Abstract
Laser-additive manufacturing technology can realize near-net forming manufacturing of structural parts by laser selective melting, and can overcome the limitation of traditional technology ...and realize the forming of complex components. Aluminum alloy has low density and high strength, and is widely used in aircraft structures. The paper introduces the research progress of laser-additive manufacturing technology, puts forward the design process of aluminum alloy structure of aircraft based on additive manufacturing technology, and illustrates the design feature extraction, topology optimization, strength analysis, test verification, etc., which provides reference for lightweight design of large passenger aircraft.
According to the happiness-income paradox, economic growth within a country does not necessarily lead to an increase in well-being. However, previous literature also showed that economic growth has a ...greater impact on well-being in a low-income country than a high-income country. China is a typical developing country that has experienced dramatic development in recent decades. How did the well-being of the Chinese change? To examine birth cohort changes in Chinese college students' subjective well-being, a cross-temporal meta-analysis that involved 100 studies was conducted (106 data points,
N
= 55,830). The results showed that Chinese college students' well-being increased by at least 0.45 standard deviations from 2002 to 2017. In addition, their subjective well-being was significantly correlated with social indicators (e.g., GDP per capita, divorce rate, and university enrollment rate) for the corresponding years and 3 years prior to the collection of subjective well-being data. It is evident that social changes play an important role in predicting changes in well-being.
Liver fibrosis is a compensatory response to the tissue repair process. The activation and proliferation of hepatic stellate cells (HSCs) are thought to be related to the occurrence of hepatic ...fibrosis. Therefore, inhibiting the activation and proliferation of HSCs is a key step in alleviating liver fibrosis. As a non-specific inhibitor of transient receptor potential melastatin 7 (TRPM7), carvacrol has anti-tumor, anti-inflammatory and anti-hepatic fibrosis activities. This study aimed to explore the protective effect of carvacrol on liver fibrosis and related molecular mechanisms. A CCl4-induced liver fibrosis mouse model and platelet-derived growth factor (PDGF-BB)-activated HSC-T6 cells (a rat hepatic stellate cell line) were employed for in vivo and in vitro experiments. C57BL/6J mice were orally administered different concentrations of carvacrol every day for 6 weeks during the development of CCl4-induced liver fibrosis. The results show that carvacrol could effectively reduce liver damage and the progression of liver fibrosis in mice, which are expressed as fibrotic markers levels were reduced and histopathological characteristics were improved. Moreover, carvacrol inhibited the proliferation and activation of HSC-T6 cells induced by PDGF-BB. In addition, it was found that carvacrol inhibits the expression of TRPM7 and mediated through mitogen-activated protein kinases (MAPK). Collectively, our study shows that carvacrol can reduce liver fibrosis by inhibiting the activation and proliferation of hepatic stellate cells, and the MAPK signaling pathway might be involved in this process.
•Carvacrol has been found to have therapeutic effects on CCl4-induced liver fibrosis in mice.•Carvacrol ameliorates the liver fibrosis and the proliferation and activation of hepatic stellate cells by inhibiting TRPM7.•Carvacrol ameliorates the liver fibrosis by modulating the MAPK signaling pathway.
1. Litter decomposition plays important roles in carbon and nutrient cycling. In dryland, both microbial decomposition and abiotic degradation (by UV light or other forces) drive variation in ...decomposition rates, but whether and how litter traits and position determine the balance between these processes is poorly understood. 2. We investigated relationships between litter quality and their decomposition rates among diverse plant species in a desert ecosystem in vertically contrasting positions representing distinct decomposition environments driven by different relative contributions of abiotic and microbial degradation. Thereto, leaf litter samples from 17 desert species were sealed into litterbags and placed on the soil surface under strong solar exposure vs. shade conditions, or buried in the soil at 10 cm depth, for a whole year. 3. Litter decomposition rates were 21% and 17% higher in burial and light-exposed treatments, respectively, than those in shade. Leaf traits, i.e. specific leaf area (SLA), litter C:N ratio and lignin concentration could predict litter decomposition to some degree, but their predictive power was dependent on litter position. However, multiple linear regressions showed that SLA, litter C and P significantly affected k values for leaf litter decomposition besides litter position, with SLA standing out as a strong determinant of litter decomposition rate as related either to solar radiation or the environment below the soil surface. Furthermore, the interspecific differences in litter decomposition rates decreased over time, implying that afterlife effects of leaf traits on decomposition were attenuated. 4. Synthesis. These findings suggest that abiotic photodegradation and soil burial mediated microbial decomposition could be responsible for higher than expected litter turnover in dryland. They point to a dual role of specific leaf area (SLA) as a promotor of decomposition rates: via relative exposure of the leaf surface to abiotic factors such as UV light vs. to soil moisture and microbes under soil burial.
