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The function of kallistatin in airway inflammation, particularly chronic rhinosinusitis with nasal polyps (CRSwNP), has not been elucidated. We sought to investigate the role of kallistatin in airway inflammation. Kallistatin and proinflammatory cytokine expression levels were detected in nasal polyps. For the in vivo studies, we constructed the kallistatin-overexpressing transgenic mice to elucidate the role of kallistatin in airway inflammation. Furthermore, the levels of plasma IgE and proinflammatory cytokines in the airways were evaluated in the kallistatin−/− rat in vivo model under a type 2 inflammatory background. Finally, the Notch signaling pathway was explored to understand the role of kallistatin in CRSwNP. We showed that the expression of kallistatin was significantly higher in nasal polyps than in the normal nasal mucosa and correlated with IL-4 expression. We also discovered that the nasal mucosa of kallistatin-overexpressing transgenic mice expressed higher levels of IL-4 expression, associating to T H 2-type inflammation. Interestingly, we observed lower IL-4 levels in the nasal mucosa and lower total plasma IgE of the kallistatin−/− group treated with house dust mite allergen compared with the wild-type house dust mite group. Finally, we observed a significant increase in the expression of Jagged2 in the nasal epithelium cells transduced with adenovirus-kallistatin. This heightened expression correlated with increased secretion of IL-4, attributed to the augmented population of CD4+CD45+Notch1+ T cells. These findings collectively may contribute to the induction of T H 2-type inflammation. Kallistatin was demonstrated to be involved in the CRSwNP pathogenesis by enhancing the T H 2 inflammation, which was found to be associated with more expression of IL-4, potentially facilitated through Jagged2-Notch1 signaling in CD4+ T cells. [ABSTRACT FROM AUTHOR]

Background.—: The role of genetics in determining an individual''s susceptibility to high altitude pulmonary edema (HAPE) is unclear. However a number of genetic polymorphisms have recently been found to be overrepresented in patients with HAPE. Changes at the mitochondrial level may play an important role in the human body''s adaptation to hypoxia. Polymorphisms of mitochondrial DNA (mtDNA) have been shown to be responsible for differences in organelle function. Therefore, the frequency of mtDNA 3397A/G and 3552T/A polymorphisms were studied to determine their potential role in HAPE. Objectives.—: To further study the role of mtDNA 3397A/G and 3552T/A variations of reduced nicotinamide adenosine dinucleotide dehydrogenase 1 in HAPE susceptibility. Methods.—: The single-nucleotide polymorphisms of mtDNA 3397 and 3552 in patients with HAPE (n = 132) and their matched control subjects (n = 233) were studied using polymerase chain reaction sequencing. Results.—: The frequency of mtDNA 3397G in the HAPE group (2.3%) was significantly higher than that of the control group (0%; P = .021; odds ratio, 2.806; 95% confidence interval, 2.443 to 3.223). The frequency of mtDNA 3552A in the HAPE group (6.8%) also was significantly higher than in the control group (1.7%; P = .012; odds ratio, 4.198; 95% confidence interval, 1.264 to 13.880). Conclusions.—: In this study, we present the first evidence of differences in mtDNA polymorphism frequencies between HAPE victims and healthy Han Chinese. Genotypes of mtDNA 3397G and 3552A were correlated with HAPE susceptibility. This result could contribute to defining the role of the mitochondrial genome in the pathogenesis of HAPE. [Copyright &y& Elsevier]

Abstract: Pikas originated in Asia and are small lagomorphs native to cold climates. The plateau pika, Ochotona curzoniae is a keystone species on the Qinghai–Tibet Plateau and an ideal animal model for hypoxic adaptation studies. Altered mitochondrial function, especially cytochrome c oxidase activity, is an important factor in modulation of energy generation and expenditure during cold and hypoxia adaptation. In this study, we determined the complete nucleotide sequence of the O. curzoniae mitochondrial genome. The plateau pika mitochondrial DNA is 17,131bp long and encodes the complete set of 37 proteins typical for vertebrates. Phylogenetic analysis based on concatenated heavy-strand encoded protein-coding genes revealed that pikas are closer to rabbit and hare than to rat. This suggests that rabbit or hare would be a good control animal for pikas in cold and hypoxia adaptation studies. Fifteen novel mitochondrial DNA-encoded amino acid changes were identified in the pikas, including three in the subunits of cytochrome c oxidase. These amino acid substitutions potentially function in modulation of mitochondrial complexes and electron transport efficiency during cold and hypoxia adaptation. [Copyright &y& Elsevier]

