•A novel stepped structure channel combining parallel and tree channel was proposed.•Effects of structure style, number, structural parameters were analyzed.•Filling CPCM to enhance cooling ...performance and reduce the weight of cooling plate.•Average temperature and pressure drop were reduced by 2.46 °C and 22.14 Pa.
Aiming at the problems of large temperature gradient of traditional parallel channel and high pressure loss of tree fractal channel, a novel stepped liquid cooling plate combining the above two structures was proposed in this paper. Firstly, based on the liquid cooling plate experimental platform, the reliability of computational fluid dynamics method was verified by experiments. Secondly, based on computational fluid dynamics and orthogonal test methods, the effects of the arrangement form of cooling channels, the number of inlets and outlets and structural parameters (number of channels, longitudinal length, width, thickness and width of inlets and outlets) were analyzed. In comparison with the original model, the average temperature and pressure drop were reduced by 1.17 °C and 22.14 Pa, respectively. Finally, in order to further improve the heat dissipation effect of the system, a new hybrid liquid cooling plates formed by filling the liquid cooling plate with composite phase change material were proposed. The results indicated that the cooling performance of the hybrid liquid cooling plate filling with more phase change material was better, meanwhile, the average temperature and pressure drop were reduced by 2.46 °C and 22.14 Pa, respectively, compared with the original model. In addition, the effect of inlet mass flow was discussed. The results revealed that the cooling performance of hybrid liquid cooling plate was better at lower mass flow rate, while the cooling performance of the liquid cooling plate was better at higher mass flow rate.
This paper proposes a reinforcement learning (RL) based path following strategy for underactuated airships with magnitude and rate saturation. The Markov decision process (MDP) model for the control ...problem is established. Then an error bounded line-of-sight (LOS) guidance law is investigated to restrain the state space. Subsequently, a proximal policy optimization (PPO) algorithm is employed to approximate the optimal action policy through trial and error. Since the optimal action policy is generated from the action space, the magnitude and rate saturation can be avoided. The simulation results, involving circular, general, broken-line, and anti-wind path following tasks, demonstrate that the proposed control scheme can transfer to new tasks without adaptation, and possesses satisfying real-time performance and robustness.
Silicate weathering, in particular basalt, accounting only for one-sixth of the continental crust volume, accounts for one-third of atmospheric CO2 drawn down during weathering, as such, playing an ...important role in long-term carbon cycling. Li contents and isotopic compositions of a tropical regolith developed on young basalt (ca. 1 Ma) were investigated to elucidate Li isotopic fractionation during basalt weathering so as to trace basalt weathering. Li isotopic composition of sand from Asian dust-source regions and local dust near the basaltic saprolite weathering profile were studied as possible atmospheric contributors of Li to the saprolite. Saprolite has δ7Li values of −6.8‰ to −2.2‰, which is much lighter than that of fresh basalt (+3.5‰). Approximately 30% of the Li was lost from the upper saprolite profile, without significant isotopic fractionation. Lithium is enriched at the bottom of the profile, showing the lightest Li isotopic composition (δ7Li = −6.6‰ to −2.6‰). Calculations indicates that marine aerosols are the main source of atmospheric Li input to the profile. Adsorption of Li by secondary minerals results Li isotopic fractionation, accompanying desorption and resorption of Li by secondary minerals, resulting enriched Li and light Li isotopic composition in the regolith. A model established that Li isotopes showed sensitivity to continental weathering, supporting that Li isotopes can serve as an indicator of continental weathering. Continental weathering in the study area recorded the reasons of heavier Li isotopic composition of river water and seawater suggesting that Li isotopes can be used to study the circulation of materials on the Earth's surface. This has a guiding role in studying the Li isotopic composition of shale and rivers. The influence of temperature and precipitation on the fractionation behavior of lithium isotopes during silicate weathering warrants further investigation.
Display omitted
•The δ7Li of saprolite in tropical area is much lighter than bedrock.•Atmospheric input, especially marine aerosols, is a great source of Li in saprolite.•The desorption and resorption of secondary minerals will lead to stronger Li isotopic fractionation.
A sharp drop in physical activity and skyrocketing obesity rate has accompanied rapid urbanization in China. The urban planning concept of transit-oriented development (TOD) has been widely advocated ...in China to promote physical activity, especially walking. Indeed, many design features thought to promote walking-e.g., mixed land use, densification, and well-connected street network-often characterize both TODs and established urban neighborhoods. Thus, it is often assumed that TODs have similar physical activity benefits as established urban neighborhoods. To verify this assumption, this study compared walking behaviors in established urban neighborhoods and transit-oriented new towns in Hong Kong. To address the limitation of self-selection bias, we conducted a study using Hong Kong citywide public housing scheme, which assigns residents to different housing estates by flat availability and family size rather than personal preference. The results show new town residents walked less for transportation purpose than urban residents. New town residents far from the transit station (800-1200 m) walked less for recreational purpose than TOD residents close to a rail transit station (<400 m) or urban residents. The observed disparity in walking behaviors challenges the common assumption that TOD and established urban neighborhoods have similar impact on walking behavior. The results suggest the necessity for more nuanced planning strategies, taking local-level factors into account to promote walking of TOD residents who live far from transit stations.
