Research on Flow Characteristics of Electronically Controlled Injection Device Developed for High-Power Natural Gas Engines

Accurate fuel supply is a key factor that influences the performance of high-power natural gas engines. The premixed and single-point natural gas supply system is the most commonly used method to ensure a large fuel supply but one of its shortcomings is the inaccuracy of the fuel supply. A new type of natural gas injection device with fungiform configuration and electronically controlled actuator was developed to achieve high efficiency and stable operation in high-power natural gas engines. Firstly, a computational fluid dynamics (CFD) model of the injection device was created. Based on this model, the key structure parameters that have a significant influence on the outlet flow were confirmed. A particle swarm optimization (PSO) model was developed to identify the optimal outflow structure. Then, a flow function for precise flow supply control was constructed based on a response surface model, according to the flow rates of the device under different control parameters. Finally, a flow-characteristic test bench and a high-power engine prototype were developed to verify the simulation and optimization results. The results indicate that the optimized outflow structure shows low pressure loss and a large flow rate, improving injection efficiency by 10.37% and mass flow by 11.78% under 0.4 Mpa pressure difference. More importantly, the cycle fuel supply could be controlled accurately for each cylinder owing to the developed flow function. Consequently, compared with the original engine using a single-point natural gas supply system, the cylinder performance imbalance was improved by 37.47%

Serum 25-hydroxyvitamin D and bone mineral density among children and adolescents in a Northwest Chinese city

Although vitamin D is essential for bone health, little is known about prevalence of vitamin D deficiency and low bone mineral density (BMD) among children, especially those in developing countries. It also remains unclear whether serum 25-hydroxyvitamin D [25(OH)D] is associated with BMD among children. We investigated these questions among children and adolescents in Yinchuan (latitude: 38° N), Ningxia, an economically underdeveloped province in Northwest China. A total of 1582 children (756 boys and 826 girls), aged 6–18 years, were recruited from schools using the stratified random sampling method in fall 2015. Serum 25(OH)D concentrations were measured by enzyme-linked immunosorbent assay, and BMD was quantified by dual-energy X-ray absorptiometry. Vitamin D deficiency (defined as serum 25(OH)D ≤ 37.5 nmol/L) was present in 35.5% of study subjects. There were no clear patterns of differences in serum 25(OH)D concentrations across the four age groups compared (6–9 years, 10–13 years, 14–16 years, and 17–18 years). The prevalence of low total body less head (TBLH) BMD (defined as a Z-score of ≤ −2.0 standard deviations away from the mean BMD values of the Chinese pediatric reference population) among children examined was 1.8% and was not significantly different among the four age groups considered. Linear regression analysis revealed that age, weight, and height were significantly and positively associated with TBLH BMD and that the strongest determinant of TBLH BMD was age in boys and weight in girls. There were no significant correlations between serum 25(OH)D concentrations and BMD obtained for total body and at various skeletal sites (r ranged from −0.005 to 0.014) regardless of whether children evaluated were sufficient, insufficient, or deficient in vitamin D. In conclusion, more than one-third of children and adolescents in a Northwest Chinese city were deficient in vitamin D but only <2% of them developed low BMD

Empirical Review of Smart Contract and DeFi Security: Vulnerability Detection and Automated Repair

Decentralized Finance (DeFi) is emerging as a peer-to-peer financial ecosystem, enabling participants to trade products on a permissionless blockchain. Built on blockchain and smart contracts, the DeFi ecosystem has experienced explosive growth in recent years. Unfortunately, smart contracts hold a massive amount of value, making them an attractive target for attacks. So far, attacks against smart contracts and DeFi protocols have resulted in billions of dollars in financial losses, severely threatening the security of the entire DeFi ecosystem. Researchers have proposed various security tools for smart contracts and DeFi protocols as countermeasures. However, a comprehensive investigation of these efforts is still lacking, leaving a crucial gap in our understanding of how to enhance the security posture of the smart contract and DeFi landscape. To fill the gap, this paper reviews the progress made in the field of smart contract and DeFi security from the perspective of both vulnerability detection and automated repair. First, we analyze the DeFi smart contract security issues and challenges. Specifically, we lucubrate various DeFi attack incidents and summarize the attacks into six categories. Then, we present an empirical study of 42 state-of-the-art techniques that can detect smart contract and DeFi vulnerabilities. In particular, we evaluate the effectiveness of traditional smart contract bug detection tools in analyzing complex DeFi protocols. Additionally, we investigate 8 existing automated repair tools for smart contracts and DeFi protocols, providing insight into their advantages and disadvantages. To make this work useful for as wide of an audience as possible, we also identify several open issues and challenges in the DeFi ecosystem that should be addressed in the future.Comment: This paper is submitted to the journal of Expert Systems with Applications (ESWA) for revie