Abstract Objective Based on the Omaha problem classification system, a sensitivity outcome index system for home nursing of elderly liver transplant patients was established. Methods Through a ...comprehensive literature review and rigorous application of the Delphi method, a panel of 20 experts completed two rounds of effective letter consultation to obtain expert consensus opinions. The contents of indicators were determined based on this process, and the analytic hierarchy process was employed to confirm the weightage assigned to each indicator. Consequently, we established a sensitivity outcome index system for home care in elderly liver transplant patients. Results The effective recovery rate of the questionnaire in two rounds of expert consultation was 100%, and the proportion of experts who gave opinions was 55% and 15%, respectively, indicating that the experts were highly active. The expert authority coefficients were calculated as 0.904 and 0.905, respectively, indicating a high degree of expert authority. In the second round, Kendall’s coordination coefficients for primary, secondary, and tertiary indicators were determined to be 0.419, 0.418, and 0.394 ( P < 0.001), indicating that expert opinions tended to be consistent. Finally, we established a comprehensive sensitivity outcome index system comprising 4 first-level indexes, 20 s-level indexes, and 72 third-level indexes specifically designed for elderly liver transplantation patients. Conclusion The sensitivity outcome index system of home nursing for elderly liver transplant patients can provide theoretical basis for nursing staff to build accurate individualized continuous nursing model.
Seed heteromorphism is a plant strategy that an individual plant produces two or more distinct types of diaspores, which have diverse morphology, dispersal ability, ecological functions and different ...effects on plant life history traits. The aim of this study was to test the effects of seasonal soil salinity and burial depth on the dynamics of dormancy/germination and persistence/depletion of buried trimorphic diaspores of a desert annual halophyte Atriplex centralasiatica. We investigated the effects of salinity and seasonal fluctuations of temperature on germination, recovery of germination and mortality of types A, B, C diaspores of A. centralasiatica in the laboratory and buried diaspores in situ at four soil salinities and three depths. Diaspores were collected monthly from the seedbank from December 2016 to November 2018, and the number of viable diaspores remaining (not depleted) and their germinability were determined. Non-dormant type A diaspores were depleted in the low salinity "window" in the first year. Dormant diaspore types B and C germinated to high percentages at 0.3 and 0.1 mol L.sup.-1 soil salinity, respectively. High salinity and shallow burial delayed depletion of diaspore types B and C. High salinity delayed depletion time of the three diaspore types and delayed dormancy release of types B and C diaspores from autumn to spring. Soil salinity modified the response of diaspores in the seedbank by delaying seed dormancy release in autum and winter and by providing a low-salt concentration window for germination of non-dormant diaspores in spring and early summer. Buried trimorphic diaspores of annual desert halophyte A. centralasiatica exhibited diverse dormancy/germination behavior in respond to seasonal soil salinity fluctuation. Prolonging persistence of the seedbank and delaying depletion of diaspores under salt stress in situ primarily is due to inhibition of dormancy-break. The differences in dormancy/germination and seed persistence in the soil seedbank may be a bet-hadging strategy adapted to stressful temporal and spatial heterogeneity, and allows A. centralasiatica to persist in the unpredictable cold desert enevironment.
