roll-off frequencies that may set the lower bounds of the targeted detection bands. The results, including the special cases of geostationary orbits (gLISA/GADFLI) and repeat orbits, can provide a useful input to orbit and constellation design for future geocentric missions.Comment: 8 pages, 9 figure

    Effect of solar free oscillations on TianQin's range acceleration noise

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    TianQin is a proposed space-based gravitational-wave detector mission to be deployed and operated in high Earth orbits. As a sequel to [Zhang et al. Phys. Rev. D 103, 062001 (2021)], we investigate a type of ``orbital noise'' in TianQin's range acceleration that is caused by gravitational perturbation associated with solar free oscillations. Frequencies of such oscillations are typically within TianQin's measurement band of 0.1 mHz--1 Hz, and the disturbance level needs careful assessment. By using high-precision orbit propagation and adding the Sun's time-variable oblateness J2J_2 to detailed gravity-field models, we examine the effect in the frequency domain and show that the solar free oscillation noise is expected to be two orders of magnitude lower than the noise requirement on single links and hence has little impact on the mission.Comment: 10 pages, 5 figure

    Modified Technique of Pancreaticogastrostomy for Soft Pancreas with Two Continuous Hemstitch Sutures: A Single-Center Prospective Study

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    Postoperative pancreatic fistula (POPF) remains a persistent problem after pancreaticoduodenectomy (PD), especially in the presence of a soft, nonfibrotic pancreas. To reduce the risk of POPF, pancreaticogastrostomy (PG) is an optional reconstruction technique for surgeons after PD. This study presents a new technique of PG for a soft, nonfibrotic pancreas with double-binding continuous hemstitch sutures and evaluates its safety and reliability. From January 2011 to June 2012, 92 cases of patients with periampullary malignancy with a soft pancreas underwent this technique. A modified technique of PG was performed with two continuous hemstitch sutures placed in the mucosal and seromuscular layers of the posterior gastric wall, respectively. Then the morbidity and mortality was calculated. This technique was applied in 92 patients after PD all with soft pancreas. The median time for the anastomosis was 12 min (range, 8–24). Operative mortality was zero, and morbidity was 16.3 % (n = 15), including hemorrhage (n = 2), biliary fistula (n = 2), pulmonary infection (n = 1), delayed gastric emptying (DGE; n = 5, 5.4 %), abdominal abscess (n = 3, one caused by PF), and POPF (n = 2, 2.2 %). Two patients developed a pancreatic fistula (one type A and one type B) classified according to the International Study Group on Pancreatic Fistula. The described technique is a simple and safe reconstruction procedure after PD, especially for patients with a soft and fragile pancreas. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11605-013-2183-8) contains supplementary material, which is available to authorized users

    Identification and characterization of a novel fumarase gene by metagenome expression cloning from marine microorganisms

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    <p>Abstract</p> <p>Background</p> <p>Fumarase catalyzes the reversible hydration of fumarate to <smcaps>L</smcaps>-malate and is a key enzyme in the tricarboxylic acid (TCA) cycle and in amino acid metabolism. Fumarase is also used for the industrial production of <smcaps>L</smcaps>-malate from the substrate fumarate. Thermostable and high-activity fumarases from organisms that inhabit extreme environments may have great potential in industry, biotechnology, and basic research. The marine environment is highly complex and considered one of the main reservoirs of microbial diversity on the planet. However, most of the microorganisms are inaccessible in nature and are not easily cultivated in the laboratory. Metagenomic approaches provide a powerful tool to isolate and identify enzymes with novel biocatalytic activities for various biotechnological applications.</p> <p>Results</p> <p>A plasmid metagenomic library was constructed from uncultivated marine microorganisms within marine water samples. Through sequence-based screening of the DNA library, a gene encoding a novel fumarase (named FumF) was isolated. Amino acid sequence analysis revealed that the FumF protein shared the greatest homology with Class II fumarate hydratases from <it>Bacteroides </it>sp. 2_1_33B and <it>Parabacteroides distasonis </it>ATCC 8503 (26% identical and 43% similar). The putative fumarase gene was subcloned into pETBlue-2 vector and expressed in <it>E. coli </it>BL21(DE3)pLysS. The recombinant protein was purified to homogeneity. Functional characterization by high performance liquid chromatography confirmed that the recombinant FumF protein catalyzed the hydration of fumarate to form <smcaps>L</smcaps>-malate. The maximum activity for FumF protein occurred at pH 8.5 and 55°C in 5 mM Mg<sup>2+</sup>. The enzyme showed higher affinity and catalytic efficiency under optimal reaction conditions: <it>K</it><sub>m</sub>= 0.48 mM, <it>V</it><sub>max </sub>= 827 μM/min/mg, and <it>k</it><sub>cat</sub>/<it>K</it><sub>m </sub>= 1900 mM/s.</p> <p>Conclusions</p> <p>We isolated a novel fumarase gene, <it>fumF</it>, from a sequence-based screen of a plasmid metagenomic library from uncultivated marine microorganisms. The properties of FumF protein may be ideal for the industrial production of <smcaps>L</smcaps>-malate under higher temperature conditions. The identification of FumF underscores the potential of marine metagenome screening for novel biomolecules.</p