Clinical and immunological characteristics of TGM3 in pan-cancer: A potential prognostic biomarker

Background: Recent studies have identified that transglutaminases (TGMs) are involved in a widespread epigenetic modification in tumorigenesis. However, it remains unclear how transglutaminase 3 (TGM3) affects in pan-cancer. The present study aimed to explore the clinical and prognostic function of TGM3 in pan-cancer as well as to explore the relationship of TGM3 expression with clinical stage, survival rate, prognosis condition, immune infiltration and mutation indicators.Methods: The relevant data of tumors were obtained from The Cancer Genome Atlas (TCGA), TARGET, Cancer Cell Line Encyclopedia (CCLE) and Genotype-Tissue Expression (GTEx) databases. According to the Human Protein Atlas (HPA) and TIMER databases, we evaluated the protein expression levels of TGM3 in different organs and tissues as well as their association with immune cell infiltration and immunotherapeutic response in pan-cancers. Expression differences between normal and tumor tissues as well as survival and prognosis situation, clinical data characteristics, tumor mutational burden (TMB), microsatellite instability (MSI), and RNA methylation were also assessed. Oncogenic analyses were also evaluated by GSEA.Results: Compared to normal tissues, some tumor tissues had a lower expression level of TGM3, while other tumor tissues had a high expression level of TGM3. Further studies showed that high TGM3 expression had a certain risk impact on pan-cancer as high TGM3 expression levels were detrimental to the survival of several cancers, except for pancreatic cancer (PAAD). High expression level of TGM3 was also related to higher clinical stages in most cancers. The expression level of TGM3 was significantly negatively correlated with the expression of immune infiltration-related cells, including B cells, CD8+ T cells, CD4+ T cells, neutrophils, macrophages and dendritic cells (DCs). Furthermore, in most cancer types, TGM3 was inversely correlated with TMB, MSI, and methylation, suggesting that TGM3 expression can be used to assess potential therapeutic response, especially immune-related targeted therapy. GSEA analysis elucidated the biological and molecular function of TGM3 in various cancer types. Taken together, these bioinformatic analyses identified TGM3 as an important biomarker for clinical tumor prognosis and evaluation of treatment efficacy.Conclusion: We comprehensively analyzed the clinical characteristics, tumor stages, immune infiltration, methylation level, gene mutation, functional enrichment analysis and immunotherapeutic value of TGM3 in pan-cancer, providing implications for the function of TGM3 and its role in clinical treatment

ULK1 phosphorylates Exo70 to suppress breast cancer metastasis

乳腺癌是威胁女性生命健康的“头号杀手”，而远处转移是乳腺癌患者死亡的主要原因。因此，了解乳腺癌如何发动侵袭和转移，对于有效治疗乳腺癌、延长病人生存期具有重要意义。本研究中，该团队发现ULK1通过结合并磷酸化胞泌蛋白复合体关键亚基Exo70来抑制乳腺癌转移。ULK1对Exo70上Ser47，Ser59和Ser89位点的磷酸化，严重地削弱了Exo70的自身寡聚化和与其它胞外分泌复合体亚基的结合，进而减少了细胞运动伪足形成以及基质金属蛋白酶的分泌，从而抑制乳腺癌细胞的迁移和侵袭。该论文首次揭示了胞外分泌复合体重要成员Exo70在乳腺癌中受到ULK1和ERK1/2的双重磷酸化调控，从而使得乳腺癌细胞可以根据外环境来决定潜伏还是发动侵袭转移，为乳腺癌的治疗提供了新的理论基础。 本论文的通讯作者为占艳艳副教授、郭巍教授和胡天惠教授。医学院博士生毛丽媛、占艳艳副教授、吴斌博士和医学院博士生于强为共同第一作者。【Abstract】Increased expression of protein kinase ULK1 was reported to negatively correlate with breast cancer metastasis. Here we report that ULK1 suppresses the migration and invasion of human breast cancer cells. The suppressive effect is mediated through direct phosphorylation of Exo70, a key component of the exocyst complex. ULK1 phosphorylation inhibits Exo70 homo-oligomerization as well as its assembly to the exocyst complex, which are needed for cell protrusion formation and matrix metalloproteinases secretion during cell invasion. Reversely, upon growth factor stimulation, Exo70 is phosphorylated by ERK1/2, which in turn suppresses its phosphorylation by ULK1. Together, our study identifies Exo70 as a substrate of ULK1 that inhibits cancer metastasis, and demonstrates that two counteractive regulatory mechanisms are well orchestrated during tumor cell invasion.This work was supported by the grants from the National Natural Science Foundation of China (81572589, U1405228, 81472568, and 31770860), the Natural Science Foundation of Fujian grant (2017J06020, 2018J01400, 2017R1036-4, 2017R1036-6, 2016R1034-1, and 2016R1034-4), and the Xiamen Science and Technology grant (3502Z20159013) to Y.-y.Z. and T.H., and National Institute of Health R01 GM111128 to W.G.该论文的研究成果是在国家自然科学基金和福建省基金的资助下，与美国宾夕法尼亚大学和清华大学共同协作完成的