Variation in plant functional traits is the product of evolutionary and environmental drivers operating at different scales. Little is known about whether, or how, this variation is coordinated ...between aboveground and belowground organs across and within spatial scales. We address these questions using a hierarchically designed dataset of pairwise leaf and root traits related to carbon and nutrient economy of 64 species belonging to 14 plant communities in northern Chinese semi-arid and arid regions. While both root and leaf traits showed most of their variance among (individuals and) species within communities, leaf trait variance tended to be relatively higher at coarser spatial scales than root trait variance. While leaf nitrogen (N) per area to root N per length ratio increased and specific leaf area to specific root length and leaf N to root N ratios decreased from semi-arid to arid environments owing to climatic/edaphic shifts, the matching pairs showed a strong pattern of positive correlation that was upheld across spatial scales and geographic areas. Thus, trade-offs in plant resource investment across organs within individual vascular plants are constrained within a rather narrow range of variation. A new challenge will be to test whether and how such trait coordination is also seen within and across other biomes of the world.
Salmonella
, the prevailing zoonotic pathogen within the Enterobacteriaceae family, holds the foremost position in global bacterial poisoning incidents, thereby signifying its paramount importance in ...public health. Consequently, the imperative for expeditious and uncomplicated detection techniques for
Salmonella
in food is underscored. After more than two decades of development, loop-mediated isothermal amplification (LAMP) has emerged as a potent adjunct to the polymerase chain reaction, demonstrating significant advantages in the realm of isothermal amplification. Its growing prominence is evident in the increasing number of reports on its application in the rapid detection of
Salmonella
. This paper provides a systematic exposition of the technical principles and characteristics of LAMP, along with an overview of the research progress made in the rapid detection of
Salmonella
using LAMP and its derivatives. Additionally, the target genes reported in various levels, including
Salmonella
genus, species, serogroup, and serotype, are summarized, aiming to offer a valuable reference for the advancement of LAMP application in
Salmonella
detection. Finally, we look forward to the development direction of LAMP and expect more competitive methods to provide strong support for food safety applications.
The identification of microorganisms with excellent flocculants-producing capability and optimization of the fermentation process are necessary for the wide-scale application of bioflocculants. ...Therefore, we isolated and identified a highly efficient flocculation performance strain of
GXUN74707 from the sludge. The optimal fermentation and flocculation conditions of strain
GXUN74707 was in fermentation medium with glucose and urea as the carbon and nitrogen sources, respectively, at pH 7.0 for 36 h, which treatment of kaolin suspension with 0.5 mL of the fermentation broth resulted in a flocculation rate of 99.0%. The bioflocculant synthesized by strain
GXUN74707 was found mainly in the supernatant of the fermentation broth. Chemical analysis revealed that the pure bioflocculant consisted of 79.70% carbohydrates and 14.38% proteins. The monosaccharide components of MBF-GXUN74707 are mainly mannose (5.96 μg/mg), galactose (1.86 μg/mg), and glucose (1.73 μg/mg). Infrared spectrometric analysis showed the presence of carboxyl (COO-), hydroxyl (-OH) groups. The SEM images showed clumps of rod-shaped bacteria with adhesion of extracellular products. Furthermore, the strain decolored dye wastewater containing direct black, direct blue, and Congo red by 89.2%, 95.1%, 94.1%, respectively. The chemical oxygen demand (COD) and biological oxygen demand (BOD) removal rates after treatment of aquaculture wastewater with the fermentation broth were 68% and 23%, respectively. This study is the first to report the performance and application of strain
in wastewater flocculation. The results indicate that strain
is a good candidate for the production novel bioflocculants and demonstrates its potential industrial practicality in biotechnology processes.
Lower levels of consumer competency are a major obstacle preventing consumers from benefitting from online shopping. However, the literature provides little information on consumers’ competency in ...online shopping. Based on the consumption decision-making process model, in Study 1, 12 college students with rich experience in online shopping were interviewed. A three-step coding process was conducted, and the results illustrated the key competencies of online shopping, i.e., product identification, self-control, support for decision-making, and consumer protection. Based on the results of Study 1 and the knowledge-attitude-skill model, Study 2 developed three subscales to evaluate college students’ knowledge, attitude, and skill regarding online shopping in standardized and systematic ways. The validity of the instrument was examined in a sample of 648 college students. Study 3 further examined and demonstrated the quality of the three subscales in a new sample of 494 residents. Moreover, a latent profile analysis (LPA) divided the participants into three groups based on their consumer competency: low-, median-, and high-competence consumers. The findings contribute to the literature on consumer competency and online shopping and have different implications for consumers, the government, and corporations.
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