    GPX8 regulates pan-apoptosis in gliomas to promote microglial migration and mediate immunotherapy responses

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    IntroductionGliomas have emerged as the predominant brain tumor type in recent decades, yet the exploration of non-apoptotic cell death regulated by the pan-optosome complex, known as pan-apoptosis, remains largely unexplored in this context. This study aims to illuminate the molecular properties of pan-apoptosis-related genes in glioma patients, classifying them and developing a signature using machine learning techniques.MethodsThe prognostic significance, mutation features, immunological characteristics, and pharmaceutical prediction performance of this signature were comprehensively investigated. Furthermore, GPX8, a gene of interest, was extensively examined for its prognostic value, immunological characteristics, medication prediction performance, and immunotherapy prediction potential. ResultsExperimental techniques such as CCK-8, Transwell, and EdU investigations revealed that GPX8 acts as a tumor accelerator in gliomas. At the single-cell RNA sequencing level, GPX8 appeared to facilitate cell contact between tumor cells and macrophages, potentially enhancing microglial migration. ConclusionsThe incorporation of pan-apoptosis-related features shows promising potential for clinical applications in predicting tumor progression and advancing immunotherapeutic strategies. However, further in vitro and in vivo investigations are necessary to validate the tumorigenic and immunogenic processes associated with GPX8 in gliomas

    Bisphenol A and 17&alpha;-Ethinylestradiol Removal from Water by Hydrophobic Modified Acicular Mullite

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    The hydrophilicity and hydrophobicity of adsorbents have an important influence on organic pollutants adsorption. To effectively remove bisphenol A (BPA) and 17-acetylene estradiol (EE2) from water, acicular mullite was modified by cetyl trimethyl ammonium bromide (CTMAB) to increase the hydrophobicity of the mullite. The adsorption process and mechanism of BPA and EE2 by modified acicular mullite were studied in detail. Results indicated that the concentration of CTMAB solution was related to the contact angle of CTMAB-modified mullite (CTMAB-M). The optimal concentration of CTMAB was 4 mmol/L. The CTMAB-M could adsorb more hydrophobic organic pollutants than virgin acicular mullite. Due to the electrostatic attraction and hydrophobic partitioning, the adsorption amount of BPA and EE2 on CTMAB-M increased with increasing pH. The adsorption amounts of BPA and EE2 on CTMAB-M increase with increasing ionic strength. The adsorption kinetics of BPA and EE2 adsorption on CTMAB-M could be best described by the pseudo second-order kinetics model. Thermodynamic analysis showed that the low temperature favored the adsorption of BPA and EE2 on CTMAB-M, and the adsorption was driven by entropy increase. Site energy studies indicated that BPA and EE2 firstly occupy high-energy adsorption sites and then switch to low-energy sites during the adsorption process. The average adsorption site energy &mu;(E*) of EE2 on CTMAB-M is smaller than BPA. CTMAB modification can significantly improve the removal efficiency of ceramsite on EDCs