Resting-State Activity of Prefrontal-Striatal Circuits in Internet Gaming Disorder: Changes With Cognitive Behavior Therapy and Predictors of Treatment Response

Cognitive behavior therapy (CBT) is effective for the treatment of Internet gaming disorder (IGD). However, the mechanisms by which CBT improves IGD-related clinical symptoms remain unknown. This study aimed to discover the therapeutic mechanism of CBT in IGD subjects using resting-state functional magnetic resonance imaging (rsfMRI). Twenty-six IGD subjects and 30 matched healthy controls (HCs) received rsfMRI scan and clinical assessments; 20 IGD subjects completed CBT and then were scanned again. The amplitude of low-frequency (ALFF) values and the functional connectivity (FC) between the IGD group and the HC group were compared at baseline, as well as the ALFF values and FC before and after the CBT in the IGD group. Prior to treatment, the IGD group exhibited significantly increased ALFF values in the bilateral putamen, the right medial orbitofrontal cortex (OFC), the bilateral supplementary motor area (SMA), the left postcentral gyrus, and the left anterior cingulate (ACC) compared with the HC group. The HC group showed significantly increased FC values between the left medial OFC and the putamen compared with the IGD group, the FC values of IGD group were negatively associated with the BIS-11 scores before treatment. After the CBT, the weekly gaming time was significantly shorter, and the CIAS and BIS-II scores were significantly lower. The ALFF values in the IGD subjects significantly decreased in the left superior OFC and the left putamen, and the FC between them significantly increased after the CBT. The degree of the FC changes (ΔFC/Pre−FC) was positively correlated with the scale of the CIAS scores changes (ΔCIAS/Pre−CIAS) in the IGD subjects. CBT could regulate the abnormal low-frequency fluctuations in prefrontal-striatal regions in IGD subjects and could improve IGD-related symptoms. Resting-state alternations in prefrontal-striatal regions may reveal the therapeutic mechanism of CBT in IGD subjects

Structure-Activity Relationship Study Enables the Discovery of a Novel Berberine Analogue as RXRα Activator to Inhibit Colon Cancer