Abstract: The better adaptation of native Tibetans to hypoxia is thought to be partly due to improved umbilical circulation, which results in reduced pre- and postnatal fatalities. We hypothesized that the difference in umbilical circulation between native Tibetans and other high-altitude inhabitants was due to differences in the expression of hypoxia-induced factor (HIF-1) and its target genes vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS). We tested this hypothesis by examining the effect of hypoxia on the expression of HIF-1α, VEGF, and iNOS in cultured umbilical venous endothelial cells (UVECs) from native Tibetans and immigrant Hans. UVECs were collected and cultured under hypoxic (0.5% oxygen) or normoxic conditions for 2, 4, 12 and 24 h. The mRNA levels of HIF-1α, VEGF, endothelial nitric oxide synthase (eNOS) and iNOS and the protein level of HIF-1α were determined with RT-PCR and Western blot analyses, respectively. In both immigrant Han and Tibetans, HIF-1α mRNA was constitutively expressed under normoxic condition, and remained constant after hypoxic exposure. In contrast, HIF-1α protein was undetectable under normoxic condition, but underwent dynamic changes in response to hypoxia. It was induced at 4 h, peaked at 12 h, and remained elevated at 24 h. Concurrent with the induction of HIF-1α protein, the mRNA levels of VEGF and iNOS were also up-regulated whereas that of eNOS was down-regulated. The lack of a hypoxia-related difference in the expression of HIF-1α and its target genes suggests that HIF-1α does not play a critical role in high altitude adaptation. Alternative mechanisms may be responsible for the better adaptation of native Tibetans. [Copyright &y& Elsevier]

In this study, food-grade glutamine transaminase (TGase) was utilized for the green-catalyzed preparation of N-butyryl amino acids. For improving the reusability of the enzyme preparation, immobilized TG enzyme (94.23% immobilization rate) was prepared. Furthermore, the yield of N-butyryl phenylalanine (BP) synthesized by TGase was obtained as 20.73% by one-factor experiment. The BP synthesis yield of immobilized TGase was 95.03% of that of TGase and remained above 60% of the initial enzyme activity after five runs. The sensory evaluation and E -tongue results showed that the addition of BP significantly increased the umami, saltiness, and richness intensities of the samples, and decreased the intensities of sourness, bitterness, and aftertaste-B. The molecular docking results indicated that hydrogen bonding dominated the binding of BP to taste receptors in the taste presentation mechanism of BP. These results confirmed the potential of BP as a flavor enhancer with promising applications in the food industry. [Display omitted] • N-butyryl phenylalanine (BP) was synthesized using glutamine transaminase (TG). • Glutamine transaminase (TG) was immobilized using macroporous resin. • The taste enhancing effects of BP were investigated by the time-intensity method. • Molecular docking was used to reveal the taste-presenting mechanisms of BP. [ABSTRACT FROM AUTHOR]

• The CH 3 Cl in flue gas can cause chloride corrosion on 12Cr1Mo alloy at 500, 600, and 700 °C. • The chlorine is enriched at defects of alloy surface during CH 3 Cl corrosion. • The thickness of oxide layer under CH 3 Cl atmosphere is larger than that of HCl. • The chlorine-rich bulges were observed in the alloy matrix under CH 3 Cl atmosphere. In biomass boilers, chlorine corrosion can be caused by various sources, including inorganic chlorine (HCl) and organic chlorine such as CH 3 Cl. This study utilized thermodynamic software, Factsage, to calculate the decomposition reaction of organic chlorine CH 3 Cl in an oxidizing atmosphere ranging from 500 to 700 °C. The results indicated the generation of HCl and Cl 2 components. With increasing temperature, the production rate of HCl increased while that of Cl 2 decreased. Meanwhile, the amount of HCl decomposition to produce Cl 2 also decreases with increasing temperature, but it remains higher than the yield of CH 3 Cl. The exposure behavior of 12Cr1MoV alloy was investigated under two chlorine sources at temperatures ranging from 500 to 700 °C. In the CH 3 Cl atmosphere, the alloy exhibited weight gains of approximately 0.6 %, 5.8 %, and 8.1 % at different temperatures, respectively. Whereas in the HCl atmosphere, the weight gains were approximately 0.1 %, 9.5 %, and 11.6 %, respectively. Corrosion products in the CH 3 Cl atmosphere at 500 and 600 °C were primarily composed of Fe 2 O 3 and FeCl 2. Increasing temperature accelerated the corrosion reaction. XRD analysis at 700 °C also identified corrosion products such as Cr 2 O 3 , (Fe, Cr) 3 O 4 , etc. Furthermore, the thickness of the oxide layer decreased with increasing temperature, leading to an increased gap with the substrate. At 600 °C in the CH 3 Cl atmosphere, the oxidation layer of the specimen consisted mainly of Fe 2 O 3 at the top and FeO and Fe 3 O 4 /Cr 3 O 4 at the bottom. With increasing temperature, the content of Cr 2 O 3 in the oxidation layer increased, and FeO transformed into the other two components. In the HCl atmosphere, the composition of the oxide layer in specimens at both temperatures remains consistent: Fe 2 O 3 /Cr 2 O 3 in the upper part and Fe 3 O 4 /Cr 3 O 4 in the lower part. Additionally, numerous chlorine-rich bubble structures were observed in the CH 3 Cl group specimens. These structures had an outer shell consisting of FeCl 2 and Fe 2 O 3 , while the inner filler comprised Fe 3 O 4 , Cr 3 O 4 , FeCl 2 , and CrCl 2. This phenomenon may be attributed to the denser corrosion products formed under the CH 3 Cl atmosphere, which led to greater obstruction of metal chloride diffusion compared to the HCl atmosphere, resulting in the accumulation of metal chlorides on the substrate. [ABSTRACT FROM AUTHOR]

