56 research outputs found

    Effects of Low Suction Temperature on the Boil-off Gas compressor

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    The Boil-off Gas (BOG) compressor is used as a key facility in the liquefied natural gas (LNG) terminal, to recycle the excessive boiled gas for re-liquefaction or direct application. The low suction temperature down to -162? brings about big challenges in design of the BOG compressor. In this paper, the three-dimensional finite element model was used to simulate both the static and periodic transient temperature distribution in the cylinder of a BOG compressor, and a computational fluid dynamics (CFD) model was established to calculate the flow and heat transfer inside the compression chamber and suction/discharge pockets. A test rig was built up to validate the simulated results. The results showed that, the average temperatures in the suction and discharge pockets were about -109? and -60?, respectively, and the temperature of the compression chamber was in-between. The maximum temperature difference between outer and inner surface of the compressor cylinder reached up to 84? during start-up of the compressor, which yielded a thermal strain and stress in the cylinder much larger than those during steady operation of the compressor with only 31? of temperature difference. A variety of pre-cooling temperatures ranging from -20? to -60? were examined, and the results showed pre-cooling down to -20? before start-up was good enough. The amplitude of temperature fluctuation due to the periodic movement of the piston was less than 0.1? in the cylinder wall. The temperature coefficient tended to decrease at lower suction temperature. As the suction temperature decreased from -54.2?to -142.2?, the suction coefficient dropped drastically by 24.4%

    Substoichiometrically Different Mitotypes Coexist in Mitochondrial Genomes of Brassica napus L

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    Cytoplasmic male sterility (CMS) has been identified in numerous plant species. Brassica napus CMS plants, such as Polima (pol), MI, and Shaan 2A, have been identified independently by different researchers with different materials in conventional breeding processes. How this kind of CMS emerges is unclear. Here, we report the mitochondrial genome sequence of the prevalent mitotype in the most widely used pol-CMS line, which has a length of 223,412 bp and encodes 34 proteins, 3 ribosomal RNAs, and 18 tRNAs, including two near identical copies of trnH. Of these 55 genes, 48 were found to be identical to their equivalents in the ā€œnapā€ cytoplasm. The nap mitotype carries only one copy of trnH, and the sequences of five of the six remaining genes are highly similar to their equivalents in the pol mitotype. Forty-four open reading frames (ORFs) with unknown function were detected, including two unique to the pol mitotype (orf122 and orf132). At least five rearrangement events are required to account for the structural differences between the pol and nap sequences. The CMS-related orf224 neighboring region (āˆ¼5 kb) rearranged twice. PCR profiling based on mitotype-specific primer pairs showed that both mitotypes are present in B. napus cultivars. Quantitative PCR showed that the pol cytoplasm consists mainly of the pol mitotype, and the nap mitotype is the main genome of nap cytoplasm. Large variation in the copy number ratio of mitotypes was found, even among cultivars sharing the same cytoplasm. The coexistence of mitochondrial mitotypes and substoichiometric shifting can explain the emergence of CMS in B. napus

    Endometriosis is a disease of immune dysfunction, which could be linked to microbiota

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    Background: Endometriosis, characterized by extrauterine endometrial tissue, leads to irregular bleeding and pelvic pain. Menstrual retrograde theory suggests fragments traverse fallopian tubes, causing inflammation and scar tissue. Prevalent among infertile women, risk factors include fewer pregnancies, delayed childbirth, irregular cycles, and familial predisposition. Treatments, medication, and surgery entail side effects. Studies link gut microbiota alterations to endometriosis, necessitating research to establish causation. We used Mendelian randomization to investigate the potential link between endometriosis and gut microbiota through genetic variants.Methods: Two-sample Mendelian randomization analyzed gut microbiotaā€™s potential causal effects on endometriosis. Instrumental variables, robustly associated with exposures, leveraged GWAS data from MiBioGen for gut microbiota and FinnGen R8 release for endometriosis. SNPs strongly associated with exposures were instrumental variables. Rigorous assessments ensured SNP impact scrutiny on endometriosis.Results: At the genus level, Anaerotruncus, Desulfovibrio, Haemophilus, and Holdemania showed causal association with endometriosis. Specific gut microbiota exhibited causal effects on different endometriosis stages. Holdemania and Ruminococcaceae UCG002 exerted reversible, stage-specific impacts.Conclusion: Mendelian randomization provides evidence for the causal link between specific gut microbiotas and endometriosis, emphasizing the pivotal role of gut microbiota dysbiosis. Modulating gut microbiota emerges as a promising strategy for preventing and treating endometriosis