黄连素是从黄连、黄柏等传统中药中提取的单体化合物，常用于治疗痢疾及其它消化道感染。近年来，黄连素的抗心律失常、调控能量代谢、降血糖血脂和抗癌等多重功效使其成为一个“明星”中药单体化合物。尽管黄连素具有很好的安全性，但其抗癌作用在临床应用上仍具有许多局限性，包括抗癌活性低、溶解度和生物利用度低等。然而，由于黄连素的分子靶点不清楚，以往对黄连素的改造比较盲目和随机，并未取得较好的进展。胡天惠团队与张延东团队紧密合作、优势互补，针对黄连素与RXR的结合模式，运用结构生物学方法和全合成相结合，设计合成了多种黄连素衍生物，并开展了构效关系分析。发现黄连素衍生物B-12在结合并激活RXR、抗肠癌活性、溶解度和生物利用度方面均明显优于黄连素，且保留了黄连素的肿瘤选择性和低毒副作用，具有很好的临床转化前景。该研究也为结构生物学指导黄连素衍生物药物设计提供了理论基础。本论文的通讯作者为医学院占艳艳副教授、张延东教授和胡天惠教授。医学院博士生徐贝贝和化学化工学院博士生江训金为共同第一作者。We reported recently that berberine, a traditional oriental medicine to treat gastroenteritis, binds and activates Retinoid X receptor α (RXRα) to suppress the growth of colon cancer cells. Here, we extended our studies based on the binding mode of berberine with RXRα by design, synthesis and biological evaluation of a focused library of 15 novel berberine analogues. Among them, 3,9-dimethoxy-5,6-dihydroisoquinolino[3,2-a]isoquinolin-7-ium chloride (B-12) was identified as the optimal RXRα activator. More efficiently than berberine, B-12 bound and altered the conformation of RXRα/LBD, thereby suppressing Wnt/β-catenin pathway and colon cancer cell growth via RXRα mediation. In addition, B-12 not only preserved berberine’s tumor selectivity but also greatly improved its bioavailability. Remarkably, in mice, B-12 did not show obvious side effects including hypertriglyceridemia as other RXRα agonists, or induce hepatorenal toxicity. Together, our study describes an approach for the rational design of berberine-derived RXRα activators as novel effective antineoplastic agents for colon cancer.This work was supported by the National Natural Science Foundation of China (31770860, 21772164, 81572589, 81602560 and 21572187), and the Natural Science Foundation of Fujian Province (2018R1036-2, 2017J06020, 2019R1001-4, and 2019R1001-5). 项目得到了国家自然科学基金委促进海峡两岸科技合作联合基金重点项目、面上项目和福建省自然科学基金的支持

Aequorea taiwanensis n. sp. (Hydrozoa,Leptomedusae) and mtCOI sequence analysis for the genus Aequorea

【中文摘要】 Aequorea taiwanensis,a new hydrozoan species from the Taiwan Strait was described using morphological and molecular characteristics.Both morphological and mitochondrial cytochrome oxidase subunit I(mtCOI) data supported A.taiwanensis n.sp.as a valid species.Sequence divergence and genetic distance of A.taiwanensis n.sp.,A.papillata and A.conica were analysed based on the mtCOI gene sequences.The mtCOI sequences from these three species of the genus Aequorea showed high variation frequency,with sequence dive... 【英文摘要】 Aequorea taiwanensis,a new hydrozoan species from the Taiwan Strait was described using morphological and molecular characteristics.Both morphological and mitochondrial cytochrome oxidase subunit I(mtCOI) data supported A.taiwanensis n.sp.as a valid species.Sequence divergence and genetic distance of A.taiwanensis n.sp.,A.papillata and A.conica were analysed based on the mtCOI gene sequences.The mtCOI sequences from these three species of the genus Aequorea showed high variation frequency,with sequence dive..

Target density effects on charge tansfer of laser-accelerated carbon ions in dense plasma

We report on charge state measurements of laser-accelerated carbon ions in the energy range of several MeV penetrating a dense partially ionized plasma. The plasma was generated by irradiation of a foam target with laser-induced hohlraum radiation in the soft X-ray regime. We used the tri-cellulose acetate (C$_{9}$H$_{16}$O$_{8}$) foam of 2 mg/cm$^{-3}$ density, and $1$-mm interaction length as target material. This kind of plasma is advantageous for high-precision measurements, due to good uniformity and long lifetime compared to the ion pulse length and the interaction duration. The plasma parameters were diagnosed to be T$_{e}$=17 eV and n$_{e}$=4 $\times$ 10$^{20}$ cm$^{-3}$. The average charge states passing through the plasma were observed to be higher than those predicted by the commonly-used semiempirical formula. Through solving the rate equations, we attribute the enhancement to the target density effects which will increase the ionization rates on one hand and reduce the electron capture rates on the other hand. In previsous measurement with partially ionized plasma from gas discharge and z-pinch to laser direct irradiation, no target density effects were ever demonstrated. For the first time, we were able to experimentally prove that target density effects start to play a significant role in plasma near the critical density of Nd-Glass laser radiation. The finding is important for heavy ion beam driven high energy density physics and fast ignitions.Comment: 7 pages, 4 figures, 35 conference