N-lauroyl-L-tryptophan (LT), which has the strongest potential flavor-presenting activity, was skillfully screened from numerous N-Lau-AAs docked to different taste receptors by molecular simulation techniques. Subsequently, LT was synthesized employing food-grade commercial enzymes and structurally characterized, the optimized yields of LT could reach 69.08%, 76.16%, and 50.40%, respectively. Sensory and E -tongue evaluations showed that LT at 1 mg/L significantly benefited the performance of different taste sensations and exhibited different bitter taste masking effects: L-Ile (68.42%), L-Trp (68.18%), D-salicylic acid (48.48%) and quinine (35.00%). The molecular docking results illustrated that LT had a high affinity for various taste receptors, dominated by hydrogen bonding and hydrophobic interactions. This work provided a rare systematic elucidation of the potential and mechanism of enzymatically synthesized LT in enhancing taste properties. It provides novel insights into the directions and strategies for the excavation and innovation of flavor enhancers and food flavors. [Display omitted] • N-lauroyl-L-tryptophan (LT) with potential taste-activity was virtually screened. • LT was synthesized using food-grade commercial enzymes. • 1 mg/L LT significantly improved the taste of food (kokumi, salty, umami, bitter). • The bitter masking potential of LT for different bitter compounds was excavated. • Molecular docking was exploited to reveal the taste-presenting mechanisms of LT. [ABSTRACT FROM AUTHOR]

N-Succinyl amino acids (N-Suc-AAs) are garnering attention for their potential as taste-active compounds. The intricate variety of N-Suc-AAs presented considerable challenges in identifying those with taste-active properties. Consequently, we employed structure-based virtual screening to pinpoint taste-active N-Suc-AAs, revealing N-succinyl-L-tryptophan (ST) as a compound with high affinity for different taste receptors. Following this discovery, ST was synthesized through an enzymatic process, achieving a yield of 40.2%, with its structure verified via NMR spectroscopy. Sensory evaluation alongside electronic tongue assessments indicated that ST at a concentration of 1 mg/L significantly enhances umami, kokumi, and saltiness intensities, while concurrently mitigating bitterness from various bitter compounds, whilst itself remaining tasteless. Additionally, time-intensity (TI) results elucidated a marked augmentation in umami duration and a notable diminution in bitterness duration for solutions imbued with 1 mg/L ST. Molecular docking study suggested ST interacted with diverse taste receptors as an agonist or antagonist, primarily through hydrogen bonds and hydrophobic interactions. This study marked the inaugural report on the enzymatic synthesis of ST and its efficacy in improving taste characteristics, underscoring the importance of ST in improving sensory qualities of food products and fostering innovation within the seasoning industry. [Display omitted] • Identification of the most taste-active N-succinyl-L-tryptophan (ST) by virtual screening. • Inaugural enzymatic synthesis of ST. • Elucidation of taste-enhancing properties of ST: umami, saltiness, and kokumi. • Reduction of bitterness intensity by ST across various bitter compounds. • Molecular docking elucidated the mechanistic basis of taste enhancement of ST. [ABSTRACT FROM AUTHOR]

• An experimental bench to simulate the running state of HDMS is built. • An explicit dynamic graph learning framework is proposed to mitigate erroneous edges. • An iterative joint optimization mechanism for graph learning and graph networks is established. • A novel strategy to couple the GCN model with the residual module is proposed to extract both global and local features. The hydrodynamic mechanical seal (HDMS) in the reactor coolant pump of third-generation nuclear power units is vulnerable to failure due to prolonged operational periods and inevitable wear. However, traditional fault diagnosis methods are not robust to noise and can not leverage both the topological relationships among samples and local features. To resolve these challenges, in this paper, we propose a novel graph convolutional network (GCN) for wear fault diagnosis of HDMS called deep dynamic high-order graph convolutional network (DDHGCN). A dynamic graph learning module is designed to control the connectivity and sparsity of the iterated graph and thus eliminate errors and redundancies caused by noise. A high-order GCN module is proposed to effectively model the correlations between nodes, capturing contextual information and mutual influences among them. A residual convolutional module is applied to extract local features hidden in individual samples to further improve the classification performance. All three modules are jointly optimized for reliable wear fault diagnosis of HDMS. Experimental results demonstrate that our DDHGCN can achieve higher performance when compared with the state-of-the-arts. [ABSTRACT FROM AUTHOR]