Recent research has emphasized the significance of investigating the interplay between organelles, with endoplasmic reticulum mitochondria contact sites (ERMCSs) being recognized as critical ...signaling hubs between organelles. The objective of the current study was to assess the impact of deoxynivalenol (DON) on jejunal mitochondria, ER, and ERMCSs. Twelve piglets (35 d, 10.22 ± 0.35 kg) were randomized into two groups: control group, basal diet; the DON group, basal diet + 1.5 mg/kg DON. The findings revealed that DON decreased growth performance, induced jejunal oxidative stress, and impaired jejunal barrier function. DON was also found to induce mitochondrial dysfunction, trigger endoplasmic reticulum stress (ERS) in the piglets’ jejunum, and activate mitochondrial and ER apoptosis pathways by upregulating apoptosis-related proteins (Caspase-8, Caspase-12, Bax, and CHOP). To investigate the involvement of ERMCSs in DON-induced intestinal injury, we measured the protein levels of ERMCS proteins, such as mitofusin 1 (Mfn1), mitofusin 2 (Mfn2), and glucose-regulated protein 75 (GRP75) and Pearson’s correlation coefficient of ERMCS proteins and ERMCS ultrastructure. Our finding showed that DON upregulated the protein level of Mfn2 and GRP75 and increased the percentage of mitochondria with ERMCSs/total mitochondria, the length of ERMCSs compared to the perimeter of mitochondria, and the Pearson’s correlation coefficient of voltage-dependent anion-selective channel protein 1 (VDAC1) and inositol 1,4,5-triphosphate receptors (IP3Rs) in piglets’ jejunum. Furthermore, DON shortened the distance between mitochondria and ER at ERMCSs. These findings suggested that DON impaired mitochondrial function, triggered ERS, and increased ERMCSs, indicating that the increased ERMCSs could be related to mitochondrial dysfunction and ERS involved in the intestinal injury of piglets induced by DON.
Display omitted
•Metal-free ionic hydrogel PAOIB-PTC was well fabricated by physical crosslinking.•Rigid PTC4− acted both as a physical crosslinking agent and an auxiliary group.•PAOIB-PTC exhibited ...a high tensile strength of 7.34 MPa.•The maximum U(VI) adsorption capacity of PAOIB-PTC was as high as 1008.03 mg g−1.•High U(VI) selectivity was achieved by hydrogen bond and synergistic coordination.
Uranium is one of the most important elements in the nuclear industry, and efficient extraction of uranium from the ocean is conducive to the sustainable development of nuclear energy. In this work, rigid perylene tetracarboxylate anion (PTC4−) was introduced by physical (non-covalent) crosslinking strategy to obtain metal-free ionic hydrogel PAOIB-PTC. PTC4− not only increased the rigid structure content of ionic hydrogel, but also formed dynamic macrocycle AO-PTC with amidoxime (AO) through hydrogen bonds. Unlike reported heterogeneous additives, PTC4− did not undergo inhomogeneity or shedding. Therefore, PAOIB-PTC exhibited high strength (7.34 MPa), excellent solvent resistance and salinity tolerance. A large number of hydrophilic groups and multistage pore structure endowed PAOIB-PTC with high hydrophilicity, which facilitated U(VI) mass transfer and led to rapid adsorption rates (88.6 mg g−1 h−1, c0 = 250 ppm). Since the metal-free component enabled more adsorption sites to be utilized, the maximum adsorption capacity of PAOIB-PTC was as high as 1008.03 mg g−1, which exceeded most reported hydrogel-based uranium adsorbents. Experiments and DFT calculations proved that PAOIB-PTC possessed high adsorption selectivity through uranyl recognition via hydrogen bonding and synergistic coordination by supramolecular structure AO-PTC. The low-concentration uranium capture capability and excellent recycling performance demonstrated the practical application potential of PAOIB-PTC. This work provides an idea for the design of metal-free ionic hydrogels with high-strength, and the established PAOIB-PTC is expected to be a candidate material for enhanced uranium extraction from seawater.
No consensus exists regarding the association between maternal chorioamnionitis and neurodevelopmental outcomes in preterm and very preterm neonates.
To investigate whether maternal chorioamnionitis ...affects neurodevelopmental outcomes and to identify the factors that may explain these effects.
We used Ovid Medline, EMBASE and Web of Science to conduct a meta-analysis of studies published in English before August 25, 2017, with titles or abstracts that discussed an association between maternal chorioamnionitis and mental/motor development.