    An Assessment on the Fermentation Quality and Bacterial Community of Corn Straw Silage with Pineapple Residue

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    The effects of pineapple residue (PR) on fermentation quality, chemical composition, and bacterial community of corn straw (CS) silage were evaluated. CS was ensiled with 0% control group (CON), 15% (P1), 30% (P2), and 45% (P3) PR on a fresh matter (FM) basis for 45 days. P3 had lower dry matter (DM) and crude protein (CP) contents but higher ammonia-N (NH3-N) content than the other three groups (p p p p Lactobacillus gradually increased, and the dominant genus in P3 was Acetobacter. In summary, the addition of PR can improve the quality of CS silage, and the optimum addition ratio for PR was 15% on a FM basis

    Bisphenol A and 17α-Ethinylestradiol Removal from Water by Hydrophobic Modified Acicular Mullite

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    The hydrophilicity and hydrophobicity of adsorbents have an important influence on organic pollutants adsorption. To effectively remove bisphenol A (BPA) and 17-acetylene estradiol (EE2) from water, acicular mullite was modified by cetyl trimethyl ammonium bromide (CTMAB) to increase the hydrophobicity of the mullite. The adsorption process and mechanism of BPA and EE2 by modified acicular mullite were studied in detail. Results indicated that the concentration of CTMAB solution was related to the contact angle of CTMAB-modified mullite (CTMAB-M). The optimal concentration of CTMAB was 4 mmol/L. The CTMAB-M could adsorb more hydrophobic organic pollutants than virgin acicular mullite. Due to the electrostatic attraction and hydrophobic partitioning, the adsorption amount of BPA and EE2 on CTMAB-M increased with increasing pH. The adsorption amounts of BPA and EE2 on CTMAB-M increase with increasing ionic strength. The adsorption kinetics of BPA and EE2 adsorption on CTMAB-M could be best described by the pseudo second-order kinetics model. Thermodynamic analysis showed that the low temperature favored the adsorption of BPA and EE2 on CTMAB-M, and the adsorption was driven by entropy increase. Site energy studies indicated that BPA and EE2 firstly occupy high-energy adsorption sites and then switch to low-energy sites during the adsorption process. The average adsorption site energy μ(E*) of EE2 on CTMAB-M is smaller than BPA. CTMAB modification can significantly improve the removal efficiency of ceramsite on EDCs

    The Whole Process CFD Numerical Simulation of Flow Field and Suspended Solids Distribution in a Full-Scale High-Rate Clarifier

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    To further reduce the contents of phosphorus and suspended solids (SS) in the effluent, the high-rate clarifier is adopted by some wastewater treatment plants (WWTPs) to upgrade their processes. However, due to the complex phosphorus species and unclear hydraulic characteristics after the addition of the high-rate clarifier, the removal efficiencies of total phosphorus and the optimization strategies of SS removal remain unclear. The high-rate clarifiers are mainly composed of the mixing zone and the settling zone. Only the hydraulic characteristics of the mixing zone have been studied. It is necessary to focus on the hydrodynamics of the settling zone to understand the sedimentation process and pollutant removal mechanism in depth. Therefore, this study focused on the whole process of high-rate clarifier of the Wuhan Nantaizi Lake WWTP in China. The distributions of flow velocity and SS in the full-scale high-rate clarifier were simultaneously simulated by the solid-liquid two-phase whole process computational fluid dynamics (CFD) model which was established in this study. The simulated results of the developed CFD model were in good agreement with the experimental data obtained in the high-rate clarifier. The normalized standard error was less than 7.66%. The overall flow velocities in the settling tank were much smaller than that in the reaction tank. After the fluid passed through the diversion effect of the overflow wall and the under-through channel, the overall kinetic energy loss was relatively large. Meanwhile, the residence time of fluid in the settling tank was longer than that in the reaction tank. The sludge sedimentation happened at the edge of the settling tank due to the vertical angle between the plug-flow fluid and the outlet. The successful construction of the CFD model could lay the foundation for the next step of the high-rate clarifier optimization operation and research on pollutant removal
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