Abstract Super 13Cr is widely used for oil country tubular goods (OCTG) in wet CO 2 environments with small amounts of H 2 S. This paper presents a case study of super 13Cr tubing that failed due to stress corrosion cracking (SCC). X-ray diffraction (XRD), energy dispersive spectrometry (EDS), scanning electron microscopy (SEM), optical microscopy (OM), and fluorescent magnetic particle inspection were used to investigate the failure mechanism. The results show that the inclusions, metallographic structure, yield strength, and tensile strength of the tubing meet the standard requirements. Furthermore, cracking analysis of the tubing shows that both secondary cracks propagating along grain boundaries and tree root branching were sunlight readable. Finally, failure was attributed to stress corrosion cracking (SCC). We concluded that the mechanism leading to stress corrosion cracking was corrosion product film breaking. Highlights • Corrosion environment was analyzed and hazardous element like Cl− and S 2 O 5 2− were found in it. • Fluorescent magnetic particle inspection, optical microscope and scanning electron microscope identify the microcrack. • Corrosion product film broken leading to stress corrosion cracking was founded. [ABSTRACT FROM AUTHOR]

Abstract: In most cases, designers have to manually specify both assembly tolerance types and values when they design a mechanical product. Different designers will possibly specify different assembly tolerance types and values for the same nominal geometry. Furthermore, assembly tolerance specification design of a complex product is a highly collaborative process, in which semantic interoperability issues significantly arise. These situations will cause the uncertainty in assembly tolerance specification design and finally affect the quality of the product. In order to reduce the uncertainty and to support the semantic interoperability in assembly tolerance specification design, an ontology-based approach for automatically generating assembly tolerance types is proposed. First of all, an extended assembly tolerance representation model is constructed by introducing a spatial relation layer. The constructed model is hierarchically organized and consists of part layer, assembly feature surface layer, and spatial relation layer. All these layers are defined with Web Ontology Language (OWL) assertions. Next, a meta-ontology for assembly tolerance representations is constructed. With this meta-ontology, the domain-specific assembly tolerance representation knowledge can be derived by reusing or inheriting the classes or properties. Based on this, assembly tolerance representation knowledge is formalized using OWL. As a result, assembly tolerance representation knowledge has well-defined semantics due to the logic-based semantics of OWL, making it possible to automatically detect inconsistencies of assembly tolerance representation knowledge bases. The mapping relations between spatial relations and assembly tolerance types are represented in Semantic Web Rule Language (SWRL). Furthermore, actual generation processes of assembly tolerance types are carried out using Java Expert System Shell (JESS) by mapping OWL-based structure knowledge and SWRL-based constraint knowledge into JESS facts and JESS rules, respectively. Based on this, an approach for automatically generating assembly tolerance types is proposed. Finally, the effectiveness of the proposed approach is demonstrated by a practical example. [Copyright &y& Elsevier]

Based on the structural features of double rotor, three characteristic parameters nondimensionalized such as the mass of downwind rotor (DR) relative to upwind rotor (UR), the total length of blades of double rotor relative to single rotor, the external size of double rotor relative to single rotor are defined, the relationship between them and geometric parameters of double rotor is established. The wind field simulation of UR is implemented, of which the results are used to compute the wind energy of the torus where the DR blades is located and the values of characteristic parameters orderly. Meanwhile, the sensitivity analysis of characteristic parameters to geometric parameters is conducted. Thus, the relationship between the power ratio and geometric parameters on the characteristic parameters can be obtained. One is that with the increase of power ratio, the mass of DR relative to UR decreases slightly, the total length of blades of double rotor and the external size of double rotor relative to single rotor decrease distinctly. Another is that for the power ratio required, the radial position of DR blade root increases, the mass of DR relative to UR and the external size of double rotor relative to single rotor also increase, while another characteristic parameter decreases; also, with the enlargement of the length of DR blades, the total length of the blades of double rotor relative to single rotor increases, while the other two characteristic parameters diminish. The last one is that the axial position of DR has no significant influence on the three characteristic parameters. Based on these influence relationships, combined with the actual requirements, the layout principle of double rotor is given. • The structure and geometric parameters of downwind rotor of dual-rotor wind turbine are developed. • Description of geometric parameters and characteristic parameters of double rotor. • Calculation of wind energy on the swept area of downwind rotor. • Influence of power ratio and geometric parameters on characteristic parameters of double rotor. • Sensitivity analysis of characteristic parameters to geometric parameters. [ABSTRACT FROM AUTHOR]