Among the 603 initially identified studies, we selected those that addressed an association between maternal chorioamnionitis and mental/motor development according to our preselected inclusion criteria as follows: (1) the study compared infants with and without exposure to maternal chorioamnionitis and (2) the neurodevelopmental outcome was followed up using the Bayley Scales of Infant Development 2nd edition.
Our meta-analysis included 10 studies. According to a random effect model, infants with maternal chorioamnionitis exposure had poorer mental development (d = -2.25 95%CI, -4.33, -0.17, p<0.05) than infants without maternal chorioamnionitis, and infants with maternal clinical chorioamnionitis exposure had poorer motor development (d = -2.37 95%CI, -4.62 to -0.12, p<0.05) than infants without maternal clinical chorioamnionitis exposure. Factors in the meta-analysis that showed differences between the two patient groups included an MDI assessment blinded to medical history, MDI assessment at the correct age, and time of the MDI assessment.
This study suggests that maternal chorioamnionitis may affect mental development in preterm and very preterm neonates, and that maternal clinical chorioamnionitis may affect motor development in offspring. Further studies are required to confirm these results and to detect the influence of variables across studies.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The study aimed to analyze the relationship between the dynamic systemic immune inflammation index (SII), human papillomavirus (HPV) infection, and the prognosis of oropharyngeal cancer patients.
We ...retrospectively obtained the data for 131 patients treated with curative treatments and calculated their SII values based on results acquired approximately 9 months after the first treatment. The entire cohort was divided into groups according to dynamic SII and HPV infection, and their prognoses were compared.
The high SII group, particularly the persistently high SII group, had a poor prognosis, and static SII levels cannot fully reflect the prognosis of patients with oropharyngeal cancer. In HPV- patients, unfavorable dynamic SII and the site of tumor locating at the tongue base were all significantly associated with decreased disease-free survival. In contrast, no characteristic was presented as a poor prognostic factor for disease-free or overall survival in HPV+ patients.
Dynamic SII values are more comprehensive prognostic indicators for oropharyngeal cancer patients, particularly HPV- patients. It could imply that an HPV- oropharyngeal cancer patient who experienced unfavorable dynamic changes in SII should receive more frequent tests or more advanced therapies.
•Formulate a trajectories-based evaluation approach for pedestrian models.•Propose eight evaluation indexes from operational level, tactical level and hybrid level.•Propose two similarity ...quantification methods for difference indexes.
The fundamental diagram and self-organized phenomena in crowds are widely used to test the applicability of evacuation models. These benchmarks are good indicators for the validity of a model, whereas they are insufficient descriptors for the realistic microscopic behaviors of pedestrians. In recent years, the rapid increase of the trajectory datasets which benefits from the development of recognition technologies open the door to new possibilities for an extensive quantitative validation of the models. In this work, a trajectories-based analysis approach which contains types of indexes is proposed. The indexes are a mix of macroscopic type (fundamental diagram index, speed choice index, and direction choice index) and microscopic type (trajectories pattern index), distribution type (route length distribution index, travel time distribution index) and time-series type (starting position distance time-series index, destination position distance time-series index. Moreover, the Kolmogorov-Smirnov (K-S) test as well as the dynamic time warping (DTW) method are introduced to quantify the similarities of results on different types of indexes. In brief, by comparing experimental and simulation trajectories, we can measure a set of performance scores in different perspectives. Here, the Social Force Model (SFM) and Heuristics Model (HM) are respectively introduced and evaluated. According to the proposed evaluation approach, we show that the HM performs better than the SFM. Our analysis approach is model agnostic and is defined in a general way, such that it can be applied for trajectory sets from different experiment settings. This work can help to improve the accuracy of simulation models, and the pedestrian safety in crowd activities and autonomous vehicle navigation will be benefited.
With the improvement of economic conditions and the increase in living standards, people’s attention in regard to health is also continuously increasing. They are beginning to place their hopes on ...machines, expecting artificial intelligence (AI) to provide a more humanized medical environment and personalized services, thus greatly expanding the supply and bridging the gap between resource supply and demand. With the development of IoT technology, the arrival of the 5G and 6G communication era, and the enhancement of computing capabilities in particular, the development and application of AI-assisted healthcare have been further promoted. Currently, research on and the application of artificial intelligence in the field of medical assistance are continuously deepening and expanding. AI holds immense economic value and has many potential applications in regard to medical institutions, patients, and healthcare professionals. It has the ability to enhance medical efficiency, reduce healthcare costs, improve the quality of healthcare services, and provide a more intelligent and humanized service experience for healthcare professionals and patients. This study elaborates on AI development history and development timelines in the medical field, types of AI technologies in healthcare informatics, the application of AI in the medical field, and opportunities and challenges of AI in the field of medicine. The combination of healthcare and artificial intelligence has a profound impact on human life, improving human health levels and quality of life and changing human lifestyles.
PDF