    A teosinte-derived allele of ZmSC improves salt tolerance in maize

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    Maize, a salt-sensitive crop, frequently suffers severe yield losses due to soil salinization. Enhancing salt tolerance in maize is crucial for maintaining yield stability. To address this, we developed an introgression line (IL76) through introgressive hybridization between maize wild relatives Zea perennis, Tripsacum dactyloides, and inbred Zheng58, utilizing the tri-species hybrid MTP as a genetic bridge. Previously, genetic variation analysis identified a polymorphic marker on Zm00001eb244520 (designated as ZmSC), which encodes a vesicle-sorting protein described as a salt-tolerant protein in the NCBI database. To characterize the identified polymorphic marker, we employed gene cloning and homologous cloning techniques. Gene cloning analysis revealed a non-synonymous mutation atĀ the 1847th base of ZmSCIL76, where a guanine-to-cytosine substitution resultedĀ in the mutation of serine to threonine at the 119th amino acid sequence (using ZmSCZ58 as the reference sequence). Moreover, homologous cloning demonstrated that the variation site derived from Z. perennis. Functional analyses showed that transgenic Arabidopsis lines overexpressing ZmSCZ58 exhibited significant reductions in leaf number, root length, and pod number, alongside suppression of the expression of genes in the SOS and CDPK pathways associated with Ca2+ signaling. Similarly, fission yeast strains expressing ZmSCZ58 displayed inhibited growth. In contrast, the ZmSCIL76 allele from Z. perennis alleviated these negative effects in both Arabidopsis and yeast, with the lines overexpressing ZmSCIL76 exhibiting significantly higher abscisic acid (ABA) content compared to those overexpressing ZmSCZ58. Our findings suggest that ZmSC negatively regulates salt tolerance in maize by suppressing downstream gene expression associated with Ca2+ signaling in the CDPK and SOS pathways. The ZmSCIL76 allele from Z. perennis, however, can mitigate this negative regulatory effect. These results provide valuable insights and genetic resources for future maize salt tolerance breeding programs

    Computational Design of Ī±-AsP/Ī³-AsP Vertical Two-Dimensional Homojunction for Photovoltaic Applications

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    Based on first-principles calculations, we design a Ī±-AsP/Ī³-AsP homojunction with minimum lattice distortion. It is found that the Ī±-AsP/Ī³-AsP homojunction has an indirect bandgap with an intrinsic type-II band alignment. The proposed Ī±-AsP/Ī³-AsP homojunction exhibits high optical absorption of 1.6Ɨ106 cmāˆ’1 along the zigzag direction. A high power conversion efficiency (PCE) of 21.08% is achieved in the designed Ī±-AsP/Ī³-AsP homojunction, which implies it has potential applications in solar cells. Under 4% in-plane axial strain along the zigzag direction, a transition from indirect band gap to direct band gap is found in the Ī±-AsP/Ī³-AsP homojunction. Moreover, the intrinsic type-II band alignment can be tuned to type-I band alignment under in-plane strain, which is crucial for its potential application in optical devices

    The Protein-Binding Behavior of Platinum Anticancer Drugs in Blood Revealed by Mass Spectrometry

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    Cisplatin and its analogues are widely used as chemotherapeutic agents in clinical practice. After being intravenously administrated, a substantial amount of platinum will bind with proteins in the blood. This binding is vital for the transport, distribution, and metabolism of drugs; however, toxicity can also occur from the irreversible binding between biologically active proteins and platinum drugs. Therefore, it is very important to study the protein-binding behavior of platinum drugs in blood. This review summarizes mass spectrometry-based strategies to identify and quantitate the proteins binding with platinum anticancer drugs in blood, such as offline high-performance liquid chromatography/inductively coupled plasma mass spectrometry (HPLCā€“ICP-MS) combined with electrospray ionization mass spectrometry (ESI-MS/MS) and multidimensional LCā€“ESI-MS/MS. The identification of in vivo targets in blood cannot be accomplished without first studying the protein-binding behavior of platinum drugs in vitro; therefore, relevant studies are also summarized. This knowledge will further our understanding of the pharmacokinetics and toxicity of platinum anticancer drugs, and it will be beneficial for the rational design of metal-based anticancer drugs

    Quality evaluation of Sojae Semen Praeparatum by HPLC combined with HS-GC-MS

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    Sojae Semen Praeparatum is a popular fermented legume product in China, with a delicious flavour and health benefits. However, the quality control methods for Sojae Semen Praeparatum are now incomplete, and there are no standards for defining its degree of fermentation. In this study, we introduced colour, acid value, ethanol-soluble extractives and six flavonoid componentsā€™ content to evaluate the quality of Sojae Semen Praeparatum comprehensively. Multiple linear regression was used to streamline the 11 evaluation indicators to 4 and confirm the evaluating feasibility of the four indicators. The degree of fermentation and odour of Sojae Semen Praeparatum were analyzed on headspace-gas chromatography-mass, and two types of odours, 'pungent' and 'unpleasant', could distinguish over-fermented Sojae Semen Praeparatum. Our research developed fermentation specifications and quality standards for Sojae Semen Praeparatum
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